Einstein’s theory of general relativity was revolutionary on many levels. One of its many groundbreaking consequences is that mass and energy are basically interchangeable at rest. The immediate implication is that you can make mass — tangible matter — out of energy, thereby explaining how the universe as we know it came to be during the Big Bang when a heck lot of energy turned into the first particles. But there may be much more to it.
In 2019, physicist Melvin Vopson of the University of Portsmouth proposed that information is equivalent to mass and energy, existing as a separate state of matter, a conjecture known as the mass-energy-information equivalence principle. This would mean that every bit of information has a finite and quantifiable mass. For instance, a hard drive full of information is heavier than the same drive empty.
That’s a bold claim, to say the least. Now, in a new study, Vopson is ready to put his money where his mouth is, proposing an experiment that can verify this conjecture.
“The main idea of the study is that information erasure can be achieved when matter particles annihilate their corresponding antimatter particles. This process essentially erases a matter particle from existence. The annihilation process converts all the [remaining] mass of the annihilating particles into energy, typically gamma photons. However, if the particles do contain information, then this also needs to be conserved upon annihilation, producing some lower-energy photons. In the present study, I predicted the exact energy of the infrared red photons resulting from this information erasure, and I gave a detailed protocol for the experimental testing involving the electron-positron annihilation process,” Vopson told ZME Science.
Information: just another form of matter and energy?
The mass-energy-information equivalence (M/E/I) principle combines Rolf Launder’s application of the laws of thermodynamics with information theory — which says information is another form of energy — and Claude Shannon’s information theory that led to the invention of the first digital bit. This M/E/I principle, along with its main prediction that information has mass, is what Vopson calls the 1st information conjecture.
However, testing these conjectures is not trivial. For instance, a 1 terabyte hard drive filled with digital information would gain a mass of only 2.5 × 10-25 Kg compared to the same erased drive. Measuring such a tiny change in mass is impossible even with the most sensitive scale in the world.
Instead, Vopson has proposed an experiment that tests both conjectures using a particle-antiparticle collision. Since every particle is supposed to contain information, which supposedly has its own mass, then that information has to go somewhere when the particle is annihilated. In this case, the information should be converted into low-energy infrared photons.
According to Vopson’s predictions, an electron-positron collision should produce two high-energy gamma rays, as well as two infrared photons with wavelengths around 50 micrometers. The physicist adds that altering the samples’ temperature wouldn’t influence the energy of the gamma rays, but would shift the wavelength of the infrared photons. This is important because it provides a control mechanism for the experiment that can rule out other physical processes.
Validating the mass-energy-information equivalence principle could have far-reaching implications for physics as we know it. In a previous interview with ZME Science, Vopson said that if his conjectures are correct, the universe would contain a stupendous amount of digital information. He speculated that — considering all these things — the elusive dark matter could be just information. Only 5% of the universe is made of baryonic matter (i.e. things we can see or measure), while the rest of the 95% mass-energy content is made of dark matter and dark energy — fancy terms physicists use to describe things that they have no idea what they look like.
Then there’s the black hole information loss paradox. According to Einstein’s general theory of relativity, the gravity of a black hole is so overwhelming, that nothing can escape its clutches within its event horizon — not even light. But in the 1970s, Stephen Hawking and collaborators sought to finesse our understanding of black holes by using quantum theory; and one of the central tenets of quantum mechanics is that information can never be lost. One of Hawking’s major predictions is that black holes emit radiation, now called Hawking radiation. But with this prediction, the late British physicist had pitted the ultimate laws of physics — general relativity and quantum mechanics — against one another, hence the information loss paradox. The mass-energy-information equivalence principle may lend a helping hand in reconciling this paradox.
“It appears to be exactly the same thing that I am proposing in this latest article, but at very different scales. Looking closely into this problem will be the scope of a different study and for now, it is just an interesting idea that must be followed,” Vopson tells me.
Finally, the mass-energy-information equivalence could help settle a whimsical debate that has been gaining steam lately: the notion that we may all be living inside a computer simulation. The debate can be traced to a seminal paper published in 2003 by Nick Bostrom of the University of Oxford, which argued that a technologically adept civilization with immense computing power could simulate new realities with conscious beings in them. Bostrom argued that the probability that we are living in a simulation is close to one.
While it’s easy to dismiss the computer simulation theory, once you think about it, you can’t disprove it either. But Vopson thinks the two conjectures could offer a way out of this dilemma.
“It is like saying, how a character in the most advanced computer game ever created, becoming self-aware, could prove that it is inside a computer game? What experiments could this entity design from within the game to prove its reality is indeed computational? Similarly, if our world is indeed computational / simulation, then how could someone prove this? What experiments should one perform to demonstrate this?”
“From the information storage angle – a simulation requires information to run: the code itself, all the variables, etc… are bits of information stored somewhere.”
“My latest article offers a way of testing our reality from within the simulation, so a positive result would strongly suggest that the simulation hypothesis is probably real,” the physicist said.
For some time now, EU governments have been pushing for natural gas and nuclear energy as an essential part of the energy transition from carbon-intensive fossil fuels like coal and oil. But since Ukraine was invaded, Europe’s reliance on Russian gas has triggered a sudden push towards energy independence, mainly via renewables. It’s increasingly looking like Putin’s invasion may succeed in pushing Europe towards renewable energy.
In Germany, Chancellor Olaf Scholz said renewable energy is “crucial” for the EU’s energy security and Finance Minister Christian Lindner called for renewables “freedom energies.” Meanwhile, in France, Barbara Pompili, Minister for Ecological Transition, said that ending the dependency on fossil fuels, especially Russian ones, is essential.
In response, the Stand with Ukraine coalition, which groups hundreds of organizations including environmental groups like Greenpeace, said a ban on Russian energy imports would step one in a path to end fossil fuel production. They called for “bold steps” towards global decarbonization and for a transition to “clean and safe” renewables.
The EU imported 155 billion cubic meters of natural gas from Russia in 2021, almost half (45%) of its gas imports and nearly 40% of the total amount used, according to the International Energy Agency (IEA). But the war has largely disrupted this. Now, the European Commission is expected to present an updated energy strategy, which will likely give renewables a larger role.
The race to end this Russian dependence will likely require boosting imports from countries like the US and Qatar in the short term, and will likely lead to more domestic fossil fuel production. However, this doesn’t have to be the path ahead, climate experts argue, suggesting energy independence via clean energy such as solar and wind. The most likely option is a mixture between the two.
No more illusions
Europe has pledged to cut its greenhouse gas emissions by at least 55% by 2030, reaching net zero emissions by 2050. According to preliminary data, EU emissions dropped 10% from 2019 to 2020 – strongly related to the Covid-19 pandemic. By comparison, EU emissions declined 4% from 2018 to 2019. Despite being one of the more ambitious climate pledges around, it’s still nowhere near what is necessary if we want to avoid the worst of climate change effects.
If Europe wants to rid itself of Russian fossil fuels, it will need some sources oil and gas — but focusing on renewabls is the smart long-term bet, researchers emphasize.
The argument that Europe could limit its dependence on Russian gas by focusing on local fossil fuel sources and importing liquid natural gas from the US is neither realistic nor cost-effective, according to the think tank Carbon Tracker. It would require decades to build new gas decades and source local deposits, meaning price pressures won’t be solved right away.
By contrast, solar and wind energy sources can be significantly scaled up as part of existing decarbonization policies. This would be more cost-effective because of the large drop in renewable energy prices. The think tank Wuppertal Institute released a study this week showing how heating in the EU could run completely on renewables by 2013 thanks to electric heat pumps.
Meanwhile, the IEA came up with a road map to help deal Europe in its energy transition. The plan would reduce the bloc’s dependence on Russian natural gas by one-third in just one year while delivering on the bloc’s climate pledges. It’s a collection of actions designed to diversify the energy supply, focused on renewables.
“Nobody is under any illusions anymore. Russia’s use of its natural gas resources as an economic and political weapon show Europe needs to act quickly to be ready to face considerable uncertainty over Russian gas supplies next winter,” IEA Executive Director Fatih Birol said in a written statement announcing the plan.
The recommendations include no renewing gas supply contracts with Russia, which are due to expire at the end of the year, increasing biogas and biomethane supply, storing more gas to have a buffer of security, accelerating the deployment of renewables, protecting vulnerable customers, and improving the energy grid reliability and flexibility.
Fully-integrating solar panels into buildings could make cities almost self-sustaining, according to new research.
Solar panels get a lot of bad press for having a low energy output; individually, that may be so. A small, single panel will not be able to keep your home lit, warmed, and all the appliances running. But the secret with solar energy is to think at scale, a new paper suggests, and to make the most of every bit of free space. According to the findings, the City of Melbourne could generate 74% of its electricity needs if solar technology was to be integrated into the roofs, walls, and windows of every building.
This study is the first to estimate the viability and impact of integrating several types of solar technology including window-integrated and rooftop-mounted photovoltaics on a city-wide scale. The results are promising, suggesting that the City of Melbourne could greatly reduce its reliance on energy produced through the burning of fossil fuels.
Lighting the way
“By using photovoltaic technology commercially available today and incorporating the expected advances in wall and window-integrated solar technology over the next ten years, we could potentially see our CBD (central business district) on its way to net zero in the coming decades,” said lead author Professor Jacek Jasieniak.
“We began importing coal-fired power from the LaTrobe Valley in the 1920s to stop the practice of burning smog-inducing coal briquettes onsite to power our CBD buildings, and it’s now feasible that over one hundred years later, we could see a full circle moment of Melbourne’s buildings returning to local power generation within the CBD, but using clean, climate-safe technologies that help us meet Australia’s Net Zero 2050 target.”
The authors report that existing rooftop photovoltaic technology alone could dramatically reduce Melbourne’s carbon footprint. If technologies that are still being developed, such as high-efficiency solar windows or facade-integrated panels, are also taken into account, solar energy can become the leading source of energy in the city. These estimates hinge on the assumption that such technologies are integrated on a wide scale across the city.
For the study, the team compared the electrical energy consumption in Melbourne in 2018 to an estimate of the energy that could be produced through wide use of building-integrated solar systems. Consumption figures were obtained from Jemena and CitiPower & Powercor distribution companies through the Centre for New Energy Technologies (C4NET), an independent research body in Victoria, Australia. The production estimates were based on city-wide mathematical modelling.
Out of the total potential energy that solar power could provide, rooftop-mounted solar panels could generate 88%, with wall-integrated and window-integrated solar delivering 8% and 4% respectively. However, wall- and window-mounted solar technologies lost a lot less of their efficiency during the winter months relative to rooftop-mounted panels, the models showed. In other words, although they have a lower total output potential, these two types of technology deliver power more reliably and at more constant levels throughout the year.
Building height had a particular impact only on window-integrated solar technologies; in highrise neighborhoods, its potential rose to around 18% of the total generated energy. In areas with low average building height, the total wall and window areas available are small, reducing their overall potential to generate power. The window-to-wall surface ratio also tends to be greater in commercial buildings compared to residential buildings.
The modeling took into account the impact of shadows cast in the city by elements such as buildings, shading systems, or balconies, and natural factors such as sun incidence angle and total solar potential of different areas across Melbourne. The technologies used as part of the simulations were selected based on their technical characteristics, limitations, and costs of installation and operation.
All in all, the study worked with the 37.4 km2 area of central Melbourne, which consists mainly of residential and commercial buildings. In 2019, a total of 35.1 km2 of the studied perimeter was built floor area. This area was selected because it offered one the greatest potential for window-integrated solar in Melbourne, the team explains.
“Although there’s plenty of policies supporting energy-efficiency standards for new buildings, we’re yet to see a substantial response to ensuring our existing buildings are retrofitted to meet the challenges of climate change,” says co-author Dr. Jenny Zhou. “Our research provides a framework that can help decision-makers move forward with implementing photovoltaic technologies that will reduce our cities’ reliance on damaging fossil fuels.”
“In the near future, market penetration and deployment of high-efficient solar windows can make a substantive contribution towards the carbon footprint mitigation of high-rise developments,” adds first author Dr. Maria Panagiotidou. “As the world transitions towards a net-zero future, these local energy solutions would play a critical role in increasing the propensity of PVs within urban environments.”
The paper “Prospects of photovoltaic rooftops, walls and windows at a city to building scale” has been published in the journal Solar Energy.
Purple bacteria are poised to turn your toilet into a source of energy and useable organic material.
Dried sewage sludge. Image credits: Hannes Grobe.
Household sewage and industrial wastewater are very rich in organic compounds, and organic compounds can be very useful. But there’s a catch: we don’t know of any efficient way to extract them from the eww goo yet. So these resource-laden liquids get treated, and the material they contain is handled as a contaminant.
New research plans to address this problem — and by using an environmentally-friendly and cost-efficient solution to boot.
The future is purple (and bacterial)
“One of the most important problems of current wastewater treatment plants is high carbon emissions,” says co-author Dr. Daniel Puyol of King Juan Carlos University, Spain.
“Our light-based biorefinery process could provide a means to harvest green energy from wastewater, with zero carbon footprint.”
The study is the first effort to apply purple phototrophic bacteria — phototrophic means they absorb photons, i.e. light, as they’re feeding — together with electrical stimulation for organic waste recovery. The team showed that this approach can recover up to 100% of the carbon in any type of organic waste, supplying hydrogen gas in return — which is very nice, as hydrogen gas can be used to create power cells or energy directly.
Although green is the poster-color for photosynthesis, it’s far from the only one. Chlorophyll’s role is to absorb energy from light — we perceive this absorption as color. Green chlorophyll, for example, absorbs the wavelengths we perceive as red (which sits opposite green on the color wheel). If you’ve ever toyed around with the color-correction feature in graphical software (a la Photoshop, for example), you know that taking out the reds in a picture will make it look green. The same principle applies here.
Plants are generally green because red wavelengths carry the most energy — and plants need energy to create organic molecules. But the substance comes in all sorts of colors in a variety of different organisms. Phototrophic bacteria also capture energy from sunlight, but they use a different range of pigment — from orange, reds, and browns, to shades of purple — for the job. However, the color itself isn’t important here.
“Purple phototrophic bacteria make an ideal tool for resource recovery from organic waste, thanks to their highly diverse metabolism,” explains Puyol.
These bacteria use organic molecules and nitrogen gas in lieu of CO2 and water as food. This supplies all the carbon, electrons, and nitrogen they need for photosynthesis. The end result is that they tend to grow faster than other phototrophic bacteria or algae and generate hydrogen gas, proteins, and a biodegradable type of polyester as waste.
But what really sealed the deal for the team is that they can decide which of these waste products the bacteria churn out. Depending on environmental conditions such as light intensity, temperature, and the nutrients available, one of these products will predominate in the material they excrete.
The team doubled-down on this property by flooding the bacteria’s environment with electricity.
“Our group manipulates these conditions to tune the metabolism of purple bacteria to different applications, depending on the organic waste source and market requirements,” says co-author Professor Abraham Esteve-Núñez of University of Alcalá, Spain.
“But what is unique about our approach is the use of an external electric current to optimize the productive output of purple bacteria.”
This concept — a “bioelectrochemical system” — works because all of the purple bacteria’s metabolic pathways use electrons as energy carriers. They use up electrons when capturing light, for example. On the other hand, turning nitrogen into ammonia releases electrons, which the bacteria need to dissipate. By applying an electrical current to the bacteria (i.e. by pumping electrons into their environment) or by taking electrons out, the team can cause the bacteria to switch from one process to the other. It also helps improve the overall efficiency of both processes (see Le Chatelier’s principle).
The team included an analysis of the optimum conditions for hydrogen production in the paper (it relies on a mixture of purple bacteria species). They also tested the effect of a negative current (electrons supplied by metal electrodes in the growth medium) on the metabolic behavior of the bacteria.
Their first key finding was that the nutrient blend that fed the highest rate of hydrogen production also minimized the production of CO2 — this would allow the bacteria to recover biofuel from wastewater with a low carbon footprint, the team explains. The negative current experiment proved that these bacteria can use cathode electrons to perform photosynthesis.
Even more striking were the results using electrodes, which demonstrated for the first time that purple bacteria are capable of using electrons from a negative electrode, or “cathode“, to capture CO2 via photosynthesis.
“Recordings from our bioelectrochemical system showed a clear interaction between the purple bacteria and the electrodes: negative polarization of the electrode caused a detectable consumption of electrons, associated with a reduction in carbon dioxide production,” says Esteve-Núñez.
“This indicates that the purple bacteria were using electrons from the cathode to capture more carbon from organic compounds via photosynthesis, so less is released as CO2.”
The paper “Biological and Bioelectrochemical Systems for Hydrogen Production and Carbon Fixation Using Purple Phototrophic Bacteria” has been published in the journal Frontiers in Energy Research.
In a series of papers beginning in 1905 Einstein’s theory of special relativity revolutionized the concepts of space and time, uniting them into a single entity–spacetime. But, the most famous element of special relativity–as famous as the man himself–was absent from the first paper.
Mass-energy equivalence, represented by E=mc2, would be introduced in a later paper published in November 1905. And just as Einstein had already unified space and time–this paper would unite energy and mass.
So what does the mass-energy equivalence tell us and what is the equation E=mc2 saying about the Universe?
If you wanted to walk away from this article with one piece of information about the equation E=mc2 (and I hope you won’t) what would that be?
Essentially the simplified version of the equation of special relativity tells us that mass and energy are different forms of the same thing– mass is a form of energy. Probably the second most important piece of information to take away is the fact that these two aspects of the Universe are interchangeable, and the mitigating factor is the speed of light squared.
Still with us? Good!
Perhaps the most surprising thing about the equation E=mc2 is how deceptively simple it is for something so profound. Especially when considering that as the equation that describes how stars release energy and thus make all life possible. Mathematical formulae don’t get much more foundational.
Gathering Momentum: Where Does the Mass-Energy Equivalence Come From?
There are actually a few ways of considering the origin of E=mc2. One way is by considering how the relationship it describes can emerge when comparing the relativistic equation for momentum and its Newtonian counterpart. The major difference between the two, as you’ll see below, is multiplication by the Lorentz factor — you might remember in the last part of this guide to special relativity —concerning space and time— I told you it gets everywhere in special relativity!
Whilst you could argue that the only difference between the two is that velocity (v) has been replaced with a more complex counterpart that approaches v when speeds are far less than light–everyday speeds that we see everyday objects around us move at–but some physicists find this more significant than a mere substitution.
These scientists would argue that this new factor ‘belongs’ to the mass of the system in question. This view means that mass increases as velocity increases, and this means there is a discernable difference between an object’s ‘moving mass’ and its ‘rest mass.’
So, let’s look at that equation for momentum again with the idea of rest mass included.
So, if mass is increasing as velocity increases, what is responsible for this rise?
Let’s conduct an experiment to find out. Our lab bench is the 2-mile long linear particle accelerator at SLAC National Laboratory, California. Using powerful electromagnetic forces, we take electrons and accelerate them to near the speed of light. When the electrons emerge at the other end of the accelerator we find that their relativistic mass has increased by a staggering factor of 40,000.
As the electrons slow, they lose this mass again. Thus, we can see it’s the addition of kinetic energy to the object that is increasing its mass. That gives us a good hint that energy and mass are interconnected.
But, this conclusion leads to an interesting question; if the energy of motion is associated with an object’s mass when it is moving, is there energy associated with the object’s mass when it is at rest, and what kind of energy could this be?
An object at rest without kinetic energy can, with the transformation of an infinitesimally small amount of mass, provide energy enough to power the stars.
As the equation E=mc2 and the fact that the speed of light squared is an extremely large number implies, in terms of energy just a little mass goes a very long way. To demonstrate this, let’s see how much energy would be released if you could completely transform the rest mass of a single grain of sugar.
That’s a lot of energy!
In fact, it is roughly equivalent to the amount of energy released by ‘little boy’– the nuclear fission bomb that devastated Hiroshima on the 6th August 1945.
That means that even when an object is at standstill it has energy associated with it. A lot of energy.
As you might have guessed by this point, as energy and mass are closely associated and there are many forms of energy there are also many ways to give an object increased mass. Heating a metal rod, for example, increases the rod’s mass, but by such a small amount that it goes unnoticed. Just as liberating a tiny bit of mass releases a tremendous amount of energy, adding a relatively small amount of heat energy results in an insignificant mass increase.
We’ve already seeen that we can accelerate a particle and increase its relativistic mass, but is there anything we can do to increase a system’s rest mass?
E=mc2: Breaking the Law (and Billiard Balls)!
Until the advent of special relativity two laws, in particular, had governed the field of physics when it comes to collisions, explosions, and all that cool violent stuff: the conservation of mass and the conservation of energy. Special relativity challenged this, suggesting instead that it is not mass or energy that is conserved, but the total relativistic energy of the system.
Let’s do another experiment to test these ideas… The first location we’ll travel to in order to do this… a billiard table at the Dog & Duck pub, London.
At the billiard table, we strike a billiard ball 0.17 kg toward a stationary billiard ball of the same mass at around 2 metres per second. We hit the ball perfectly straight on so that all of the kinetic energy of the first ball is transferred to the second ball.
If we could measure the kinetic energy of the initial ball, then measure the kinetic energy of both balls after the collision, we would find that–accounting for the small losses of energy to heat and sound–the total energy of the system after the collision is the same as the energy before the collision.
That’s the conservation of energy.
Let’s rerun that experiment again, but this time we launch the billard ball so hard that instead of knocking the target ball across the table, it shatters it. Collecting together the fragments of the shattered ball and remeasuring the mass of the system, we would find the final mass is exactly the same as the initial mass.
And that’s the conservation of mass.
We’re starting to get funny looks from the Dog & Duck regulars now, and the landlord looks angry about the destruction of one of his billiard balls. Luckily, the third part of our test requires we relocate to CERN, Geneva. So we down our drinks, grab our coats and hurry out the door.
Trying the experiment a third time, we are going to replace the billiard table with the Large Hadron Collider (LHC)–that’s some upgrade– and the billiard balls with electrons and their equal rest mass anti-particles– positrons.
Using powerful magnets to feed these fundamental particles with kinetic energy we accelerate them to near light speed, directing them towards each other and colliding them. The result is a shower of particles that previously weren’t present. But, unlike in our billiard ball example, when we measure the rest mass of the system it has not remained the same.
Just one of the particles we observe after the collision event is a neutral pion–a particle with a rest mass 264 times the rest mass of an electron and thus 132 times the initial rest mass we began with.
Clearly, the creation of this pion has taken some of the kinetic energy we poured into the electrons and converted it to rest mass. We watch as the pion decays into a muon with a rest mass 204 times that of an electron, and this decays into particles that are lighter still. Each time the decay releases energy in the form of pulses of light.
Relativistic Energy .vs Rest Energy
By now it is probably clear that in special relativity rest mass and relativistic mass are very different concepts, which means that it shouldn’t come as too much of a surprise that rest energy and relativistic energy are also separate things.
Let’s alter that initial infographic to reflect the fact that the equation E=mc2 actually describes rest energy.
This raises the questions (if I’m doing this right that is) what is the equation for relativistic energy?
It’s time for another non-surprise. The equation for relativistic energy is just the equation for rest energy with that Lorentz factor playing a role.
Ultimately, it is this relativistic energy that is conserved, thus whilst we’ve sacrificed earlier ideas of the conservation of mass and the conservation of energy, we’ve recovered a relativistic version of those laws.
Of course, the presence of that Lorentz factor tells us that when speeds are nowhere near that of light — everyday speeds like that of the billiard balls in the Dog & Duck–the laws of conservation of mass and energy are sufficeint to describe these low-energy systems.
The Consequences of E=mc2
It’s hard to talk about the energy-mass equivalence or E=mc2 without touching upon the nuclear weapons that devasted Hiroshima and Nagasaki at the close of the Second World War.
It’s an unfortunate and cruel irony that Einstein–a man who was a staunch pacifist during his lifetime–has his name eternally connected to the ultimate embodiment of the most destructive elements of human nature.
Nuclear radiation had been discovered at least a decade before Einstein unveiled special relativity, but scientists had struggled to explain exactly where that energy was coming from.
That is because as rearranging E=mc2 implies, a small release of energy would be the result of the loss of an almost infinitesimally small amount of rest mass –certainly immeasurable at the time of discovery.
Of course, as we mention above, we now understand that small conversion of rest mass into energy to be the phenomena that power the stars. Every second, our own star–the Sun– takes roughly 600 tonnes of hydrogen and converts it to 596 tonnes of helium, releasing the difference in rest mass between the two as around 4 x 1026 Joules of energy.
We’ve also harnessed the mass-energy equivalence to power our homes via nuclear power plants, as well as using it to unleash a terrifying embodiment of death and destruction into our collective imaginations.
We could probably ruminate more about special relativity and its elements, as its importance to modern physics simply cannot be overstated. But, Einstein wasn’t done.
Thinking about spacetime, energy and mass had open a door and started Einstein on an intellectual journey that would take a decade to complete.
The great physicist saw special relativity as a great theory to explain physics in an empty region of space, but what if that region is occupied by a planet or a star? In those ‘general’ circumstances, a new theory would be needed. And in 1915, this need would lead Einstein to his greatest and most inspirational theory–the geometric theory of gravity, better known as general relativity.
Sources and Further Reading
Stannard. R., ‘Relativity: A Short Introduction,’ Oxford University Press, .
Lambourne. R. J., ‘Relativity, Gravitation and Cosmology,’ Cambridge University Press, .
Cheng. T-P., ‘Relativity, Gravitation and Cosmology,’ Oxford University Press, .
Fischer. K., ‘Relativity for Everyone,’ Springer, .
Takeuchi. T., ‘An Illustrated Guide to Relativity,’ Cambridge University Press, .
Wind power is mostly associated with sweeping white blades, taking advantage of the strong gusts that blow over the land or the sea. But what if we could forget about the blades and even the wind and instead just have a turbine? That’s the idea of a group of European companies, who have come up with new ways to expand wind energy without the limitations of a conventional turbine.
Wind has gradually turned into a leading energy source around the globe, with costs dropping every year. But turbines can be problematic: they’re unsuited for some areas, they can harm birds, and they’re not recyclable. This has led green energy pioneers to start thinking of ways to reinvent wind power – even forgoing the need for the blades in a tower.
In Spain, the small startup Vortex Bladeless has come up with a design that can create energy from winds without the actual blades. The company claims not to be against traditional windfarms but instead hopes to fill the gaps in locations where traditional wind farms may not be appropriate, such as in urban or residential areas.
“We hope to offer people the possibility of harvesting the wind that passes over their roofs or through gardens and parks with devices that are cheaper to install and easier to maintain than conventional wind turbines,” David Yañez, Vortex co-founded, said in a statement. “Bladeless turbines can adapt more quickly to changes in wind direction than conventional ones.”
Vortex’s design of a turbine is similar to a slender wobbling or oscillating cylinder. The device has only a few moving parts, doesn’t need much maintenance, generates very little noise and is relatively easy to install. The company argues the turbine also has less visual effect and impact on wildlife compared to conventional bladed turbines.
Instead of relying on the wind to move a blade, Vortex’s device oscillates as the air passes around it and vortices build up behind – a process known as vortex shedding. As the wind blows and vortices build up, a lightweight cylinder affixed vertically to an elastic rod oscillates on its base, where an alternator converts the mechanical movement into electricity.
Initial tests by Vortex suggested that their device can generate electricity about 30% cheaper than conventional wind turbines on a levelized cost of energy basis. This is largely because of the lower installation costs and the minimal maintenance requirements. Still, the turbine so far developed is small and Vortex is now looking for an industrial partner to create a larger one.
“Our machine has no gears, brakes, bearings, or shafts. It does not need lubrication and has no parts that can be worn down by friction. Thanks to being very lightweight and having the center of gravity closer to the ground, anchoring or foundation requirements have been reduced significantly compared to regular turbines, easing installation,” Yáñez said in a statement.
Other companies are taking similar steps across Europe, with high hopes of expanding wind energy. Alpha 311, a UK organization, has developed a small vertical wind turbine that they claim can generate electricity without wind. The turbine, made of recycled plastic, fits on to existing streetlights and generates electricity as passing cars displace the air.
The company argues that each turbine could generate as much electricity as 20 squared meters of solar panels, more than enough electricity to keep the streetlight on and help power the local energy grid. As a starting point, Alpha 311 will install a scaled-down version of the turbine in the 02 Arena in London, an entertainment venue, that will generate enough electricity for its visitors.
“While our turbines can be placed anywhere, the optimal location is next to a highway, where they can be fitted onto existing infrastructure. There’s no need to dig anything up, as they can attach to the lighting columns that are already there and use the existing cabling to feed directly into the grid,” Mike Shaw, a spokesperson for the company, told The Guardian.
Meanwhile, in Germany, the startup SkySails hopes to use an airborne design to harness wind power directly from the sky. The company builds fully automated kites that can fly up to 400 meters to capture wind power. As it goes up, the kite pulls a rope secured to a winch and a generator on the ground. Electricity is generated as the kite goes up into the sky.
The design can generate a maximum capacity of 100 to 200 kilowatts, but the company hopes to increase the output from kilowatts to megawatts. Stephan Wrage, the chief executive of SkySails, told The Guardian that the technology has a minimal impact on people and the environment, “working very quietly” and with “no visible effects on the landscape.
Located in Southern Spain, Seville is the European city with the largest number of orange trees — more than 45,000. In fact, there are so many oranges that despite the city’s healthy appetite, tons of oranges end up being discarded every year. Now, the city came up with a solution, using them to obtain electricity. It’s only a pilot program for now but it could be expanded in the medium-term.
Oranges originated in Asia and were introduced to Spain about 1,000 years ago. Seville alone produces about 15,000 tons of oranges per year but the Spanish don’t eat all of them. Instead, they are exported (mainly to the UK, where they are turned into marmalade). The oranges are also used as an ingredient of Cointreau and Grand Marnier.
There were only 5,000 orange trees in Seville in 1970 but since then the city has seen an orange boom. The tree was linked to the concept of happiness, which led to people start planting it in the streets. The Azahar flower that blossoms from the tree have also been associated with health benefits, leading to its use in essential oils and perfumes. In fact, the Arabs wanted Seville to be the world’s leading perfume producer.
With trees scattered across the city, the excess of the fruit has become a sort of problem for the City Hall. Once they fall, the oranges are squashed under the wheels of the cars and the streets become sticky with juice and filled with flies. About 200 people are employed to collect the fruit from the streets.
There had to be a better solution, which now is being tried in a pilot program.
The city has launched a pilot program with Emasesa, the municipal water company, through which 35 tons of fruit will be used to power a water purification plant. It’s a simple mechanism. The oranges are placed in a facility that already generates electricity from organic matter. Once they ferment, the methane is used to drive the generator and produce electricity.
“It’s an innovative experience of the circular economy through which we are taking advantage of organic matter. We want to recycle all the city’s discarded oranges,” Enrique Vaquerizo, head of residual waters at Emasesa, said in a statement. “Through the pilot, we are transforming a plant that used to consume a lot of energy to now starting to produce it.”
For each ton of orange approximately 500 liters of juice and 500 kilos of peel are obtained. With the amount of fruit to be used in the water plant, the government expects to generate 1,500 KWh– enough electricity for 150 households. If the pilot works, the plan is for the plant to process about 1.700 tons of oranges, which would power 73,000 households.
Seville’s Mayor Juan Espadas said the pilot will help to reduce the city’s greenhouse emissions, push for a circular economy and allow the water plant to become an energy producer, using the surplus for the city’s needs. The project follows other environmental initiatives in Seville, such as a recent plan to save and reuse water to tackle the rising temperatures.
Despite the coronavirus pandemic overtaking most of the 2020 agenda, this was also a big year for environmental, climate, and energy news. There were some positive developments (such as the falling cost of renewable energy and the surge of solar and wind power) but also a lot of bad news, especially in regards to greenhouse gas emissions and plastic pollution.
We selected what we consider some of the environmental highlights of the year and compiled a 2020 list. With 2021 around the corner, we hope this review will help to reflect on what has happened over the year and consider how to take to better take care of the planet.
2020 set to be one of the warmest years on record
The World Meteorological Organization (WMO) published in December its State of the Climate Report, which showed that 2020 is on track to be one of the three warmest ever recorded as emissions continue to rise, despite the pandemic which kept us more time inside. The average global temperature is set to reach about 1.2º above pre-industrial levels.
To make matters even worse, this year has been unusually hot despite the cooling effect of La Niña, the climate phenomenon associated with below-normal sea surface temperatures in the Pacific Ocean with global implications. Its impact has been more than offset by heat trapped in the atmosphere by greenhouse gasses.
Arctic sea ice reached its second-lowest level in the 42-year-old satellite record. Arctic sea ice for July and October 2020 Almost 10 million people were displaced, largely due to hydro-meteorological hazards and disasters, mainly in South and South-east Asia and the Horn of Africa. Two ice caps in Nunavut, Canada have disappeared completely, confirming predictions of a study published in 2017 that they would melt completely within five years.
Deforestation record in Brazil
Deforestation in the Amazon rainforest in Brazil reached a 12-year high. A total of 4,281 square miles (11,088 square kilometers) of the forest were destroyed in the 12 months to August 2020, according to Brazil’s space agency PRODES program, which monitors deforestation.
While most of the Amazon lies in Brazil, the rainforest affects all of us. Rainforests like the Amazon play a key role in controlling climate as they absorb carbon, a greenhouse gas, from the atmosphere. Nevertheless, when they die or burn, trees release carbon back into the environment.
Brazilian President Jair Bolsonaro came to power in 2019 promoting an agenda based on more extractive activities in the Amazon. He even asked Congress to change environmental protection laws and cut the budget and the staff of the federal environmental protection agency IBAMA. Many high-ranking politicians, including French President Emmanuel Macron and president-elect Joe Biden have criticized Brazil for not doing enough to protect the forest.
The 2019-2020 Australian bushfire season started in June 2019. Several uncontrolled fires were reported. Amplified by drought, the fires continued to spread, and by January 2020, fires had burnt an estimated 18.6 million hectares (46 million acres). For comparison, the California wildfires burnt 800,000 hectares (2,000,000 acres) and the 2019 Amazon rainforest wildfires burnt 900,000 hectares (2,200,000 acres) of land.
It was the worst bushfire season on record and the “worst wildlife disaster in modern history,” according to a report by the World Wild Fund for Nature (WWF), with three billion animals affected. This includes 143 million mammals, 2.46 billion reptiles, 180 million birds, and 51 million frogs which were harmed.
Authorities and firemen (both professional and volunteers) put up a tremendous effort to limit the fire, but all they could do was limit the scale of the damage. Much of the affected areas had been in drought for three years and the lack of water transformed green plants into perfect fuel for the fire, helping spread the damage. As Australian researchers had predicted for over a decade, higher temperatures are starting to take a toll.
The world’s largest offshore wind farm
The UK, already the world’s leader in offshore wind, is getting ready to start construction of what will be the world’s biggest offshore wind park, Dogger Bank. The British utility company SSE and the Norwegian energy firm Equinor agreed to invest $8 billion in the project, which will be used to build the first two phases. The wind farm is being developed in three phases and each phase will have an installed generation capacity of up to 1.2 gigawatts (GW).
The construction of the first two phases, with 2.4 GW capacity, will be financed by a group of 29 banks and three credit export agencies. They will be built at the same time starting in 2021 to maximize the synergies due to their geographical proximity and make use of common technology and contractors. Offshore wind in the UK now powers the equivalent of 4.5 million homes per year and in many areas, and wind is now the lowest cost option for new power in the UK.
US set to rejoin the Paris Agreement under Biden
Democratic candidate Joe Biden won the presidential elections in the United States and he’s already lining up big changes on climate change as soon as he takes office on 20 January. The biggest change will be rejoining the Paris Agreement on climate change, following President Donald Trump’s decision to leave the pact.
Biden has promised measures to put the US will on track for net-zero emissions by the middle of the century. This would have a big effect on meeting the Paris Agreement’s goals. An analysis by Climate Action Tracker, a non-profit organization, said Biden’s climate plan could put the Paris’ goals “within striking distance”.
Biden vowed to eliminate carbon emissions from the electric sector by 2035 and spend $2 trillion on investments ranging from weatherizing homes to developing a nationwide network of charging stations for electric vehicles. If he can’t implement it through Senate, he’ll have to rely on executive orders to advance his agenda.
Air pollution drops with the pandemic
The lockdown measures implemented across the world at the start of the pandemic improved air quality and averted thousands of deaths in regions with severe air pollution, according to several studies. Scientists are increasingly calling for more ambitious policies to achieve larger air quality improvements in the future.
A team of scientists at the University of Notre Dame found that particulate matter concentrations in China and parts of Europe dropped by 29.7% and 17.1% respectively during the lockdown. They measured air quality between February and March in China and February and May in Europe, when stay-at-home orders were in place. The European Environmental Agency (EEA) published the report “COVID-19 and Europe’s environment” and showed how concentrations of NO2 — a pollutant mainly emitted by road transport — fell sharply in many European countries. Reductions variated between countries, depending on how severe was the lockdown.
Particulate matter, small airborne particles, comes from combustion-related sources such as industrial emissions, transportation, wildfires, and chemical reactions of pollutants in the atmosphere. This has turned air pollution into the leading environmental cause of death, according to the World Health Organization.
Record number of storms
The 2020 hurricane season broke several records, especially regarding the number of storms in the tropical Atlantic and the Caribbean Sea.
In May, the Climate Prediction Center of the National Oceanic and Atmospheric Administration (NOAA) forecasted that 2020 would be an above-average hurricane season. The main reason for this is the above normal sea surface (SST) in tropical Atlantic and the Caribbean Sea and stronger West African monsoon, key conditions for the formation of tropical cyclones. But few would predict what ended up happening.
To the surprise of everyone, it wasn’t long before we reached a point where there were no more new names for storms. Tropical Storm Arthur was the first to form on May 16th and lasted until May 19th. Eight days later another tropical storm was formed and the list continued until the last name, Wilfred, on September 13th. It’s not just the number of storms, its intensity was also pretty scary. During this season, there were four simultaneous events, at least 2 storms happening at the same time. Laura and Marco, both hurricanes, started together and continued staying active almost at the same time. Laura was the strongest storm to hit Louisiana in the US.
Over 80% of 2020’s new energy is renewable
Led by solar power, renewable energy could account for 80% of the growth in electricity generation over the next decade, according to a report by the International Energy Agency (IEA). It’s now consistently cheaper to generate electricity from the sun than by burning coal or natural gas in most countries, IEA said.
The IEA, an intergovernmental organization, said electricity costs from large-scale solar photovoltaic installations have fallen from roughly 38 cents per kilowatt-hour in 2010, to a global average of 6.8 cents per kilowatt-hour last year. This means solar could become “the new king” of the world’s electricity markets, IEA head Fatih Birol said.
At the same time, a report by the energy consultancy Ember found that wind and solar doubled their share of global electricity generation since the Paris Climate Agreement was signed in 2015, reaching almost 10% in the first half of the year.
Coral reefs take a big hit
Australia’s Great Barrier Reef has lost more than half of its coral population in the last three decades, according to a new study, with climate change being the main driver of this loss. The researchers found that all types of coral had suffered a decline here, in the world’s largest reef system.
The year 2020 was not kind to the reefs. A third mass coral bleaching event in five years was recorded at the Great Barrier Reef, showing that for the first time, all the major regions in the Barrier Reef experienced severe bleaching. This is largely caused by global warming and ocean acidification — which is also a result of carbon dioxide being pumped into the atmosphere and then absorbed by the oceans.
Coral reefs are some of the most vibrant marine ecosystems on the planet. They are called the rainforests of the sea, as between a quarter and one-third of all marine species rely on them at some point in their life cycle. Fishes and other organisms’ shelter, find food and reproduce near them. The Great Barrier Reef covers nearly 133,000 square miles and is home to more than 1,500 species of fish, 411 species of hard corals, and 4,000 types of mollusk.
Carbon neutrality targets
Around the world, countries have started committing to carbon neutrality targets by 2050 or 2060, a vital step to addressing global warming. Chinese President Xi Jinping announced in September that China will aim to reach peak emissions before 2030 and then carbon neutrality by 2060. The country is the world’s largest source of carbon dioxide, accountable for about 28% of the global emissions. Emissions in China rose in 2018 and 2019.
South Korea’s president, Moon Jae-in, declared in October that the country will go carbon neutral by 2050. He vowed to end its dependence on coal and replace it with renewables as part of its Green New Deal, a multibillion-dollar plan to invest in green infrastructure, clean energy, and electric vehicles.
Several countries have already mandated carbon neutrality by law. France, Germany, Hungary, Denmark, New Zealand, Scotland, the UK, and Sweden have legally committed to carbon neutrality by 2050, while several other countries (including South Africa, Belgium, Norway, and Portugal) have adopted policies to do so.
Microplastics, microplastics everywhere
The world’s seafloor is riddled with 14 million tons of microplastics, broken down from the masses of rubbish entering the oceans every year, according to a study. It’s the first global estimate of sea-floor microplastics and the amount registered is 25 times greater than that shown by previous localized studies.
Plastic pollution in the world’s oceans is an internationally recognized environmental problem. Millions of tons of plastic enter marine ecosystems every year, and quantities are expected to increase in the coming years. Over time, plastic items in the ocean can degrade or break down into smaller pieces, known as microplastics.
Another study published in July found that about 1.3 billion tons of plastic will be dumped into our environment by 2040, both on land and in the ocean, according to a global model of the scale of the plastic problem. Roughly 460 million tons will end up on land on land and 250 million tons in watercourses.
Lack of biodiversity action
World leaders have failed to meet a set of important biodiversity goals, according to a United Nations report. In fact, not one single biodiversity target has been met ten years after they were proposed, and ecosystems all around the world are still experiencing massive strain.
The Global Biodiversity Outlook, published by the Convention of Biological Diversity (CDB), showed the progress the world has made (or hasn’t made) since we first laid down solid biodiversity goals ten years ago. They are the equivalent to the Paris Agreement on climate change but on biodiversity — and none of them have been achieved.
According to scientists, we are currently causing a sixth mass extinction, with wildlife populations dropping more than two thirds since 1970 and continuing to decline in the past decade, according to the report. Meanwhile, governments are falling short on funding to protect biodiversity.
A not so green recovery
Activists, academics, and politicians are drawing attention to the need for the economic recovery from the coronavirus pandemic to be a green one that can help the world to tackle climate change. Nevertheless, most countries have gone in the opposite direction, giving trillions to fossil fuels.
A report by Climate Transparency found that the G20 spent US$393 billion on support to the energy sector, with 53.5% going to fossil fuels ($175 billion to oil and gas, and $16.2 billion to coal). Of this, 86% has been provided without conditions for improved environmental action or performance.
G20 economies represent more than 80% of global GDP and three-quarters of global trade. The group is also responsible for 75% of global emissions and therefore has a major role in fulfilling the goal of the Paris Agreement to avoid a temperature increase of more than 2C, or ideally 1.5C, above the pre-industrial levels.
Popular belief in India that using firewood for cooking is healthier than Liquefied Petroleum Gas (LPG) is making the transition to clean cooking fuels more difficult, a new study showed. This means better information programs are needed to train people, the researchers argued.
India has more people who rely on solid fuels for cooking than any other country in the world (780 million), and estimates indicate that it will stay in this top position at least until the end of 2030. The scale of solid fuel use in rural areas signals that the widespread uptake of clean fuels is a distant reality.
Women are the main family cooks in rural India. That’s why researchers decided to focus their study on them and their views on fuel transition. The team performed a qualitative analysis of data from focus group discussions with comparable groups of women who have those who have not transitioned to LPG, seeking to understand their views.
The findings showed women believe firewood causes health problems but feel that it contributes more to wellbeing than cooking with LPG. For the researchers, this helps explain why India’s switch from traditional solid fuels is going slower than expected.
Study co-author Rosie Day said in a statement: “Whilst cooking is not solely a woman’s job, the reality is that, in rural India, women are considered the primary cooks. It is, therefore, critical to unravel how women see the relationship between wellbeing and cooking fuel if India is to make progress in transitioning to clean fuels.”
The researchers from the Universities of Birmingham (UK) and Queensland (Australia) focused on women from four villages in the Chittoor district of Andhra Pradesh. This allowed to do a comparison, as two of the villages mostly used firewood and the other two LPG, having switched from using firewood.
Those who use firewood believed that cooking with this fuel improved their financial wellbeing because they generated income from its sale, whilst collecting firewood gave them an opportunity to socialize and is a tradition they would like to continue. They viewed LPG as a financial burden that gave food an undesirable taste.
On the other hand, LPG users said their fuel allowed them to maintain or improve social status, as well as making it easier to care for children and other family members. Cooking with LPG freed up time which they could use to work outside the home and earn money. They also enjoyed extra leisure time with their family.
The researchers suggested future interventions to promote new fuels should actively involve women who used solid fuels and clean fuels, opening discussion about the benefits of each and allowing cooks to observe different cooking practices. They said information should be distributed on the positive wellbeing of LPG.
“We have gained important understanding of women’s views in this setting, but further research is needed to analyze the perceived relationship between women’s fuel use and multi-dimensional wellbeing in other settings. This will help to increase our understanding of how social and cultural factors come into play in transition to clean fuels,” said Day.
The study was published in the journal Nature Energy.
Whilst you’ll still find ghostly goings-on here at ZME manor, they come accompanied with rational scientific explanations and reference to the well-evidenced the laws of physics.
This is a haunted house where gravity grounds goblins, thermodynamics fights Fetches, physics faces down phantoms, mathematics melts muck-men, quantum confronts Qiqirns, and science lays the smackdown on spooks.
As you pass through the dusty halls of ZME Manor, abandoned for decades, you will also get the chance to observe a gallery of questionable ghostly images, some conclusively debunked, others still open for interpretation.
So, sign your waiver, prepare yourself for unknown frights, and enter the house that drips science.
Arrival at ZME Manor: What is a Ghost?
It’s an ideal night for a ghost hunt, you think, as you pull up to ZME manor. Lightning forks through the sky and the rain lashes the overgrown grounds of the manor. As you exit your car you are in a philosophical mood. You don’t really give much thought to the paranormal, outside the odd horror film. You wonder to yourself exactly what is a ghost, and why are we so fascinated with the idea of life after death?
The idea of a person’s spirit surviving death and returning to be glimpsed by the living is something that is rooted in almost every culture, thus it’s extremely hard to come up with a conclusive answer to these questions. Once portents of doom, death and disease, carrying warnings from beyond the grave, or attempting to finish business left unfinished in life, ghosts have also found an interpretation in modern scientific culture.
One might expect that more enlightened times, in which more people than ever are aware of the principles of science, belief in things like ghosts would fade away like the proverbial spectre. But, that hasn’t been the case.
A recent YouGov poll showed that ghost belief is particularly prominent in the UK, with 1 in 3 British citizens saying they believe in ghosts. Compare that to less than 1 in 4 who claimed to be religious.
Ghost hunters who claim to operate scientifically offer several modern definitions of a ‘ghost’ — one of the common features of these scientific spooks is the idea of a person’s ‘energy’ surviving after death. If that sounds a bit woolly and ill-defined, that’s because it is.
There are some common qualities of ‘ghosts’ that most paranormal enthusiasts agree upon.
With those qualities in mind, we can start to see if science can offer a way to ‘debunk’ them.
One of your ghost hunt companions joins you on the porch. You vaguely recognise his face. To your surprise, you realise you’ve seen him running around in the dark on one of the multitudes of ghost hunting TV shows that haunt your television after 10 pm on a Wednesday night.
Who better to ask about ghosts?
“Good question,” the ghost hunter, who introduces himself simply as ‘Nick’, says in a most self-assured way. “Energy can’t be created or destroyed; it can only change forms — that’s a law of physics. Not a theory of physics — a law. It’s called the law of conservation of energy.
“It means that if you take an isolated system, such as a person, the energy contained in that person can’t be destroyed. It can change forms from chemical energy — like the signals that travel down your nerve pathways — into kinetic energy, the energy required to move your arm, for example, but the energy is always there.“1
The Hallway: Elaborating on energy
“This law makes sense to me,” says Nick smiling at you as he opens the door, and strides purposefully into ZME Manor. “It means that when we die, our energy must go somewhere. The flesh and bones — the empty vessel — is left behind, but the energy survives.”1
As a third figure steps up to the porch, as you follow the ghost hunter through the doorway into the impressive, if deteriorating, main hallway. You are just thinking that his explanation kind of makes sense, you know Einstein’s theory does say that energy can’t be created or destroyed, so what about the energy that makes up ‘you’? Where does that go?
“Nick is quite wrong you know,” says the third hunt participant, giving you something of a start. You hadn’t noticed the young woman, short and quite unassuming, thus far, and she has followed you silently into the cavernous hallway. “Einstein’s theory of mass-energy equivalence does say energy can’t be created or destroyed, but it’s a bit more complicated than that…”
The big difficulty with the rationalisation offered by Nick and other ghost hunters as it doesn’t really consider what the energy that makes up a human being actually is.
Energy is a property of matter that is used to do work on a system. If we want to change the state of a system we put energy into it. We are aware of the forms energy takes, electrical, nuclear, chemical, heat, kinetic and potential (stored) energy being the main types we encounter every day.
Nick, our ghost hunter, is correct when he says energy cannot be created or destroyed, only converted, but when we consider that statement we must bear in mind the forms energy takes in our body. This is where Nick starts to go wrong.
Our bodies aren’t thermodynamically isolated systems. An isolated system, such as the one described by Nick, cannot exchange either matter or energy with its environment. Clearly, we do both, and in both directions. We absorb both matter and energy and pass it into the environment, energy via heat and matter via… well… you know. When we die, this process only halts in one direction. We stop taking in matter, but our bodies continue to expel heat until we’re in thermal equilibrium with the environment.
As for the rest of the energy that comprises us?
Grim though it may be, why should we suspect that our carcass is any different to the animal matter many of us consume? The chemical energy in ‘you’ goes back into the food chain. Not very romantic. But true.
“Well, that’s food for thought. Thanks!” you chuckle. The young woman flashes a mischievous smile, her green eyes twinkling. She then moves off to inspect some very complicated scientific doodahs that Nick is unpacking from over the ghost hunter’s shoulder. He pays her no attention, continuing his unpacking.
Nick calls over to you. “Hey, you. Why don’t you check out one of the rooms down here? That one maybe.” He points to an imposing oak door. You move closer and inspect the carvings of goblin-like faces etched into the wood.
“Erm… Sure…” you reply somewhat trepidatiously. And look back to see if Nick and your other companion noticed your wavering voice. The ghost hunter pays you no mind, but the young woman smiles back sweetly. Somewhat buoyed by this, you grip the handle and push.
The Library: You’ve got Chills, they’re multiplying…
The door swings open much more freely than you you were expecting, it’s huge weight not impeding its operation one bit, nor does it’s age or apparent disuse. Beyond the door lies row upon row of oak shelves, filled with ancient books. Your senses are overwhelmed with the smell of damp and musty paper.
Unperturbed by the smell, you navigate your way around a well-worn armchair and circular table and move down the shelves of books. You grip your coat tighter, as you approach the shelves. The temperature has dropped considerably.
“Coldspot,” Nick sniffs, with the air of a mechanic who has found a problem with your car that he’s amazed that you, a grown adult who drives the vehicle, has missed. “One of the most common signs of paranormal activity. Everything that enters an environment, even ghosts, change it in some way. When we move and breath we stir up the air around us, our collective body temperatures raise the temperature.
“The most common theory for why cold spots occur is when a ghost is in an area they use the heat in order to manifest.”
Nick moves away pointing a laser thermometer at the far wall. Your other fellow ghost hunter takes up space he previously occupied. “Of course,” she smiles again. “That’s not how thermodynamics works…”
Let’s say we have our free-floating blob of “vital energy” or ghost if you prefer, there’s going to be a pretty immediate restriction placed on that energy. If it manages to stay in one compressed form the second law of thermodynamics states that the amount of useless energy within that lump–its entropy–is going to grow.
Every time our spook startles a photogenic ghost hunter on a syndicated US TV show by throwing something, or slowly shutting a door, it’s going to lose energy. Furthermore, the energy our spook holds on to is going to become gradually more and more useless. To keep its structure, the ghost would have to convert energy from its surroundings. This is something that should be measurable and demonstrable, and yet no-one has either measured or demonstrated it as of yet.
Therefore, ghosts would need a pretty much constant source of energy to remain ordered. Nick and many other ghost hunters claim that cold-spots represent just such an attempt by a ghost or spirit to draw energy from its surroundings.
The problem with this is that according to the zeroth law of thermodynamics, heat is only exchanged between a colder body and a hotter one until a thermal equilibrium is reached and both bodies are at the same temperature.
The principle of thermodynamic equilibrium simply doesn’t allow for heat to be drawn at will in a limited area, the exchange of heat would spread to all areas in thermal contact with a smaller region.
“A far more likely explanation for cold spots are draughts,” the young woman explains with a smile. “The feeling of cold is not actually due to temperature as such, but the rate at which heat is drawn from us, a far more likely explanation for a sudden cold sensation is exposure to a column of frigid air.
“Thermodynamically speaking, heat is often associated with entropy as it’s not a usable form of energy. Heat is generally an end product of various thermodynamic processes, the final energy transformation.”
“Makes sense,” you think, as your companion moves off to inspect the staircase outside the library. Before climbing the stairs she turns back to the doorway and points in Nick’s rough direction. “Also, you might want to tell Nick, that laser thermometers don’t work like that. He thinks he’s taking the temperature of the middle of the room when he’s actually measuring the temperature of the point the laser is shining on!”
You turn and look, sure enough, you tell from the red spot like an assassin’s target shining on a far wall that the laser is moving through the centre of the room and bouncing back off that wall. Nick notices you watching. “Yup, definite coldspot right here!” he says pointing at the centre of the room. You just smile and then carefully follow your other companion up the stairs, registering the creek of the wooden steps as you do.
The Staircase: Every Step you take…
After climbing the stairs you round the corner and see a corridor with several rooms branching off it. Your companion is nowhere to be seen, so she must have ducked into one of these doors.
You hear a bang and a muttered swearword from the library. Nick is still inaccurately measuring temperature is the room. As you are about to try the first door, you freeze. Another sound sends a figurative chill through your heart.
A creak from the stairs– the same as you heard when you climbed the staircase. Another. Then yet another. Someone is climbing the stairs, and you know it isn’t you or any of your companions.
You duck into the first bedroom and shut the door. As you lean against the doorframe, you hear slow but deliberate footsteps in the hallway…
Ghostly footsteps are one of the most commonly reported ‘haunting phenomena.’ Ignoring the fact that these footsteps usually have very rational explanations for the moment, the concept raises the question; what do the laws of physics say about how ghosts could move?
Newton’s First Law states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. Therefore, from this, we can gather that for a ghost to begin to move, there must be some force acting on our spook.
You and I move by applying a downward force on the floor, which in turn applies an equal and opposite force on us according to Newton’s third law, which states: “For every action, there is an equal and opposite reaction. The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. The size of the forces on the first object equals the size of the force on the second object.”
It wouldn’t be unreasonable to assume ghosts move in the same way. In support of this, there are accounts of experiencers seeing spirits walking through hallways or up staircases in addition to hearing ghostly footsteps. Ghost hunting groups often advise spook seeking amateurs to detect ghost pathways by dusting surfaces with flour or other fine powders to detect footprints. This leads us to conclude that the ghost must be material, as it is the only way they could exert the required force to propel themselves.
But, if they are material and able to interact with matter, how can they suddenly turn intangible?
To your horror, the door handle begins to turn. The hair stands up on the back of your neck as the door swings open. “You in ‘ere?” says Nick. You find yourself surprised to actually be happy to see him.
After your nerves settle, you explain your story to Nick. “Yup, definite activity there,” he mumbles clearly not that impressed with your experience. He continues off down the corridor trying doors.
As you poke your head out of the door, your more science-minded companion, the young woman joins you. She clearly has excellent hearing as she seems to have heard the entire conversion. “Of course,” she begins. “The ‘ghostly footsteps’ people hear usually have some very rational explanations. For example, houses absorb a lot of heat during the day, and as they cool at night, contracting materials can cause a lot of bumps and creaks.”
With regards to the staircase, she adds: “One of the most common causes of footsteps on the stairs is an adjoining building having a staircase positioned next to the one from which the footsteps seem to be coming from.”
“By the way,” she adds. “Why did you close the door when you hid in the room? Ghosts can just walk through walls, right?”She gives me a comforting wink and drifts down the hall. I notice the floorboards don’t creak when she walks over them.
I exit the doorway quickly, leaving the door open.
The Upper Floor: It’s Just a Phase…
You catch up with Nick. “So how common is it for ghosts to be seen just walking through walls?” I ask the ghost hunter who is waving around an EMF meter like a kid playing Ghostbusters in the school playground. “Oh, very common. You see,” he adds professorially “ghosts don’t follow our floor plans. They follow the floor plans that the building had when they died. That means if there wasn’t a wall there when they were alive, they just ignore it like it isn’t there now.”
Nick goes on to explain about The Grey Lady of Gainsborough Hall. “Sightings of the Grey Lady walking the Ghost Corridor have been part of local legend from before the Victorian era. Dressed in grey and in Tudor style, the grey lady walks the length of the corridor and turns right before the end to disappear through a wall. In the 1960’s the lath and plaster were removed from this wall revealed a Tudor doorway — at the exact spot where the grey lady walks through the wall!”2
As Nick continues down the corridor, the young passes me and says with a smile: “I guess the ‘Grey Lady’ never heard of the Pauli Exclusion Principle!”
The Pauli exclusion principle is the facet of matter that forbids particles known as Fermions, including protons, neutrons and electrons, from cramming into the same state defined by four principle quantum numbers.
That’s exactly the kind of ‘cramming’ that phasing would require. In addition to this, even though most of an atom’s volume is technically empty space (a popular analogy being a football placed on the center circle of a football stadium representing the nucleus and a fruit fly orbiting the outer wall representing an electron), that “empty space” is filled with electromagnetic force.
It’s the repulsion between these forces that forbids matter from passing through matter. The reason you don’t fall through the floor into the center of the Earth is a result of the electromagnetic repulsion between the electrons in your atoms and those in the ground.
Thus, phasing on a macroscopic scale isn’t possible.
If ghosts are material, they can’t possibly pass through a wall as an immaterial object, otherwise logically they would just pass through the floor, even if this can be controlled at will, a ghost would have to be simultaneously material and immaterial in order to both exert force on the floor and pass through the wall at once.
The ability to pick up and interact with objects like doors is another aspect of ghost accounts that would require them to be physical material objects consisting of atoms. To move, pick up or interact with an object there must be friction.
Friction is generated when two surfaces move against each other, again requiring that our spook is composed of physical matter. Ghost hunters and believers, in general, seem to have no objection to the physical nature of ghosts, but the ability to interact with the physical world comes at a price; restriction to the known and well-established laws of physics.
I catch up with the young woman who is examining a dusty portrait on the wall. “But wait! Isn’t energy and matter interchangeable according to Einstein’s energy/mass equivalence. Couldn’t ghosts quickly switch between matter and energy, so after they interact with matter they quickly flip to energy and pass through it?
She turns and fixes me with piercing green eyes. “Boom!” “Boom?” “BOOOOOOOM!” she gesticulates a theatrical explosion spreading her arms wide and then steps into the master bedroom.
The Master Bedroom: Ghosts go Boom!
I observe the master bedroom. Despite its undeniably old-fashioned decor, the room is remarkably well preserved. I could easily imagine the owner of the house had slipped out of the bed that very morning. For a brief moment, I worry that he or she could walk into the room at any moment, angered by the presence of two intruders in their bed-chamber, despite the fact the house’s owner has been dead for decades. I dismiss the thought with a shiver.
“So ghosts would explode?” I ask my companion. She smiles at my question and raises a finger as if to make a point. “Think about another example of mass quickly changing to energy.” I search through my knowledge of high school physics. “The atom bomb?” It’s more of a further question than a definitive answer. “Exactly!” she responds with a flourish spreading her arms wide.”Boom!”
When considering Einstein’s energy/mass equivalence, it’s important to understand that it doesn’t state that MATTER and energy are interchangeable, but that MASS and energy are interchangeable.
Both energy and mass are properties intrinsic to particles. When mass and energy are interchanged, the matter associated with the mass is annihilated. Also, the factor involved, the speed of light squared, c² (9.0 x 1016 m2 / s2 ) ensures that the tiniest amount of mass yields a huge release of energy.
Let’s consider a ghost that has enough mass to open a door pulling a disappearance act as they are prone to do, and assess the typical amount of energy that would be released as our phantom disappears.
Assuming our ghost has the same mass as the average US female–roughly 74.4kg — If the dematerialisation represents an instant switch between mass and energy, just how much energy would be instantly released?
“About 6.7 x 1018 Joules,” the young woman interjects. “To put that into perspective, the nuclear weapon that devastated Hiroshima released 6.3 x 1013 Joules. So a ghost switching between mass and energy could realise the equivalent of the yield of over one-hundred-thousand nuclear detonations!” You consider this for a moment and then ask; “And it would take the same amount of energy for them to then manifest again, right?“
“Spot on!” she laughs. “And as even the Sun only generates 3.8 x 1026 Joules per second. So, by Nick’s own logic that’s one hell of a cold spot!”
“Ok,” I say as the first sunlight of the day illuminates the hallway. “But what if ghosts are made of some form of energy we aren’t aware of yet?”
Time to Leave: Known Unknowns and Unknown Unknowns…
You notice the first light of morning breaking through the large window at the end of the corridor. “Time flies when you’re having fun! Time to leave, I think,” your young companion says as she heads back towards the staircase. She then stops and considers your question. “A lot of scientific research is based on investigating what we call ‘known unknowns.’
“So, whilst we don’t yet know about physics beyond the standard model, we pretty much know what is left that needs to be explained.”
With the discovery of the Higgs Boson, CERN completed what is known as the standard model of particle physics. This is relevant to the idea of “vital energy” as energy is a property of matter, it doesn’t sit in isolated clumps.
If there is some new energy, carried by an as-yet-undiscovered particle, then it should exist at everyday energy levels. Yet, in our search for the Higgs Boson, everyday energy levels have been thoroughly-probed and well understood, and this “vital particle” remains undiscovered.
There are lots of questions left to ask in physics, Cosmologist, Tim O’Brien, defines these gaps in our knowledge as “known unknowns”. In that we know the physical definitions of things such as dark matter, we know what it does, we can measure its effect of the universe very precisely. We just don’t know what it is.
There is no evidence of any kind of ‘vital energy’ that differentiates between dead matter and living matter, and perhaps most worryingly for physicists, we don’t see any physical phenomena that require the addition of such an extension to the standard model.
You’ve arrived at the front door with your companion, Nick is following you down the stairs. “So, you’re saying ghost don’t exist?” you ask. “Who knows? The evidence doesn’t seem to point that way, not scientifically. And think how long people like Nick,” she points to the ghost hunter struggling down the stairs with an arm full of electronics “have been searching for ghosts. And yet they’ve turned up nothing that stands put to scientific testing or conforms to what we understand about physics.
“The fact is. If ghosts do exist, pretty much everything we know about physics is wrong. And there’s just too much robust evidence that isn’t the case.”
She then seems to sense my disappointment from my slumped shoulders. “But who knows?” she adds. “And whether ghosts are real or not, it’s fun to think about these things, right?”
You smile as she squeezes past you and into the morning light. “I guess you’re right. Who doesn’t love a ghost story?” Nick looks at me quizzically. “Sorry, what was that?” “Oh, I was just talking to… Sorry, what is your name again?” Nick looks nervous for the first time since you arrived at ZME manor. “Who are you talking about? It’s just you and me here pal.” Your jaw drops open and the colour drains from your face. Nick, however, doesn’t seem to notice. “Oh, by the way,” the ghost hunter says. “I grabbed this from upstairs as a souvenir for you. No use letting it rot away here.”
He passes you the picture that your other mysterious companion was transfixed by upstairs. You sweep your hand over the dust, instantly recognising the twinkling green eyes and the mischievous smile under the decades of dust and grime.
Sources and Further Reading
1This quote actually comes from TV ghost hunter Nick Groff in an interview he gave to the Huffington Post in 2012. Nick has continued his nonsensical wittering about ‘energy’ releasing a single of the same name–it’s as terrible as it sounds.
2 Nick is quoting the website of Gainsborough Hall here: https://www.gainsborougholdhall.com/about-the-old-hall/the-old-halls-ghost
New research at Soochow University, China, is looking at how and why perovskite materials degrade — with the hope of engineering solar panels with much longer lives.
Perovskite panels aren’t the only type of solar panels out there, but they are very popular ones. They’re constructed around an active layer of perovskite, which forms crystal structures. Over time, stresses inside the material sandwich can create distortions in these crystals, which reduces their symmetry — essentially wearing them out. Environmental factors like sunlight or temperatures also degrade the layer.
The weakest link
“It is important to understand the degradation mechanisms under different conditions, including light, heat, humidity, electrochemical environment, and intrinsic stability, if you want to improve the durability of perovskite solar cells,” said co-author Zhao-Kui Wang.
“It is important to guarantee that the perovskite and the other layers have the best intrinsic stability and then to do some adjustments for further improving environmental resistance.”
The paper, together with a research update published in the journal APL Materials looked at the factors that influence the degradation of this layer, how degradation influences its performance, and examined possible approaches to making them more resilient.
The update focuses on chemical degradation, caused mainly by the transporting layers (integral parts required for the devices to work which sit in direct contact with the perovskite layer). The authors also analyzed the intrinsic stability of the perovskite layer and how factors such as moisture, oxygen, light, and heat affect it.
One of the most promising ways of reducing degradation seems to be bonding passivation — the removal of tiny gaps formed when assembling the layers together.
The team also points to hydrophobic (water-repelling) and ionic liquids as useful for this purpose under several types of environmental conditions. Ionic liquids can help maintain a stable internal temperature while the panels generate energy, and hydrophobic materials keep moisture out — which further improves the devices’ lifespan. Ionic liquids can be easily modified to possess hydrophobic properties, they add.
“The low volatility means ion liquids can be considered an environmental-friendly solvent for perovskites, yet the efficiency of the device still needs improvement,” Wang said.
“We have proposed the concepts of pure oxygen stability and flexible stability, which are valuable for other researchers to pay attention. Moreover, we hope that these strategies are not only useful in perovskite solar cells but also in other photoelectrical systems, such as organic photovoltaics, photodetectors, and light-emitting diodes.”
As solar power stands poised to take the lead in our energy grids, such research could help dramatically slash operation costs and increase the active lifespans of solar power plants — which would mean less pollution and cheaper energy for us all.
The paper “Durable strategies for perovskite photovoltaics” has been published in the journal APL Materials.
The world’s third-largest economy is aiming to cut greenhouse gases to zero and become a carbon-neutral society by 2050, said Prime Minister Yoshihide Suga. The move represents a major shift in the country’s position on climate change, following weaker commitments questioned by environmental organizations.
“We will bring the total amount of greenhouse gas (emitted by Japan) to net-zero by 2050, meaning carbon neutral,” Suga said in his first policy address to parliament since taking office. “I declare we will aim to realize a decarbonized society,” he added, to applause from lawmakers.
Japan had previously aimed at achieving an 80% reduction in emissions by 2050 followed by carbon neutrality “as soon as possible”, likely sometime in the second half of the century. This has been repeatedly criticized by climate activists as vague and unambitious. The Paris Agreement asks all countries to achieve decarbonization by 2050.
Takaharu Niimi, a climate change specialist at the Japan Research Institute, told AFP that Suga’s announcement was in line with an international move towards stronger commitments on the environment. “Considering the international trend, I think the time is right for Japan to declare the plan,” Niimi told AFP.
The country was under pressure to clarify its long-term ambitions, especially after carbon neutrality announcements earlier this year by China and South Korea. The shift puts Japan in line with its neighboring countries.
Suga didn’t give precise details on how Japan, still heavily reliant on coal, will achieve the goal but said the technology would be essential. He said the key will be innovation, citing examples including next-generation solar batteries. The country will push for more renewable energy and nuclear power, he added.
Japan was the sixth-largest contributor to global greenhouse emissions in 2017, according to the International Energy Agency. Following the meltdown in Fukushima, after which the nuclear reactors were shut down, the country has struggled to reduce its carbon emissions. Its reliance on fossil fuels only increased since then.
The country has regularly received criticism for continuing to build coal-fired plants at home, as well as financing projects to build them abroad, especially in Southeast Asia. Japan has 140 coal-fired power plants under operation, which provide a third of its total electricity generation.
The carbon neutrality goal will likely mean a big shift in the country’s energy plan, currently under review. The most recent plan, from 2018, aims to have between 22% to 24% of the country’s energy needs met by renewable sources including wind and solar by 2030. This has been described as unambitious by energy experts.
Greenpeace Japan welcomed Suga’s commitment to carbon neutrality but said there should be no role in the country’s future for nuclear power.
“Nearly 10 years on from Fukushima we are still facing the disastrous consequences of nuclear power, and this radioactive legacy has made clear that nuclear energy has no place in a green, sustainable future,” the group’s executive director, Sam Annesley, said in a statement.
Led by solar power, renewable energy could account for 80% of the growth in electricity generation over the next decade, according to a report by the International Energy Agency (IEA). It’s now consistently cheaper to generate electricity from the sun than by burning coal or natural gas in most countries, IEA said.
Maturing technologies and policies have significantly reduced the cost of solar power investments, making photovoltaic cells one of the cheapest sources of electricity. These energy systems can be used not only in large-scale solar parks but also in homes or businesses across the world.
In its annual report, the EIA presented three scenarios for the future development of global energy markets, which have been disturbed by the coronavirus pandemic. The prospect for non-conventional renewable energy goes from strong to spectacular, with solar leading the way. Meanwhile, fossil fuels face a precarious future.
The IEA, an intergovernmental organization, said electricity costs from large-scale solar photovoltaic installations have fallen from roughly 38 cents per kilowatt-hour in 2010, to a global average of 6.8 cents per kilowatt-hour last year. This means solar could become “the new king” of the world’s electricity markets, IEA head Fatih Birol said.
One of the scenarios explored by the report involves bringing the pandemic under control and global energy returning to its previous levels by early 2023. If this happens, the number of solar power systems would grow rapidly, increasing solar capacity by about 12% a year until 2030. This would lead to renewables meeting 80% of the growth in global electricity generation over the same period, overtaking coal by 2025 as the primary means of producing electricity. Even in a scenario in which the pandemic continues, affecting the economy and the energy demand, solar power still remains a cost-effective choice.
Solar performed even better in the “Sustainable Development” scenario. This would imply a surge in clean energy policies and investment that puts the world on track to reach the goals of the Paris Climate Agreement. If this happens, the combined share of solar and wind rises from 8% globally in 2019 to almost 30% in 2030.
The IEA called governments and investors to step up their clean energy efforts to achieve an even larger growth in renewables. In fact, some governments have included environmental goals as part of their coronavirus recovery plans. Even oil companies such as BP and Shell have unveiled shifts towards low-carbon energy.
While solar seems to have a bright future, coal has a dark one, according to IEA’s report. The lower economic activity and electricity demand due to the pandemic have caused a “structural fall in global coal demand”, with the IEA expecting 275 gigawatts of coal-fired capacity to be retired by 2025. That’s 13% of total coal capacity of last year.
“The rise of renewables, combined with cheap natural gas and coal phase-out policies, means that coal demand in advanced economies drops by almost half to 2030,” the report said. Growth in coal use in developing economies in Asia is much lower than previously expected and is not enough to offset declines elsewhere.
Wind and solar have doubled their share of global electricity generation since the Paris Climate Agreement was signed in 2015, reaching almost 10% in the first half of the year, according to a new report.
Nevertheless, it’s still not yet enough to meet the climate targets and sustained action is needed further on.
The energy consultancy Ember looked at 48 countries that make up more than 80% of the global electricity production. Wind and solar generation rose by 14% in the first half of the year, compared to the same period in 2019, according to the report.
In total, both energy sources explained 9.8% of the electricity generation.
Renewable has become a big player
Many major countries now generate around a tenth of their electricity from wind and solar, the report showed. This includes China (10%), the US (12%), India (10%), Japan (10%), Brazil (10%), and Turkey (13%). The EU and UK were substantially higher with 21% and 33% respectively. Within the EU, Germany rose to an impressive 42%, nearing a tipping point where half of its energy would be renewable.
But other countries are lagging behind the global average: Canada’s share has barely changed since 2015. South Korea’s share has been increasing, but at 4% is still less than half the global average, and Vietnam is making up for lost time increasing from 0.2% in 2018 to 6.4% in the first half of 2020.
The pandemic barely impacted solar and wind generation, the report showed. Nevertheless, COVID-19 has impacted the rate of new renewables installed this year, slowing it down significantly. A forecast by the International Energy Agency predicts a 13% decrease in the installation of renewable energy in 2020. Stimulus packages focusing on a clean transition can help that bounce back.
While solar and wind generation largely expanded, coal generation is also decreasing, the report showed, dropping 8.3% in the first half of the year. This breaks a new record, following on from a year-on-year fall of 3% in 2019.
For the first time, coal plants were needed for less than half the time. Coal generation fell by almost 9%, but coal capacity fell only 0.1%. That means the utilization of coal plants has fallen to 47% in the first half of 2020, from 51% utilization in 2019.
However, it’s not just the world’s transition to renewable energy that can explain that. Renewables definitely play a role, but there’s also by the drop in electricity demand amid the Covid-19.
India has seen remarkable results, with wind and solar moving from having 3% of the market share in 2015 to 10% in the first half of the year. At the same time, coal’s share fell from 77% to 68%. In China, coal’s share fell from 68% to 62%, while in the US coal’s market share was reduced by 17% as natural gas expanded.
Despite this rapid change, it’s still not enough to limit global temperature rises to 1.5 degrees Celsius, a goal mentioned in the Paris Agreement. The IPPC, a global group of climate experts, estimated coal use needs to fall by about 79% by 2030 from 2019, a fall of 13% every year throughout the 2020s. So while there are encouraging signs, we’re still not on track for climate stability.
“It’s clear that even with the rapid trajectory from coal to wind and solar over the last five years, progress is so far insufficient to limit coal generation in line with 1.5-degree scenarios,” the researchers wrote in the report, calling for further expansion of renewable energy sources.
The white, sleek exterior of the wind turbine definitely looks good to me. But birds probably wouldn’t agree. According to a new paper, the current design of our wind turbines makes them hard to see for birds, promoting impacts.
Not only would such a change help save bird lives, but it would also help our bottom line. Birds in flight hit hard, and turbines are expensive to repair or replace. Taking one of them off for repairs also incurs costs (as they can’t produce power during the same time). All in all, the paper argues, painting one of the three rotor blades black is enough to help birds see the turbines and avoid collisions.
Seeing is avoiding
“As wind energy deployment increases and larger wind‐power plants are considered, bird fatalities through collision with moving turbine rotor blades are expected to increase. However, few (cost‐) effective deterrent or mitigation measures have so far been developed to reduce the risk of collision,” the authors explain in their paper.
“We tested the hypothesis that painting would increase the visibility of the blades, [which reduced bird fatalities] by over 70% relative to the neighboring control (i.e., unpainted) turbines.”
Growing awareness of climate change has prompted countries all over the world to move away from fossil fuels into clean energy sources; wind is a particular favorite, as wind farms can be installed in otherwise unusable (and quite unpleasant areas) such as windy coastal areas.
That isn’t to say, however, that wind energy is flawless. As with everything else in life, it comes with good and bad both. Although they won’t release CO2 and heat up the planet, turbines can be quite disturbing to wildlife as they’re quite noisy, they bring humans to the area, and they’re a significant collision risk for birds. We have procedures in place to ensure that the sites we choose for such farms pose the lowest possible risk to wildlife. However, as more and more wind capacity is being installed, it’s unavoidable that it will impact local animals.
The current paper tested whether painting one of the three rotor blades of each turbine can help lower collisions with birds. The experiment was carried out at the Smøla wind-power in Norway. The plant was built in two phases: 20 turbines of 2.1 MW were finished in September 2002, and an additional 48 turbines of 2.3 MW in August 2005. the team used trained dogs to look for bird carcasses in a radius of 100 m around the turbines “at regular intervals”.
Roughly 9,560 turbine searches were performed between 2006–2016, finding 464 carcasses. The team explains that “there was an average 71.9% reduction in the annual fatality rate after painting at the painted turbines relative to the control turbines”. Despite this, they note that annual fatalities fluctuated significantly. All in all, there is enough evidence to seriously consider this approach as an effective way to protect birds from impacts with wind turbines. However, more long-term research is needed to establish exactly how effective it is in absolute numbers.
“The in situ experiment was performed comparing only four treated turbines to the neighboring four untreated turbines. We must therefore be careful what we deduce from the experiment given the limited number of turbine pairs,” the authors note.
“However, the experiment ran over a long timeframe, encompassing seven and a half years pretreatment and three and a half years post‐treatment”
The paper “Paint it black: Efficacy of increased wind turbine rotor blade visibility to reduce avian fatalities” has been published in the journal Ecology and Evolution.
Life as we know it hinges on us maintaining order. Our bodies die if not kept fueled and at the proper conditions. Appliances break down when you scramble their wires. Our parents get disappointed when we don’t make the bed.
But regardless of how hard we work at keeping our rooms clean and tidy, the Universe seems to be against us. One value — entropy — describes disorder. And, according to physics, we can’t win against it. No matter what we do, the second law of thermodynamics says that entropy in the universe will stay constant, or increase.
“Technically, physicists define a number called the entropy to measure how scrambled-up the universe is at a given moment of time,” wrote George Musser for Scientific American.
Thus, entropy is perhaps the only truly unstoppable force in the universe, even though it isn’t a force. It started acting ever since the Big Bang. It won’t stop until the heat death of the Universe.
But far from being a malign influence, cynically plotting our demise from the shadows, entropy is simply a product of statistics. It could very well be the thing that gives meaning and direction to the concept of time.
If nothing else, it is a great reminder that in the large picture, what we call order could in fact be chaos, that our planet, our bodies, and our works are the exception, a statistical fluke against a law-abiding, empty Universe.
Sounds cool? Well it does to me, and I’m the guy with the keyboard, so today we’re going to talk about entropy.
The mess of the messy room
The most common way entropy is explained is as disorder or randomness. A clean room, for example, has less entropy than that same room after it hasn’t been tidied for two weeks. It will grow more cluttered over time, but sadly never clean itself by chance.
Both this example and the equation with disorder have some flaws, as we’ll see later on, but they’re descriptive enough that they’re a good starting point. To get more specific about this concep, we’ll have to look at physics and probability.
Each system has a macrostate (its shape, size, temperature, etc) and several microstates. Microstates define the arrangement of all molecules within that system and how they interact. Each arrangement (each microstate) has a chance of ‘happening’. Entropy is a way of quantifying how likely the system’s current microstate is.
A coin is a very good analogy. Its macrostate is its shape, size, color, temperature. Flip it two times, however, and you get four possible microstates — alternating heads and tails, two heads, or two tails. All are possible, but one outcome (a sequence of heads and tails) has a 1 in 2 chance of happening, while the others have a 1 in 4. Because of that, the heads-and-tails sequence is the one with the highest entropy.
This statistical understanding of the term is rooted in the physical definition of entropy, and I’m simplifying things a lot, but I feel it’s the best rough idea of how it works.
Castles grow moss and crumble, heels snap off of shoes. Ordered systems break down over time because there’s a single microstate in which they stay the same, and countless in which they change. It’s immensely more likely to happen.
Spontaneous reductions in entropy are possible, such as the formation of life or crystals. Josiah Willard Gibbs, an American engineer from the early 1900’s even found a way to calculate why (more on that later). However, overall, entropy in a system increases over time, because changes towards disorder are overwhelmingly more likely than those towards order.
From a physical point of view
We all instinctively understand that disorder is more likely than order, but why?
The meat of it is that randomness is simple and low on energy. It’s homogeneous. Nature loves that.
A glass of ice is more orderly than a glass of water. Molecules in ice are kept in a very specific arrangement, forming a lattice that we perceive as ice cubes. If you were to simulate a glass of it, you’d have to program their molecular composition, shape, size, and position relative to one another. For the glass of water, all you need to do is define the shape of the glass and how high you’re filling it because its molecules move in an undefinable manner. The ice takes more data to make it what it is, it’s more complicated, so it’s less probable.
Entropy also moves things along towards low states of energy (including potential energy) because spontaneous processes tend to work towards fixing imbalances and thus expending energy. A glass filled half with ice and half with boiling water has a higher imbalance and a lower entropy than a glass where they’re mixed — so they do.
Some probabilities are more likely than others — which is our statistical entropy — because they lead to simpler, more homogenous systems by transforming energy — our physical entropy. And in nature, quite like in finances, nothing happens unless you pay for it (with free energy).
Bringing us neatly to:
Gibbs’ Free Energy
In short, Gibbs’ free energy formula tells us if a process will happen spontaneously, or not.
The free energy of a system can be used to perform physical work (to move things). It’s enthalpy (heat) minus the product of temperature and entropy. As long as it’s negative, the system — such as a chemical reaction — can start spontaneously. This means that either a transfer of heat, which is energy, or an increase in entropy can provide power for the system. This latter one is usually seen as changes to volume, especially in endothermic (heat absorbing) reactions.
Gibbs’ formula shows us that there is energy to be had from breaking apart chemical bonds, so molecules generally try to become as small as they can. Fluids, like liquids or gas, are generally made of smaller, lighter molecules. They’re also an a higher entropy state than solids, for example, since their molecules can move freely among themselves.
The arrow of time
Since things naturally tend to gain entropy, then complex systems tend to break down into disorganized ones. It is one of few physical notions that require a very definite direction in time.
There’s technically no natural laws which say that a piece of burnt wood and a puddle of water can’t un-burn and freeze back, apart from entropy. All the energy and matter in the world was at some point concentrated in a single point during the Big Bang. It’s still here. The only difference since then is that there’s way more entropy around, and it’s always growing.
Because entropy flows a single way, it has been argued that entropy makes time-travel impossible — but only time will tell.
From what we know so far, one of two possible outcomes is for entropy to win out in the end. We call this hypothetical scenario the Big Freeze or Big Chill, or “the heat death of the Universe“. I personally like the last one because it just seems appropriately dramatic. In such a scenario, there is no more free energy in the whole universe. As such, there can be no increase in entropy. But it also means that nothing would happen, nothing would ever move.
So are we doomed? Not necessarily. We could subvert this if we learn how to create hydrogen from pure energy. Hydrogen powers stars, and those could (maybe?) be used to stave off this heat death. There’s also the other alternative, the Big Rip, but that one doesn’t sound pleasant either.
All in all, entropy is a very complex topic. It can only be defined through the system it’s being applied to, so different academic areas will somewhat focus on particular elements of this concept.
But it definitely is a fascinating subject. It’s a bit humbling to know that the same thing making your bedroom dirty is also probably going to end the universe one day.
The coronavirus pandemic is taking a toll on the US economy, with 36 million people having asked for unemployment aid so far. Many sectors have been severely hit, but renewable energy jobs are some of the worst affected.
More than half a million clean energy jobs have been lost in March and April, a new report showed, reversing years of growth in an industry that has helped reduce damaging air pollution and the emissions responsible for climate change.
Clean energy employment has fallen by 17% since the coronavirus brought normal life to a screeching halt, according to unemployment data analyzed by BW Research and published by advocacy group Environmental Entrepreneurs.
Clean energy job losses in April were far greater than March, when 147,139 claims were made. Total claims for March and April amount to 594,347. For the purposes of the analysis, the term “clean energy” encompassed energy efficiency; renewables; grid and storage; and “clean” vehicles and fuels.
The numbers are especially grim in California, where 105,000 clean energy workers have lost their jobs, more than any other state. Los Angeles County lost nearly 15,000 clean energy jobs in April alone, 2 ½ times as many as any other U.S. county.
“These are higher numbers than expected, and we were expecting bad numbers,” Greg Wetstone, president of the American Council on Renewable Energy, a trade group, said in a statement. “It’s painful to see three years of growth essentially wiped out in a single month.”
Before the epidemic, nearly 3.4 million Americans worked in clean energy — three times the workforce of the U.S. fossil fuel industry. The Bureau of Labor Statistics projected last year that the country’s two fastest-growing jobs over the next decade would be solar panel installer and wind turbine technician.
The report said that the federal government has offered little support for renewable energy so far. In a tweet last month, President Trump said that his administration would “never let the great U.S. Oil & Gas Industry down” and that he had instructed top officials “to formulate a plan which will make funds available” to the sector.
Looking ahead, the report forecasts more job losses unless the U.S. administration and Congress “take quick and substantive action to support the clean energy industry and its workers.” If no action is taken, it’s projected that 850,000 people in the sector will have filed for unemployment by June 30.
Around the world, firms working in sectors such as renewable energy are having to adapt to the new challenges posed by Covid-19. Last week, Nordex became the latest wind turbine manufacturer to withdraw guidance for the 2020 financial year, while in April Vestas suspended guidance for this year.
“Unprecedented economic impacts of COVID-19 are beyond daunting, for the whole clean energy industry — though the industry is nevertheless setting its sights on recovery and adapting to seek possible solutions,” Steve Cowell, President, E4TheFuture said in a statement.
Researchers at the National Renewable Energy Laboratory (NREL) have created a record-shattering new solar cell. The device can convert sunlight to energy at nearly 50% efficiency, much better than present alternatives.
Solar cells today typically run with between 15% and 23% efficiency, meaning they convert roughly 1/6th to 1/4th of incoming energy (in the form of sunlight) to electricity. But a new, “six-junction solar cell” designed at NREL boasts an efficiency of almost 50%, a huge increase.
More bang for your sun
“This device really demonstrates the extraordinary potential of multijunction solar cells,” said John Geisz, a principal scientist in the High-Efficiency Crystalline Photovoltaics Group at NREL and lead author of a new paper on the record-setting cell.
The cell has a measured efficiency of 47.1% under concentrated illumination, with one variant setting a new efficiency record under one-sun (natural) illumination of 39.2%.
The team used III-V materials — so called because of their position in the periodic table, also known as the boron group of semiconductors — to build their new cell; such materials have a wide range of light absorption properties that made them ideal for the task. Due to their highly efficient nature and the cost associated with making them, III-V solar cells are most often used to power satellites
The cell’s six junctions represent photoactive layers, and each is designed to capture light from a certain part of the solar light spectrum — in essence, each layer is specialized in absorbing as much as it can from certain parts of incoming light. The device also contains about 140 layers of various III-V materials to support these junctions, however, it’s only one-third the thickness of a human hair, the team explains.
“One way to reduce cost is to reduce the required area,” says Ryan France, co-author and a scientist in the III-V Multijunctions Group at NREL, “and you can do that by using a mirror to capture the light and focus the light down to a point. Then you can get away with a hundredth or even a thousandth of the material, compared to a flat-plate silicon cell. You use a lot less semiconductor material by concentrating the light. An additional advantage is that the efficiency goes up as you concentrate the light.”
France adds that exceeding the 50% efficiency mark is “actually very achievable”, but reaching 100% efficiency is impossible due to the fundamental limits of thermodynamics — then again, that stands true for all engines and devices used to generate or convert power.
Geisz explains that the current hurdle in exceeding 50% efficiency is presented by resistive barriers that form inside the cell which make it harder for electrical currents to flow. While the team is working on tackling this issue, NREL overall is working heavily towards making III-V solar cells more affordable, to give this technology a competitive edge on the market.
The paper “Six-junction III–V solar cells with 47.1% conversion efficiency under 143 Suns concentration” has been published in the journal Nature Energy.
Bumblebees can carry surprisingly heavy loads of nectar, a new paper explains, potentially bearing up to their own body weight in the sweet liquid. Furthermore, the insects use a more energy-efficient flight pattern when heavily encumbered.
The humble bumblebees definitely lift, the authors report. In fact, they may be the ‘big lifters’ of the insect world. The team set out to understand how the bumblebees manage to fly with such impressive loads, and uncovered the surprising flexibility and adaptability of their flight mechanics.
The burdens we bear
“[Bumblebees] can carry 60, 70, or 80 percent of their body weight flying, which would be a huge load for us just walking around,” said Susan Gagliardi, a research associate in the College of Biological Sciences at the University of California (UoC) Davis and co-author of the paper.
“We were curious to see how they do it and how much it costs them to carry food and supplies back to the hive.”
For the study, the team emptied a snowglobe (to be used as an experimental chamber) and released bumblebees inside it. Each insect had various lengths of solder wide attached to it in an effort to adjust its weight. High-speed video cameras were used to record their wing beats and movements, while the team charted how much energy each bee needed to expend.
“We have the bees in a little chamber and we measure the carbon dioxide they produce. They are mostly burning sugar so you can tell directly how much sugar they are using as they are flying,” Gagliardi said.
Unlike our aircraft, which generate lift from the smooth flow of air over their fixed, horizontal wings, bees move their wings at a high angle to generate tiny wind vortices. These churning bodies of air curl around the insect’s wings and lift them up. The team explains that while the bee’s approach does generate more lift than the smooth-airflow approach out planes rely on, it’s also more unstable mechanically — the vortices are chaotic and they break down very quickly. Bees are only able to fly because they move their wings rapidly to re-generate the vortices.
We didn’t know, however, the energy-efficiency of this mode of flight. It seems reasonable to assume that the bees would use less energy the lighter their load is, but the team was surprised to find out this isn’t the case: bumblebees are actually more efficient per unit of weight when they’re heavily laden. In other words, they’re more “economical in flying” when they’re heavily loaded — “which doesn’t make any sense in terms of energetics,” says Stacey Combes. Combes is an associate professor in the Department of Neurobiology, Physiology, and Behavior at the UoC and the paper’s lead author.
The team explains that bumblebees have two ways to deal with heavy loads. They can either increase the amplitude of their strokes (i.e. how far the wings flap), which helps but isn’t enough on its own for the heaviest of loads, or increase the frequency of their wingbeats, which helps them stay aloft but costs more energy. However, they also observed an alternative flying mode being used — one the team calls their “economy mode” — in which the bees can carry lots of nectar while using less energy than faster flapping requires.
Exactly how they do this is still unclear, Combes said, although the team believes it may involve the wings rotating when reversing direction between strokes. However, it seems to be something that the bees themselves can choose to do, or not. The team explains that overall, when lightly-loaded or rested, the bumblebees were more likely to increase the frequency of their wingbeats. However, they switch to the ‘economy mode’ only when heavily loaded, which produces more lift without an increase in flapping frequency.
“It turns out to be a behavioral choice they are making in terms of how they support the load,” Combes said.
But why don’t they always fly in this mode? The team is still unsure, but it may be that high wingbeat frequency brings other advantages to the table that are more attractive to the bees in a lighter-load scenario.
“When I started in this field there was a tendency to see them as little machines, we thought they’ll flap their wings one way when carrying zero load, another way when they’re carrying 50 percent load and every bee will do it the same way every time,” Combes adds.
“This has given us an appreciation that it’s a behavior, they choose what to do. Even the same bee on a different day will pick a new way to flap its wings.”
The paper “Kinematic flexibility allows bumblebees to increase energetic efficiency when carrying heavy loads” has been published in the journal Science Advances.
New research is allowing solar cells to work at night.
Although it sounds like fantasy, Jeremy Munday, a professor in the Department of Electrical and Computer Engineering at the University of California (UC) Davis says it’s completely possible. In fact, a new study by Munday and graduate student Tristan Deppe describes a specially-designed photovoltaic cell that could generate up to 50 watts of power per square meter at night.
“A regular solar cell generates power by absorbing sunlight, which causes a voltage to appear across the device and for current to flow. In these new devices, light is instead emitted and the current and voltage go in the opposite direction, but you still generate power,” Munday said.
“You have to use different materials, but the physics is the same.”
The whole system relies on the property of physical bodies to radiate heat to their surroundings (if these are cooler). In essence, it works as a reverse to a traditional solar cell, which absorbs light and energy from the sun.
Munday’s approach cashes in on the fact that outer space is a very cold place. Therefore, if you take a warm object and point it at the night’s sky, it will radiate out heat as infrared light — this mechanism has been used for nighttime cooling for hundreds of years now. In the last five years, Munday explains, there has been a lot of interest in devices that can do this during the daytime (by filtering out sunlight or pointing away from the sun).
Another kind of device, called a thermoradiative cell, can generate power by radiating heat to its surroundings. Research into such cells mostly focuses on applying them to capture waste heat from engines or other applications to later convert into useful energy. Munday and Deppe, however, adapted them for use in the night-time ‘solar’ panels.
“We were thinking, what if we took one of these devices and put it in a warm area and pointed it at the sky,” Munday said.
It’s a simple premise, but pointing a thermoradiative cell towards the night’s sky was enough to generate some electricity. Munday believes that it will probably also work during the day, assuming it’s placed in the shade or at least pointed away from the sun.
One advantage this approach has over conventional solar panels is that a thermoradiative cell can work throughout the day, potentially serving as a source of energy to complement traditional solar and wind arrays. Still, Munday and Deppe are currently working on improving the output and efficiency of these devices to get them ready for wide-scale use.
The paper “Nighttime Photovoltaic Cells: Electrical Power Generation by Optically Coupling with Deep Space” has been published in the journal ACS Photonics.