Tag Archives: matter

Leaf blowers are not only annoying but also bad for you (and the environment)

The seemingly-innocuous leaf blower may actually cause a lot more damage than you’d think — to both your health and the climate.

A groundskeeper blows autumn leaves in the Homewood Cemetery, Pittsburgh.
Image via Wikimedia.

It’s that time of the year: trees are shedding their leaves, and people are blowing them off the pavement. According to the Centers for Disease Control and Prevention (CDC), this quaint image actually hides several health concerns for operators and the public at large.

The inefficient gas engines typically used on leaf blowers generate large amounts of air pollution and particulate matter. The noise they generate can lead to serious hearing problems, including permanent hearing loss, according to the CDC.

Sounds bad

Some noise may not seem like much of an issue, but the dose can make it poison. The CDC explains that using your conventional, commercial (and gas-powered) leaf-blower for two hours has an adverse impact on your hearing. Some emit between 80 and 85 decibels (dB) while in use. Most cheap or mid-range leaf blowers, however, can expose users to up to 112 decibels (a plane taking off generates 105 decibels). At this level, they can cause instant “pain and ear injury,” with “hearing loss possible in less than [2 to] 5 minutes”.

The low-frequency sound they emit fades slowly over long distances or through building walls. Even at 800 meters away, a conventional leaf blower is still over the 55 dB limit considered safe by the World Health Organization, according to one 2017 study. Because they’re so loud, they can be heard “many homes away” from where they are being used, Quartz explains.

This ties into the greater issue of noise pollution. The 2016 Greater Boston Noise Report (link plays audio,) which surveyed 1,050 residents across the Boston area, found that most felt they “could not control noise or get away from it,” with leaf blowers being a major source of noise. Some 79% of responders said they believed no one cared that it bothered them. Leaf blowers are also seeing more use — in some cases becoming a daily occurrence. As homeowners and landscaping crews create an overlap of noise, these devices can be heard for several hours a day.

Image credits S. Hermann & F. Richter / Pixabay.

With over 11 million leaf blowers in the U.S. as of 2018, this adds up to a lot of annoyed people. Most cities don’t have legislation in place that deals with leaf blower noise specifically, and existing noise ordinances are practically unenforceable for these devices. However, there are cities across the U.S. that have some kind of leaf blower noise restrictions in place or going into effect.

Noisy environments can cause both mental and physical health complications, contributing to tinnitus, hypertension, and generating stress (which leads to annoyance and disturbed sleep).

Very polluting

A report published by the California Environmental Protection Agency (CalEPA) in the year 2000 lists several potential hazards regarding air quality when using leaf blowers:

  • Particulate Matter (PM): “Particles of 10 Fm and smaller are inhalable and able to deposit and remain on airway surfaces,” the study explains, while “smaller particles (2.5 Fm or less) are able to penetrate deep into the lungs and move into intercellular spaces.” More on the health impact of PM here.
  • Carbon Monoxide: a gas that binds to the hemoglobin protein in our red blood cells. This prevents the cell from ‘loading’ oxygen or carbon dioxide — essentially preventing respiration.
  • Unburned fuel: toxic compounds from gasoline that leak in the air, either through evaporation or due to incomplete combustion in the engine. Several of these compounds are probable carcinogens and are known irritants for eyes, skin, and the respiratory tract.

To give you an idea of the levels of exposure involved here, the study explains that landscape workers running a leaf blower are exposed to ten times more ultra-fine particles than someone standing next to a busy road.

Additionally, these tools are important sources of smog-forming compounds. It’s not a serious issue right now, but as more people buy and use leaf blowers, lawnmowers, and other small gas-powered engines, these are expected to overtake cars as the leading cause of smog in the United States.

What to do about it

Well, the easiest option is to use a rake — or just leave the leaves where they are, which is healthier for the environment.

But leaf blowers didn’t get to where they are today because people like to rake. Electrical versions, either corded or battery-powered, would address the air quality and virtually all of the noise concerns (albeit in exchange for less power).

While government regulation might help with emission levels, noise concerns might best be dealt with using more social approaches. Establishing neighborhood-wide leaf blowing intervals, or limiting the activity to a single day per week, would help make our lives a little better. As an added benefit, this would also help people feel that their concerns are being heard, and foster a sense of community.

Field Fire.

Air pollution levels rise by 30% in India as farmers align to new groundwater depletion policy

New research shows how well-meaning environmental measures can backfire if they don’t take into account the wider picture.

Field Fire.

Image credits Natalya Kollegova.

A new groundwater conservation policy in northwestern India is increasing air pollution in the already haze- and smog-filled area, new research reports. The problem is caused by how water-use policies require farmers to shift rice crops to later in the year, which in turn delays the harvests and results in the burning of agricultural residue in November — a month when breezes stagnate, leading to increased air pollution.

Late burners

“This analysis shows that we need to think about sustainable agriculture from a systems perspective, because it’s not a single objective we’re managing for — it’s multidimensional, and solving one problem in isolation can exacerbate others,” said Andrew McDonald, associate professor of soil and crop sciences at the Cornell University, and a co-author of the paper.

India has quite a water problem. Being a (generally) pretty dry place, agriculture here relies heavily on groundwater resources — and they’re being rapidly depleted. First, authorities tried to convince farmers to plant less water-intensive crops than rice, but this failed due to a number of reasons (such as free electricity for irrigation, assured output markets, and minimum support price
guarantees for rice). So in March 2009, the government passed The Punjab Preservation of Subsoil Water Act and the Haryana Preservation of Subsoil Water Act, legislation that forced farmers to delay rice transplanting (basically rice sowing) after the onset of the monsoon season on June 10; this was later adjusted to after the 20th of June.

So far, so good — the team notes that these groundwater acts helped “significantly reduce” groundwater depletion in northwestern India. However, they’ve also inadvertently helped increase air pollution levels. The team analyzed their effect on the timing of farmers’ planting and harvesting crops, and burning crop residues. They also connected this information with meteorological and air pollution data.

The team explains that residue burning patterns shifted following the groundwater acts, declining within October but significantly increasing in the first three weeks of November. “With the advent of combine harvesting in the 1980s, [on-field] burning of rice residues became the method of choice for accelerating the turn-around time between crops to ensure timely wheat planting and maintenance of yield potential,” the team explains. The sowing date imposed by the groundwater acts leaves farmers very little time to clear out reside apart from burning before the wheat season begins.

“Before the acts, maximum occurrence was on 24 October at 490 fires per day. After implementation of the acts, this increased to 681 fires per day, peaking around 4 November,” they add.

“Groundwater act implementation is associated with a concentration of crop residue burning into a narrower window, later in the season, and with a peak intensity that is 39% higher.”

The team further notes that this date coincides with weaker winds compared to October, which favors the build-up of air pollution. Daily PM2.5 (atmospheric particulate matter with a diameter under 2.5 micrometers) in November rose 29% after the groundwater acts.

On one hand, northwest India needs to tackle groundwater depletion. On the other hand, air pollution claimed the lives of almost 1.1 million Indians in 2015, and costs 3% of the country’s gross domestic product, according to the study. The team suggests technology that would allow farmers to plant new seeds without burning rice residue as a possible solution. Alternatively, they recommend the use of shorter-duration rice varieties that offer flexibility in planting and harvesting dates.

The paper “Tradeoffs between groundwater conservation and air pollution from agricultural fires in northwest India” has been published in the journal Nature Sustainability.

Researchers estimate the monetary and health cost associated with particulate matter

New research at the University of New Mexico is looking into how much particulate matter air pollution costs the US every year — and how best to tackle it.

Smoke Plume.

Image via Pixabay.

Fine particulate matter (PM2.5) air pollution caused an estimated 107,000 premature deaths in 2011, the study reports. The authors say these deaths cost society at large around $886 billion, and than 57% of them were at least partially the result of pollution caused by energy consumption (i.e. transportation or electricity generation).

Bad air

“The impact of particulate matter air pollution is enormous even in countries with relatively good air quality like the U.S.,” says University of New Mexico economics professor Andrew Goodkind.

“There is still substantial room for improvement to the public health from reducing emissions, even though we have dramatically improved our air quality over the last 40 years.”

PM2.5 are particles with a diameter of or under 2.5 micrometers. They’re exceedingly small, so small, in fact, that we can only see them under an electron microscope. You could string 30 such particles along and they would still be shorter than the diameter of a single one of your strands of hair. Not just invisible to the naked eye, these particles are also quite toxic. They often carry along microscopic amounts of solid or liquid leftovers of the chemical reactions that created the particles themselves — these residues can be quire hazardous to human health.

What makes PM2.5 really troublesome, however, is that they’re so tiny they don’t really decant from they air; they just float around for long stretches at a time. Because of this, they have a very high chance, compared to other pollutants, to make their way into your lungs and bloodstream.

However, the effect of PM2.5 on general health depends greatly on where they are emitted or released. So, Goodkind’s team set about understanding how geography plays a part in their effect.

The team developed a model for calculating location-specific damages due to primary PM2.5 and PM2.5 precursor emissions. Based on these models, the team can estimate the impact of PM2.5 emissions in any location throughout the US, they say. And that’s exactly what they did —  they applied the modeling tool to the U.S. emissions inventory to understand how each economic sector contributes to reduced air quality.

They found that 33% of health damages associated with PM2.5 occur within 8 km of emission sources, but 25% occur more than 150 miles away. These results emphasize the importance of tracking both local and long-range impacts, which is another element of what the paper addresses.

“Sources in the same urban area, releasing the same quantity of emissions, can have orders of magnitude difference in their impacts on health,” Goodkind said. “Identifying those sources with the largest impacts can help improve our decision making about how to reduce pollution.”

The team hopes policymakers will use their results to decide how and where to prioritize pollution mitigation efforts. They also plan to expand on their research by focusing more directly on certain sectors of the economy where emission reductions have been limited.

“Coal-fired electricity generation has, rightly, received substantial attention, and emissions have dropped substantially, but many people do not realize that agriculture is the source of a significant share of emissions,” Goodkind concluded. “We are looking into how and where we grow crops and raise livestock, what inputs are used, and how we can improve the system to continue to produce the food we need but with fewer environmental and health impacts.”

The paper “Fine-scale damage estimates of particulate matter air pollution reveal opportunities for location-specific mitigation of emissions” has been published in the journal Proceedings of the National Academy of Sciences (PNAS).

It Is Possible Jupiter Could Support Life, Scientists Say

Jupiter and its shrunken Great Red Spot. Credit: Wikimedia Commons.

Jupiter and its shrunken Great Red Spot. Credit: Wikimedia Commons.

A new factor has been added to the debate on whether or not living organisms could exist on Jupiter. You probably know Jupiter is a Jovian planet, a giant formed primarily out of gases. So how could alien life be able to exist in an environment where most of the phases of matter are absent? The answer is simply found in the element of water.

Within the rotating, turbulent Great Red Spot, perhaps Jupiter’s most distinguishable characteristic, are water clouds. Many of the other clouds in this enormous perpetual storm are comprised of ammonia and/or sulfur. Life theoretically cannot be sustained in water vapor alone; it thrives in liquid water. But according to some researchers, the fact alone that water exists in any form on the planet is a good first step.

The Great Red Spot is still a planetary feature which stumps much of the scientific community today. As it has been observed for the past century and a half, the Great Red Spot has been noticeably shrinking. The discovery of water clouds may lead to a deeper understanding of the planet’s past, including whether or not it might have sustained life, as well as weather-related information.

Some scientists have pondered the possibility that, due to the hydrogen and helium content in its atmosphere, Jupiter could be a diamond-producing “factory.” They have further speculated that these diamonds could enter into a liquid state and a rainfall of liquid diamonds would be in the Jovian’s weather forecast.

Likewise, the presence of water clouds means that water rain (a liquid) is not entirely impossible. Máté Ádámkovics, an astrophysicist at Clemson University in South Carolina, had this to say on the matter:

“…where there’s the potential for liquid water, the possibility of life cannot be completely ruled out. So, though it appears very unlikely, life on Jupiter is not beyond the range of our imaginations.”

Scientists are acting accordingly, researching the part which water plays in the atmosphere and other natural systems on Jupiter. They remain skeptical but eager to follow up on the new discovery. They shall also strive to find out just how much water the planet really holds.

Air pollution.

Air pollution seems to promote diabetes — even at officially ‘safe’ pollution levels

Air pollution may increase the risk of diabetes — even at levels currently deemed safe.

Air pollution.

Image credits Chris LeBoutillier.

A new study published by researchers from the Washington University School of Medicine in St. Louis and the Veterans Affairs (VA) St. Louis Health Care System suggests that heavily polluted countries such as India or the U.S. could see major health benefits — should they adopt tighter air pollution regulations.

A veterany affair

After sifting through all the research related to diabetes and outdoor air pollution, the team devised a model to evaluate diabetes risk across various pollution levels. They first looked at the levels of particulate matter — microscopic bits of dust, dirt, smoke, soot, and fluids that float around in the atmosphere — as recorded by the EPA’s land-based air monitoring systems and NASA satellites. They focused their research on particulate matter as these materials can pass into the bloodstream from the lungs, contributing to major health conditions such as heart disease, stroke, cancer, or kidney disease.

The team also analyzed data from 1.7 million U.S. veterans (who were followed for a median of 8.5 years). None of the veterans had a history of diabetes. Finally, they analyzed data from the Global Burden of Disease study — conducted annually with contributions from researchers worldwide —  to estimate annual cases of diabetes and healthy years of life lost due to pollution.

All this data was fed through statistical models meant to test whether any link can be observed between air pollution levels and diabetes incidence. The validity of the link was tested through the introduction of two other variables: ambient sodium concentrations, which have no link to diabetes, and lower limb fractures, which have no link to outdoor air pollution. The addition of these datasets helped the team spot any suspicious associations between the pollution and diabetes datasets.

Diabetes is one of the fastest growing diseases worldwide. An unhealthy diet, a sedentary lifestyle, and obesity are considered the main drivers behind the disease — and, according to more recent research, white paint. The findings today, however, suggest that air pollution may also shoulder a large part of the blame:

“Our research shows a significant link between air pollution and diabetes globally,” said Ziyad Al-Aly, MD, study senior author. “We found an increased risk, even at low levels of air pollution currently considered safe by the U.S. Environmental Protection Agency (EPA) and the World Health Organization (WHO).”

“This is important because many industry lobbying groups argue that current levels are too stringent and should be relaxed. Evidence shows that current levels are still not sufficiently safe and need to be tightened.”

The team estimates that air pollution contributed to 3.2 million new cases of diabetes throughout the world in 2016 — about 14% of all cases that year. Pollution-linked diabetes led to the loss of some 8.2 million years of healthy life in the same year, which again corresponds to roughly 14% of all healthy life lost to diabetes overall. In the United States, the study attributed 150,000 new cases of diabetes per year to air pollution and 350,000 years of healthy life lost annually.

The findings suggest that reducing air pollution may also help curb cases of diabetes in heavily polluted countries or areas.

Among the sample of veterans exposed to pollution levels between 5 to 10 micrograms per cubic meter of air, 21% developed diabetes. At exposures of between 11.9 to 13.6 micrograms per cubic meter of air, roughly 24% developed diabetes. In the United States, the EPA-set maximum safe pollution threshold sits at 12 micrograms per cubic meter of air. Al-Aly’s team, however, says that their results show pollution levels as low as 2.4 micrograms per cubic meter of air lead to a noticeably increased risk of developing diabetes.

People in lower-income countries such as India are also at a higher overall risk of pollution-related diabetes. This may come down to these countries lacking resources to invest in environmental mitigation systems or policy. Countries whose citizens are at higher risk of pollution-related diabetes include Afghanistan, Papua New Guinea, and Guyana. Countries such as France, Finland, and Iceland experience a lower risk, while the U.S. sees a moderate risk of pollution-related diabetes.

The paper ” The 2016 Global and National Burden of Diabetes Mellitus Attributable to Fine Particulate Matter Air Pollution” has been published in the journal The Lancet Planetary Health.

Ceres organic matter.

New analysis reveals that Ceres’ spots harbor a lot of organic material

New research shows Ceres’ surface is dotted with organic matter — much more of it that we’ve previously realized. The findings raise questions regarding how this material came to be, and why it concentrates in patches.

Ceres organic matter.

Spots of organic material near Ernutet crater on the dwarf planet Ceres.
Credit: NASA / Hannah Kaplan.

There seems to be more to the organic material the Dawn craft discovered on Ceres last year than we initially thought. The patches of carbon-based compounds may contain a much higher abundance of organic matter than initial analysis revealed, according to a new analysis from Brown University.

Organic, free-range Ceres

“What this paper shows is that you can get really different results depending upon the type of organic material you use to compare with and interpret the Ceres data,” said Hannah Kaplan, lead researcher of the study. “That’s important not only for Ceres, but also for missions that will soon explore asteroids that may also contain organic material.”

The discovery of these organic patches on Ceres last year was made using the Visible and Infrared (VIR) Spectrometer on the Dawn spacecraft, which has been in orbit of the dwarf planet since 2015. The finding was met with enthusiasm at NASA and beyond: organic molecules are, after all, the building blocks of life. So, scientists are understandably keen on finding out how such matter is distributed on planets other than our own. The presence of these compounds on Ceres isn’t proof that there was once life on this bit of rock. However, it definitely increases the odds. Factor in that Ceres also boasts a sizeable stash of water ice, another fundamental requirement for life as we know it, and you get quite the exciting place.

The picture may get even better, however. Dawn’s VIR instrument analyzed the patches on Ceres’ surface using the way its surface interacts with incoming light. By looking at what wavelengths these patches reflected and absorbed, ground control could estimate their chemical makeup. In the region of Ernutet Crater (Ceres’ northern hemisphere), Dawn picked up signals consistent with organic molecules. Next, NASA needed to know just how much organic material they had found — so they compared the VIR data to similar readings performed on samples of organic material from Earth. Based on this comparison, they concluded that Ceres’ spots comprised roughly 10% organic matter.

Kaplan and her team, however, weren’t satisfied with the reference standard NASA used — so they re-did the comparison using a different one. Instead of using Earth-borne rocks, they used samples of carbonaceous chondrite meteorites. Previous analysis of such space rocks that fell to Earth revealed that they contained organic material that is slightly different from that native to our planet.

“What we find is that if we model the Ceres data using extraterrestrial organics, which may be a more appropriate analog than those found on Earth, then we need a lot more organic matter on Ceres to explain the strength of the spectral absorption that we see there,” Kaplan said.

“We estimate that as much as 40 to 50 percent of the spectral signal we see on Ceres is explained by organics. That’s a huge difference compared to the six to 10 percent previously reported based on terrestrial organic compounds.”

Unknown origin

The team proposes two possible explanations for how organic material popped up on Ceres in such high concentrations. They could either have been produced on Ceres itself and then blasted to the surface. Alternatively, they could have been delivered by impacts with organic-rich comets or asteroids.

In the case of delivery, comets are more likely culprits than asteroids — the former tend to have higher contents of organic material, around 40 to 50 percent, which would be consistent with Ceres’ patches. However, this explanation seems unlikely, the team notes. The violence and heat of these impacts would likely destroy a substantial amount of the original organic material, meaning we’d see much lower concentrations on the surface.

The other explanation, that of in-situ generation, is also problematic. Organic material has only been identified in small patches on Ceres’ northern hemisphere — and, if the team’s findings are correct, in high concentrations. It’s a lot of organic material spread over a very small area, and we have no idea how it could get like this.

“If the organics are made on Ceres, then you likely still need a mechanism to concentrate it in these specific locations or at least to preserve it in these spots,” said Ralph Milliken, a study co-author.

“It’s not clear what that mechanism might be. Ceres is clearly a fascinating object, and understanding the story and origin of organics in these spots and elsewhere on Ceres will likely require future missions that can analyze or return samples.”

It’s not all unanswered questions. The research will help improve our ability to analyze the chemical make-up of extraterrestrial bodies. The team hopes their findings will “provide a framework of how to better interpret data of asteroids and make links between spacecraft observations and samples in our meteorite collection.”

With NASA announcing that it discovered organic material on Mars just one week ago, it seems that the universe may be a much more organic place than we’d assumed.

The paper “New Constraints on the Abundance and Composition of Organic Matter on Ceres” has been published in the journal Geophysical Research Letters.

Credit: The Reality Files.

Scientists make most precise measurements of antimatter — but only deepen mystery

Credit: The Reality Files.

Credit: The Reality Files.

Antimatter is, you’ve guessed it, the opposite of matter. When the two meet, they annihilate each other. According to the Big Bang theory, at the ‘T zero’, equal amounts of matter and antimatter were created in the early universe. But today, everything we see from the smallest life forms on Earth to the largest stellar objects is made almost entirely of matter. Why hasn’t all that early matter and antimatter annihilated each other, leaving behind a void as large as the universe itself?

While attempting to answer this very important scientific question, researchers found themselves opening a bigger, more philosophical one. Researchers part of the ALPHA collaboration at the European Organization for Nuclear Research (CERN) performed the most precise measurement of antihydrogen yet, looking for even the slightest differences from hydrogen that might explain the matter-antimatter disparity.

The researchers had to mix 90,000 antiprotons with 3 million positrons (electron anti-matter) to produce 50,000 antihydrogen atoms. The resulting antihydrogen atoms are held in a magnetic trap to prevent them from coming into contact with matter and self-annihilating.

The team led by Jeffrey Hangst, a physicist at Aarhus University in Denmark, studied the anti-matter by analyzing its reaction when it was probed with laser light. Atoms from different types of matter absorb different frequencies of light, and according to one prevailing theory, hydrogen and anti-hydrogen should absorb the same frequencies of light.

According to the latest measurements, the two types of matter indeed seem to absorb the same frequencies. The two types of measurements agreed with a precision of 2 parts per trillion, which marks a 100-fold improvement over the previous research.

Unfortunately, despite the impressive science involved, the new study doesn’t tell us anything more than we already knew. However, Ulmer says that perhaps a deviation at an even greater level of precision could have tipped the scale, which is why he and his team is shooting for even better precision for the next experiment.

“Although the precision still falls short for that of ordinary hydrogen, the rapid progress made by ALPHA suggests hydrogen-like precision in antihydrogen (measurements)… are now within reach,” said Hangst in a statement.

Scientific reference: M. Ahmadi et al. Characterization of the 1S–2S transition in antihydrogen, Nature (2018). DOI: 10.1038/s41586-018-0017-2. 

Three Old Scientific Concepts Getting a Modern Look

If you have a good look at some of the underlying concepts of modern science, you might notice that some of our current notions are rooted in old scientific thinking, some of which originated in ancient times. Some of today’s scientists have even reconsidered or revamped old scientific concepts. We’ve explored some of them below.

4 Elements of the Ancient Greeks vs 4 Phases of Matter

The ancient Greek philosopher and scholar Empedocles (495-430 BC) came up with the cosmogenic belief that all matter was made up of four principal elements: earth, water, air, and fire. He further speculated that these various elements or substances were able to be separated or reconstituted. According to Empedocles, these actions were a result of two forces. These forces were love, which worked to combine, and hate, which brought about a breaking down of the elements.

What scientists refer to as elements today have few similarities with the elements examined by the Greeks thousands of years ago. However, Empedocles’ proposed quadruplet of substances bares resemblance to what we call the four phases of matter: solid, liquid, gas, and plasma. The phases are the different forms or properties material substances can take.

Water in two states: liquid (including the clouds), and solid (ice). Image via Wikipedia.

Compare Empedocles’ substances to the modern phases of matter. “Earth” would be solid. The dirt on the ground is in a solid phase of matter. Next comes water which is a liquid; water is the most common liquid on Earth. Air, something which surrounds us constantly in our atmosphere, is a gaseous form of matter.

And lastly, we come to fire. Fire has fascinated human beings for time beyond history. Fire is similar to plasma in that both generate electromagnetic radiation such as light. Most flames you see in your everyday life are not hot enough to be considered plasma. They are typically considered gaseous. A prime example of an area where plasma is formed is the sun. The ancient four elements have an intriguing correspondent in modern science.

Ancient Concept of Dome Sky vs. Simulation Hypothesis

Millennia ago, people held the notion that his world was flat. Picture a horizontal cooking sheet with a transparent glass bowl set on top of it. Primitive people thought of the Earth in much the same way. They considered the land itself as flat and the sky as a dome. However, early Greek philosophers such as Pythagoras (c. 570-495 BC) — who is also known for formulating the Pythagorean theorem — understood that Earth was actually spherical.

Fast forward to the 21st century. Now scientists are considering the scientific concept of the dome once again but in a much more complex manner.

Regardless of what conspiracy lovers would have you believe, the human race has ventured into outer space, leaving the face of the Earth to travel to the stars. In the face of all our achievements, some scientists actually question if reality is real, a mindboggling and apparently laughable idea.

But some scientists have wondered if we could be existing in a computer simulation. The gap between science and science fiction starts to become very fine when considering this.

This idea calls to mind classic sci-fi plots such as those frequently played out in The Twilight Zone in which everything the characters take as real turns out to be something entirely unexpected. You might also remember the sequence in Men in Black in which the audience sees that the entire universe is inside an alien marble. Bill Nye even uses the dome as an example in discussing hypothetical virtual reality. This gives one the feeling that he is living in a snowglobe.

Medieval Alchemy vs. Modern Chemistry

The alchemists of the Middle Ages attempted to prove that matter could be transformed from one object into an entirely new object. One of their fondest goals they wished to achieve was the creation of gold from a less valuable substance. They were dreaming big, but such dreams have not yet come to fruition. Could it actually be possible to alter one type of matter into another?

Well, modern chemists may be well on their way to achieving this feat some day. They are pursuing the idea of converting light into matter, as is expressed in Albert Einstein’s famous equation. Since 2014, scientists have been claiming that such an operation would be quite feasible, especially with extant technology.

Einstein’s famous equation.

Light is made up of photons, and a contraption capable of performing the conversion has been dubbed “photon-photon collider.” Though we might not be able to transform matter into other matter in the near future, it looks like the light-to-matter transformation has a bright outlook.

The proton and antiproton are incredibly similar — indicating that perhaps, our universe shouldn’t exist

Matter and antimatter violently annihilate each other. If they’re absolutely symmetrical, then maybe — just maybe — the universe shouldn’t exist.

We see matter around us every day. Unlike matter, antimatter is much more elusive. Researchers are now playing the world’s most complex ‘spot the difference’ game with matter and antimatter. (Depicted here, two nitrogen gasses Image credits: Greenhorn1)

Just like there is matter in the universe (pretty much everything that exists), there is also antimatter. Basically, all particles have a corresponding anti-particle — with the same mass, but opposite electric charge, and other differences in quantum parameters. The proton, for instance, has a positive charge, while the antiproton has a negative charge. When a proton and an antiproton collide, they annihilate each other in a violent outburst.

Researchers at CERN in Switzerland have made the most precise measurement ever of the magnetic moment of an antiproton. The magnetic moment determines how a particle reacts to an external magnetic force. They found that the two moments are absolutely identical but with an opposite sign. This is really problematic.

“All of our observations find a complete symmetry between matter and antimatter, which is why the universe should not actually exist,” says Christian Smorra, a physicist at CERN’s Baryon–Antibaryon Symmetry Experiment (BASE) collaboration. “An asymmetry must exist here somewhere but we simply do not understand where the difference is.”

“It is probably the first time that physicists get a more precise measurement for antimatter than for matter, which demonstrates the extraordinary progress accomplished at CERN’s Antiproton Decelerator,” added Smorra, who is first-author of the study.

Since matter and antimatter annihilate themselves and the universe exists and hasn’t annihilated itself (yet), there’s good reason to believe that there is much more matter than antimatter in the universe. But why? There must be some discrepancy in the parameters of these particles that allows matter to dominate, but researchers haven’t found it yet. It’s like playing spot the difference at a particle level.

The work of Smorra and his colleagues is an elegant design, a two-particle measurement method developed in Stefan Ulmer’s RIKEN laboratory. Researchers simultaneously capture and measure two separate antiprotons one at a high temperature (350 degrees Kelvin / 76 C / 170 F) and the other at a very cold temperature (0.15 K / -273 C / -459 F), very close to absolute zero. The first particle is used for calibration, while the colder one is used to measure a parameter called the Larmor frequency, which governs how a particle precesses (rotates and spins) under a magnetic influence. Even doing this for protons was a breakthrough (published in Nature in 2014), but doing it for antiprotons is a whole new ball game.

The BASE experiment at the CERN antiproton decelerator in Geneva. Image credits: Stefan Sellner, Fundamental Symmetries Laboratory, RIKEN, Japan.

With this method, they managed to keep an antiproton captured for inside a special chamber about as big as a tall pint. Measurements were incredibly accurate, indicating a value for the antiproton magnetic moment of −2.7928473441 μNN is a constant called the nuclear magneton). Precise to nine significant digits, this measurement is 350 times more accurate than the previous measurement. It’s the equivalent of measuring the Earth’s circumference to a few centimeters.

Their results are identical to those obtained for the proton, aside from the minus sign.

“It is probably the first time that physicists get a more precise measurement for antimatter than for matter, which demonstrates the extraordinary progress accomplished at CERN’s Antiproton Decelerator, ” added first-author of the study Christian Smorra.

However, for all these elegant improvements, they still couldn’t answer the fundamental question of why our universe exists — why matter and antimatter are so unevenly distributed through the universe, allowing us to exist. Still, Smorra says that they can still improve significantly.

“By upgrading the experiment with several new technical innovations, we feel that some further improvement can still be made, and in the future, following the CERN upgrade expected to finish in 2021, we will be able to achieve an at least ten-fold improvement.”

In the meantime, nature continues to consist of matter and we still don’t know why there’s not much antimatter around. Researchers continue to try and solve this mystery which could unlock one of the keys to understanding the universe.

Plasma lamp.

Scientists just found half of the universe’s missing matter, and strengthened the Standard Model in the process

The missing matter in our universe has been found — and it’s exactly where we thought it would be.

Matter.

Image via Pixabay.

Chances are you’re familiar with dark matter, that ‘stuff’ which can exert gravity but doesn’t yet seem to do much else. It makes up around 27% of all the universe. We also have dark energy, which makes up about 68% of everything, and then there’s the normal, regular matter you or me are made of. This latter variety only makes up 5% of the known universe, which may come as a surprise, since it literally makes up our whole world.

We’re still trying to understand dark matter and dark energy, but in the meantime, scientists have put another scientific mystery to rest: accounting for all ‘normal’ matter.

Where my matter at?

Simply put, scientists couldn’t account for half of all matter that has to be out there, that 5% that we can actually see and interact with. Our working theory was that this matter could be found as very diffuse strands of plasma spread between galaxies. Given the huge spans of space involved here, even a very wispy gas could add up to a huge amount, as much as that contained by all visible galaxies combined.

Problem is, if that matter keeps floating around in such a thin and insubstantial form, how do we actually detect it?

Two groups of astronomers have developed a method that allows them to do just that. A research team at the Institute of Space Astrophysics (IAS) in Orsay, France, and one from the University of Edinburgh, used data from the Planck satellite to see the effect this matter has on the cosmic background radiation, CBR.

To do so they relied on a physical phenomenon known as the Sunyaev-Zel’dovich effect. The boiled down version is that when CBR passes through hot plasma (which is ionized gas) this latter one brightens just enough for us to capture it. Using data from the Sloan Digital Sky Survey, each team chose pairs of galaxies believed to be connected by baryon strands (baryons are elemental particles of ‘normal’ matter). To make the individual strands more visible, they then stacked the Planck signals for these areas. The French team worked with about 260,000 pairs of galaxies, while their Scottish counterparts worked with over a million pairs.

Plasma lamp.

Image via Wikipedia.

Both reached a similar result. The IAS team calculated that the baryon gasses are three times denser than the baseline mass of matter in the universe, while the Edinburgh team calculated them to be six times denser than the baseline. While the numbers differ a bit (we’re talking super small values here, so the differences between the team are minute), both were dense enough for filaments to form. Overall, the extra matter in this filaments is enough to account for the missing half of normal matter in the universe.

It also shows that the physical models we use to explain the world around us are sound. The theory of matter filaments is decades old, but scientists have simply lacked the technological means to test it up to now. Finding the filaments, and a way to detect them in the future could even help us navigate in inter-galactic space — if we ever get so far.

The two papers “A Search for Warm/Hot Gas Filaments Between Pairs of SDSS Luminous Red Galaxies” (IAS) and “Missing baryons in the cosmic web revealed by the Sunyaev-Zel’dovich effect” (Edinburgh) have both been published in the preprint server ArXiv.

Supermassive black hole spotted struggling with its galactic meal

Even supermassive black holes can bite off more than they can chew, it seems, based on observations of a nearby pair of colliding galaxies.

Messier51_sRGB.

NGC 5194 & 5195.
Image credits NASA, ESA.

A study analyzing emissions throughout the electromagnetic spectrum released by a nearby supermassive black hole gobbling up matter has revealed that even they can suffer from ‘indigestion’.

The mammoth body, weighing in at some 19 million times the mass of the Sun, lies at the center of a small galaxy named NGC 5195. Once every few hundred millions of years, NGC 5195 collides with the outer arms of its larger neighbor, known as NGC 5194 or (the more palatable) ‘Whirlpool’ galaxy. This happens because the two are locked in a gravitational wooing period that — in a few billion more years — will see them merge into a single galaxy.

But in the meantime, when these two galaxies touch, the supermassive black hole at the center of NGC 5195 picks up a lot of matter from Whirlpool into an accretion disk — so much matter, in fact, that it can’t absorb it all. But it still collapses onto the black hole since it’s subjected to enormous gravity. So all that excess matter eventually gets blown out into space. Last year, NASA’s Chandra X-Ray Observatory caught a whiff of X-ray emission that appeared to result from this process, but we didn’t really understand the how it happens.

Now, using high-resolution images of NGC 5195’s core taken with the e-MERLIN radio array, and drawing from archive images of the area taken with the Very Large Array (VLA), Chandra and the Hubble Space Telescope, a team of astronomers at the University of Manchester’s Jodrell Bank Centre for Astrophysics revealed the details of how these huge blasts of matter occur, and their behavior in space.

Letf: Image of the Whirlpool galaxy and NGC 5195.
Right: False colour image of NGC 5195 created by combining the VLA 20 cm radio image (red), the Chandra X-ray image (green), and the Hubble Space telescope H-alpha image (blue).
Image credits Jon Christensen.

They report that when the accretion disk surrounding NGC 5195’s supermassive black hole breaks down, the immense forces and pressures involved create a shock wave which blasts all that matter back out into space — if you’re thinking this is kinda like how supernovae form, you’re pretty much on point.

Electrons, accelerated by this event close to the speed of light, interact with magnetic fields from neighboring bodies and emit energy in the radio wavelength spectrum. The X-ray emissions e-MERLIN picked up are created when the shock wave hits the gasses in the interstellar medium, inflating and heating them up. This process strips electrons from hydrogen gas atoms and ionizes them, creating the features seen by Chandra and Hubble.

“Comparing the VLA images at radio wavelengths to Chandra’s X-ray observations and the hydrogen-emission detected by Hubble, shows that features are not only connected, but that the radio outflows are in fact the progenitors of the structures seen by Chandra and Hubble,” explains Dr Hayden Rampadarath, who will be presenting his findings at the National Astronomy Meeting at the University of Hull explains.

“This is an event of galactic proportions that we can see right across the electromagnetic spectrum.”

According to him, the arcs seen in the NGC 5195 system are 1 to 2 million years old, meaning the first bits of matter were being pushed away from the black hole at about the same time as humans were learning how to make fire.

This isn’t the first time we’ve seen a black hole struggling to eat everything on its plate, and that event also had many of the features Dr Rampadarath identified here. Knowing this, it may be easier to spot overly-greedy black holes in the future.

Physicists think they might have found a dark boson — a dark matter particle

The mountains of data retrieved back in 2012 when physicists were trying to confirm the existence of the Higgs boson could yield a new and unexpected find — a new particle dubbed the Madala boson.

Proton-proton collisions events in which 2 high energy electrons and two high energy muons are observed. Image credits Taylor L, McCauley T/CERN.

The first evidence of the Madala boson was seen in the data recorded at CERN in 2012 from the Large Hadron Collider (LHC,) says the High Energy Physics Group (HEP) from South Africa’s Withstander University. The new particle’s case has since been strengthened by repeat experiments in 2015 and 2016.

“Based on a number of features and peculiarities of the data reported by the experiments at the LHC and collected up to the end of 2012, the Wits HEP group in collaboration with scientists in India and Sweden formulated the Madala hypothesis,” says Professor Bruce Mellado, team leader of the HEP group at Wits.

“The experiments at the Large Hadron Collider (LHC) display a number of hints in their data that are indicative of the existence of new bosons,” their report reads.

Its existence hasn’t yet been confirmed, but the group claims that if their ‘Madala hypothesis’ is correct, then we could finally begin to understand dark matter. This amounts to an estimated 27 percent of all the mass and energy in the observable Universe, but otherwise, it’s completely foreign to us. We can’t touch it, we can’t see it…the only way we know it’s there is because we can detect its gravitational pull — and nothing else.

So it’s hardly surprising that, despite years of trying to figure out, we have no clue what dark matter actually is. The way scientists are going about it today is to find out what it isn’t, hoping we’ll have enough data to explain it at some point in the future.

“Physics today is at a crossroads similar to the times of Einstein and the fathers of Quantum Mechanics,” said Mellado.

“Classical physics failed to explain a number of phenomena and, as a result, it needed to be revolutionised with new concepts, such as relativity and quantum physics, leading to the creation of what we know now as modern physics.”

When they confirmed the existence of the Higgs boson four years ago, physicists finally verified the Standard Model of Physics. But even the fully fleshed model can’t explain the existence or properties of dark matter. The Madala boson would do just that — if it’s real. As Mellado and his team explain, while the Higgs boson only interacts with known matter, the Madala boson seems to interact only with dark matter.

The four fundamental forces are gravity, electromagnetism and the weak and strong nuclear forces. Each force has a corresponding boson or force carrier that gives rise or mediates the forces between other particles. For instance, the electromagnetic force is carried by photons — perhaps the most famous particles — while weak and strong forces are carried by W bosons, Z bosons, and gluons, respectively. Though we’ve yet to find a force carrier particle for gravity, physicists predict there should be one, for now hypothetically called a graviton.

The discovery of the Higgs boson did not signify the discovery of a new force or family of particles, but the Madala boson might.

Details of the discovery are still scarce, but what we do know up to now has been outlined in the South African scientific collaboration with CERN’s 2015-2016 Annual Report (SA-CERN.) Here, the Madala boson is described as having a mass of around 270 giga electronvolts (GeV) – or roughly 270 billion electron volts. To put that into perspective, the Higgs boson has a mass of either 123.5 GeV or 126.5 GeV. The paper also details how the same repeat experiments that strengthened the case for the Madala boson also suggested there’s an even heavier potential new boson, weighing in at a whopping 750 GeV, waiting to be found…maybe. We don’t know. It’s all an educated guess at this point.

Evidence of the Madala boson’s existance on the left, and for the heavier boson on the right. Image credits SA-CERN.

So right now, we just have to play the waiting game until the teams come up with more evidence and the physics community gets a chance to analyze them. But should these new particles be confirmed, it will set the world of physics alight.

“The significance of the discovery of new bosons goes beyond that of the Higgs boson. The Higgs boson was needed to complete the Standard Model of Particle Physics,” the SA-CERN report reads.

“However, this boson did not signify the discovery of a new force or family of particles. The discovery of new bosons would be evidence for forces and particles formerly unknown. Therefore, and without a reasonable doubt, the discovery of new bosons would be worth a Nobel Prize in Physics.”

Update:

Since we’ve written this article, CERN has tweeted this:

So does this mean there isn’t such a thing as the Madala boson? Not necessarily, it just means that there isn’t any data to support its existence in the LHC measurements. Something obviously went wrong here — someone from HEP jumped the gun or their findings just didn’t stand up to scrutiny.

Stay tuned for more updates.

Scientists uncover unique speed and direction of Milky Way’s spinning ‘halo’

A team of NASA-funded astronomers from the University of Michigan has discovered that the hot gas in the Milky Way’s halo is spinning in the same direction, as well as at a similar speed, as its disk.

Illustration of the Milky Way's high temperature gaseous halo (seen in blue). Credit: NASA/CXC/M.Weiss/Ohio State/A Gupta et al.
Illustration of the Milky Way’s high temperature gaseous halo (seen in blue).
Credit: NASA/CXC/M.Weiss/Ohio State/A Gupta et al.

The Milky Way’s disk contains our stars, planets, gas and dust, and the findings from the new study shed light on how stars, planets, and galaxies such as our own form from individual atoms.

“This flies in the face of expectations,” said Edmund Hodges-Kluck of the University of Michigan and lead author of the study. “People just assumed that the disk of the Milky Way spins while this enormous reservoir of hot gas is stationary – but that is wrong. This hot gas reservoir is rotating as well, just not quite as fast as the disk.”

The study used data from the European Space Agency’s (ESA’s) XXM-Newton telescope to examine the nature of the Milky Way’s gaseous halo, which is composed of ionized plasma and is several times larger than its disk.

Motion creates shifts in the wavelengths of light and using lines of hot oxygen, the team was able to pinpoint these shifts. These shift measurements revealed that the our galaxy’s halo spins in the same direction as its disk, as well as at a similar speed – the halo spins at approximately 400,000 miles per hour compared to the disk, which spins at around 540,000 miles per hour.

“The rotation of the hot halo is an incredible clue to how the Milky Way formed,” Hodges-Kluck said. “It tells us that this hot atmosphere is the original source of a lot of the matter in the disk.”

The data could help scientists better understand the nature of dark matter, the mysterious undetectable matter that is believed to make up around 80 percent of the universe, as well as the other missing “normal” matter that appears to be missing from galaxy disks. The answers to these missing matter mysteries could lie in the gaseous halos of the universe’s many galaxies.

“Now that we know about the rotation, theorists will begin to use this to learn how our Milky Way galaxy formed – and its eventual destiny,” said Joel Bregman, a professor of astronomy from the University of Michigan and senior author of the study. “We can use this discovery to learn so much more – the rotation of this hot halo will be a big topic of future X-ray spectrographs.”

Journal Reference: THE ROTATION OF THE HOT GAS AROUND THE MILKY WAY. 27 April 2016. 10.3847/0004-637X/822/1/21

The Universe expands much faster than we thought, and current models can’t explain why

Scientists have completed the most precise measurement of the Universe’s rate of expansion to date,  but the result just isn’t compatible with speed calculations from residual Big Bang radiation. Should the former results be confirmed by independent techniques, we might very well have to rewrite the laws of cosmology.

Data from galaxies such as M101, seen here, allow scientists to gauge the speed at which the universe is expanding.
Image credits X-ray: NASA/CXC/SAO; Optical: Detlef Hartmann; Infrared: NASA/JPL-Caltech

“I think that there is something in the standard cosmological model that we don’t understand,” says astrophysicist Adam Riess, a physicist at Johns Hopkins University in Baltimore, Maryland, who co-discovered dark energy in 1998 and led the latest study.

This discrepancy might even mean that dark energy — thought to be responsible for observed acceleration in the expansion of the Universe — has steadily been gaining in strength since the dawn of time. Should the results be confirmed, they have the potential of “becoming transformational in cosmology” said Kevork Abazajian, cosmologist at the University of California, Irvine.

In our current cosmological model, the Universe is the product of a tug of war of sorts between dark matter and dark energy. Dark matter uses its gravitational pull to slow down expansion, while dark energy is pushing everything apart, making it accelerate. Riess and others suggest that dark energy’s strength has been constant throughout the history of the Universe.

Most of what we know about dark matter-dark energy interaction and how each of them affects the Universe comes from studying remanent Big Bang radiation, known as the cosmic microwave background. The most exhaustive study on this subject was done by the European Space Agency’s Planck observatory. Those measurements essentially give researchers a picture of the Universe when it was really young — 400.000 years of age. Based on them, they can determine how the Universe evolved up to now, including the rate of expansion at any point in its history. Knowing where it was and where it is now, they can also predict those two parameters in the future.

But here’s the thing: they don’t add up to the observed rate of expansion. These predictions are invalidated by direct measurements of the current rate of cosmic expansion — also known as the Hubble constant. This constant is calculated by observing how rapidly nearby galaxies move away from the Milky Way using stars of known intrinsic brightness called ‘standard candles’. Until now the errors were small enough that the disagreement could be ignored, but Riess and his team warn that the discrepancy is too great to ignore any longer.

Riess’s team studied two types of standard candles in 18 galaxies using hundreds of hours of observing time on the Hubble Space Telescope.

“We’ve been going gangbusters with this,” says Riess.

They managed to measure constant with an uncertainty of 2.4%, down from a previous best result of 3.3%. Based on this value, they found that the actual rate of expansion is about 8% faster than what the Planck data predicts, Riess reports.

If both the new Hubble constant and the earlier Planck team measurements are accurate, then there’s a problem with our current model. Either we misunderstood dark energy, or we got it right but it just got stronger as time progressed. Planck researcher François Bouchet of the Institute of Astrophysics in Paris says he doubts that the problem is in his team’s measurement, but that the new findings are “exciting” regardless of what the solution turns out to be.

However, when working on such (forgive the pun) astronomical scales, a lot of things can go wrong. One last possibility is that standard candles aren’t that reliable when it comes to precision measurements, says Wendy Freedman, astronomer at the University of Chicago in Illinois. In 2001 she led the first precision measurement of the Hubble constant. She and her team are working on an alternative method based on a different class of stars. We’ll just have to wait and see.

The full paper, titled “A 2.4% Determination of the Local Value of the Hubble Constant” has been published on the arXiv online repository on and can be read here.

Depression in children changes the brain for life

Researchers at the Washington University School of Medicine in St. Louis, looking into the effects depression has on the brain have found proof linking the disorder with abnormal brain development in preschoolers. Their study, published in the journal JAMA Psychiatry, shows how gray matter is thinner and lower in volume in the cortex, an area of the brain that plays a key role in processing emotions.

The findings may help explain why children and others who are depressed have difficulty regulating their moods and emotions. The research builds on earlier work by Luby’s group that detailed other differences in the brains of depressed children.

Image via deviantart

Feeling gray?

Joan L. Luby, Samuel and Mae S. Ludwig Professor of Child Psychiatry, and her team compared the brains of 90 children who had been diagnosed with depression as preschoolers with those of 103 children that didn’t suffer from this disorder. The study involved several clinical evaluations of the children as they aged, including three MRI scans as they grew older; the first scans were performed when the children were 6 to 8 years old and the last at ages 12 to 15. A total of 116 of the subjects received all three brain scans.

“What is noteworthy about these findings is that we are able to see how a life experience — such as an episode of depression — can change the brain’s anatomy,” said first author Joan L. Luby, MD, whose research established that children as young as 3 can experience depression.

“Traditionally, we have thought about the brain as an organ that develops in a predetermined way, but our research is showing that actual experience — including negative moods, exposure to poverty, and a lack of parental support and nurturing — have a material impact on brain growth and development.”

The brain is made up largely of two types of tissue, while and gray matter. White matter predominantly contains axons with some support cells thrown in the mix, and its role is to connect different parts of the brain and transmit information to and fro. In contrast, gray matter is rich in brain cell bodies, and associated with cognition and information processing.

So let’s say that I am a neuron and you reading this, another neuron. Together we make up gray matter and process, share and create information and ideas. White matter would then be the high-speed cables, servers and so on that makes up the Internet and allows you to read what I’m typing.

The proportion of gray and white matter isn’t fixed through time. We know that around puberty, the amount of gray matter begins to decline as communication between neurons gets more efficient and redundant processes are eliminated. But Luby’s team wanted to see how depression influences the brain, and this is why the study was carried out over such a long period.

“Gray matter development follows an inverted U-shaped curve,” Luby said. “As children develop normally, they get more and more gray matter until puberty, but then a process called pruning begins, and unnecessary cells die off.”

“But our study showed a much steeper drop-off, possibly due to pruning, in the kids who had been depressed than in healthy children.”

The cables are there, but there’s no one on-line

Deanna M. Barch, PhD, (left) and Joan L. Luby, MD, examine brain images for differences in brain tissue between children diagnosed with depression as preschoolers and those who were not.
Image via eurekalert

The data also shows a correlation between the drop-off in gray matter volume and thickness in the brain and the severity of depression — the more severe the condition, the more loss in volume and thickness was observed. They also had information about the subjects’ families, and when studying the brains of children whose parents suffered from depression — meaning the kids were at higher risk of developing the condition themselves — they didn’t see any abnormalities unless the child had suffered from depression too.

This is how the team determined that depression played a fundamental role in gray matter development. MRI also showed that the differences in gray matter volume and thickness were typically more pronounced that differences seen in other brain structures known to take part in processing emotions.

Luby explains that because gray matter is involved in emotion processing, it is possible some of the structures involved in emotion, such as the amygdala, may function normally but the cortex may be unable to regulate signals coming from it properly.

The team now plan to perform brain scans of even younger children, to see if depression may cause pruning in the brain’s gray matter to begin earlier than normal, changing the course of brain development as a child grows.

“A next important step will involve determining whether early intervention might shift the trajectory of brain development for these kids so that they revert to more typical and healthy development,” said Barch, also the Gregory B. Couch Professor of Psychiatry.

Luby said that is the main challenge facing those who treat kids with depression.

“The experience of early childhood depression is not only uncomfortable for the child during those early years,” she said. “It also appears to have long-lasting effects on brain development and to make that child vulnerable to future problems. If we can intervene, however, the benefits might be just as long-lasting.”

A new measurement by RHIC's STAR collaboration reveals that the force between antiprotons (p with bar above it) is attractive and strong--just like the force that holds ordinary protons together within the nuclei of atoms. Credit: Brookhaven National Laboratory

Matter and antimatter have the same properties, experiment suggests

All models of particle physics are based on the mundane assumption that matter and anti-matter behave indistinguishably, but we can’t be sure. Luckily, an experiment at Brookhaven National Lab seems to confirm this basic caveat of particle physics after it found the attractive forces between antiprotons are the same as those seen in regular matter.

The quest for antimatter

A new measurement by RHIC's STAR collaboration reveals that the force between antiprotons (p with bar above it) is attractive and strong--just like the force that holds ordinary protons together within the nuclei of atoms. Credit: Brookhaven National Laboratory

A new measurement by RHIC’s STAR collaboration reveals that the force between antiprotons (p with bar above it) is attractive and strong–just like the force that holds ordinary protons together within the nuclei of atoms. Credit: Brookhaven National Laboratory

For every type of matter particle we’ve found, there also exists a corresponding antimatter particle, or antiparticle. These should look and behave just like their corresponding matter particles, except with opposite charge. A proton is naturally positively charged, as thought in any basic chemistry or physics class. The antiproton, however, is negatively charged. When matter and anti-matter these annihilate each other, releasing energy in the process.

During the Big Bang, matter and antimatter were created in equal amounts, but that’s clearly not what we’re seeing today. In fact, it’s difficult if not impossible to detect antimatter outside of a laboratory setting. For that matter, we wouldn’t have existed in the first place if antimatter and matter were still in equal proportion, given their tendency to annihilate each other. There has to be an explanation, but at this point opinions are mixed.

Some physicists think that after the Big Bang, fractions of a second in, all matter and antimatter canceled each other out but in the process created radiation. Out of this radiation new matter-antimatter pairs were formed, which again annihilated each other creating new radiation and so on. When the universe expanded and cooled to below the temperature where particle-antiparticle pair production could happen, all the antimatter and matter that were in equal proportions annihilated with each other, leaving only radiation. Here’s the kick though. It may be that matter and antimatter weren’t created equal. There is a tiny, *tiny* chance that you only get matter when you try to create matter and antimatter or one particle of matter for every billion annihilation event.  As the universe evolved after the Big Bang, these very small symmetry violations may have resulted in the abundance of matter and the dearth of antimatter we see today.

Zhengqiao Zhang, a graduate student from the Shanghai Institute of Applied Physics, with STAR physicist Aihong Tang at the STAR detector of the Relativistic Heavy Ion Collider (RHIC). Credit: Brookhaven National Laboratory antimatter.

Zhengqiao Zhang, a graduate student from the Shanghai Institute of Applied Physics, with STAR physicist Aihong Tang at the STAR detector of the Relativistic Heavy Ion Collider (RHIC). Credit: Brookhaven National Laboratory antimatter.

We can’t don’t this for certain yet. “Although this puzzle has been known for decades and little clues have emerged, it remains one of the big challenges of science. Anything we learn about the nature of antimatter can potentially contribute to solving this puzzle,” says  Aihong Tang, a Brookhaven physicist.

Tang was involved with  Relativistic Heavy Ion Collider where he and colleagues smashed accelerated gold ions together at high energy and relativistic speeds. When the gold ions smashed instead of forming new gold particles, the collision created mostly forms of hydrogen and helium, but also exotic particles like  heavy quarks or their antimatter counterparts.

“We see lots of protons, the basic building blocks of conventional atoms, coming out, and we see almost equal numbers of antiprotons,” said Zhengqiao Zhang, a graduate student in Professor Yu-Gang Ma’s group from the Shanghai Institute of Applied Physics of the Chinese Academy of Sciences, who works under the guidance of Tang when at Brookhaven. “The antiprotons look just like familiar protons, but because they are antimatter, they have a negative charge instead of positive, so they curve the opposite way in the magnetic field of the detector.”

“By looking at those that strike near one another on the detector, we can measure correlations in certain properties that give us insight into the force between pairs of antiprotons, including its strength and the range over which it acts,” he added.

Ultimately, the researchers were able to investigate the effective and scattering range of two antiprotons. The effective range between two particles is a measure of how close they have to be to influence each other with their electric charge, while the scattering range is a measure of how much these particles deviate as they travel from source to destination. During this experiment the  the scattering length was around 7.41 femtometers and the effective range was 2.14 femtometer, which is roughly the same as the those of a proton pair. Whether matter or antimatter, it seems these types of interactions are virtually indistinguishable.

“This discovery isn’t a surprise,” said Kefeng Xin, a graduate student at Rice. “We’ve been studying the interaction between nucleons (particles that make up an atom’s nucleus) for decades, and we’ve always thought the forces between antimatter particles are the same as for matter. But this is the first time we’ve been able to quantify it.”

“There are many ways to test for matter/antimatter asymmetry, and there are more precise tests, but in addition to precision, it’s important to test it in qualitatively different ways. This experiment was a qualitatively new test,” said Richard Lednický, a STAR scientist from the Joint Institute for Nuclear Research, Dubna, and the Institute of Physics, Czech Academy of Sciences, Prague.

“The successful implementation of the technique used in this analysis opens an exciting possibility for exploring details of the strong interaction between other abundantly produced particle species,” he said, noting that RHIC and the Large Hadron Collider (LHC) are ideally suited for these measurements, which are difficult to assess by other means.

We’ve yet to solve the puzzle. Namely, we still don’t know why there’s so little antimatter left in the universe, but at least we now know that it’s not due to some difference in how the two types of matter interact.

A star like our Sun is shown with an orbiting planet in the foreground in this artist's impression. Image credit: Illustration by Gabriel Perez Diaz, Instituto de Astrofisica de Canarias (MultiMedia Service)

Astronomers find the sun’s first sibling: a star made of the same stuff

A star like our Sun is shown with an orbiting planet in the foreground in this artist's impression. Image credit: Illustration by Gabriel Perez Diaz, Instituto de Astrofisica de Canarias (MultiMedia Service)

A star like our Sun is shown with an orbiting planet in the foreground in this artist’s impression. Image credit: Illustration by Gabriel Perez Diaz, Instituto de Astrofisica de Canarias (MultiMedia Service)

In what’s considered the first find out of a slew to follow, a team of astronomers have identified a star that originated out of the same matter as our own sun. In lack of a better analogy, the two are siblings and probably share many more sisters. Apart from telling us where in the galaxy our solar system first formed some 4.3 billion years ago, by finding and studying more of the sun’s siblings, certain secrets might become unraveled, even those pertaining to the origin of life.

Made from the same star stuff

From studies of other stars which astronomers can see in many different stages of their ‘life cycle’, it seems pretty convincing from the data that the sun must have started out as a large collapsing cloud of gas and dust inside some ancient interstellar cloud. This cloud was ‘polluted’ by a supernova several million years before the collapse phase ended, because we see certain isotopes of aluminum which could not have been a part of this cloud for very long unless they had been implanted by such an event.

The cloud collapsed for millions of years until it formed a rotating disk with a large central bulge. Out of the disk would eventually form the planets, and out of this central bulge where most of the mass wound up, formed the sun. We see such rotating disks of gas around many infant stars embedded in nebulae so this has confirmed this basic picture during the last 15 years or so. So this is where the sun comes from, but a more interesting question may be where does the gas and dust that initially comprised it came from?

The first sister of many

star_Stuff

The star is not visible to the unaided eye but easily can be seen with low-power binoculars, not far from the bright star Vega. Image credit: Ivan Ramirez/Tim Jones/McDonald Observatory

How and where the sun formed exactly and even how life in the solar system eventually appeared might be answered by this question and a  first step is identifying other stars made from the same original matter as our sun. Ivan Ramirez of The University of Texas and colleagues have for the first time identified such a sibling star after shifting through 30 possible candidates found by several groups around the world looking for stars in the Sun’s family. The candidates where carefully surveyed using the Harlan J. Smith Telescope at McDonald Observatory, while high-resolution spectroscopy was employed to get a deep understanding of the stars’ chemical make-up.

[RELATED] Most Earth-like planet orbiting around sun-like star: extraterrestrial life likely

Besides chemical analysis, the team of astronomers also mapped out each of the stars’ orbits around the center of the Milky Way. Data from these two important characteristics combined narrowed the field of candidates down to one: HD 162826 – a star 15 per cent more massive than the Sun, located 110 light-years away in the constellation Hercules.

Chances have it that this particular star had been studied by astronomers for at least 15 years so we’ve got a wealth of data at our disposal which can be used to characterize the star and its planetary system. For one, from what astronomers can tell, the star can’t possibly host any gas giant like Jupiter, and a small terrestrial planet might orbit it, although nobody’s entirely sure yet.

“We want to know where we were born,” Ramirez said. “If we can figure out in what part of the galaxy the Sun formed, we can constrain conditions on the early solar system. That could help us understand why we are here.”

Ramirez and colleagues’ ultimate goal is that of using data from this first sibling and those sure to follow in order to create a cook-book; a guideline that will narrow down future candidates and help find those stars that originated from the same material as the sun. This will definitely come most in handy once projects like the massive Gaia, a European Space Agency mission to create the largest and most precise 3-D map of the Milky Way, which includes accurate distances and proper motions for a billion stars. For instance, the team has found that a rather solid indicators the elements barium and yttrium, whose concentrations vary very much from star to star depending on where these were formed.

This diagram depicts the spatial distribution of the five types of light-sensitive cells known as cones in the chicken retina. (c) Washington University in St. Louis

Weird state of matter found in chicken’s eye

You may not find many interesting things to see when glaring into a chicken’s eye, but after closely studying its retina researchers at Washington University have come across a most fascinating discovery. It seems chicken eyes bear a never before seen state of matter in biology, an arrangement of particles that is both ordered and disordered – neither crystal, nor liquid. This state is called “disordered hyperuniformity”  and could only previously be found in non-biological systems , like liquid helium or simple plasmas.

Typically, the retina is comprised of several layers, but only the cones and rods are photosensitive allowing us to see and visually sense our surroundings. In the eye of a chicken, like many other bird species, the retina is comprised of five different types of cones – violet, blue, green and red, while the fifth is responsible for sensing light level variance. Most importantly, however, each type of cone is of a different size.

This diagram depicts the spatial distribution of the five types of light-sensitive cells known as cones in the chicken retina. (c) Washington University in St. Louis

This diagram depicts the spatial distribution of the five types of light-sensitive cells known as cones in the chicken retina. (c) Washington University in St. Louis

Most animal species have their cones arranged around an orderly pattern. Insects for instance have their cones arranged in a hexagon pattern. Those of a chicken, however, seem to be in complete disarray. At first, if one didn’t know better, you might think that they shouldn’t be able to see anything. Upon closer inspection, the shroud was lifted and most peculiar discovery was made.

After making a computer model, the scientists found that the arrangement of chicken cones is particularly tidy. Each cone has a so-called exclusion area that blocks other cones of the same type from straying too close, but this means each individual cone has its own uniform arrangement. At the same time, the five different patterns of the five different cone types are layered on top of each other in a disorderly way as opposed to the orderly structure found in other species’ eyes.

“Because the cones are of different sizes it’s not easy for the system to go into a crystal or ordered state,” study researcher Salvatore Torquato, a professor of chemistry at Princeton University, explained in a statement. “The system is frustrated from finding what might be the optimal solution, which would be the typical ordered arrangement. While the pattern must be disordered, it must also be as uniform as possible. Thus, disordered hyperuniformity is an excellent solution.”

Simply put, systems like the arrangement of chicken cones or liquid helium act both at the same time like crystals, keeping the density of particles consistent across large volumes, and liquids, having the same physical properties in all directions. This is the first time, however, that disordered hyperuniformity  has been observed in a biological system.

Their findings were detailed on Feb. 24 in the journal Physical Review E.

 

The atomic patterns in quasicrystals like this model of an aluminium-palladium-manganese surface exhibit order, but never repeat. (Photo: J.W. Evans, Ames Laboratory, U.S. Department of Energy)

State of matter difference between liquids and solids redefined

What’s the difference between a solid and liquid? You might find this question trivial – naturally, liquids flow and solids… well, they don’t. From a physical point of view, however, things aren’t that simple. Intrigued by some ever so often encountered exceptions in the current accepted theory that describes the differences between the states of matter, scientists have tried to provide a new explanation. American researchers now argue that  the main difference between liquids and solids is the way they respond to shear, or twisting forces and not the way atoms are arranged.

The atomic patterns in quasicrystals like this model of an aluminium-palladium-manganese surface exhibit order, but never repeat. (Photo: J.W. Evans, Ames Laboratory, U.S. Department of Energy)

The atomic patterns in quasicrystals like this model of an aluminium-palladium-manganese surface exhibit order, but never repeat. (Photo: J.W. Evans, Ames Laboratory, U.S. Department of Energy)

The water in the ocean, in liquid state, and a glacier, in solid state, are made out of the same H2O molecules. It’s how the atoms are arranged that governs what state of matter water will hold, or so classic textbooks have it. In liquids, atoms slosh around freely, while in solids the atoms are locked together in a crystal lattice. Because this crystal lattice is so stable, it needs a considerable amount of energy for the atoms to break rank.

This theory of rigidity fails to account for a number of exceptions – too many to remain unnoticed. For instance, it  fails to account for quasicrystals — bizarre solids first discovered in the lab in 1982 and found in nature in 2009, which are arranged in patterns that never repeat, but the material is nonetheless rigid. Glass, one of the most familiar materials, is classed as amorphous – noncrystalline solid in which the atoms and molecules are not organized in a definite lattice pattern – and behaves like a solid, but if one looks closely enough it looks more like a liquid frozen in time.

“Glasses have been around for thousands of years,” said Daniel Stein, a professor of physics and mathematics at New York University. “Chemists understand them. Engineers understand them. From the point of view of physics, we don’t understand them. Why are they rigid?”

Even glaciers can’t be rigidly classified, since their atoms still flow, albeit very slowly. Even liquid water seems rigid if it collides with an object dropped from a large distance or if it’s crossed at high speeds. All these problems have prompted scientists to look for new ways to define the physical differences between liquids and solids, and a team of researchers from France and America believe they have pinpointed a more precise factor to mark the transition between the two states of matter – the way they respond to shear.

Response to shear delimits solids from liquids

Liquids pose minimal resistance to shear and can be twisted in any manner, while solids, even glass or quasi-crystals, pose resistance to shear in an attempt to maintain their shape. The liquid-solid phase transition should thus be marked, the researchers say, by the “shear response” of a material jumping from zero to a positive value.

Physicists typically make their phase boundary calculations for a material through an oversimplified model which assumes the material is boundless – otherwise, in their defense, things would take forever to complete. Unfortunately, this simplification ignores the shape of the material, making it difficult to determine whether the shape will change in response to shear.

Charles Radin, a mathematical physicist at the University of Texas at Austin, and his former student, David Aristoff, now a mathematician at the University of Minnesota built a 2-D model material in which atoms are represented by disks: At low densities corresponding to the material’s liquid phase, it showed no response to shear, but when the disks were densely packed, like the atoms in a solid, shear caused the material to expand. “The crossover where it shows this effect is exactly the density where the system becomes crystalline,” Radin said. “We propose this as a different way of understanding what a solid is.”

Meanwhile, in France, took an alternative route to describe the phase boundary and reasoned that the difference between solids and liquids is the rate at which they flow. Glass, though by all means a solid, still flows, very slowly that is. Even diamonds flow- their atoms that is, as some hop between defects or empty spots in the crystal lattice. To see a diamond flowing under the pull of Earth’s gravity, “one would have probably to wait more than the age of the universe,” said Giulio Biroli of the Institute of Theoretical Physics at CEA in Paris.

The researchers hypothesized that glass would fall somewhere in between a crystalline solid and a liquid by exhibiting a large but finite viscosity under small shear.

“Our ways are complementary,” said Biroli, of the American and French approaches. “If we take both of them, I think we start to understand the difference between a solid and a liquid.”

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Antimatter excess in space hints of tangible evidence of dark matter

A $1.6 billion cosmic ray experiment on the International Space Station has come across evidence of antimatter in space, a remarkable finding that was recently presented during a seminar at CERN and which might help probe the mysteries of dark matter – one of the major components that make up the Universe.

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The AMS-02 experiment is a state-of-the-art particle physics detector that is constructed, tested and operated by an international team composed of 56 institutes from 16 countries and organized under United States Department of Energy (DOE) sponsorship. Seen here as the round instrument labeled as “AMS”. (c) NASA

The find was made using the Alpha Magnetic Spectrometer (AMS), an instrument mounted on the International Space Station which has been likened by many as an LHC in space. AMS job is that of  surveying the sky for high-energy particles, or cosmic rays and has so far recorded 25 billion events. It’s main mission is that of identifying and describing dark matter, a mysterious component which we can not see, unlike regular matter, but which we know for sure exists because of the gravitational effects it holds on regular matter.

It’s believed that whenever dark matter collides, it forms antimatter as a result of what’s called annihilation. Antimatter is, naturally, the reverse of matter and every particle in the Universe has its corresponding antiparticle. For instance, the electron’s antiparticle is the antielectron, known as a positron. The electron and the antielectron have exactly the same masses, but they have exactly opposite electrical charges. Scientists believe that in the wake of the Big Bang an equal amount of matter and antimatter was ejected through out the Universe, however why they didn’t cancel each other out or why there seems to be more matter than anti-matter is a subject that’s giving physicists really big headaches.

Normal matter contributes just 4.9% of the mass/energy density of the Universe, dark matter is believed to range somewhere in the 26.8% margin, while dark energy – the force thought to be accelerating the expansion of the Universe – sits atop a comfortable majority of 68.3%.

Anyway, the AMS instrument shines by counting the numbers of electrons and their anti-matter counterparts from space – positrons – falling on an array of detectors. At the CERN seminar, completed just mere hours ago, AMS spokesperson and lead scientist Professor Samuel Ting unveiled some spectacular results. According to Ting, a slight excess of positrons in the positron-electron count was experienced, something expected in the aftermath of dark matter annihilation.

Evidence of dark matter finally found? Don’t get too excited…

This positron count excess could have come from pulsars, the spinning remnants of dead stars that throw off wild winds of radiation. Analysis has shown however that the positrons fall on the AMS from all directions, rather than a specific signal direction like one given off by a pulsar, suggesting what the researchers have come across are actually dark matter decay remnants. What this also suggests is that we may be on the brink of a monumental discovery in physics. According to the CERN press release:

“The AMS results are based on some 25 billion recorded events, including 400,000 positrons with energies between 0.5 GeV and 350 GeV, recorded over a year and a half. This represents the largest collection of antimatter particles recorded in space. The positron fraction increases from 10 GeV to 250 GeV, with the data showing the slope of the increase reducing by an order of magnitude over the range 20-250 GeV. The data also show no significant variation over time, or any preferred incoming direction. These results are consistent with the positrons originating from the annihilation of dark matter particles in space, but not yet sufficiently conclusive to rule out other explanations.”

CERN scientists, as they should be, are cautious and don’t mean to make bold statements as of yet.

“As the most precise measurement of the cosmic ray positron flux to date, these results show clearly the power and capabilities of the AMS detector,” said AMS spokesperson, Samuel Ting. “Over the coming months, AMS will be able to tell us conclusively whether these positrons are a signal for dark matter, or whether they have some other origin.”

If the more positrons than expected at higher energies can be attributed to dark matter remains to be seen, as we anxiously await new findings from AMS and CERN in the coming months. What’s certain is that only two years in its ten year mission, the AMS has already shown us a great deal, so expect much more from its behalf.

The findings are slated for publishing in the journal Physical Review Letters.