# Could we use a Dyson sphere to harvest energy around a black hole?

The Search for ExtraTerrestrial Intelligence (SETI) is more than just pointing our telescopes to distant stars hoping that some habitable planet is orbiting it. It also has to do with imagining all possibilities, but more importantly the plausible ones.

In a recent study, scientists analyzed the possibility of an advanced civilization harvesting energy from a black hole. The idea comes from the concept of the Dyson sphere, a hypothetical structure built around a star by an advanced civilization to collect energy remotely from it.

## What is a Dyson Sphere?

Dyson spheres were proposed by Freeman Dyson in 1960. The concept tries to explain how advanced civilizations could satisfy their ever-growing thirst for energy as they explore the stars.

The more advanced the civilization, the more energy it may require to sustain itself. At some point, the only realistic source of energy becomes the star itself, so to harvest the most possible energy, you build a Dyson sphere around it.

The sphere was first thought of as a shell orbiting the Sun. Later, more plausible structures were suggested, like the Dyson swarm which, as the name suggests, is a group of objects forming the orbit required for the energy collection. The other suggestion is the Dyson bubbles, which is also a swarm of objects, but stationary relative to the energy source.

## Kardashev scale

So what type of civilization would use a Dyson sphere? Based on how far they have spread and how much energy they would use, they can be roughly split into three categories, using the Kardashev scale defined by Soviet astronomer Nikolai Kardashev

• The Type I civilization (a planetary civilization) consumes around 4 x 10^16 Watts;
• The Type II civilization (a stellar civilization) consumes around 4 x 10^26 Watts;
• and Type III civilization (a galactic civilization) consumes around 4 x 10^37 Watts.

So in general terms, to get from a planetary to a stellar civilization, you’d need about 10^10 times more energy — or 10,000,000,000 times more energy to get to the next stage of civilization. That’s where the Dyson sphere comes in.

The Dyson sphere would be only possible with the Type II and III civilizations. Type II would be the ones capable of harnessing energy from their parent star, while Type III is thought to be a race apt to consume energy from multiple stars in their own galaxy. Mankind is still not even a Type I yet, we’re probably around 100-300 years from that. But that doesn’t mean we can’t think about it.

## Different sources

In the recent study, scientists considered different types of energy sources for a promising Type II civilization. One energy source could be the inverse of a Dyson Sphere, where the civilization would be surrounded by the source itself. In this case, the best candidate is the Cosmic Microwave Background (CMB).

Your position in the universe does not matter, wherever you are the CMB surrounds you bringing photons from all directions of the sky in the microwave spectrum.

The CMB nowadays is close to the lowest possible temperature (at 2.73 K) but it was much hotter at the beginning of time. As the universe expanded, the CMB cooled down — which is a good thing for life in the universe. The universe became habitable when it was 300K, so if you consider a civilization formed during that epoch it could get an advantage from its energy.

A civilization able to harvest energy from the CMB would have to reject waste energy into a black hole. Crazy as it may sound, this is obeying the laws of thermodynamics and falls within the realm of reason. However, the researchers concluded that the amount of energy made from CMB, even if it was from a younger universe, would not be enough to sustain a Type II civilization.

What about the black holes, how could you extract energy from a black hole using a Dyson swarm? Aren’t black holes supposed to absorb everything, including light? Turns out, yes and no — there still potential sources of energy around a black hole.

The team considered Hawking radiation as one of the possible sources of energy. Stephen Hawking proposed that contrary to popular belief at the time, black holes don’t suck everything in — they let some radiation escape. This is called Hawking radiation.

Around the event horizon, the threshold around the black hole where even light can’t escape, there are still some virtual particles: pairs of a particle and an antiparticle created from quantum fluctuations. The strong gravitational field from the black hole separates the pair; one gets inside the event horizon, and the other is emitted as Hawking radiation.

If a Type II civilization could build a Dyson sphere around a black hole to use the Hawking radiation, its luminosity wouldn’t be sufficient.

The accretion disk, on the other hand, could be a more plausible candidate. An accretion disk is a structure (typically shaped like a disk) formed by dust and other diffuse material, orbiting around a central body — in this case, a black hole.

Being the region in which friction heats up a large number of materials swirling around the event horizon. With enough heat, a Type II civilization could obtain what they need, even if the black hole is not so large. For a Type III civilization, things would not be so difficult technology-wise, but the accretion disk would have to belong to an intermediate-mass black hole to produce enough energy.

Of course, deciding on where the place the Dyson swarm is not an easy decision. Too far away from the source would reduce its efficiency, but too close to the source you’ll need materials that can survive temperatures up to 2,700 degrees Celsius. You’ll need to consider the number of objects placed to collect the energy and how much of the energy can be transferred.

## Detecting Type II or Type III civilizations

If such a civilization would be undergoing this type of energy harvest, would we even know?

At our current level of technology, finding civilizations like those described here would require some tricks. The best way is to look at the waste heat. Just like our car’s engine, some energy must be rejected from the machine.

First, you look for the best candidates and search for an unusual signal. Of course, that sounds far easier than it actually is. If we are too close to the black hole, the brightness of the disk could make it hard to see the wasted energy. Another problem is everything in our path — the Milky Way, star formation, dust — all these objects are noise in our data, obfuscating our observations.

All in all, we kind of (maybe) have the technology to detect a Dyson sphere, if there is any civilization around that uses one. But even if we were to detect it, we’ll have to try to solve another SETI puzzle: how do we talk to them?

The study was published in MNRAS.

# Game theory could be the key for finding intelligent alien life

Dr. Eamonn Kerins, an astrophysicist from the University of Manchester, has an idea for the Search for Extraterrestrial Intelligence (SETI). It consists of a strategy called Mutual Detectability based on coordination game, a strategy in which both players make the same decision.

Imagine you’re at a concert and your phone battery is dead, but you need to find a friend. How do you do it?

Here’s an approach: both of can you employ the same strategy and find each other in the middle of the crowd. In this situation, both parties win a payoff for having the same desire and the same decisions. This is what Mutual Detectability is about. If two civilizations have enough knowledge of each other, it is likely they will try to communicate and reach each other. This type of strategy rationalization is the basis of game theory, and Kerins believes applying game theory to SETI could be a fruitful strategy.

## Opposites don’t always atract

One obstacle for the civilizations looking for other civilizations has to do with technological advancement. When one civilization is more powerful than the other, the less powerful will feel less comfortable in making contact — for obvious reasons. Any civilization looking for others would have an incentive to listen, but not send out signals, so our galaxy might be full of listeners not able to find each other.

However, even if two civilizations are trying to find each other, they might not be able to if they use very different technologies. This could be avoided, says Kerins, if the more advanced civilization would use less-advanced signals. But you’d still need to actually be able to find them. This leads to the SETI paradox, if intelligent beings are looking for intelligent beings but not trying to reach out, then SETI is in vain.

## Where to look?

Kerins points to the importance of the region of the Earth Transit Zone(ETZ). The idea is simple: not all planets in the universe can see us. If an alien civilization can observe us when our planet passes in front of the Sun and reduces its luminosity, they will be able to detect us. This is called the transit method, used by astronomers to detect exoplanets.

ETZ is the optimal area in which other beings could detect us in the galaxy using the transit method. Success in mutual detectability could mean detecting planets in the habitable zone and that are in the ETZ region. Similarly, we should focus on detecting potentially habitable planets that could be able to see us.

## Good news is, there’s at least one planet that fits the bill.

K2-155 d is a Super-Earth in the habitable zone that happens to be in ETZ. The planet orbits an M dwarf star, the smallest type of star we know of, but it orbits it close enough to potentially have habitable temperatures. This type of star also makes the transit method easier to succeed, because a relatively small star has a clearer response to the transit. In other words, we see it blinking more clearly. That would be one starting to point SETI telescopes at.

But we already know many exoplanets. Only the Kepler mission discovered 2,662 planets in nearly 10 years of service. If we continue the search for planets and match the criteria stated by Dr. Kerins, our chances of communication would increase and the loneliness of Earth could end.

The theory was published in The Astronomical Journal.

# We probably aren’t the first civilization in the Milky Way. It’s just that the others are dead

Are there other intelligent lifeforms in the universe besides humans capable of founding a civilization? That’s the million-dollar question that people of all walks of life have, to their best of their ability, attempt to answer. There are many theories that attempt to explain the utter lack of, well, alien signals. For instance, one new study concludes that intelligent life may have appeared several times in the Milky Way, however, the vast majority of these civilizations have wiped themselves out already.

Ever since people first realized we are all living on a giant rock orbiting one of many stars, a heartbreaking thought must have crept the mind: we’re not that special after all. But since there are countless stars in the Milky Way, and countless galaxies in the universe, there must be other civilizations out there. This thought comes as a consolation, so we might not be the only ones drifting through the frightening darkness of outer space.

But if it’s true that we’re not that special after all, where is everybody else? Enrico Fermi, the creator of the world’s first nuclear reactor, thought about this long and hard, and his correspondence with fellow scientists on the subject has remained known in history as the ‘Fermi Paradox’ — the notion that there is a virtually limitless number of stars, but nevertheless you don’t see any life floating around besides us. Where is everybody?

The question is a valid one when considering:

• There’s nothing special about our sun – it’s young, medium-sized and similar to billions of other stars in our galaxy.
• It’s believed there are between 100 and 400 billion planets in the Milky Way. Considering intelligent life appeared on one, it’s reasonable to consider there should be at least some other kind of intelligent life elsewhere in the galaxy.
• Millions of years of technological progress mean that an intelligent species should have the capability to travel to distant stars and even other galaxies. Just look at how our world has changed in the past 100 years alone.
• According to mathematicians Duncan Forgan and Arwen Nicholson from Edinburgh University, self-replicating spacecraft traveling at one-tenth of the speed of light — admittedly a quick speed — could traverse the entire Milky Way in a mere 10 million years. This means that civilization could potentially colonize the whole galaxy in a mere couple of millions of years. Except it didn’t happen.

Then there’s the Drake equation, first proposed in 1961 by American astronomer and astrophysicist Frank Drake, which describes the variables involved in fostering intelligent life. This equation estimates the number “N” of civilizations in the Milky Way based on variables such as the rate of star formation, the number of planets in solar systems that may support life, or the necessary technological prowess to signal a civilization’s existence.

Drake’s equation was made famous by the late Carl Sagan, who featured it during an episode of his timeless series Cosmos. But since Sagan first talked about Drake’s equation, much has changed. Thanks to observations by the Kepler telescope, we now have a much firmer grasp of how many Earth-like worlds may be out there.

In a new study, researchers affiliated with NASA’s Jet Propulsion Laboratory and Caltech, as well as a high school student, have updated Drake’s equation with all the new things scientists have learned in the past decades, including the prevalence of sun-like stars harboring Earth-like planets or the frequency of supernovas that are unfriendly to life.

When they modeled the evolution of the Milky Way, the researchers found that life was most likely to emerge around 13,000 light-years from the galactic centers, where there is the greatest density of sun-like stars. The optimal time frame for the development of alien civilizations was also estimated at 8 billion years after the formation of the galaxy. For comparison, Earth is about 25,000 light-years from the galactic core and complex intelligent life evolved around 13.5 billion years after the Milky Way formed.

In other words, this study suggests that there are other regions of the Milky way where life is more likely to appear than in our corner of the galaxy. What’s more, other civilizations might have had a five billion-year headstart. The problem is they may have had a headstart for their self-annihilation.

According to the researchers, most civilizations that have appeared before us have likely self-annihilated. Other civilizations that are still active in the galaxy are likely young, due to the propensity of intelligent life to eradicate itself. Over a long-enough timeframe, the probability of self-annihilation borders on certainty.

“As we cannot assume a low probability of annihilation, it is possible that intelligent life elsewhere in the Galaxy is still too young to be observed by us. Therefore, our findings can imply that intelligent life may be common in the Galaxy but is still young, supporting the optimistic aspect for the practice of SETI (search for extraterrestrial intelligence),” the authors wrote in their study that appeared in the pre-print server arXiv.

“Our results also suggest that our location on Earth is not within the region where most intelligent life is settled, and SETI practices need to be closer to the inner Galaxy, preferably at the annulus 4 kpc (kiloparsec) from the Galactic Center.”

The search for alien life is nowhere settled, though. The study’s biggest limitation is its sample size of confirmed civilizations: just one. Humans are biased to think that other civilizations might behave just like us. As such, these inherent biases may cloud our judgment, believing that other civilizations might also nuke themselves out of existence.

# SETI project uses AI to track down mysterious light source

Credit: Breakthrough Listen.

Last year, astronomers tasked with hunting alien signals identified 21 repeating light pulses emanating from a dwarf galaxy located 3 million-light years away. The source could be a fast-rotating neutron star — or it could be alien technology, perhaps meant to propel a space-sailing craft. Now, the researchers used artificial intelligence to pore through the dataset to discover 72 new fast radio bursts generated by the mysterious light source.

Fast radio bursts (FRBs) are bright pulses of radio emission mere milliseconds in duration. The signals acquired by the Green Bank Telescope in West Virginia and then initially analyzed through traditional methods by the Breakthrough Listen — a SETI project led by the University of California, Berkeley — lasted only an hour.

What sets the source in question — called FRB 121102 — apart from other on-off fast radio bursts is that the emitted bursts fired in a repeated pattern, alternating between periods of quiescence and frenzied activity.

Since the first readings made on August 26, 2017, the team of astronomers has devised a machine-learning algorithm that scoured through 400 terabytes of data recorded over a five-hour-long period.

The machine learning algorithm called a “convolutional neural network” is often employed by tech companies to display online search results or sort images. It found an additional 72 bursts not detected originally, bringing the total number of detected bursts from FRB 121102 to around 300 since it was initially discovered in 2012.

“This work is exciting not just because it helps us understand the dynamic behavior of fast radio bursts in more detail, but also because of the promise it shows for using machine learning to detect signals missed by classical algorithms,” said Andrew Siemion, director of the Berkeley SETI Research Center and principal investigator for Breakthrough Listen, the initiative to find signs of intelligent life in the universe.

The mystery still lingers, though. We still don’t know much about FRBs or what produced this sequence, but the new readings help put some new constraints on the periodicity of the pulses generated by FRB 121102. It seems like the pulses are not fired all that regularly after all, at least not if the pattern is longer than 10 milliseconds. More observations might one day help scientists figure out what is driving these enigmatic light sources, the authors of the new study wrote in The Astrophysical Journal.

“Whether or not FRBs themselves eventually turn out to be signatures of extraterrestrial technology, Breakthrough Listen is helping to push the frontiers of a new and rapidly growing area of our understanding of the Universe around us,” said UC Berkeley Ph.D. student Gerry Zhang.

# The Search for Alien Life: We Have Been Looking in the Wrong Places

SETI Initiative. Source: Traces Online.

Humanity has pondered the existence of alien life for centuries. However, it has been in just the past 100 years or so that modern science has backed some of this thinking. Scientists of the late 1800’s and early 1900’s believed that objects appearing on the surface of Mars were canals constructed by aliens. Particularly, astronomer Percival Lowell believed this concept and promoted it in works such as the book Mars As the Abode of Life (1908).

This belief in the scientific community led to a huge amount of pop culture based around the concept of extraterrestrials. This has resulted in some people even believing in the existence of aliens like the ones in the movies. Who knows? They could be out there. But some wonder how probable their existence is.

With aliens constantly being depicted in entertainment, even after the Martian alien canal hypothesis was busted, scientists considered communicating with otherworldly life forms. The first scientists looking for a close encounter believed the best bet was to use radio waves as the communication medium. The first of such proposed experiments was conducted in 1960 by astronomer Frank Drake.

One of the most eye-opening quotes about extraterrestrial alien life comes from the book Time for the Stars by Alan Lightman. The author states, “Are we alone in the universe? Few questions are more profound… Extraterrestrial contact would forever change the way we view our place in the cosmos” (Lightman 21).

Drake would definitely not be the last scientist to attempt to summon a response from an alien. But this was the first modern example of tests which would now be referred to as part of SETI, the search for extraterrestrial intelligence. In 1980, to bring more of a public interest to SETI, the legendary astrophysicist, astronomer, and astrobiologist Carl Sagan and several others formed The Planetary Society. In more recent years, other programs with goals similar to SETI’s have been established such as METI, messaging extraterrestrial intelligence.

Apart from radio waves, humans have tried other ways of communicating with hypothetical aliens. One example is a plaque which was attached to the Pioneer 10 probe in 1972. This plaque would be a unique kind of “message in a bottle,” except the ocean it was doomed to drift in was far more vast than any sea on Earth. It was inquired of Carl Sagan about sending such a message several months before the scheduled departure of the craft. So Sagan went to work, and assisting him with this undertaking was none other than Frank Drake, the man who had conducted the first modern SETI tests in 1960. The fruit of numerous labors and laborers, the Pioneer 10 plaque that was sent into space depicted a man and a woman and several objects. Through the imagery, the scientists were trying to give any aliens who might see this plaque an idea of what humans are like and where Earth is located.

This could be the first big mistaken researchers are making. They are looking to make contact. They are putting their faith in a sci-fi movie concept. What these scientists are attempting to do is call up and have a conversation with an alien or, better yet, a race of aliens. This is not to say that SETI is pointless, but it might not be the most opportune method for seeking alien life.

Perhaps scientists should strive to discover life in its simpler forms. As Lee Billings of Scientific American states in a recent article, if you were able to travel to another planet it is likely “you would find a planet dominated by microbes rather than charismatic megafauna.” Many scientists are now suggesting microscopic organisms could be more plentiful throughout the cosmos than macroscopic creatures.

Microbes Are a Realistic Form of Alien Life. Source: Joi Ito’s PubPub.

A specific search for such minuscule life forms is not a new practice. Bacteria are, of course, microbes. Astrobiologists like Richard Hoover and Dave McKay have examined certain meteorites. Some of the microscopic structures found embedded in or on the space relics resemble bacteria. They have released their findings in past years. They have admitted that even though the fossilized structures appear to be remnants of bacteria there is still some skepticism as to whether those structures are alien in origin. This is because bacteria from Earth could have been attached to the meteorites once they entered our atmosphere.

So how do scientists narrow down the search for alien life even further? Billings’ piece may give us the best idea available at the moment. He informs his readers that one of oxygen’s properties is that it tends to descend from an atmosphere in the form of mineral oxides. It does not remain in its gaseous phase for long. Because of its nature, in an atmosphere such as Earth’s, the oxygen has to be reinstituted on a regular basis.

Astrobiologists have to accept oxygen may be one of the least familiar elements they come upon when studying potential life-supporting bodies. For example, atmospheric chemist David Catling has said the atmosphere of a world dominated by microscopic life could be largely comprised of methane and carbon dioxide gases. Keeping this in mind, this will hopefully narrow down the most likely planet candidates for life.

# SETI observes a “strong signal,” but don’t get your hopes up just yet

A star system 94 light-years away stepped in as a potential candidate for intelligent life, after Russian astronomers detected a radio signal emerging from within.

The SETI Institute is using the Allen Telescope Array in Northern California to confirm an intriguing signal coming from the star HD 164595, but so far there have been no results. Credit: SETI Institute

HD 164595 is a solar system a few billion years older than the Sun, centered on a star of comparable size and brightness to the Sun. The only planet we know of so far in the system is Neptune-sized, which makes it highly unlikely to host life, but other planets may still lurk undiscovered in the system.

Before recently, HD 164595 was relatively uninteresting, a solar system like any other, but Russian scientists working with an Italian researcher, Claudio Maccone, the chair of the International Academy of Astronautics Permanent SETI Committee found an interesting signal originating there. Just to be clear: no one is saying that this is an alien signal, but it’s a possibility – unlikely, but still a possibility.

Based on the signal’s characteristics, a potential alien society would have to generate about 100 billion billion watts of energy to blast it out in all directions – a tremendous effort. Even if they somehow sent the signal only in Earth’s direction, they’d still need to produce over a trillion watts. That’s a huge figure, says Seth Shostak, of the SETI Institute in Mountain View, California, who was not part of the team.

“The first number is hundreds of times more than all the sunlight falling on Earth,” he said. “That’s a very big energy bill.”

This is an effort much larger than what we could do from Earth, and the possibility that this is indeed an alien signal doesn’t seem terribly promising.

“Nonetheless, one should check out all reasonable possibilities, given the importance of the subject,” a SETI statement reads. “Consequently, the Allen Telescope Array (ATA) was swung in the direction of HD 164595 beginning on the evening of August 28. According to our scientists Jon Richards and Gerry Harp, it has so far not found any signal anywhere in the very large patch of sky covered by the ATA.”

There’s a good chance we may have gotten worked up for nothing and the signal could have natural (astronomic) causes. In the end, we can only say that this is something “interesting,” Shostak writes.

“So what’s the bottom line? Could it be another society sending a signal our way? Of course, that’s possible. However, there are many other plausible explanations for this claimed transmission – including terrestrial interference. Without a confirmation of this signal, we can only say that it’s “interesting.” “

# Observing Alien Armageddon could be our first sign of advanced civilizations in space.

We humans have a lot of reason to be proud.  In the short span of a few million years we have become self-aware and clever, learning to manipulate our world in ways that have greatly enhanced our survival.  The last 100,000 years have seen the evolution of anatomically modern humans, which migrated from our African birthplace to colonize and populate essentially all corners of the globe.  Using sophisticated brains we learned about the world, deciphering patterns in nature, designed and constructed tools, and formed societies and civilizations.

Unfortunately, there has also been much about our success that is less praiseworthy.   At the same time that we have been building ingenious devices to better feed, clothes, shelter, and move ourselves from point A to point B, we have also been in the business of making ever more efficient weapons to destroy one another.  As our technological progress seems to outpace our societal ethics and maturity, we now have it in our power to completely annihilate our entire species.  In the not too distant future it could conceivably be possible to extinguish all life on planet earth, whether through horrible accident or intentional destruction.

While we sit on this world powder cake of self destruction, perhaps at times in a little more danger, and at times in a little less, we often wonder if we are alone in the universe.  Not only are we the only example of intelligent life that we know of in the universe, but our little planet is home to the only example of life we know of anywhere.   All evidence seems to indicate that there are a vast number of planetary systems and potential habitable worlds in the universe.  We have detected over 2000 exoplanets, so far, with the first one being discovered only as recently as 1992, and with advancing techniques the numbers have been skyrocketing in recent years.  Yet, there is still no sign of alien life, and even with SETI (Search for Extraterrestrial Intelligence) listening for alien radio transmissions since 1960, we have not detected any confirmed signs of intelligent aliens.

A few of the exoplanets that the Kepler space telescope has discovered orbiting other stars.

In the October 23, 2015 issue of The International Journal of Astrobiology, authors Adam Stevens, Duncan Fogan, and Jack O’Malley James, make an interesting case that we may soon have the technology necessary to detect alien civilizations in the act of self-destruction.  In fact, alien armageddon may provide us with our most likely opportunity to detect the presence of intelligent alien life – even if we are only witness to their last moments.  The authors summarize some of the possible ways that an intelligent civilization could go horribly wrong, and how evidence for these tragic events could potentially be detected by our instruments here on earth.

The first major scenario would be that of global nuclear war.  There are several characteristics of a world that has been annihilated by an intense exchange of nuclear weapons that might be  detectable from our distant vantage point.  The detonation of the devices would emit high energy gamma radiation that would last for a short period of time – on the order of thousandths of a second.  Even given the high energy involved in the detonation of a world arsenal of nuclear devices, it is not very likely we could detect the energy output from so many light years away.  Naturally occurring gamma ray bursts (GRBs) are some of the most intense energy generating events in the universe, and can be observed at the edges of the visible universe, but they are also around 10 billion billion billion times more energetic than the predicted energy release of all the nuclear weapons on earth combined.

The intense radiation from global nuclear war would, however, ionize the planet’s atmosphere, resulting in an “air glow” due to light emission from energized nitrogen and oxygen.  The atmosphere would have a lovely green glow in the the visible spectrum, is predicted to last several years, and could be observed as an increase in the light intensity at the expected wavelength.  There would also be a depletion of the planet’s ozone layer as reactive chemicals are produced by the explosions.  This too, might be observable as a change in the planet’s atmosphere.  Nuclear war would also generate a great deal of dust and small particles that enter the air, altering the transparency of the atmosphere.  A combination of a gamma ray burst, air glow, drop in ozone concentration, and loss of transparency of the atmosphere would be good evidence for this alien-made disaster.  Any one event on its own might not be enough evidence to be certain of an artificial event.  For example, a change in the atmosphere from transparent to opaque could also be caused by natural events like a large asteroid impact.

Second on the list for a self-induced civilization-stopping calamity would be use of potent biological weapons.  Genetically engineered organisms, like viruses and bacteria, would potentially be much more deadly than any naturally occurring epidemic.  If the infectious agent was designed to attack all animals and plants, the entire biosphere would be jeopardized.  How would such a horror be detected by us?  Well, a rapid demise of the planet’s multicellular life would result in a huge amount of organic material for bacteria to consume.  The result of this massive decay would be the release of certain chemicals such as methane and ethane, that could be observed by spectroscopic analysis of the atmosphere.

Artistis depiction of an exoplanet surface in a distant solar system.

The next deadly scenario is the so called, “grey goo” event.  This involves the engineering of self-replicating nanomachines – tiny machines that use some building material as substrate and convert it into more tiny nanomachines.  The authors of the paper point out that this could be the result of either “goodbots” or “badbots”.  In the goodbot case the self-replicating nanomachines were never intended for destruction, but due to poor system controls, got out of hand leading to world destruction.  Badbots, on the other hand, were designed to cause complete and total destruction – the ultimate doomsday machine!   These replicators would take all carbon containing material on the planet’s surface, (ie. living organisms), and convert them into a growing mass of more replicators that do the same.  K. Eric Drexler – who coined the term nanotechology- pointed out in his ‘Engines of Creation’:  “Replicators can be more potent than nuclear weapons: to devastate Earth with bombs would require masses of exotic hardware and rare isotopes, but to destroy all life with replicators would require only a single speck made of ordinary elements.”

It might take as little as a few weeks to convert the worlds living biomass into a lifeless desert of tiny replicators – grey goo!  Pretty scary!!  From earth we might be able to detect this as a large increase in atmospheric dust (the masses of nanomachines).  The nanomachines would form giant sand dunes (bot dunes in this case) and would change the apparent brightness of the planet as we observe it.  There would be visual effects of shadowing, as the planet orbits its star due to the changing angle that light hits the grains of nanomachines in the bot dunes.  This is similar to the effect we see as light passes through the small particles in Saturn’s rings at different angles.  Over a period of thousands of years the nanomachines would be recycled through the planet’s interior, as the planet’s normal geological processes continue to operate.

Another apocalyptic possibility would be intentional pollution of the planet’s star.  To dispose of harmful radioactive waste, a civilization might launch such materials into its parent star.  Detecting uncommon radioactive elements in the star’s atmosphere would be evidence for this unnatural process.  Carl Sagan, called this “salting” the star.   We would know that this was an artificial process by the fact that elements present would be produced only in such high amounts by nuclear processes that don’t occur naturally.  Models have shown that if this was carried out to extremes, it would affect the star’s internal balance of forces and cause it’s size to increase, while dropping the surface temperature.  This change in the star’s characteristics could change the location of the habitable zone around the star, making life difficult or impossible on the alien planet that did the salting.  The authors suggest that, “compiling a sample of stars that are bright, cool, and slightly larger than expected as an initial step to search for this particular death channel.”

Finding evidence for intelligent life in the cosmos would radically change our view of ourselves, and our place in the universe.  If aliens have a similar psychology to ourselves (a big if to be sure), they could be prone towards potentially fatal flaws that could escalate to total catastrophe.  Their demise at their own hands (or equivalent body structures) might also be the signal that informs us that they were ever there at all.  Finding one or more civilizations that self-destructed might also give us a way to prognose the long-term health of the human race.  Do civilizations reach a point where their technological power is too great for their wisdom?  Could Homo sapiens one day end up as a signal to the stars that we were here for a brief time, an intelligent species, but just not quite intelligent enough to solve the problem of surviving peacefully with one another?
Journal Reference:

Observational signatures of self-destructive civilizations.”  Oct. 23, 2015,  The International Journal of Astrobiology.   Adam Stevens, Duncan Forgan and Jack O’Malley James.

# Alien megastructure turns out to be passing comets — SETI confirms

If you’re an alien buff or just really, really bored with knowing just one species that can hold a decent conversation, this might come as a bummer. SETI has confirmed that KIC 8462852, the 1,500 light-years away star that’s been all over the news as potentially having signs of an advanced alien megastructure built around it is just a regular, run of the mill, alien-free ball of atomic fire.

Image via universetoday

“The hypothesis of an alien megastructure around KIC 8462852 is rapidly crumbling apart,” said Douglas Vakoch, President of SETI International and an author of the paper published in The Astrophysical Journal Letters, available on Arxiv, in a statement. “We found no evidence of an advanced civilization beaming intentional laser signals toward Earth.”

The story sprung up in the media after The Atlantic picked up Pennsylvania State University astrophysicist Jason Wright’s suggestion that the huge dip in brightness seen from the star — some 20% of its total brightness — could be due to an artificial structure. People started excitedly discussing Dyson spheres, orbiting space stations, but most importantly — advanced alien intelligence.

Last month however, a separate research effort came to the conclusion that the dip in brightness was most likely caused by a swarm of comets passing in front of the star. Since then, SETI had all eyes and ears pointed at the star to catch any signal that the presumed aliens might be broadcasting to us. The latest one to join the search was the Boquete Optical SETI Observatory in Panama which, from October 29 trough to November 28 used its incredibly powerful single photometer to look for pulses that repeat in a regular manner.

But after all this time spent listening in, scientists have come up empty-handed. I admit, I’m a bit sad and actually a little bit disappointed that we didn’t find any aliens. It’s not all bad though — the methods we employed to study KIC 8462852 are now tried and tested and in case an actual detection is made, SETI will be fully prepared to receive “hello.”

“If some day we really detect a signal from an extraterrestrial civilization, we need to be ready to follow up at observatories around the world, as quickly as possible,” added Vakoch in the statement.

# Astrobiologists testify before Congress that alien life will be encountered by 2034

SETI’s Alien Telescope Array (ATA) listens day and night for a signal from space (SETI)

This past week, a few scientists took the bench and gave the U.S. Congress a relative date by which they expect we’ll have discovered signs of intelligent life elsewhere in the universe. According to their estimates, by 2034 we should make first contact or 30 years ahead of Star Trek’s first contact. Whether this was just a stunt, a ploy meant to convince Congress to up SETI’s budget, or a genuine estimate is difficult to tell.

### Aliens: we’ll find them soon enough

The claim was made during a hearing of the House Committee on Science, Space and Technology. Astronomers shuffled in front of the US officials and assured them that aliens would be found in the near future.

“At least a half-dozen other worlds besides Earth that might have life are in our solar system. The chances of finding it, I think, are good, and if that happens, it’ll happen in the next 20 years, depending on the financing,” said Seth Shostak, a renowned astrobiologist.

Depending on the financing, indeed. Shostak is a Senior Astronomer at the SETI Institute, an agency tasked with finding out about the existence of intelligent life anywhere in the universe by discovering radio signals which have artificial origin from outer space. The project was first launched in 1984 with great enthusiasm, following popular interest for extraterrestrial entities after movies like E.T. and Alien swept the globe. Today, SETI has a budget of only \$1 million and was nearly shut down and would have been were it not for the support of thousands who donated to keep SETI alive.

With this in mind, I have to admit I was astonished to read Shostak’s statement, but how far off is he really? What Shostak and his colleagues at SETI are actually trying to point out is that given our current rate of technological advancement, it will only be a matter of time until we manage to pick up extraterrestrial signals. The next generation of supercomputers and telescopes will definitely aid in attaining this objective, and recent discoveries by the now famous Kepler telescope have been more than encouraging. Thanks to Kepler we now have a much better and broader understanding of the Universe. We know for instance that there are innumerable Earth-like planets that orbit stars in a habitable zone.

“Recent analyses of Kepler data suggest that as many as one star in five will have a habitable, Earth-size planet in orbit around it,” Shostak told the lawmakers. “This number could be too large by perhaps a factor of two or three, but even so it implies that the Milky Way is home to 10 to 80 billion cousins of Earth.”

SETI certainly is currently equipped for the job, with its deployment of Arecibo’s 305-meter telescope, the largest in the world, and throughout the entire year Arecibo’s 305-meter telescope scans the cosmos for signals from alien civilization. With only 1\$ million funding a year, however, one can only wonder how the staff manages to survive, let alone have time and energy to search for aliens. Shostak hopes that by investing in SETI now, we will be able to take advantage of our dramatically increased computing power to tune into a very distant talk show or whatever it is that aliens might have broadcast at one point.

“It’s unproven whether there is any life beyond Earth…I think that situation is going to change within everyone’s lifetime in this room,” Shostak said.

# SETI to check recently discovered Kepler science

There’s been a lot of buzz around the planets discovered by the Kepler telescope, particularly about Kepler-22b – the planet which, outside Earth, has the biggest chances to host life (that we know of). Now, SETI will tune in and start listening to see if there are any aliens with something to say on those planets.

### SETI struggles

Sadly, SETI has been through a lot of problems lately; the University of Berkeley cut all support, and they were actually in danger of being shut down, even though all the funding they needed was a fraction of an Apache Helicopter, for example. However, due to funding received mostly by donations, the Allen Telescope Array (ATA) is back in business, and they can start looking for aliens once again.

“This is a superb opportunity for SETI observations,” says Jill Tarter, director of the Center for SETI Research at the SETI Institute. “For the first time, we can point our telescopes at stars, and know that those stars actually host planetary systems – including at least one that begins to approximate an Earth analog in the habitable zone around its host star. That’s the type of world that might be home to a civilization capable of building radio transmitters.”

### Kepler’s planets

Of course, the top priority will be given to the recently discovered Kepler planets – some of which have every chance of hosting life.

“In SETI, as with all research, preconceived notions such as habitable zones could be barriers to discovery,” says Tarter. “So, with sufficient future funding from our donors, it’s our intention to examine all of the planetary systems found by Kepler.”

During the next two years, SETI will systematically tune in to these planets, listening for something out of the ordinary in this naturally quiet region. If something is happening there, they will ‘hear’ it, as they can search tens of millions of 1Hz-wide channels at any one time.

“Kepler’s success has created an amazing opportunity to focus SETI research. While discovery of new exoplanets via Kepler is backed with government monies, the search for evidence that some of these worlds might be home to intelligence falls to SETI alone,” says Tarter. “And our SETI exploration depends entirely on private donations, for which we are deeply grateful to our donors.”

You can follow the SETI activity at any time by tuning in to Seti Stars.

# Shorties: SETI is just \$6.000 from achieving the necessary funds

A while ago, we were telling you how SETI (site here) is closing down due to lack of funding. We also published an infographic showing the relative cost of the program – which is about as much as a Tomahawk missile.

Thankfully, they have been receiving a whole lot donation, and now they’re really close to the amount they need to restart the program. You can help too, and every bit counts, especially since there is so little left required ! Here is where you can donate, if you are interested. If not, then spreading the word and creating awareness is still valuable.

# Infographic: the cost of SETI

As previously reported, SETI, the international organization which handles the search for electromagnetic transmissions from civilizations on distant planets, will shut down soon due to lack of funding. What’s really bothersome is that, although we all know we live in trouble economic times, the cost of keeping SETI going is simply peanuts for the US government or the huge corporations. The cost is \$2.5 million – a travesty by all means when you consider the benefits such a project might provide. Imagine, the first contact with an extraterrestrial signal – it would certainly be greatest milestone in human civilization history. Sure, more pragmatic objectives have to be taken into consideration when budgeting, but heck a measly \$2.5 million?

If you’re not really sure what \$2.5 million really means for SETI, then here’s a really well put together infographic by microcosmologist, which puts into perspective the sum across other sectors of the US budget and other corporations. Click on the image for a larger view.

# SETI shuts down due to lack of funding

Carl Sagan must be twisting and twitching in his grave. SETI, the project which became synonymus with searching for extraterrestrial intelligent life, was unable to gether the \$5 million it needed – which is just 0.0074% (!) of the United States military budget; talk about priorities…

Anyway, SETI has shut down its telescope array, which consists of 42 20-foot-wide telescopes spread across a field 300 miles north of San Francisco and was used to scan the sky for clues about extraterrestrial life, due to lack of support and funding. The US government was never a big supporter of the SETI project, and as a matter of fact, it could have never gone live without the help of Microsoft co-founder Paul Allen, who donated \$25 million to the project.

However, the state seems unable even to support such a laudable and potentially revolutionary project; now, SETI has been forced to ask for public help, in an attempt to raise the 5\$ million until 2013, in the hope that it could eventually go up again; this has a chance of succeeding, given the major amount of publicity that the project has received along the years (albeit not in recent ones), and considering that thousands of users participate in SETI@home, which requires donating CPU power of your computer to help interpret the immense amount of data which the SETI telescopes receive. Now, they are asking for help again, only this time, it’s donations instead of computer power. You can make the search possible once more, and you can help to one of the most monumental projects of all time, which requires a (relatively) very small amount of money to function. Each dollar you contribute buys 4 million channels scrutiny of a single world, and one of those channels might just show clues of hidden alien life – if you ask me, that’s definitely something worth participating in. So if you want to donate to SETI, go here. If you support the project, but can’t afford to donate, then help spread the word ! SETI is in desperate need of money, and sometimes, awareness is more important than anything else.

# Terrestrial Planets might form around stars similar to the Sun

What seemed to be a very natural and obvious conclusion needed a whole lot of studies and research to be proven; terrestrial planets might form around many, if not most, of the nearby stars which are similar to the sun, or at least resemble it greatly. These studies suggest that life may be actually quite common in our galaxy.

Michael Meyer from the “>University of Arizona led a Legacy Science Program with NASA’s Spitzer Space Telescope to determine whether planetary systems like ours are common or rare in the Milky Way galaxy. They found that at least 20 percent, and possibly as many as 60 percent, of stars similar to the sun are candidates for forming rocky planets.

They got to these conclusions by analyzing six groups of stars with masses comparable to our sun, which were grouped by age 10-to-30 million years, 30-to-100 million years, 100-to-300 million years, 300 million to one billion years and one-to-three billion years old.

“We wanted to study the evolution of the gas and dust around stars similar to the sun and compare the results with what we think the solar system looked like at earlier stages during its evolution,” Meyer said.

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“An optimistic scenario would suggest that the biggest, most massive disks would undergo the runaway collision process first and assemble their planets quickly. That’s what we could be seeing in the youngest stars. Their disks live hard and die young, shining brightly early on, then fading,” Meyer added.

Now it remainsto be seen whether these studies will actually be important, or whether they will remain just of statistic importance.