Child in a 3D world unaware of other dimensions. NASA.
Does string theory excite you? Mathematically, it holds up. Aspects about it suggest not one but several different dimensions, ones we’re not generally privy to, though we may be interacting with some of them all the time, completely unaware. Were it true, what would these dimensions look like and how might they affect us? And what is a dimension anyway?
Two dimensions is just a point. We may remember the coordinate plane from math class with the x and y-axes. Then there’s the third dimension, depth (the z-axis). Another way to look at it is latitude, longitude, and altitude, which can locate any object on Earth. These are followed by the fourth dimension, space-time. Everything has to occur somewhere and at a certain time. After that, things get weird.
Superstring theory, one of the leading theories today to explain the nature of our universe, contends that there are 10 dimensions. That’s nine of space and one of time. Throughout the 20th century, physicists erected a standard model of physics. It explains pretty well how subatomic particles behave, along with the forces of the universe, such as electromagnetism, the stronger and weaker nuclear forces, and gravity. But that last one standard physics can’t account for.
Even so, this model has allowed us the startling ability to peer back to the moments just after the Big Bang took place. Before that, scientists believe that everything was condensed into a single point of infinite density and temperature, known as the singularity, which exploded, forming everything in the observable universe today. But the problem is, we can’t peer back beyond that point. That’s where string theory comes in. The innovations it provides can account for gravity and help explain what existed before the Big Bang.
Aftermath of the Big Bang. NASA.
So what are these other dimensions and how might we experience them? That’s a tricky question, but physicists have some idea of what it might be like. Really, other dimensions are related to other possibilities. How we interact with these is difficult to explain. At the fifth dimension other possibilities for our world open up.
You’d be able to move forward or backward in time, just as you can in space, say while walking down a corridor. You’d also be able to see the similarities and differences between the world we inhabit and other possible ones. In the sixth dimension, you’d move along not a line but a plane of possibilities and be able to compare and contrast them. In the fifth and sixth dimensions, no matter where in space you inhabit, you’d witness every possible permutation of what can occur past, present, and future.
In the seventh, eighth, and ninth dimensions, the possibility of other universes open up, ones where the very physical forces of nature change, places where gravity operates differently and the speed of light is different. Just as in the fifth and sixth dimensions, where all possible permutations in the universe are evident before you, in the seventh dimension every possibility for these other universes, operating under these new laws, becomes clear.
In the higher dimensions, you’d witness every possible world future, past, and present, simultaneously. Flikr.
In the eighth dimension, we reach the plane of all possible histories and futures for each universe, branching out into infinity. In the ninth dimension, all universal laws of physics and the conditions in each universe become apparent. Finally, in the tenth dimension, we reach the point where everything becomes possible and imaginable.
For string theory to work, six dimensions are required for it to operate in a manner that’s consistent with nature. Since these other dimensions are on such a small scale, we’ll need another way to find evidence of their existence. One way would be to peer into the past using powerful telescopes which can hunt for light from billions of years ago, when the universe was first born.
String theory has an answer for what came before the Big Bang. The universe was made up of nine perfectly symmetrical dimensions, the tenth being time. Meanwhile, the four fundamental forces were united at extremely high temperatures. The structure was under high pressure. It soon became unstable and broke in two. This became two different forms of time and led to the three dimensional universe we recognize today. Meanwhile, those other six dimensions shrunk way down to the subatomic level.
A fascinating new book seriously tackles the question of extraterrestrial life from the perspective of leading astronomers, astrophysicists, geneticists, and neuroscientists.
Theoretical physics may be difficult and complicated, “but it does have sex appeal.” So says quantum physicist Jim Al-Khalili. “It’s easy to find an audience for popular science or for a TV documentary about the Big Bang or about black holes,” he recently told me. Al-Khalili’s work in the field has led to the fascinating new book Aliens: The World’s Leading Scientists on the Search for Extraterrestrial Life, which explores what he believes is the likely possibility of alien life.
The Iraqi-born, UK-based Al-Khalili’s intro opens with an anecdote: The Nobel Prize–winning physicist Enrico Fermi is jokingly discussing flying saucers with some colleagues at the Los Alamos National Laboratory when he poses a simple question: “Where is everybody?” His point, Al-Khalili writes, is that the universe is so massive and contains so many planets, that it makes little sense for Earth to be the only place where life blossomed, unless our planet is “astonishingly and unjustifiably special.”
Aliens, out this week from Picador, proceeds in the way that one imagines that Fermi’s conversation at Los Alamos might have: serious scientists, in occasionally cheeky dialogue with one another, acknowledging that the question they’re pursuing—Is anybody out there?—has long been pursued by kookier personalities, conspiracy theorists obsessed with Area 51, and alien abductions. Instead, Al-Khalili’s book offers research-driven essays by prominent astronomers, astrophysicists, geneticists, and neuroscientists, and their pieces offer a wide range of ways to think about the question of extraterrestrial life. Several astrobiologists consider what life requires and which planets and moons might have the right mix: neuroscientist Anil Seth considers the “alien” intelligence of the octopus here on Earth; cosmologist Martin Rees speculates on the possibility of humans merging with machine intelligence and setting out to explore the universe as a new cyborg species.
But for the most part, these experts are weighing in on one fundamental question: Is life special, a unique and almost impossible trick that happened here on Earth? Or is it easy, almost inevitable, a spark that just arises where the conditions are right? It’s an age-old question, that, as Al-Khalili explains, we may finally have the technology to answer.
Photo courtesy of Jim Al-Khalili
VICE: What drew you to the questions that the book addresses? Are you someone who has had a lifelong interest in the idea of aliens?
Jim Al-Khalili: It’s not so much aliens, but more to do with the question of what is special about life. Probably all scientists find that topic fascinating. There are certain questions in science that we don’t have answers to, which we say, those are the big questions: What was there before the universe, before the Big Bang? How did life begin on Earth? How did chemistry turn into biology? What is the nature of consciousness? These are the questions that transcend disciplines. If you get a chemist, a physicist, a biologist, a computer scientist—all of them are going to be fascinated by this.
When I was young, I suppose I was interested in aliens like anyone else. I’m a sci-fi fan. But, for me, the question was really what is so special about life—how did it start on Earth and whether it is unique to Earth.
The book is serious, but the interest in extraterrestrial life has a reputation for being pretty quirky.
Someone once told me that half the internet is devoted to conspiracy theories to do with alien abductions and UFOs. Half is probably too much, but there’s so much out there, from X-Files to science fiction in movies, that it is surprising to think that scientists would treat the question of extraterrestrial life seriously at all. And that’s what made this so refreshing. The book is highlighting the fact that there are lots of questions that are of interest to scientists that you can actually treat seriously. If you really want to know the possibility of whether there are little green men out there, here are the serious scientific takes on it, from all angles. So, it’s meant to be of interest to the wider lay audience but dealt with in a grown-up way.
You mention that there has been a shift within the scientific community toward taking this seriously and away from the era of imagining little green men. Do you have thoughts on when and how that changed? This shift has come about because of advances in astronomy and space exploration in the last decade or two. We have started to send probes to Mars, to the moons of the gas giants Saturn and Jupiter, and we are seriously starting to be able to study the places where there potentially could be life in our solar system. And at the same time, in the past decade, we have discovered planets around stars outside our solar system, exoplanets. Astronomy has been advancing so quickly that what was unthinkable a decade ago is now reality. We can now not only pinpoint which stars have planets going around them, but we can look at those planets and even tell whether they have an atmosphere. Just from the light passing through the atmosphere from the star that they are going around, we can study that light and that can tell us the chemical composition of the atmosphere—and that can tell us what elements, what molecules, what compounds are in that atmosphere, and would they be there naturally or would there have to be life present to have made them. So, these advances in astronomy and space exploration suddenly mean that we can actually address this question. It’s got to the point now where I’m quite optimistic that in my lifetime, it’s likely that we will discover life elsewhere.
Wow. Ten years ago, I wouldn’t have thought that. Now, all these things are coming together. One of the contributors in the book, [professor of evolutionary biochemistry] Nick Lane, talks about the building blocks of life. What do you need? Is there anything magical? You get molecules getting more and more complicated, and then eventually you get something that can make copies of itself, and that’s the first precursor of life. Well, until recently we thought there was a missing step—”and then some magic happens”—and then you get biology from chemistry! But there seems to be no magical steps necessary. I now reckon that the consensus among most scientists is that it would be quite surprising if we don’t find life elsewhere, probably within our lifetime. It might not be interesting life—it won’t be men in flying saucers—it will be some form of microbial life. But, hey, for scientists that will be enough.
“Astronomy has been advancing so quickly that what was unthinkable a decade ago is now reality. It’s got to the point now where I’m quite optimistic that in my lifetime, it’s likely that we will discover life elsewhere.”
So on the big question in the book, which is something like “is life on Earth special and unique or is it common?”—and there are great arguments posed for each side—where do you fall on that spectrum personally? There’s a wide spectrum of opinion among informed scientists. So the fact that I sit somewhere in the middle is because I’ve been influenced by both sides. My kind of naïve view is that we only know of life happening somewhere: on Earth. We are beginning to see that the conditions on Earth are not unique. Forgive the metaphor, but a lot of stars have to have aligned for that—we have to be the right distance from the sun, we have to have an atmosphere, we have to have a moon that gives us tides, we have to have a big planet like Jupiter that is sucking up the debris so it doesn’t bombard us. But there are so many other star systems; there are so many other exoplanets, just in our galaxy alone, that there must be millions, billions of other Earths that have the conditions necessary for life. So in that sense we know we are not unique.
But that doesn’t mean that we know how life got started, just because those conditions exist. We know that life began on Earth very soon after Earth cooled down enough for life to possibly exist, almost 4 billion years ago. Now, over 4 billion years ago, the Earth was just a ball of fire. It wasn’t conducive to anything. So, as soon as the conditions were right for life, life got started. But it didn’t develop into complex life until much, much later. So I’m of the view that life as a simple single cellular form may well be not that difficult. It may be almost ubiquitous in the universe. But multicellular life, life that could then evolve into complex organisms, some of which could develop consciousness and intelligence and civilizations—that actually may be the harder step. How hard it is, we don’t know yet.
I wonder if you can talk a little bit about the role of human radio, TV, and satellite communication and how that factors into the search for alien life. Why do people assume that aliens would also use this same kind of signaling?
We’re starting with the assumption with the idea that the laws of physics and the forces of nature are the same throughout the universe. We know of four of these forces. Two of them are active inside of atoms, the nuclear forces. And the only other ones are gravity and the electromagnetic force. Gravity is limited technologically, but the electromagnetic force is versatile: Light is the electromagnetic force, and radio waves are the electromagnetic force. So it’s a means of sending information from one place to the other. So we’re assuming that whatever form life takes elsewhere, even if its not carbon based—it could be something really beyond our imagination—we still think they will make use of electromagnetic forces. It is a potentially universal way of communicating.
So if we are announcing our existence to the rest of the universe, then it may be that life elsewhere that is doing the same thing. Which is why the whole SETI program is about listening out into the universe to hear some electromagnetic signal that we don’t think could have just happened naturally. Of course, we’ve only been announcing our existence to the world for about 100 years or so, when we first developed radio. So our electromagnetic signals have only extended out to a radius of 100 light years. And actually there aren’t that many star systems within 100 light years. The universe is vast—there’s billions of stars in our own galaxy—but there are only a handful within that range. Of course, an alien civilization may have been announcing their existence to the universe millions of years ago, for all we know, so those signals, if we do receive those signals, they may have traveled across vast distances—it won’t mean that we can then say, “Hi, we’re here,” and then make contact with them. But just the knowledge that there is life out there somewhere would be profound.
Rachel Riederer is co-editor-in-chief of Guernica. Follow her on Twitter.
There’s sound in the stars – but not as much as scientists had hoped. NASA’s Cassini spacecraft beamed back an eerily empty recording of the space between Saturn’s rings. Less ‘Star Trek’, more dial-up modem, the area appears to be surprisingly dust-free.
“It was a bit disorienting – we weren’t hearing what we expected to hear,” said William Kurth, team lead with Cassini’s Radio and Plasma Wave Science (RPWS) instrument. “I’ve listened to our data from the first dive several times and I can probably count on my hands the number of dust particle impacts I hear.”
The recording, which was made on April 26, consists of mainly static with some erratic pings, signalling to NASA’s Jet Propulsion Laboratory that the area between Saturn’s rings consists of much less space dust than previously believed. If there are aliens living between the rings they love to dust.
NASA said the particles they did encounter were no larger than those in smoke, roughly one micron across, or 1,000th of a millimeter. In contrast, Cassini detected hundreds of particles per second when it crossed the plane of Saturn’s rings.
The sounds produced by RPWS, which detects radio and plasma waves and then converts them to sounds, differs to what would be heard with a human ear, which would be unable to pick up on any noises in the vacuum of space, if you’re unlucky enough to end up floating around there.
More data is expected back from Cassini in the coming days as it approaches the end of its mission. On September 15 the craft is scheduled to plunge into Saturn, beaming back as much as possible until its eventual demise as it burns up.
Launched in 1997, Cassini has provided never-seen-before images of Saturn’s atmosphere and nearby moons, including the heat of an ocean beneath the surface of the moon Enceladus and Saturn’s hexagon-shaped jet stream.
Film director Ridley Scott, who delights in terrifying moviegoers with his cinematic blend of horror and science fiction, suggested in a recent interview that the scary prospect of belligerent invading aliens might transcend the realm of sci-fi. According to Scott, hundreds of alien species are “out there” on distant worlds, and Earth’s inhabitants should prepare for the worst if they ever decide to visit our planet.
One scientist, though, says that Scott’s information about such hostile, and abundant, aliens is off-base and unsupported.
Scott told Agence France-Presse (AFP) about his belief in “superior beings,” while fielding questions about his latest movie, “Alien: Covenant,” opening in theaters in the U.S. on May 19. He warned that any extraterrestrial travelers who are technologically advanced enough to show up on our doorstep would likely be very intelligent and very hostile. And unlike the scenarios that dominate movies — if we go toe-to-toe with these invaders, we probably won’t be the victors, he said.
In the interview, Scott explained that “the experts” estimate there are “between 100 and 200 entities” on other planets, following what could be a similar evolutionary path to ours. And if they get here first, our best bet would be to “run for it,” AFP reported.
Astronomers have detected an atmosphere around an Earth-like exoplanet called Gliese 1132b (GJ 1132b for short), which is located around 39 light-years away in the constellation Vela.
This is the first time atmosphere has ever been detected around a planet with a mass and radius so similar to Earth’s, and that makes it a hugely promising (and exciting) target for researchers searching for signs of extraterrestrial life.
“While this is not the detection of life on another planet, it’s an important step in the right direction: the detection of an atmosphere around the super-Earth GJ 1132b marks the first time that an atmosphere has been detected around an Earth-like planet other than Earth itself,” said lead researcher John Southworth from Keele University in the UK.
So far, we know that GJ 1132b has a mass about 1.6 times that of Earth’s, and has roughly 1.4 times its radius – which in terms of exoplanets makes it remarkably similar to our home planet.
But as with all exoplanet discoveries, the researchers are quick to remind the public that the observations to date still really don’t give us much insight into how similar GJ 1132b could be to Earth – or how habitable.
Some bad news upfront is it has an estimated surface temperature of 370 degrees Celsius (698 degrees Fahrenheit), which makes it unlikely that it could host life like us.
But none of those planets had ever gotten as far as having an atmosphere detected, so GJ 1132b is already doing pretty well in terms of a spot that could potentially host life.
Right now, the top strategy for astronomers in the search for life on another planet is to detect the chemical composition of that planet’s atmosphere, looking for certain chemical imbalances that could hint at the presence of living organisms. For example, on Earth, the large amount of oxygen in our atmosphere is that ‘smoking gun’.
Martin Rees is Emeritus Professor of Cosmology and Astrophysics, at the University of Cambridge, the Astronomer Royal, a member of Britain’s House of Lords, and a former President of the Royal Society. The following interview was conducted at Trinity College, Cambridge, by The Conversation’s Matt Warren.
Q: How big is the universe … and is it the only one?
Our cosmic horizons have grown enormously over the last century, but there is a definite limit to the size of the observable universe. It contains all the things from which light has been able to reach us since the Big Bang, about 14 billion years ago. But the new realisation is that the observable universe may not be all of reality. There may be more beyond the horizon, just as there’s more beyond the horizon when you’re observing the ocean from a boat.
What’s more, the galaxies are likely to go on and on beyond this horizon, but more interestingly, there is a possibility that our Big Bang was not the only one. There may have been others, spawning other universes, disconnected from ours and therefore not observable, and possibly even governed by different physical laws. Physical reality on this vast scale could therefore be much more varied and interesting than what we can observe.
The universe we can observe is governed by the same laws everywhere. We can observe a distant galaxy and see that the atoms emitting the light are just the same as the ones in the lab. But there may be physical domains that are governed by completely different laws. Some may have no gravity, or not allow for nuclear physics. Ours may not even be a typical domain.
Even in our own universe, there are only so many ways you can assemble the same atoms, so if it is large enough it is possible that there is another Earth, even another avatar you. If this were the case, however, the universe would have to be bigger than the observable one by a number which to write down would require all the atoms in the universe. Rest assured, if there’s another you, they are a very, very long way away. They might even be making the same mistakes.
Q: So how likely is alien life in this vast expanse?
We know now that planets exist around many, even most, stars. We know that in our Milky Way galaxy there are likely millions of planets that are in many ways like the Earth, with liquid water. The question then is whether life has developed on them – and we can’t yet answer that.
Although we know how via Darwinian selection a complex biosphere evolved on Earth around 4 billion years ago, we don’t yet understand the actual origin of life – the transition from complex chemistry to the first metabolising, replicating structures. The good news is that we will have a better idea of how that happened within the next ten or 20 years and crucially, how likely it was to happen. This will give us a better understanding of how likely it is to happen elsewhere. In that time, we will also have technologies that will allow us to better search for alien life.
But just because there’s life elsewhere doesn’t mean that there is intelligent life. My guess is that if we do detect an alien intelligence, it will be nothing like us. It will be some sort of electronic entity.
If we look at our history on Earth, it has taken about 4 billion years to get from the first protozoa to our current, technological civilisation. But if we look into the future, then it’s quite likely that within a few centuries, machines will have taken over – and they will then have billions of years ahead of them.
In other words, the period of time occupied by organic intelligence is just a thin sliver between early life and the long era of the machines. Because such civilisations would develop at different rates, it’s extremely unlikely that we will find intelligent life at the same stage of development as us. More likely, that life will still be either far simpler, or an already fully electronic intelligence.
Q: Do you believe that machines will develop intelligence?
There are many people who would bet on it. The second question, however, is whether that necessarily implies consciousness – or whether that is limited to the wet intelligence we have within our skulls. Most people, however, would argue that it is an emergent property and could develop in a machine mind.
Q: So if the universe is populated by electronic super minds, what questions will they be pondering?
We can’t conceive that any more than a chimp can guess the things that we spend our time thinking about. I would guess, however, that these minds aren’t on planets. While we depend on a planet and an atmosphere, these entities would be happy in zero G, floating freely in space. This might make them even harder to detect.
Q: How would humanity respond to the discovery of alien life?
It would certainly make the universe more interesting, but it would also make us less unique. The question is whether it would provoke in us any sense of cosmic modesty. Conversely, if all our searches for life fail, we’d know more certainly that this small planet really is the one special place, the single pale, blue dot where life has emerged. That would make what happens to it not just of global significance, but an issue of galactic importance, too.
And we are likely to be fixed to this world. We will be able to look deeper and deeper into space, but travelling to worlds beyond our solar system will be a post-human enterprise. The journey times are just too great for mortal minds and bodies. If you’re immortal, however, these distances become far less daunting. That journey will be made by robots, not us.
Q: What scientific advances would you like to see over the coming century?
Cheap, clean energy, for one. Artificial meat is another. But the idea is often easier than the application. I like to tell my students the story of two beavers standing in front of a huge hydroelectric dam. “Did you build that?” asks one. “No,” says the other. “But it is based on my idea”. That’s the essential balance between scientific insight and engineering development.
Q: Michael Gove [the British politician who was a leader of the campaign for the UK to leave the EU] said people have had enough of experts. Have they?
I wouldn’t expect anything more from Mr Gove, but there is clearly a role for experts. If we’re sick, we go to a doctor, we don’t look randomly on the internet. But we must also realise that most experts only have expertise within their own area, and if we are scientists we should accept that. When science impacts on public policy, there will be elements of economics, ethics and politics where we as scientists speak only as laymen. We need to know where the demarcation line is between where we are experts and where we are just citizens.
If you want to influence public policy as a scientist, there are two ways to do it. You can aspire to be an adviser within government, which can be very frustrating. Or you can try and influence policy indirectly. Politicians are very much driven by what’s in their inbox and what’s in the press, so the scientists with the greatest influence are those who go public, and speak to everyday people. If an idea is picked up by voters, the politicians won’t ignore it.
Q: Brexit – good or bad?
I am surprised to find myself agreeing with Lord Heseltine [former UK Conservative government minister] and Tony Blair [former Labour prime minister], but it is a real disaster, which we have stumbled into. There is a lot of blame to be shared around, by Boris Johnson et al, but also by Jeremy Corbyn [leader of the UK Labour party] for not fighting his corner properly. I have been a member of the Labour Party for a very long time, but I feel badly let down by Corbyn – especially as Labour voters supported Remain two to one. He has been an ineffective leader, and also ambivalent on this issue. A different leader, making a vocal case for Remain, could have tilted the vote.
On the other side, Boris Johnson [now UK foreign secretary – who campaigned for Britain to leave the EU] has been most reprehensible. At least Gove has opinions, which he has long expressed. Boris Johnson had no strong opinions, and the honourable thing to do if that is the case is to remain quiet. But he changed his stance opportunistically (as in the Eton debating society) and swung the vote.
Q: But why is it such a disaster?
My concerns are broad geopolitical ones. In the world as it is now, with America becoming isolationist and an increasingly dominant Russia, for Europe to establish itself as a united and powerful counterweight is more important than ever. We are jeopardising something that has held Europe together, in peace, for 60 years, and could also break up the United Kingdom in the process. We will be remembered for that and it is something to deplore.
One thing astronomers bring to the table is an awareness that we have a long potential future, as well as the universe’s long past – and that this future could be jeopardised by what happens in the coming decades.
Q: More broadly, how much danger is the human race in?
I have spent a lot of time considering how we as a species can make it into the next century – and there are two main classes of problems. First, the collective impact of humanity as its footprint on the planet increases due to a growing population more demanding of resources. Second, the possible misuse by error or design of ever more powerful technology – and most worryingly, bio-tech.
There is certainly a high chance of a major global setback this century, most likely from the second threat, which increasingly allows individual groups to have a global impact. Added to this is the fact that the world is increasingly connected, so anything that happens has a global resonance. This is something new and actually makes us more vulnerable as a species than at any time in our past.
Q: So terrorism will pose an even greater threat in the coming century?
Yes, because of these technologies, terrorists or fanatics will be able to have a greater impact. But there’s also the simple danger of these technologies being misused. Engineering or changing viruses, for example, can be used in benign ways – to eradicate Zika, for example – but there’s obviously a risk that such things can get out of control.
Nuclear requires large, conspicuous and heavily-protected facilities. But the facilities needed for bio-tech, for example, are small-scale, widely understood, widely available and dual use. It is going to be very hard indeed properly to regulate it.
In the short and intermediate term, this is even more worrying than the risks posed by climate change – although in the long term, that will be a very major problem, especially as both people and politicians find it very difficult to focus on things further down the line.
I have been very involved in campaigns to get all countries involved in research and development into alternative, clean energy sources. Making them available and cheap is the only way we are going to move towards a low carbon future. The level of money invested in this form of research should be equivalent to the amount spent on health or defence, and nuclear fusion and fourth generation nuclear fission should be part of that.
Q: In the medieval world, people would start building cathedrals that only later generations would finish. Have we lost that long-term perspective?
That’s right. In fact, one very important input behind the political discussion prior to the Paris climate agreement was the 2015 Papal Encyclical. I’m a council member of the Pontifical Academy of Sciences, which helped to initiate the scientific meetings which were important in ensuring that the encyclical was a highly respected document. Whatever one thinks of the Catholic church, one cannot deny its long-term vision, its global range and its concern for the world’s poor. I believe that the encyclical, six months before the Paris conference, had a big impact on the leaders and people in South America, Africa and Asia. Religion clearly still has a very important role to play in the world.
Q: Have you ever encountered anything in the cosmos that has made you wonder whether a creator was behind it?
No. Personally, I don’t have any religious beliefs. But I describe myself as a cultural Christian, in that I was brought up in England and the English church was an important part of that. Then again, if I had been born in Iran, I’d probably go to the mosque.
The existence of life beyond Earth, popularly known as alien life, is a highly contentious issue among researchers. However, based on the available evidence, it appears those arguing that alien life exists or existed is winning the debate.
Since the mid-20th century, there has been a significant surge in the search for signs of alien intelligence by researchers. Radios have been deployed to detect possible extraterrestrial signals; telescopes have also been mounted to search for potentially habitable extra solar planets.
The British Theoretical Physicist, Professor Stephen Hawking explained some time ago that alien life exists. According to Hawking, in a universe with 100 billion galaxies, with each containing hundreds of millions of stars, it is unlikely that Earth is the only place where life has evolved. He said his brain has rationalized that there is life somewhere apart from what exists on Earth.
The Sunday Times quoted Hawking as saying: “To my mathematical brain, the numbers alone make thinking about aliens perfectly rational. The real challenge is working out what aliens might actually be like.”
Moving away from Professor Hawking and what his mathematical brain is telling him about alien life, a new study published in the journal Nature has shed some light on the topic. Although the objective of the study was not to look for alien life, the analytical stage of the study chanced upon a possible life somewhere apart from Earth.
A team of researchers from University College London discovered ancient fossils in Canada’s Nuvvuagittuq Supracrustal Belt, which hosts some of the oldest sedimentary rocks known on Earth. The tiny microfossils were found to be half the width of a human hair and up to half-a-millimeter in length. Their appearance is of blood-red tubes and filaments, formed by ocean-dwelling bacteria that fed on iron.
When the fossils were studied, the researchers found they are between 3.77 billion and 4.29 billion years old. This makes these fossils the oldest ever to be discovered. The oldest microfossils previously reported were found in Western Australia and dated to 3.46 billion years old.
Lead author of the study, Matthew Dodd was quoted by Reuters as saying that if the dating is accurate, it would represent an almost instantaneous emergence of life after ocean formation. He said the discovery represents a significant milestone, demonstrating life existed on Earth at its infancy.
The researchers said their discovery shows “direct evidence” that life existed on Earth 4 billion years ago. They also stated that the emergence of life could be simple enough to begin on other planets.
However, the researchers acknowledged skepticism about whether the discovered fossils are biological in nature, or merely natural mineral formations.
“One of the big questions when it comes to early life studies is whether or not the organic carbon we find in these rocks is actually biological in origin,” Dodd said.
To answer the big question, Dodd and his colleagues used several methods; including laser-imaging to analyze the minerals associated with the organic material. They concluded that the presence of two minerals in particular – apatite and carbonite – provide strong evidence for life.
Moreover, the researchers said they noted that the microfossils’ structure closely resembles modern bacteria that dwell near iron-rich hydrothermal vents. The researchers then theorized that there’s no reason to rule out similar evidence of early life being found on other planets.
“We could expect to find evidence for past life on Mars 4 billion years ago. If life happened so quickly on Earth, then could we expect it to be a simple process that could start on other planets?” Dodd asked, stating that Earth and Mars had liquid on their surfaces at the same time.
Of course, this is not the first time researchers are suspecting that life exists or might have existed on Mars. In November 2016, NASA said it was unable to rule out possible alien life somewhere in the universe. NASA reached this conclusion after it discovered methane gas on Mars in data brought to Earth by the Curiosity Rover, a car-sized robotic machine exploring Gale Crater on Mars as part of NASA’s Mars Science Laboratory mission.
According to NASA researchers, the methane gas may have been produced by bacteria on Mars. Most methane on Earth is produced as a waste gas by living organisms, but there are many non-biological processes that can also generate the gas.