When it comes to places with the potential for habitability, Venus isn’t usually considered on that list. The hot, greenhouse-effect-gone-mad neighboring planet with a crushing surface pressure and sulfuric acid clouds certainly isn’t friendly to life as we know it, and the few spacecraft humanity has sent to Venus’ surface have only endured a few minutes.
But up about 40 to 60 km (25 to 37 miles) above the surface, the atmosphere of Venus is the most Earth-like of any other place in the Solar System. There, Venus has air pressure of approximately 1 bar and temperatures in the 0°C to 50°C range. It’s not quite a shirtsleeves environment, as humans would need air to breathe and protection from the sulfuric acid in the atmosphere. Plus, also consider that Venus is considered to be in the habitable zone of our star.
Remember back in 2008 when the Phoenix lander on Mars scraped away a few inches of rust-colored regolith to reveal water ice? Or in 2009, when Mars Reconnaissance Orbiter observations revealed vast areas of subsurface ice, event at low latitudes?
These findings – and many more like them – indicate there’s a lot of interesting things going on underneath Mars’ lifeless surface. Since we know from experience on Earth that anywhere there is water, there is life, the question of life on – or under – Mars’s surface is always provocative.
Over the years, scientific estimates of potential intelligent life in our galaxy have ranged widely. Some estimates say just one (only us Earthlings) to just a handful, to possibly thousands or even millions. A new study attempts to quantify the number of other worlds we could potentially talk to by estimating the number of intelligent civilizations within the Milky Way that are actively communicating.
In our search for exoplanets, we have found more than three dozen potentially habitable worlds. It’s estimated that there are 8 to 20 billion potentially habitable, Earth-like worlds in our galaxy alone. But there is a big difference between potentially habitable and actually habitable, and scientists are starting to narrow their definitions.
What do coal, crude oil, and truffles have in common? Go ahead. We’ll wait.
The answer is thiophenes, a molecule that behaves a lot like benzene. Crude oil, coal, and truffles all contain thiophenes. So do a few other substances. MSL Curiosity found thiophenes on Mars, and though that doesn’t conclusively prove that Mars once hosted life, its discovery is an important milestone for the rover. Especially since truffles are alive, and oil and coal used to be, sort of.
The title of Earth’s Earliest Life has been returned to the fossils in the Pilbara region of Australia. The Pilbara fossils had held that title since the 1980s, until researchers studying ancient rocks in Greenland found evidence of ancient life there. But subsequent research questioned the biological nature of the Greenland evidence, which put the whole issue into question again.
Now a new study of the Pilbara fossils has identified the presence of preserved organic matter in those fossils, and handed the ‘Ancient Life’ crown back to them.
People are always worried that alien civilizations will detect the transmissions from our old radio shows and television broadcasts, and send in the invasion fleet. But the reality is that life itself has been broadcasting the existence of life on Earth for 500 million years.
Three times in October, 2017 researchers turned a powerful radar telescope near Tromsø, Norway towards an invisibly faint star in the constellation Canis Minor (the small dog) and beamed a coded message into space in an attempt to signal an alien civilization. This new attempt to find other intelligent life in the universe was reported in a presentation at the ‘Language in the Cosmos’ symposium held on May 26 in Los Angeles, California.
METI International sponsored the symposium. This organization was founded to promote messaging to extraterrestrial intelligence (METI) as a new approach to in the search for extraterrestrial intelligence (SETI). It also supports other aspects of SETI research and astrobiology. The symposium was held as part of the International Space Development Conference sponsored by the National Space Society. It brought together linguists and other scientists for a daylong program of 11 presentations. Dr. Sheri Wells-Jensen, who is a linguist from Bowling Green State University in Ohio, was the organizer.
This is the second of a two part series about METI International’s symposium. It will focus on a presentation given at the symposium by the president of METI International, Dr. Douglas Vakoch. He spoke about a project that hasn’t previously gotten much attention: the first attempt to send a message to a nearby potentially habitable exoplanet, GJ273b. Vakoch led the team that constructed the tutorial portion of the message.
Message to the stars
The modern search for extraterrestrial intelligence began in 1960. This is when astronomer Frank Drake used a radio telescope in West Virginia to listen for signals from two nearby stars. Astronomers have sporadically mounted increasingly sophisticated searches, when funding has been available. The largest current project is Breakthrough Listen, funded by billionaire Yuri Milner. Searches have been made for laser as well as radio signals. Researchers have also looked for the megastructures that advanced aliens might create in space near their stars. METI International advocates an entirely new approach in which messages are transmitted to nearby stars in hopes of eliciting a reply.
The project to send a message to GJ273b was a collaboration between artists and scientists. It was initiated by the organizers of the Sónar Music, Creativity, and Technology Festival. The Sónar festival has been held every year since 1994 in Barcelona, Spain. The organizers wanted to commemorate the 25th anniversary of the festival. To implement the project, the festival organizers sought the help of the Catalonia Institute of Space Studies (IEEC), and METI International.
To transmit the message, the team turned to The European Incoherent Scatter Scientific Association (EISCAT) which operates a network of radio and radar telescopes in Finland, Norway, and Sweden. This network is primarily used to study interactions between the sun and Earth’s ionosphere and magnetic field from a vantage point north of the arctic circle. The message was transmitted from a 32 meter diameter steerable dish at EISCAT’s Ramfjordmoen facility near Tromso, Norway, with a peak power of 2 megawatts. It is the first interstellar message ever to be sent towards a known potentially habitable exoplanet.
The target system
The obscure star known by the catalogue designation GJ273 caught the attention of the Dutch-American astronomer Willem J. Luyten in 1935. Luyten was researching the motions of the star. The star caught his attention because it was moving through Earth’s sky at the surprising rate of 3.7 arc seconds per year. Later study showed that this fast apparent motion is due to the fact that GJ273 is one of the sun’s nearest neighbors, just 12.4 light years away. It is the 24th closest star to the sun. Because of Luyten’s discovery it is sometimes known as Luyten’s star.
Luyten’s star is a faint red dwarf star with only a quarter of the sun’s mass. It caught astronomers’ attention again in March 2017. That’s when an exoplanet, GJ273b, was discovered in it’s habitable zone. The habitable zone is the range of distances where a planet with an atmosphere similar to Earth’s would, theoretically, have a range of temperatures suitable to have liquid water on its surface. The planet is a super Earth, with a mass 2.89 times that of our homeworld. It orbits just 800,000 miles from its faint sun, which it circles every 18 Earth days.
This exoplanet was chosen because of its proximity to Earth, and because it is visible in the sky from the transmitter’s northerly location. Because GJ273b is relatively nearby, and radio messages travel at the speed of light, a reply from the aliens could come as early as the middle of this century.
The message carried aboard each Voyager spacecraft was encoded digitally on a phonographic record. It was largely pictorial, and attempted to give a comprehensive overview of humans and Earth. It also included a selection of music from various Earthly cultures. These spacecraft will take tens of thousands of years to reach the stars. So, no reply can be expected on a timescale relevant to our society.
In some ways the GJ273b message is very different from the Voyager message. Unlike the Voyager record, it isn’t pictorial and doesn’t attempt to give a comprehensive overview of humans and Earth. This is perhaps because, unlike the Voyager message, it is intended to initiate a dialog on a timescale of decades. It resembles the Voyager message in that it contains music from Earth, namely, music from the artists that performed at the Sónar music festival.
The message consists of a string of binary digits—ones and zeros. These are represented in the signal by a shift between two slightly different radio frequencies. The ‘hello’ section is designed to catch the attention of alien listeners. It consists of a string of prime numbers (numbers divisible only by themselves and one). They are represented with binary digits like this:
The message continues the sequence up to 193. A signal like this almost certainly can’t be produced by natural processes, and can only be the designed handiwork of beings who know math.
After the ‘hello’ section comes the tutorial. This, and all the rest of the message, uses eight bit blocks of binary digits as the basis for its symbols. The tutorial begins by introducing number symbols by counting. It uses base two numbers like this:
The tutorial then proceeds to geometry using combinations of numbers and symbols to illustrate the Pythagorean theorem. It eventually progresses to sine waves, thereby describing the radio wave carrying the signal itself. Finally the tutorial describes the physics of sound waves and the relationships between musical notes.
Besides the numbers, the tutorial introduces 55 8-bit symbols in all. It provides the instructions that aliens would need to properly reproduce a series of digitally encoded musical selections from the Sónar Festival.
During its journey of 70 trillion miles, the message is sure to become corrupted with noise. To compensate, the tutorial was transmitted three times during each transmission, requiring a total of 33 minutes to transmit. The entire transmission was repeated on three separate days, October 16, 17, and 18, 2017. A second block of three transmissions was made on May 14, 15, and 16, 2018.
Each transmission included a different selection of music, with the works of 38 different musicians included in all. You can hear recordings of all this music at the Sónar Calling GJ273b website.
The rationale behind the message
Current and past SETI projects conducted by astronomers here on Earth assume that advanced aliens would make things easy for newly emerging civilizations by establishing powerful beacons that would broadcast in all directions at all times. Thus, SETI searchers generally use the same sort of highly directional dish antennae often used for other research in radio astronomy. They listen to any one star for only a few minutes, searching each one in turn for the beacon.
Unlike the always-on beacons imagined as the objects of Earth’ SETI searches, the Sónar message was only transmitted for 33 minutes on each of three days, and on only two occasions. Vakoch admits that “our message would likely be undetected by a civilization on GJ273b using the same strategy” favored by beacon searching SETI researchers on Earth.
However, some researchers have called traditional SETI assumptions and strategy into question, and studies of alternative search technologies have already been conducted. Vakoch notes that “we humans already have the technological capacity, and need only the funding, to conduct an all-sky survey that would detect intermittent transmission like ours”.
A larger problem is that the message was directed at just one planet. Although GJ273b orbits within its star’s habitable zone, we really know little what that means for whether the planet is actually habitable, or whether it has life or intelligence. Earth itself has been habitable for billions of years. But it has only had a civilization capable of radio transmissions for a century.
Vakoch conceded that “The only way we will get a reply back from GJ273b is if the galaxy is chock full of intelligent life, and it is out there just waiting for us to take the initiative. More realistically, we may need to replicate this process with hundreds, thousands, or even millions of stars before we reach one with an advanced civilization that can detect our signal”. METI International aims to conduct a design study for such a large scale METI project in hopes that funding will materialize from governmental or other sources.
How could you devise a message for intelligent creatures from another planet? They wouldn’t know any human language. Their ‘speech’ might be as different from ours as the eerie cries of whales or the twinkling lights of fireflies. Their cultural and scientific history would have followed its own path. Their minds might not even work like ours. Would the deep structure of language, its so called ‘universal grammar’ be the same for aliens as for us? A group of linguists and other scientists gathered on May 26 to discuss the challenging problems posed by devising a message that extraterrestrial beings could understand. There are growing hopes that such beings might be out there among the billions of habitable planets that we now think exist in our galaxy. The symposium, called ‘Language in the Cosmos’ was organized by METI International. It took place as part of the National Space Society’s International Space Development Conference in Los Angeles. The Chair of the workshop was Dr. Sheri Wells-Jensen, a linguist from Bowling Green State University in Ohio.
What is METI International?
‘METI’ stands for messaging to extraterrestrial intelligence. METI International is an organization of scientists and scholars that aims to foster an entirely new approach in our search for alien civilizations. Since 1960, researchers have been looking for extraterrestrials by searching for possible messages they might send to us by radio or laser beams. They have sought the giant megastructures that advanced alien societies might build in space. METI International wants to move beyond this purely passive search strategy. They want to construct and transmit messages to the planets of relatively nearby stars, hoping for a response.
One of the organization’s central goals is to build an interdisciplinary community of scholars concerned with designing interstellar messages that can be understood by non-human minds. More generally, it works internationally to promote research in the search for extraterrestrial intelligence and astrobiology, and to understand the evolution of intelligence here on Earth. The daylong symposium featured eleven presentations. It main theme was the role of linguistics in communication with extraterrestrial intelligence.
This article is the first in a two part series. It will focus on one of the most fundamental issues addressed at the conference. This is the question of whether the deep underlying structure of language would likely be the same for extraterrestrials as for us. Linguists understand the deep structure of language using the theory of ‘universal grammar’. The eminent Linguist Noam Chomsky developed this theory in the middle of the twentieth century.
Despite its name, Chomsky originally took his ‘universal grammar’ theory to imply that there are major, and maybe insuperable barriers to mutual understanding between humans and extraterrestrials. Let’s first consider why Chomsky’s theories seemed to make interstellar communication virtually hopeless. Then we’ll examine why Chomsky’s colleagues who presented at the symposium, and Chomsky himself, now think differently.
Before the second half of the twentieth century, linguists believed that the human mind was a blank slate, and that we learned language entirely by experience. These beliefs dated to the seventeenth century philosopher John Locke and were elaborated in the laboratories of behaviorist psychologists in the early twentieth century. Beginning in the 1950’s, Noam Chomsky challenged this view. He argued that learning a language couldn’t simply be a matter of learning to associate stimuli with responses. He saw that young children, even before the age of 5, can consistently produce and interpret original sentences that they had never heard before. He spoke of a “poverty of the stimulus”. Children couldn’t possibly be exposed to enough examples to learn the rules of language from scratch.
Chomsky posited instead that the human brain contained a “language organ”. This language organ was already pre-organized at birth for the basic rules of language, which he called “universal grammar”. It made human infants primed and ready to learn whatever language they were exposed to using only a limited number of examples. He proposed that the language organ arose in human evolution, maybe as recently of 50,000 years ago. Chomsky’s powerful arguments were accepted by other linguists. He came to be regarded as one of the great linguists and cognitive scientists of the twentieth century.
Universal grammar and ‘Martians’
Human beings speak more than 6000 different languages. Chomsky defined his “universal grammar” as “the system of principles, conditions, and rules that are elements or properties of all human languages”. He said it could be taken to express “the essence of human language”. But he wasn’t convinced that this ‘essence of human language’ was the essence of all theoretically possible languages. When Chomsky was asked by an interviewer from Omni Magazine in 1983 whether he thought that it would be possible for humans to learn an alien language, he replied:
“Not if their language violated the principles of our universal grammar, which, given the myriad ways that languages can be organized, strikes me as highly likely…The same structures that make it possible to learn a human language make it impossible for us to learn a language that violates the principles of universal grammar. If a Martian landed from outer space and spoke a language that violated universal grammar, we simply would not be able to learn that language the way that we learn a human language like English or Swahili. We should have to approach the alien’s language slowly and laboriously — the way that scientists study physics, where it takes generation after generation of labor to gain new understanding and to make significant progress. We’re designed by nature for English, Chinese, and every other possible human language. But we’re not designed to learn perfectly usable languages that violate universal grammar. These languages would simply not be within the range of our abilities.”
If intelligent, language-using life exists on another planet, Chomsky knew, it would necessarily have arisen by a different series of evolutionary changes than the uniquely improbable path that produced human beings. A different history of climate changes, geological events, asteroid and comet impacts, random genetic mutations, and other events would have produced a different set of life forms. These would have interacted with one another in a different ways over the history of life on the planet. The “Martian” language organ, with its different and unique history, could, Chomsky surmised, be entirely different from its human counterpart, making communication monumentally difficult, if not impossible.
Convergent evolution and alien minds
The tree of life
Why did Chomsky think that the human and ‘Martian‘ language organ would likely be fundamentally different? How come he and his colleagues now hold different views? To find out, we first need to explore some basic principles of evolutionary theory.
Originally formulated by the naturalist Charles Darwin in the nineteenth century, the theory of evolution is the central principle of modern biology. It is our best tool for predicting what life might be like on other planets. The theory maintains that living species evolved from previous species. It asserts that all life on Earth is descended from an initial Earthly life form that lived more than 3.8 billion years ago.
You can think of these relationships as like a tree with many branches. The base of the trunk of the tree represents the first life on Earth 3.8 billion years ago. The tip of each branch represents now, and a modern species. The diverging branches connecting each branch tip with the trunk represent the evolutionary history of each species. Each branch point in the tree is where two species diverged from a common ancestor.
Evolution, brains, and contingency
To understand Chomsky’s thinking, we’ll start with a familiar group of animals; the vertebrates, or animals with backbones. This group includes fishes, amphibians, reptiles, birds, and mammals, including humans.
We’ll compare the vertebrates with a less familiar, and distantly related group; the cephalopod molluscs. This group includes octopuses, squids, and cuttlefish. These two groups have been evolving along separate evolutionary paths-different branches of our tree-for more than 600 million years. I’ve chosen them because, as they’ve traveled along their separate branch of our evolutionary tree, each has evolved it own sort of complex brains and complex sense organs.
The brains of all vertebrates have the same basic plan. This is because they all evolved from a common ancestor that already had a brain with that basic plan. The octopus’s brain, by contrast, has an utterly different organization. This is because the common ancestor of cephalopods and vertebrates lies much further back in evolutionary time, on a lower branch of our tree. It probably had only the simplest of brains, if any at all.
With no common plan to inherit, the two kinds of brains evolved independently of one another. They are different because evolutionary change is contingent. That is, it involves varying combinations of influences, including chance. Those contingent influences were different along the path that produced cephalopod brains, than along the one that led to vertebrate brains.
Chomsky believed that many languages might be theoretically possible that violated the seemingly arbitrary constraints of human universal grammar. There didn’t seem to be anything that made our actual universal grammar something special. So, because of the contingent nature of evolution, Chomsky assumed that the ‘Martian’ language organ would arrive at one of these other possibilities, making it fundamentally different from its human counterpart.
This sort of evolution-based pessimism about the likelihood that humans and aliens could communicate is widespread. At the symposium, Dr. Gonzalo Munévar of Lawrence Technological University argued that intelligent creatures that evolved sensory systems and cognitive structures different from ours would not develop similar scientific theories or even similar mathematics.
Evolution, eyes, and convergence
Now lets consider another feature of the octopus and other cephalopods; their eyes. Surprisingly, the eyes of octopuses resemble those of vertebrates in intricate detail. This uncanny resemblance can’t be explained in the same way as the general resemblance of vertebrate brains to one another. It’s almost certainly not due to inheritance of the traits from a common ancestor. It’s true that some of the genes involved in the building of eyes are the same in most animals, appearing far down towards the trunk of our evolutionary tree. But, biologists are almost certain that the common ancestor of cephalopods and vertebrates was much too simple to have any eyes at all.
Biologists think eyes evolved separately more than forty times on Earth, each on its own branch of the evolutionary tree. There are many different kinds of eyes. Some are so strangely different from our own that even a science fiction writer would be surprised by them. So, if evolutionary change is contingent, why do octopus eyes bear a striking and detailed similarity to our own? The answer lies outside of evolutionary theory, with the laws of optics. Many large animals, like the octopus, need acute vision. There is only one good way, under the laws of optics, to make an eye that meets the needed requirements. Whenever such an eye is needed, evolution finds this same best solution. This phenomenon is called convergent evolution.
Life on another planet would have its own separate evolutionary tree, with the base of the trunk representing the appearance of life on that planet. Because of the contingency of evolutionary change, the pattern of branches might be quite different from our Earthly evolutionary tree. But because the laws of optics are the same everywhere in the universe, we can expect that large animals under similar conditions will evolve an eye that looks a lot like that of a vertebrate or a cephalopod. Convergent evolution is potentially a universal phenomenon.
Not just for humans anymore?
Taking apart the language organ
By the beginning of the twenty-first century, Chomsky and some of his colleagues started to look at the language organ and universal grammar in a new way. This new view made it seem like the properties of universal grammar were inevitable, much as the laws of optics made many features of the octopus’s eye inevitable.
In a 2002 review, Chomsky and his colleagues Marc Hauser and Tecumseh Fitch argued that the language organ can be decomposed into a number of distinct parts. The sensory-motor, or externalization, system is involved in the mechanics of expressing language through methods like vocal speech, writing, typing, or sign language. The conceptual-intentional system relates language to concepts.
The core of the system, the trio proposed, consists of what they called the narrow faculty of language. It is a system for applying the rules of language recursively, over and over, thereby allowing the construction of an almost endless range of meaningful utterances. Jeffrey Punske and Bridget Samuels similarly spoke of a ‘syntactic spine’ of all human languages. Syntax is the set of rules that govern the grammatical structure of sentences.
The inevitability of universal grammar
Chomsky and his colleagues made a careful analysis of what computations a nervous system might need to perform in order to make this recursion possible. As an abstract description of how the narrow faculty works, the researchers turned to a mathematical model called the Turing machine. The mathematician Alan Turing developed this model early in the twentieth century. This theoretical ‘machine’ led to the development of electronic computers.
Their analysis led to a striking and unexpected conclusion. In a book chapter currently in press, Watumull and Chomsky write that “Recent work demonstrating the simplicity and optimality of language increases the cogency of a conjecture that at one time would have been summarily dismissed as absurd: the basic principles of language are drawn from the domain of (virtual) conceptual necessity”. Jeffrey Watumull wrote that this strong minimalist thesis posits that “there exist constraints in the structure of the universe itself such that systems cannot but conform”. Our universal grammar is something special, and not just one among many theoretical possibilities.
Plato and the strong minimalist thesis
The constraints of mathematical and computational necessity shape the narrow faculty to be as it is, just like the laws of optics shape both the vertebrate and the octopus eye. ‘Martian’ languages, then, might follow the same universal grammar as human languages because there is only one best way to make the recursive core of the language organ.
Through the process of convergent evolution, nature would be compelled to find this one best way wherever and whenever in the universe that language evolves. Watumull supposed that the brain mechanisms of arithmetic might reflect a similarly inevitable convergence. That would mean that the basics of arithmetic would also be the same for humans and aliens. We must, Watumull and Chomsky wrote “rethink any presumptions that extraterrestrial intelligence or artificial intelligence would really be all that different from human intelligence”.
This is the striking conclusion that Watumull, and in a complementary way, Punske and Samuels presented at the symposium. Universal grammar may actually be universal, after all. Watumull compared this thesis to a modern, computer age version of the beliefs of the ancient Greek philosopher Plato, who maintained that mathematical and logical relationships are real things that exist in the world apart from us, and are merely discovered by the human mind. As a novel contribution to a difficult ages-old philosophical problem, these new ideas are sure to stir controversy. They illustrate the depth of new knowledge that awaits us as we reach out to other worlds and other minds.
Universal grammar and messages for aliens
What are the consequences of this new way of thinking about the structure of language for practical attempts to create interstellar messages? Watumull thinks the new thinking is a challenge to “the pessimistic relativism of those who think it overwhelmingly likely that terrestrial (i.e. human) intelligence and extraterrestrial intelligence would be (perhaps in principle) mutually unintelligible”. Punske and Samuels agree, and think that “math and physics likely represent the best bet for common concepts that could be used as a starting point”.
Watumull supposes that while the minds of aliens or artificial intelligences may be qualitatively similar to ours, they may differ quantitatively in having bigger memories, or the ability to think much faster than us. He is confident that an alien language would likely include nouns, verbs, and clauses. That means they could probably understand an artificial message containing such things. Such a message, he thinks, might also profitably include the structure and syntax of natural human languages, because this would likely be shared by alien languages.
Punske and Samuels seem more cautious. They note that “There are some linguists who don’t believe nouns and verbs are universal human language categories”. Still, they suspect that “alien languages would be built of discrete meaningful units that can combine into larger meaningful units”. Human speech consists of a linear sequence of words, but, Punske and Samuels note that “Some of the linearity imposed on human language may be due to the constraints of our vocal anatomy, and already starts to break down when we think about signed languages”.
Overall, the findings foster new hope that devising a message comprehensible to extraterrestrials is feasible. In the next installment, we will look at a new example of such a message. It was transmitted in 2017 towards a star 12 light years from our sun.
Since the Universe is big and old, and life on Earth didn’t take relatively long to evolve, then life should be everywhere in the Universe. And yet, no matter how hard we look, we don’t see any evidence of it out there, not on Mars, not sending us radio messages, and not taking over entire galaxies and using up all their energy.
This, of course, is the Fermi Paradox, and it’s an absolutely fascinating concept to think about. There are many possible resolutions to the Fermi Paradox, but most of them are unsatisfying. Sure, we could be living in a cosmic zoo, or we fundamentally misunderstand how difficult it’ll be to travel to another star.
And maybe we’re just the first lifeforms in the observable Universe that have reached the level of technology that can conceive of exploring the Universe. But then, what are the chances of that? That really seems unlikely.
But then there’s the idea of the Great Filter. That there’s some kind of event that affects every single intelligent civilization, stopping it from reaching out into the galaxy, sending out signals, and exploring other worlds. Something wipes them out every time.
And considering the fact that we’re on the verge of becoming a multi-planet species ourselves, this concept of the Great Filter becomes even more unsettling.
It could be right around the corner from us.
Our friends at Kurzgesagt just released a video all about the Great Filter, and honestly, I think it’s the best video they’ve ever done. The animation, as always, is excellent, but the way they approach the Great Filter is really innovative, showing how evidence of life in the Universe is actually a bad sign, since it means we’re probably not the first life forms out there.