https://www.theguardian.com/commentisfree/2018/jun/27/aliens-exist-survival-universe-jim-alkhalili
#1: Aliens may not exist – but that’s good
news for our survival
By Jim Al-Khalili
The Guardian June 27, 2018
In 1950 Enrico Fermi, an Italian-born American Nobel prize-winning physicist, posed a
very simple question with profound implications for one of the most important scientific
puzzles: whether or not life exists beyond Earth. The story goes that during a lunchtime
chat with colleagues at the Los Alamos National Laboratory in New Mexico, the issue of
flying saucers came up. The conversation was lighthearted, and it doesn’t appear that
any of the scientists at that particular gathering believed in aliens. But Fermi merely
wanted to know: “Where is everybody?”
His point was that, since the age of the universe is so great and its size so vast, with
hundreds of billions of stars in the Milky Way alone, then unless the Earth is
astonishingly special, the universe should be teeming with life. This might include
intelligent species advanced enough to have the knowledge and technology necessary
for space travel. They ought to have colonized the entire galaxy by now. So where are
they all?
More recently, the late Stephen Hawking argued along similar lines. He said. “To my
mathematical brain, the numbers alone make thinking about aliens perfectly rational.”
Hawking was articulating the same popular argument as Fermi—that the sheer
vastness of the universe all but guarantees we have company.
In recent years, scientists have begun to take the subject more seriously again. One of
the most exciting areas of research in astronomy has been the discovery of extra-solar
planets, worlds orbiting starts other than our sun. Many of them even appear to be
Earth-like in size and climate. Astronomers now believe there are billions of these other
worlds, many of which will have conditions suitable for life. The probability of life, maybe
even intelligent life, existing on at least one of them must surely, therefore, be
overwhelming.
Now, however, scientists at the wonderfully named Future of Humanity Institute in
Oxford have poured cold water on Hawking’s and others’ optimism. They have carried
out a thoughtful statistical analysis by dissecting a mathematical relation known as the
Drake equation, which allows us to calculate the probability of extraterrestrial life based
on the combined probabilities of all the ingredients for life being in place.
Let me make clear at the outset that the Drake equation is not very scientific, for the
sole reason that some of the factors that need to be fed into it are pure guesswork at
this stage. Not the least of these is the big question: given all things we believe are
necessary for life (a source of energy, liquid water and organic molecules), how likely is
it that life will emerge?
The authors of the new study offer two insights, one pessimistic and the other more
cheery. The first is that Fermi’s paradox is easy to resolve. The reason we have not had
any messages from ET is because, well, there is no ET out there. They calculate the
probability we are alone in the universe to be in the range of 39%-85% and the
probability that we are alone in our own galaxy to be between 53% and 99.6%.
Basically, don’t hold your breath.
Biologists, of course, hate all this silly speculation. They quite rightly point out that we
still do not properly understand how life originated here on Earth, so how can we
possibly have any confidence in anticipating its existence or nonexistence elsewhere?
There are some who argue that life on Earth appeared pretty quickly after the right
conditions emerged almost 4bn years ago, which was when our planet had cooled
sufficiently for liquid water to exist. Doesn’t that mean it could easily appear elsewhere
too? Actually, no. A statistical sample of one tells us nothing. It is quite possible that
biology is a freak local aberration, the product of a chemical fluke so improbable that it
didn’t happen anywhere else in the observable universe.
So where do we stand? Well, there are reasons to believe that we may have an answer
in the coming decade or two, one way or the other. Astrobiologists are about to search
exoplanets for the gases produced by microbial life using sophisticated next-generation
space telescopes. There is also the possibility of finding microbial life closer to home,
under the ice of several of the moons of Jupiter and Saturn.
I did say that the study also provided some cheer. Some have claimed we have not
found ET yet because intelligent life (including us) always annihilates itself before it can
successfully develop the technology for interstellar travel or communication. But maybe
the silence is simply because no such alien civilizations exist. So, as the authors puts it,
pessimism about our own future is therefore unfounded. We may be alone, but we may
just survive.
The author, Jim Al-Khalili, is a professor of physics and professor of the public
engagement in science at the University of Surrey.
https://www.theatlantic.com/technology/archive/2018/06/but-seriously-where-iseverybody/563498/
#2: But, Seriously, Where Are the Aliens?
By Derek Thompson
The Atlantic June 22, 2018
Enrico Fermi was an architect of the atomic bomb, a father of radioactivity research, and
a Nobel Prize–winning scientist who contributed to breakthroughs in quantum
mechanics and theoretical physics. But in the popular imagination, his name is most
commonly associated with one simple, three-word question, originally meant as a
throwaway joke to amuse a group of scientists discussing UFOs at the Los Alamos lab
in 1950: Where is everybody?
Fermi wasn’t the first person to ask a variant of this question about alien intelligence.
But he owns it. The query is known around the world as the Fermi paradox. It’s typically
summarized like this: If the universe is unfathomably large, the probability of intelligent
alien life seems almost certain. But since the universe is also 14 billion years old, it
would seem to afford plenty of time for these beings to make themselves known to
humanity. So, well, where is everybody?
In the seventh episode of Crazy/Genius, a new podcast from The Atlantic on tech,
science, and culture, we put the question to several experts, including Ellen Stofan, the
former chief scientist of NASA and current director of the Smithsonian National Air and
Space Museum; Adam Frank, a writer and astrophysicist at the University of Rochester;
Anders Sandberg, a scientist and futurist at the University of Oxford; and Tim Urban, the
science essayist at Wait But Why.
Proposed solutions to Fermi’s Paradox fit into three broad categories.
One: They’re nowhere—and no-when. Aliens don’t exist, and they never have. This
scenario might have seemed more likely in the universe imagined by Aristotle and
Ptolemy—a small assortment of celestial orbs spinning around a singular Earth. But that
isn’t the universe anybody lives in. After searching the skies for Earthlike planets for
centuries, cosmologists have, in the last two decades, broken open the cosmic piñata.
Today they estimate as many as 500 billion billion sunlike stars, with 100 billion billion
Earthlike planets. The more we learn about the universe, the more absurd it would
seem if all but one of those bodies were bereft of life. To my mind, this is both the least
likely answer to Fermi’s Paradox and the only one that fits all the evidence currently
available to astrophysicists.
Two: Life is out there—but intelligence isn’t. Ellen Stofan predicts that we’ll find
evidence of simple life on Mars or a faraway moon within the next 10 to 30 years. But
she’s imagining something more like microbes or algae, not underwater cities in
the liquid-methane lakes of Titan. This shifts the question from “Where is everybody?” to
a more sophisticated query: What precisely is keeping an infinitude of dumb molecules
from assembling to form an abundance of intelligent life?
Think about all the factors that add up to the creation of a human. First the spark of life,
followed by the creation of simple cells, then complex multicellular organisms, then the
formation of organs like brains. If humanlike intelligence is rare, one of these steps must
be quite insurmountable. For example, it’s notable that Earth has several million species
of life, but only one has produced a civilization—that we know of. The relative silence of
the universe suggests some kind of “Great Filter” that is restricting the creation of more
intelligent beings. More ominously, some scientists think it’s possible that this Great
Filter isn’t in our distant past, but rather in our future; so, it’s not that intelligent life is
rare, but rather that it pops into existence for a few thousand years before getting wiped
out of existence for mysterious reasons.
Three: Intelligent life is abundant—but quiet. This possibility, known as the zoo
hypothesis, invites some of the strangest speculation. Maybe humanity is still so basic
and primitive that advanced civilizations don’t think we’re worth talking to. Or maybe
those other civilizations have learned that broadcasting their existence leads to
extermination at the hands of violent, intergalactic colonizers. Or maybe our solar
system just happens to be located in a quiet, exurban cul-de-sac of the universe, an
accident of cosmic geography. But none of these theories hold a candle to my favorite
conjecture of all: slumbering digital aliens. To understand why intelligent life might prefer
to be based in a computer or cat-napping through the Anthropocene, check out the
episode.
The author, Derek Thompson, is a staff writer at The Atlantic, where he writes
about economics, labor markets, and the media. He is the author of Hit Makers.
https://www.cnn.com/2018/01/04/opinions/alien-life-opinion-lincoln/index.html
#3: Does alien life exist?
By Don Lincoln
CNN January 4, 2018
Last month, The New York Times published an article describing a secret government
program investigating reports by military pilots of unidentified flying objects they
encountered in the course of their daily duties. The media was awash with stories of
flying saucers and extraterrestrial encounters, with scientists downplaying the likelihood
of alien visitation and UFO enthusiasts exclaiming their excitement.
While I sit very firmly on the side that believes these reports more likely have an
unremarkable and terrestrial explanation, whether alien life exists is a very real and
credible scientific question. What is the possibility that life—and even intelligent life—
exists around a star other than our own? And how can we find out?
In 1961, Frank Drake wrote down what is now called the Drake Equation, which is
frequently used to help guide thinking about extraterrestrial life. The equation multiplies
a string of probabilities—such as the fraction of stars with planets, the fractions of
planets that are habitable, and the percentage of times intelligent life forms—to give an
estimate of the likelihood that we are not alone in the universe.
When Drake wrote down his equation, very little was known about any of these
probabilities. They were all pretty much guesses. However, using the best guesses of
the day, he estimated there were 10 planets in the Milky Way galaxy emitting radio
waves and thereby detectable in principle by Earth-based radio telescopes.
A lot has changed in the last half-century and we now have a much better
understanding of some of these numbers.
So, what do we know for sure?
While the universe is vast, let's restrict our investigation to only our own Milky Way, as
other galaxies are very far away and the idea of traveling between them is even more
daunting than interstellar travel. So, I'll only talk about our celestial neighbors.
The Milky Way has about a hundred billion stars in it, with some estimates four times
larger than that. In 2009, NASA launched the Kepler spacecraft to search for planets
around distant stars. What the Kepler mission found was nothing short of astounding.
We know that most stars have planets (over 80%). About a quarter of those planetary
systems have a planet at a distance from the star that would allow for liquid water. And,
of those, 10% to 20% of the time those planets are around the same size as Earth.
Combining those numbers, we can estimate with some accuracy that the number of
possibly habitable planets in our galaxy is in the neighborhood of 2 billion.
While there is some uncertainty in this estimate, it is relatively firm. We are far less
certain in our estimation of whether life will be created, if it will survive, and if
intelligence will evolve. If these life-related probabilities are high, say above 50%, then
life should be extremely common in our galaxy. If those numbers are low, we could be
alone.
For all these factors, we only have our own Earth to guide us. And, of course,
generalizing from a single instance is not a wise thing to do. However, we are not
completely ignorant even with just our single planet to study.
The Earth is about 4.55 billion years old. However, the early Earth was molten and
inimical to life. However, by about 4.4 billion years ago, the Earth cooled enough for
water to exist on it. We are not certain exactly when life formed on Earth, but
conservative estimates suggest that it was no later than 3.8 billion years ago, with some
estimates suggesting the earlier date of 4.29 billion years ago.
No matter the estimate, it is clear that life formed on Earth very soon after the planet
cooled enough to have liquid water. This suggests that the formation of life is easy.
Were it difficult, one would expect that it would have taken longer. This is not an airtight
argument, to be sure. But it is a reasonable one.
Although life formed very early in the life of our planet, multicellular life came much later.
It wasn't until oxygen permeated the atmosphere that more complex life could be
supported. It was about 540 million years ago that life from which humans evolved
came into existence. The fact that it took 3-4 billion years for "our" kind of cells to evolve
suggests this process is slow and not at all guaranteed. It requires an abundant supply
of a volatile chemical like oxygen to happen at all.
However, we also know that life has survived for about 4 billion years, no matter how
many times the universe has tried to snuff it out. The impact 65 million years ago
that killed the dinosaurs was a dramatic event in the history of Earth, but it was dwarfed
by the Permian extinction 250 million years ago, when 90% of the species on the planet
went extinct. Yet life survived. Under Earth-like conditions, life is hardy.
The evolution of intelligence seems to be rarer. Until humans evolved, no other forms of
comparable intelligence existed. It is somewhat arbitrary where to draw the line, but our
own species, Homo sapiens, came into existence perhaps 200,000 years ago. The
earliest species of the genus Homo was Homo Habilis and they first evolved around 2
million years ago. By either definition, humanlike intelligence took a long time to appear.
Further, if humanity were to go extinct tomorrow, there are no species around that are
likely to quickly evolve intelligence. Granted, there are species that are more intelligent
than others, but their path to humanlike intelligence is by no means assured. From this,
it is possible to provisionally conclude that the evolution of intelligence is rare.
Thus, from what we know and can infer from observation, planets are common, life is
probably common and intelligence is rare. We can also conclude that life is hardy on
Earth, but Earth may exist in an unusual environment. After all, for life to exist, its host
star must be stable and it must not be too close to other stars that could go supernova
and bathe the Earth with sterilizing radiation. Indeed, some calculations predict that
stars near the center of our galaxy -- a relatively hostile environment -- are not good
candidates for life to flourish. Some predictions say that only about 2% of stars exist in
benign portions of the galaxy, which means that there are maybe 40 million Earth-like
planets in our galaxy.
So, what's the answer? Are we alone in the universe? The honest answer is that we
don't know. We know that planets that could support liquid water are common. But we
don't know much about the origin of life and the probability that it will evolve as it did on
Earth. From what we have seen on Earth, it seems that the creation of life is relatively
easy, but the evolution of intelligence is hard. Taken in aggregate, it does seem that
extraterrestrial life should exist and there may be planets where our cosmic cousins also
look at the sky and dream.
Nobody can tell you for sure what those Navy pilots saw (although I'd bet real money
that it was something ordinary). But it's a big universe and it seems that life could very
well be common. There may come a day when an alien craft lands on the White House
lawn like in the 1950s movie "Earth vs. the Flying Saucers," or, more likely, we hear the
first signals in our giant radio telescopes.
Then we would know, once and for all, that we are not alone.
The author, Dr. Don Lincoln, is a physics researcher who studies the laws of
nature. He is the author of Alien Universe: Extraterrestrial Life in Our Minds and in the
Cosmos.
https://www.washingtonpost.com/blogs/post-partisan/wp/2017/12/19/the-aliens-are-coming-and-no-onecares/?noredirect=on&utm_term=.4c82aecaed09
#4: The Aliens are coming, and no one cares
By Molly Roberts
The Washington Post December 19, 2017
Hold on to your tinfoil hats.
The New York Times reported this weekend that the Pentagon houses a program
devoted to the study of unidentified flying objects. The Defense Department claims the
10-year-old initiative has been shut down, but others say the funding ended and the
work went on — between officials’ other duties, in the shadows, as mysterious as its
extraterrestrial subjects.
The government, apparently, thinks those subjects are real enough to have spent $22
million per year on probing their whereabouts. (Skeptics point out that then-Senate
Majority Leader Harry M. Reid (Democrat-Nevada) requested much of the initial funding
and that most of it went to an aerospace research company run by a longtime billionaire
friend of his.)
The program gathered recordings of reported UFO sightings, including
military footage of a glowing ship shooting through the sky. It also collected metal alloys
of, well, alien composition. Its director declared in a 2009 briefing summary that “what
was considered science fiction is now science fact.”
And we don’t care.
Well, some of us do. The extraterrestrial exposé has prompted some commentators to
raise a digital eyebrow. But mostly, the possibility of alien invasion has not managed to
break through the Trump bubble. It’s not prompting columnists to columnize, or even
that many tweeters to tweet. We’re too busy placing bets on whether special counsel
Robert S. Mueller III’s investigation will meet an early end, or crying out against
misbegotten votes by moderates for a bad tax bill. We have no time to contemplate the
cosmos.
This makes some sense. The aliens might be coming, but they’re probably not coming
anytime soon. Rate hikes and health-care collapses and an unopen Internet, on the
other hand, may all be here to ring in the new year. It’s hard to worry about a threat that
might not even exist when there are so many threats that do, right here, right now. And
it’s even harder to think about extraterrestrial life not as a threat but just as a thing, or as
an idea. It’s too distant. What’s the point?
I don’t know much about what lives beyond our solar system, or even what lives beyond
Earth. Scientists, as far as I can tell, think statistics say that aliens are out there
somewhere, but whether we can reach them or they us is far less certain. I definitely
don’t know the proper price tag to put on finding out more. But I do remember the
eclipse.
It says something that it took the sun disappearing for us to tear our eyes away from
Trump and look somewhere else for a second. But however disheartening the allconsuming chaos of today’s politics may be, this summer’s astronomical rarity was a
reprieve, and a comfort.
A total solar eclipse, those who have seen one all seem to say, reminds you that the
universe is very big and you are very small. On one level, that’s terrifying. No one likes
to hear they don’t matter. On another level, it’s reassuring to think that each of us is
connected to some transcendental community. Even if we don’t matter alone, we matter
together — as a collective piece of something much, much larger.
Extraterrestrial life tells us the same story. It’s less tangible than the eclipse, and it will
take more than dark glasses to get a good look. But it also situates us in a vast universe
that makes us feel both tiny and tremendous at the same time. It tells us there’s a lot we
don’t understand, and a lot we never will, but that we’re all striving, seeking and
sometimes finding together.
So we should talk about aliens this holiday season. Not only because it’s important, and
our ho-hum response so far belies the striking reality that the Defense Department
believes they’re closer than we knew, but also because the continued hunt for
nonhuman intelligent life, amid all the uncertainty, is part of what makes us human.
The author, Molly Roberts, is a Harvard graduate with a BA in English and is an
editorial writer for The Washington Post.
https://slate.com/technology/2017/12/2017-was-a-banner-year-for-searching-for-aliens.html
#5: We Wanted to Believe
Why 2017 was a banner year for discussing, searching for, and panicking over aliens.
By Neel V. Patel
Slate December 29, 2017
If you wanted to believe, 2017 was the year to do it. Thanks to an explosion of new
discoveries of potentially habitable planets outside our solar system, a better
understanding of how life might evolve on other worlds, and not inconsequentially a shift
in the culture, aliens are no longer regarded as just another realm of paranormal
craziness. We now have a modern-dayNASA that is explicitly directed to look for life,
billionaires pouring money into the search for extraterrestrial intelligence, and a
Department of Defense that admits it was studying UFO sightings for some time.
Sandwiched between the 10th and 11th seasons of The X-Files, 2017 felt like the year
aliens finally, actually, for real this time went mainstream. Nearly 61 percent of the
world’s population believes alien life exists somewhere in the universe. That’s little
surprise when you think about how much happened this year.
For starters, NASA scientists began the year with the announced discovery of seven
potentially habitable exoplanets in the TRAPPIST-1 star system, 40 light-years away.
It’s going to take more some powerful instruments to really determine whether any of
those planets possess the essentials for life (liquid water, an atmosphere that keeps
things warm and fuzzy, a star that isn’t spewing out violent radiation in every direction),
and the system is way too far for anyone to even dream about sending a spacecraft
there before we’re all dead and gone. But the system’s discovery is a critical sign that
potentially habitable worlds are probably much more common—and closer—than we
had ever imagined.
Let’s not forget some of the other exoplanets that stoked our hopes of finding
extraterrestrial neighbors. Ross 128 b, 11 light-years away, is probably our best chance
at finding living aliens thanks to its quiet host star (the detection of strange radio
signals fed hopes that an alien civilization was living nearby). GJ 237 b, a little over 12
light-years away, is a “super-Earth” that could support life as well (SETI scientists
actually beamed a musical message over to the system to make contact with any
intelligent lifeforms in the neighborhood). And 39 light-years away, astronomers found
evidence that an Earth-sized bugger called GJ 1132 b had an atmosphere to potentially
allow life on the surface to thrive.
Within our own solar system, NASA found new hopes that aliens might actually just be a
quick hop away, living on worlds like Jupiter’s moon Europa or Saturn’s moon
Enceladus. These rocks possess underground liquid oceans that could be the perfect
mixing pots for the evolution of extraterrestrial life. The knowledge that even Earthbound
life can withstand extreme environments is spurring the potential greenlight for missions
to Saturn’s moon Titan or to a nearby comet to look for life or the ingredients for life—
part of what looks like the agency’s new emphasis of astrobiology missions.
Could we one day find lifeforms that are as smart or smarter than our own species?
There’s no shortage of sharp minds pondering the question. New theories are being
pitched that maybe the aliens aren’t actually all dead—they’re just in a deep sleep.
Maybe it’s actually better off this way? Movies like Alien: Covenant and Life were good
reminders that not all lifeforms are peaceful. Maybe we should just count our blessings
and stay quiet until we figure out how we might be able to defend ourselves from a
hostile alien invasion.
There’s little chance of that actually happening. A strange interstellar asteroid decided
to stop by the solar system for a visit, and one of the first things scientists decided to do
was see whether it was actually an alien ship. It wasn’t, of course, but it just goes to
show you that even the most implausible explanation wouldn’t go uninvestigated in
2017. In the future, however, we’ll probably just let the intelligent machines handle the
hard work.
But all of these developments were at least grounded in the processes and logic that
define scientific research. There was another facet to this year’s obsession with aliens
that hewed closer to what most of us have heard before: UFOs and government
involvement. Hacking collective Anonymous got things heated in the middle of the
summer when it claimed NASA was about to reveal the existence of aliens. That didn’t
happen—perhaps because the agency decided it to hold off on such a bombshell
announcement, or almost definitely because it has never found evidence of aliens.
OK, so a bunch of hackers turned out to be wrong about aliens. That’s nothing special.
What is special, however, is the New York Times publishing a piece detailing the
government’s five-year, $22 million program to investigate UFOs. It’s been a few weeks,
and the media is still trying to make sense of it all. Only in 2017 could the craziest news
of the year not be that the Pentagon actually admitted that such a program once
existed.
(Also, I still can’t believe Tom DeLonge was onto something real.)
And less than a week after the New York Times piece was published, SpaceX’s final
launch of the year turned Southern California’s skies into an eerie scene out of an alieninvasion movie. It wasn’t a UFO, of course, but the timing couldn’t have been better.
If 2017 was a banner year for talking about aliens and UFOs with earnestness and
enthusiasm, 2018 seems poised to take all of those conversations to new heights. The
rapid advancement of new technology and the circulation of new data—combined
with increasingly favorable odds that something is out there—means that as time
passes, our search for cosmic companionship will only get more intense.
The author, Neel V. Patel, is a science and tech journalist from New York City,
reporting for publications like Slate, Popular Science and WIRED. He is an alum
of New York University’s Arthur L. Carter Journalism Institute (M.A., Journalism,
’14), as a part of the school’s Science, Health and Environmental Reporting
Program (SHERP).
https://www.nytimes.com/2016/06/12/opinion/sunday/yes-there-have-been-aliens.html
#6: Yes, There Have Been Aliens
By Adam Frank
June 10, 2016
Last month astronomers from the Kepler spacecraft team announced the discovery of
1,284 new planets, all orbiting stars outside our solar system. The total number of such
“exoplanets” confirmed via Kepler and other methods now stands at more than 3,000.
This represents a revolution in planetary knowledge. A decade or so ago the discovery
of even a single new exoplanet was big news. Not anymore. Improvements in
astronomical observation technology have moved us from retail to wholesale planet
discovery. We now know, for example, that every star in the sky likely hosts at least one
planet.
But planets are only the beginning of the story. What everyone wants to know is
whether any of these worlds has aliens living on it. Does our newfound knowledge of
planets bring us any closer to answering that question?
A little bit, actually, yes. In a paper published in the May issue of the journal
Astrobiology, the astronomer Woodruff Sullivan and I show that while we do not know if
any advanced extraterrestrial civilizations currently exist in our galaxy, we now have
enough information to conclude that they almost certainly existed at some point in
cosmic history.
Among scientists, the probability of the existence of an alien society with which we
might make contact is discussed in terms of something called the Drake equation. In
1961, the National Academy of Sciences asked the astronomer Frank Drake to host a
scientific meeting on the possibilities of “interstellar communication.” Since the odds of
contact with alien life depended on how many advanced extraterrestrial civilizations
existed in the galaxy, Drake identified seven factors on which that number would
depend, and incorporated them into an equation.
The first factor was the number of stars born each year. The second was the fraction of
stars that had planets. After that came the number of planets per star that traveled in
orbits in the right locations for life to form (assuming life requires liquid water). The next
factor was the fraction of such planets where life actually got started. Then came factors
for the fraction of life-bearing planets on which intelligence and advanced civilizations
(meaning radio signal-emitting) evolved. The final factor was the average lifetime of a
technological civilization.
Drake’s equation was not like Einstein’s E=mc2. It was not a statement of a universal
law. It was a mechanism for fostering organized discussion, a way of understanding
what we needed to know to answer the question about alien civilizations. In 1961, only
the first factor — the number of stars born each year — was understood. And that level
of ignorance remained until very recently.
That’s why discussions of extraterrestrial civilizations, no matter how learned, have
historically boiled down to mere expressions of hope or pessimism. What, for example,
is the fraction of planets that form life? Optimists might marshal sophisticated molecular
biological models to argue for a large fraction. Pessimists then cite their own scientific
data to argue for a fraction closer to 0. But with only one example of a life-bearing
planet (ours), it’s hard to know who is right.
Or consider the average lifetime of a civilization. Humans have been using radio
technology for only about 100 years. How much longer will our civilization last? A
thousand more years? A hundred thousand more? Ten million more? If the average
lifetime for a civilization is short, the galaxy is likely to be unpopulated most of the time.
Once again, however, with only one example to draw from, it’s back to a battle between
pessimists and optimists.
But our new planetary knowledge has removed some of the uncertainty from this
debate. Three of the seven terms in Drake’s equation are now known. We know the
number of stars born each year. We know that the percentage of stars hosting planets
is about 100. And we also know that about 20 to 25 percent of those planets are in the
right place for life to form. This puts us in a position, for the first time, to say something
definitive about extraterrestrial civilizations — if we ask the right question.
In our recent paper, Professor Sullivan and I did this by shifting the focus of Drake’s
equation. Instead of asking how many civilizations currently exist, we asked what the
probability is that ours is the only technological civilization that has ever appeared. By
asking this question, we could bypass the factor about the average lifetime of a
civilization. This left us with only three unknown factors, which we combined into one
“biotechnical” probability: the likelihood of the creation of life, intelligent life and
technological capacity.
You might assume this probability is low, and thus the chances remain small that
another technological civilization arose. But what our calculation revealed is that even if
this probability is assumed to be extremely low, the odds that we are not the first
technological civilization are actually high. Specifically, unless the probability for
evolving a civilization on a habitable-zone planet is less than one in 10 billion trillion,
then we are not the first.
To give some context for that figure: In previous discussions of the Drake equation, a
probability for civilizations to form of one in 10 billion per planet was considered highly
pessimistic. According to our finding, even if you grant that level of pessimism,
a trillion civilizations still would have appeared over the course of cosmic history.
In other words, given what we now know about the number and orbital positions of the
galaxy’s planets, the degree of pessimism required to doubt the existence, at some
point in time, of an advanced extraterrestrial civilization borders on the irrational.
In science an important step forward can be finding a question that can be answered
with the data at hand. Our paper did just this. As for the big question — whether any
other civilizations currently exist — we may have to wait a long while for relevant data.
But we should not underestimate how far we have come in a short time.
Adam Frank is an astrophysics professor at the University of Rochester, a cofounder of NPR’s 13.7 Cosmos and Culture blog, and the author of About Time:
Cosmology and Culture at the Twilight of the Big Bang.
Comparative Rhetorical Analysis
You have been exploring the topic of aliens (extraterrestrial life) and have read six op-ed pieces:
“Aliens May Not Exist but That’s Good News for Our Survival” (Jim Al-Khalili)
“But Seriously, Where Are the Aliens?” (Derek Thompson)
“Does Alien Life Exist?” (Don Lincoln)
“The Aliens Are Coming, and No One Cares” (Molly Roberts)
“We Wanted to Believe” (Neel V. Patel)
“Yes, There Have Been Aliens” (Adam Frank)
Choose two articles, and write a comparative rhetorical analysis, answering the following key question:
Key Question
Of the two articles, which author makes a more convincing argument and why?
Purpose: Analyze and evaluate rhetorical choices in complex traditional texts (SLO #1).
Audience: Someone who is interested in the topic of aliens but unfamiliar with the articles.
Point-of-View: 3rd person (avoid “I” or “you” pronouns in this paper)
Requirements:
o The MLA-formatted essay must be 1,500-2,000 words. No Works Cited page is necessary.
o Students must highlight their essays in Microsoft Word or Google Docs using the pattern on
the following page before submitting the rough draft or final draft on Canvas.
o The essay must focus on evaluating the authors’ arguments for effectiveness and should
avoid the student’s personal opinions regarding the topic or existence of aliens.
o The essay must contain 4-6 body paragraphs focused on comparing and analyzing both
authors’ use of claims, reasoning, assumptions, evidence, organizational strategies,
rhetorical appeals, fallacies, etc.
Comparative Rhetorical Analysis Essay Grading Rubric/Checklist
Category
Rationale/Comments
Points
Title is appropriate and original: Yes/No
Title
Introduction includes a hook/attention-grabber: Yes/No
&
Context regarding the topic of aliens is provided: Yes/No
Introduction
20
Both authors are introduced and sources are summarized: Yes/No
Thesis answers the Key Question and is highlighted yellow: Yes/No
Body paragraphs have a clear topic: Yes/No
Organization
Body paragraphs discuss both authors: Yes/No
20
Body paragraphs progress in a logical order: Yes/No
Support &
Integration of
Adequate evidence is used from both articles to support points: Yes/No
Paraphrase and quotation are used effectively: Yes/No
20
Sources
Comparison of rhetorical moves each author makes is effective: Yes/No
Rhetorical Analysis
&
Evaluation of
Sources
Analysis of rhetorical moves is clear and in-depth: Yes/No
Discussion of strengths and weaknesses of each text included: Yes/No
Evaluation of which article is more effective is clear: Yes/No
50
Personal opinions regarding aliens are avoided: Yes/No
Restates thesis and summarizes key points: Yes/No
Conclusion
Ends with a global statement about significance of analysis: Yes/No
10
Highlighting Pattern:
Grammar,
Highlighting,
&
MLA Format
Thesis Statement=Yellow (Last sentence of introduction)
Topics or Points of Comparison=Green (Hopefully, you have one
topic or point of comparison for each body paragraph. This should
be one word or phrase.)
Examples from Article #1=Orange (Identify either article as Article
#1--just be consistent. Highlight any quotes, evidence, or
explanation regarding this article.)
Examples from Article #2=Pink (Identify either article as Article #2-just be consistent. Highlight any quotes, evidence, or explanation
regarding this article.)
Evaluation of Effectiveness=Blue (Any time you are arguing why an
article was effective or ineffective, highlight this blue.)
Total
30
150
English 124 ◊ Spring 2019 ◊ Prof. Sarah Martin
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