
Why We’ll Have Evidence of Aliens–If They Exist–By 2035 - dnetesn
http://nautil.us/blog/why-well-have-evidence-of-aliensif-they-existby-2035
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jmiserez
FYI: The title sounds like clickbait, but is actually explained in the
article. As technology improves further in the next few years, we’ll be able
to scan so many more stars simultaneously that a possible discovery would be
have to be made (if they exist).

Overall an interesting article by Seth Shostak of the SETI Institute.

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sillysaurus3
I've never understood claims like this. For all we know, the universe could be
infinite. Yes, that would mean the universe contains an infinite amount of
energy and that we'd find dopplegangers of ourselves if we travel far enough,
but we can't be sure it's not true. We can't even be more or less confident in
one hypothesis vs another.

Articles like this would be more persuasive if they had qualifiers like
"Within our observable universe."

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liberte82
A lot of people don't realize just how much bigger the universe might be than
"the observable universe".

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bluGill
Not quite true. If Aliens exist AND they had radio technology in use [distance
from us in lightyears] years ago we will find them by 2035.

Aliens 200 light years away will not detect life on earth for 100 years or so
yet (depending on if they are listening and how sensitive their radios are).
If they immediately send a reply it will be 200 more years before we can get
their reply.

Note that 200 light years is insignificant even on the scale of our galaxy,
much less the universe.

What this means is even if we detect aliens that doesn't mean they still
exist, we could well detect them, learn about them and then watch as die (war,
plague, or any other doomsday scenario) before we can get our "we are here"
message to them. That is we might find aliens that do not exist anymore! The
universe is large enough that this would not surprise me (though it might be
my great-great-great grandchild who discover they have been dead for thousands
of years).

Or maybe we will not find any, and then in 2036 discover the first radio
transmission of some aliens only a few light years away.

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civilian
Well, yeah, no shit. We're obviously just looking at the "observable
universe", which means light-as-it-is-arriving-now.

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evanlivingston
My amature take on intelligent alien life is that humans as a technological
society have developed extremely quickly, if other intelligent species exist
and have a focus on technics, then I think it's safe to assume they've
developed with as much speed. Continuing with that assumption, it seems
extremely unlikely to me that other technological civilizations are at the
same point in the timeline as we are, or slightly further ahead. I would
imagine them to be massively further ahead. As such, they would surely know
about us, but haven't made contact. Why not? I think this is a very important
question to ask in the search for other advanced cultures.

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bluGill
All our current physics says that the speed of light is a real limit to
travel, and to get close to that requires far more energy that a society is
likely to have. I can well believe that aliens if they exist may conclude
leaving their solar system is not worth the cost. Sure they could do it, but
many will die when their spaceship on the way. Even robot spaceships are
unlikely to make it very far (on the scale of the galaxy) before suffering a
critical failure.

Thus I can well believe that aliens have colonized the other habitable planets
in their solar system and failed at all attempts to do anything more. They
might have got one robot to a different star, but that is it.

Of course this assumes they are there before us by a significant amount. Maybe
humans are first to reach our level - it is an arrogant idea but we cannot
completely discard it until proven wrong.

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icebraining
_Even robot spaceships are unlikely to make it very far (on the scale of the
galaxy) before suffering a critical failure._

That seems like a limited vision of the possibilities of spaceships. Remember
that we're now traveling through space ourselves, and barring self-inflicted
problems, we're not in great danger of suffering critical failure.

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NoPiece
Given enough time an asteroid impact presents the possibility of non self
inflicted critical failure.

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gwbas1c
From reading the article, I don't believe the statement "We’ll Have Evidence
of Aliens–If They Exist–By 2035." An alien civilization broadcasting via radio
at the same moment we're looking could be very unlikely.

[Edit] Who's to say that we're going to broadcast via radio for thousands or
millions of years? What if, in 300 years, we discover a much better system?
Then we can reasonably assume that a 400 year radio burst is the sign of a
species developing intelligence. We can also reasonably assume that SETI chose
a poor indicator in their search.

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yodon
Which is why they are also thinking about signals like neutrinos and gravity
waves (which are much harder to produce but much better suited to interstellar
distances).

While it's never possible to say "everything has been discovered/invented" we
know a great deal about the types of particles and waves that can exist at
realistic energy levels for use in communication systems because those energy
scales have been so well studied. The odds that there is "new physics" to be
discovered at a scale that will supplant radio waves for broadcast
communications on a terrestrial scale are pretty low.

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jerf
"neutrinos and gravity waves (which are much harder to produce but much better
suited to interstellar distances)."

No, they aren't. Both are freakishly difficult to detect, and we have no
reason at this point to expect that to ever change. And gravity waves are
actually terrible for interstellar distances because it is completely unclear
how you would produce a source of gravity waves powerful enough to transmit
across interstellar distances, and also transmit in a _beam_. If you can't
transmit in a beam, you're stuck with very unfavorable dropoffs as distance
increases.

It is also unclear why, having built the utterly massive complexes for
transmission or detection of gravity waves, or the massive complexes required
for high-probability neutrino reception (transmission in their case is a bit
simpler, though collimating the beam is rough) it would not simply be easier
to use electromagnetic waves, which are by comparison _so easy_ that if we
_had_ a receiver in another star system we could transmit to them _today_.

Barring some major revelation in physics, aliens will use electromagnetic
waves because everything else is literally (and I mean that in its original
correct sense) dozens of orders of magnitude worse. Smart aliens do not
demonstrate how much smarter they are than us by using engineering solutions
dozens of orders magnitude inferior to what we could build today. However, as
my previous text implies and as other commenters have already pointed out, the
problem there is that efficiency is obtained at that scale with beams, not
broad transmission. The galaxy could be hopping with point-to-point links and
they would be much harder for us to notice.

(They wouldn't be impossible, because there would be some scattering on the
interstellar medium. But they'd be much more difficult than if we were
directly the target.)

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yodon
We're in agreement that gravity waves and neutrinos are harder to produce and
detect.

They are better for long interstellar distance communications because their
weakly interacting nature and difficult to produce nature means there is no
dispersion relationship to worry about, no absorbtion/attenuation issues to
worry about, and no noise sources to worry about. The galaxy is a surprisingly
difficult medium to send radio waves through if you want them to be received
at great distances (difficult medium, not impossible medium). That's one of
the things that led early SETI thinkers like Barney Oliver to propose using
the spectral Water Hole[0] as a search target.

Gravity waves and neutrinos are harder to produce and detect but the galaxy
itself is much less likely to interfere with their propagation if you can
produce and detect them. Also, communications uses of gravity waves would
presumably be at much higher frequencies so the detector sizes would be much
smaller (the size of an interferometer or Weber bar detector is a function of
the center detection frequency of the device... sensitivity is largely
independent of the size, other than the choice of center detection frequency).

[0]
[https://en.wikipedia.org/wiki/Water_hole_(radio)](https://en.wikipedia.org/wiki/Water_hole_\(radio\))

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kylec
These methods focus on finding extraterrestrials with an equivalent or greater
technological advancement to our own. How would you find an alien civilization
with a 17th-century Earth level of technological development? We were not
emitting radio signals or using light pulses to communicate, nor were we
flying around in antimatter-powered rockets.

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nkoren
In the main, I think we'd simply have no chance of detecting such
civilisations. In the next couple of decades, however, advanced space
telescopes with starshade coronagraphs could be able to start doing
spectroscopy on exoplanet atmospheres.[1] This would definitely reveal (some
kinds of) biologically-active atmospheres, although it wouldn't necessarily to
be able to tell the difference between a complex biosphere with a low-tech
civilisation, and a uni-cellular algae soup.

I suppose there's an outside chance that such a telescope could detect
combustion compounds that are difficult to explain geologically or
biologically, and that might be used to hypothesise a civilisation. Something
like lead smelting might leave a pretty distinct signature, for example. But
that would just lead to a hypothesis, not proof, and I imagine it'd be pretty
contentious.

Longer-term, it should be possible to create arbitrarily large space-based
optical interferometers[2], to the point where one would be capable of imaging
cities and agricultural activity on exoplanets. That'd settle matters (Unless
it's under water or impenetrable cloud decks, and then you're just out of
luck). But that level of resolution is probably a couple of centuries and/or
one singularity away from happening, so don't hold your breath.

1: [http://www.planetary.org/blogs/guest-
blogs/2017/20170623-sta...](http://www.planetary.org/blogs/guest-
blogs/2017/20170623-starshade-helping-space-telescopes.html)

2: [https://www.noao.edu/meetings/interferometry/workshop-
files/...](https://www.noao.edu/meetings/interferometry/workshop-
files/Carpenter-Space-comp.pdf)

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aaroninsf
Yawn.

All such proclamations, predictions, and earnestness about the Drake Equation
is limited, absolutely, by the boundaries of what we currently believe is
possible.

To be specific, it has always seemed to me hubris of the first order to
presume that we know the principles underlying a more advanced civilization's
communications (or, maybe, travel).

We aren't aware of mechanisms more efficient, fast, whatever, than e.g.
radiowaves, or, polarized lasers, or [insert latest notion]'.

But what the authors of these things seem to never take seriously is what we
don't know, is almost certain to be a lot more significant than what we do.

There is a chart in my office lounge showing the advancement of human symbolic
reasoning and technology from pre-history, through 15 years ago.

What is striking to me is that in a few brief thousand years, utterly
insignificant evolutionarily speaking, we have gone from first formulating
written language and mathematics, to e.g. Cassini, rovers, and LIGO.

Ever if the pace of advancement were plateaued (and it isn't) it is baffling
to me that someone would think, oh, we've got the basic constraints now in
hand; it's just an exercise of application at this point, to e.g. detect other
civilizations.

That doesn't even begin to get into the Liu Cixin style game theory issues...

Anyway. Lack of evidence merely means we're not looking in the right way, IMO.

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squatsandsci
The author of this article is focusing only on SETI-based methods of finding
extraterrestrial life. The most promising IMO, and one that I don't see talked
about much, is the James Webb Telescope's ability to measure contents of the
atmospheres of exoplanets. From what I understand O2 is only known to be
created by metabolic processes of living organisms.

Also one thing that's curious to me is the math here assumes these millions of
civilizations all exist now or have set up systems to broadcast these beams
forever whether or not they go extinct. So if we make the following
assumptions:

These civilizations only last a couple hundred years after they create these
powerful directional radio wave beams (which if we use ourselves as an example
seems to be a reasonable assumption)

One civilizations dies and another sequentially starts broadcasting radio
waves (most favorable option)

It takes 2 billion years to create life

Galaxy is about 13 billion years old

There's been about 2M advanced civilizations in the Milky Way

That means there's a 3.6% chance there's a civilizations broadcasting right
now. This goes up if some last longer than 200 years, and if some create
machines that can broadcast either indefinitely or for a long time. Within 1
magnitude of relative certainty is pretty good I guess.

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ChuckMcM
The short version is: "Hypothesis: there are millions of alien civilizations,
by 2035 we will have sampled enough possible stars to achieve statistical
significance, and either there are no aliens or we'll see a positive result."

Which I agree with (and I also agree with folks who point out that at some
point being found may be a bad thing which would encourage hiding).

Like many people I know, I assume there must be other civilizations out there.
However it is fun to ask the question, "What if we are unique in all the
galaxy?" (really it would be the light cone associated with what we can
perceive) What sort of responsibility would it put on humans to get their act
together and keep from dying out if we knew we were unique?

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iokevins
Dr. Shostak quoted 2015-2025, in 2008, as the expected dates to discover alien
life:
[http://www.saukvalley.com/articles/2008/02/12/news/national/...](http://www.saukvalley.com/articles/2008/02/12/news/national/doc47b1e094681c3055532104.txt)

Just under 10 years later, he quotes 2035.

Not saying he's wrong.

~~~
civilian
What's it called when a research event is always 20 years away?

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m1n1
A key decision for any sentient species would be whether to broadcast one's
existence or snoop around quietly first.

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steve_adams_86
This reminds me of a trilogy called Remembrance of Earth's Past by Liu Cixin.
He creates a sort of analogy in the second novel, saying civilizations in
space should be like hunters in a dark forest (The book is called The Dark
Forest). He hypothesizes that you should sneak around quietly, looking to kill
others, lest you be killed yourself. I won't say more - it's a great read.

~~~
richsinn
A great summary of the Dark Forest theory without giving away too much of the
plot. This trilogy is one of the best books/stories I've ever read.

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t1o5
According to my tinfoil hat, if we plugin sensible defaults to the drake
equation, the aliens should have been broadcasting something around 21,000
light years ago for us to get something in 2035.

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jpm_sd
What if "typical" technological civilizations only go through a very brief
period of broadcasting detectable TV signals and then they wire up the entire
planet with leak-free fiber optic cables? Then all we can count on is
intentional transmissions that say "find us here"?

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InitialLastName
Presumably, they would still need a way to communicate with remote
(unwireable) entities? We find quite a lot of use for devices in orbit. It's
hard to imagine that use disappearing, especially as we move towards mining
resources in our local solar neighborhood.

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AnimalMuppet
So if we _don 't_ find evidence of aliens by 2035, we should assume they don't
exist? Cynically, I'm pretty sure that's not how this will play out...

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gooseus
> We can never prove that aliens are not out there, only that they are.

No, he's just saying if we don't find them by 2035 he owes the Internet
coffee. Pretty excited, though I'm hoping I can substitute tea.

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AnimalMuppet
But the contrapositive is logically equivalent to the original statement. "If
aliens exist, we'll have evidence by 2035" is logically equivalent to "If we
don't have evidence by 2035, aliens don't exist".

But it won't be taken that way.

Now, I'm overstating the attention-grabbing headline to reflect a greater
degree of certainty than Shostak genuinely believes. But he's stating it with
more certainty than he genuinely believes, at least in the headline. If he
_really_ believed the headline, he'd say, "If we don't find them by 2035, I
will believe that they don't exist" instead of "I will buy everyone coffee".

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DougN7
This seems to be the very definition of hubris.

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0xdeadbeefbabe
Science can't tell me how to lose weight, but SETI can find intelligent life
or the absence of it? Maybe the scientists at SETI are better, or maybe
searching for intelligent life is an easier problem?

Didn't Carl Sagan already find the answer by doing math?

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maxerickson
Science knows the mechanics of losing weight. Monitor and restrict calories.
For example, lots of people do this successfully with their pets.

