
When will we find aliens? - prostoalex
http://www.bbc.com/earth/story/20150429-will-we-find-aliens
======
mapt
Basically, what the last several decades has shown is that while they're
probably out there, we won't find aliens until we make serious attempts to
look, rather than token efforts.

That means funding astronomy an order of magnitude more than we do now, and
flat-out demanding that we mitigate risk and reduce R&D cost-share by building
ten to a hundred of everything. Presently we spend a decade and a half
perfecting a design's technical aspects and securing funding only to build one
unit over five years, with a 70% chance of scaling back that unit or
stretching out construction by five more years because of insecure funding
late in the game. We should instead spend 3 years designing, 2 years building
a prototype and iterating, and 5 years building and installing a large number
of production-run units, before moving on to the next design.

Nearly every instrument on every large telescope today is 'couture', with at
most 2 units in existence. Telescopes _designed_ for mass replication, like
the ATA or PAN-STARRS, end up getting their funding cut off for further units
as soon as first light is reached on the prototype, because of the perverse
incentives and interests associated with astronomical research.

It also means devoting actual resources to SETI, instead of having it be
something tenured professors do as a hobby, with nearly zero funding.

~~~
ZanyProgrammer
And yet, if alien civilizations are using a method of communicating other than
radio, it won't matter how much resources and funding we devote to SETI (often
assumed to be the same as radio astronomy).

~~~
imglorp
Don't forget optical.

[https://seti.berkeley.edu/opticalseti](https://seti.berkeley.edu/opticalseti)

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millstone
> Undoubtedly, the most exciting kind of alien life would be the intelligent
> kind

But intelligent non-life would be even more exciting! Note that SETI is the
search for ET intelligence, not ET life.

I mean, read this:

> As robotic space probes continue to explore the solar system, visiting
> planets, moons, and asteroids, they're finding watery environments where
> microbial life could grab hold

If robots are better than life for exploring the solar system and visiting
remote planets, why are we looking for signs of life, instead of signs of
robots?

~~~
lloeki
Spin is a great read.

[0]:
[http://en.wikipedia.org/wiki/Spin_(novel)](http://en.wikipedia.org/wiki/Spin_\(novel\))

~~~
thomasahle
Hm, now I just read the entire plot on the Wikipedia page. Does that mean I
don't have to read the book?

~~~
bjelkeman-again
A shame, I think the novel was more entertaining than the plot summary. But
then I didnt know the outcome.

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huhtenberg
> _Touching down on Mars for the first time was a big deal, sure._

Viking 1 wasn't the first to land on Mars. It landed July 20, 1976. Mars 3
landed in December 2, 1971.

M3 didn't last long, granted, but that's hardly a reason to twist the facts
(presumably for the benefit of narration and not because of any sort of anti-
Soviet bias, because that would've been just way too ridiculous coming from
BBC, wouldn't it).

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lordnacho
I reckon we'll quite soon have the telescope/spectroscopy stuff needed to
determine whether life is abundant or very rare. New exoplanets are found
quite often now, and it's only a matter of improving the technology a bit so
we can know whether there's a few or very many interesting places out there.

As for meeting any of these, I think it will be a loooong time.

~~~
hliyan
We will. The TESS (Transiting Exoplanet Survey Satellite) and the JWST (James
Webb Space Telescope) will be launching in a few years. The two will sort of
act as a spotter-sniper pair -- TESS detecting planets and JWST zooming in.
Both are far more powerful than their predecessors, Kepler and Hubble.

There is also plans (not yet funded) to use "starshade" occulter to directly
observe planets that don't pass in front of the parent star (by blocking the
starlight).

My personal estimate is that we'll definitely detect oxygen in a planetary
spectrum within the next 10 years. Which will mostly likely mean
photosynthesis on the surface.

------
Ilverin
[http://mason.gmu.edu/~rhanson/greatfilter.html](http://mason.gmu.edu/~rhanson/greatfilter.html)

"Humanity seems to have a bright future, i.e., a non-trivial chance of
expanding to fill the universe with lasting life. But the fact that space near
us seems dead now tells us that any given piece of dead matter faces an
astronomically low chance of begating such a future. There thus exists a great
filter between death and expanding lasting life, and humanity faces the
ominous question: how far along this filter are we?

"Combining standard stories of biologists, astronomers, physicists, and social
scientists would lead us to expect a much smaller filter than we observe. Thus
one of these stories must be wrong. To find out who is wrong, and to inform
our choices, we should study and reconsider all these areas."

------
3stripe
A better question is probably: When will aliens find us?

"ET is 99% likely to be more than 50 million years in front of us and that’s
ample time to completely explore this galaxy. So it’s 99% likely they know we
are here."

Source: [http://www.bbc.com/earth/story/20150429-will-we-find-
aliens](http://www.bbc.com/earth/story/20150429-will-we-find-aliens)

~~~
simonh
If there are aliens out there yes, they most likely didn't just happen to
develop a civilisation at the same time as us, and so are likely to have been
around a long time. I don't think that means they're likely to have even
reached a neighbouring star yet, other than perhaps a flyby probe, let alone
colonised the galaxy. Interstellar travel is just too many orders of magnitude
too hard to be practical, and even if you manage it all it takes is one GRB
and your whole civilization is toast anyway. I suspect that within about a
thousand years we'll pretty much top out technologically. Once we know
everything these is to know about the physical universe, we'll start hitting
the limits of what is possible with the physical elements and forms of energy
available in our universe. Then we'll start hitting the limits of what's
possible with the actual materials and sources of energy in our solar system,
and face some hard choices about what we do with them.

~~~
ZanyProgrammer
So many assumptions and guesswork embedded in your statement!

~~~
simonh
Yes, you are quite right. But show me an analysis of this issue that is not
based on any assumptions or guesswork.

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coldcode
Tomorrow is as good an estimate as any.

Seriously from earth we are only likely to find aliens at the same or slightly
ahead of our own technology. If one visits us first it might come sooner. If
the aliens are far ahead of us we may never even notice them. It's like
dumping Newton in a modern corn field and telling him he is surrounded by
people communicating. He would have no idea about cell phone, microwave and
other transmissions. Take technology from 300 years in the future in an alien
today and we might be equally clueless.

------
jacquesm
Whether, not when for now. Even if the odds are for it there is absolutely no
guarantee we will. It could happen tomorrow, in the next thousand years or not
before we manage to exterminate ourselves (or some great filter does it for
us).

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Thiz
I hope never.

It's like amerindians wanting to find spaniards.

~~~
ZanyProgrammer
Why should we assume ETs will behave like humans, especially humans of 500
years ago?

~~~
gknoy
Given that our civilization(s) have nearly always behaved that way when
colonizing places, why should we assume that aliens are more "enlightened",
and will see us as anything better than we've seen "native savages", or
(worse) an "infestation"?

~~~
ZanyProgrammer
How can we possibly assume other aliens will behave exactly the way we do?
That seems presumptuous. A very human centric view of life.

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stillsut
It seems like Moore's-law-like trend can get us to telescopes by 2050 that can
detect the chemical composition of exo-planets. Significant oxygen would be a
sign, as on Earth, of ongoing chemical respiration from life - otherwise O2
would react and decay to other forms without being replenished.

There would still be the possibility that the presence of oxygen was geologic
in nature, and if we sampled a billion exo-planets, it's reasonable that some
could have an exotic geology to cause this 'false positive'.

The next step might be to look for a pattern in the carbon-cycle connected
with orbits: e.g on Earth the North vs. South hemisphere have different
amounts of plant life, and we see C02 wobble several ppm in summer vs. winter.
Getting accurate readings of exo-planets to the ppm level might take a while
for telescope technology to acheive. For these reasons, I'd say 2100 is a good
estimate for when we would have the ability to sample 1B exoplanets, and
promote at least one to the rank of 'strong possibility of harboring life'.

------
natejenkins
I think the Drake equation is worth mentioning here. It estimates the number
of civilizations in the Milky Way Galaxy whose electromagnetic emissions are
detectable ([https://www.authorea.com/11048](https://www.authorea.com/11048)).
Knowing some of the numbers involved, it can be reduced to approximately:

N ~= 2 _fl_ fe _fc_ L

where fl is the fraction of habitable planets hosting life, fe is the fraction
of life-bearing planets that develop an intelligent life-form, fc is the
fraction of intelligent life-forms that decide to communicate, and L is the
length of time a given civilization is transmitting "visible" communications.
Taking ourselves as an example, L is already on the order of 100 years. The
original estimates for these values were fl = 1, fe = 1, fc = 0.1-0.2, and L =
1000-100,000,000
([http://en.wikipedia.org/wiki/Drake_equation](http://en.wikipedia.org/wiki/Drake_equation)).

------
khorwitz
[http://en.wikipedia.org/wiki/Fermi_paradox](http://en.wikipedia.org/wiki/Fermi_paradox)

------
forgottenacc56
We won't, because it doesn't exist within the time period, lifeform type and
distance that correlates with ours.

~~~
allemagne
I'm very suspicious of the hypothesis that our earth is just special or rare.
It's a clean solution to the Fermi paradox, but there's no way of knowing
this. There's no reason to even think that this is more probable than any
other answer.

~~~
deelowe
What if earth isn't special, but the time frame when which life flourishes is
extremely small on a cosmological scale? This seems to be the most difficult
part for me. Everywhere we look, the universe seems to be a fairly violent
place. It may just be that life is common, but short lived. So, due to the
distances involved, the chances of life existing in two places at once _and_
being able to observe each other is near 0.

~~~
lovemenot
From known data, I don't believe your hypothesis is likely to be correct:

1) 13.8 - Age of Universe (Billion years)

2) 4.5 - Age of Earth

3) 3.5 - (minimum) Age of life on Earth

Our ancestors have already been alive here for at least 25% of the duration of
the universe. To me, the most fascinating number is the small gap between 2)
and 3). Suggesting that life here, at least, was almost inevitable. Whether
through panspermia or ab initio, it appears difficult neither for life to get
started nor to keep hanging around.

I read last year about a hypothesis that iirc 100,000 years after the big
bang, as the entire Universe was cooling, for some duration it was lukewarm in
patches all over. Ideal for the first iteration of life and perhaps for an
initial panspermia event that seeded all parts of the expanding universe.

~~~
deelowe
Interesting. Thanks!

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bikamonki
We won't, they will find us and they won't come in bio form.

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innguest
We know right where a bunch of aliens are: the bottom of the ocean.
Incredibly, it's so hard to go there that it's considered a joke to suggest
it, whereas with space it seems if it weren't for the problem of the sheer
distances involved, we could really do it and just go anywhere.

------
hrbrtglm
If an intelligent extraterrestrial life exists, it's surely looking for a
pizzeria in space : [http://pizzeria.space](http://pizzeria.space)

~~~
alienhackers
Or they're busy hacking : [http://alienhackers.com](http://alienhackers.com)

------
cymetica
[https://www.youtube.com/watch?v=fOZk--
oZdQk](https://www.youtube.com/watch?v=fOZk--oZdQk)

