

It's too late to worry that the aliens will find us - aresant
http://www.newscientist.com/article/mg20727676.400-its-too-late-to-worry-that-the-aliens-will-find-us.html

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jerf
I was pondering this a few weeks back, and after some thought I realized it's
even later than I thought. The logic that an alien civilization should smash
its neighbors before it can be smashed doesn't just hold for intelligence, it
holds for _life_ ; if we can go from metaphorically crawling in the mud in the
early 20th century (before radio) to potentially firing our own relativistic
projectiles by, say, 2200, in 300 years, who's to say there isn't a species
that could pull that trick in 30 years instead of 300? (Maybe somebody who can
work together even better than we can, living with a faster biochemistry on a
hotter planet? Something like Eliezer's "Maximum Fun-Fun Ultra Super Happy
People"? Who knows? It's hard to imagine the human experience has been truly
optimal on the technological development speed front.) In which case you may
literally have no time at all to try to pick up the "intelligence". You need
to smash _all life_ , _before_ you think it might have "intelligence".

And Earth has been broadcasting "I'm alive!" for at least 2.4 billion years,
since the Great Oxygenation Event:
<http://en.wikipedia.org/wiki/Great_Oxygenation_Event> Ever since then, any
intelligence within the area of probably several hundred light years or more
has had the ability to take a simple spectrograph of our planet, observe free
O2 in the atmosphere, decide that's too likely to be the result of life for
comfort, and obliterate the planet.

Nobody has. (Unless you believe the official Current Earth Destruction Status:
<http://qntm.org/board> However, it appears to simply be instrument failure.
Somebody really ought to fix that.)

Even on the galactic timescale, 2.4 billion years is not chump change.

Either the game theoretic optimum is not to smash your neighbors immediately
(for instance, widespread orbital colonization is indeed practical and is what
happens, which as people have observed changes the balance away from "smash"),
or we are effectively alone. Either way I think we can discard the
relatavistic-projectile-death scenario, except as a major, unplannable fluke.

~~~
hugh3
Heck, screw oxygen. Rationally, defense-oriented civilizations should smash
all habitable-zone planets just to be on the safe side.

But you're right: the fact that our suspiciously life-supporting planet has
been sitting here for billions of years unmolested does appear to indicate
that there aren't any planet-destroying game theorists in our neighbourhood.

Alternative scenario: instead of a relativistic projectile, they sent a
starship, which will leave us alone unless we develop enough technology to be
a threat to its home planet. If we think that's a likely scenario we should
all be sitting around worrying about how to _not_ piss off the starship.

On the other hand, since knowing about the starship is a threat to the
starship, we should try to avoid even thinking about whether there might be a
starship.

~~~
jerf
"Heck, screw oxygen. Rationally, defense-oriented civilizations should smash
all habitable-zone planets just to be on the safe side."

Yeah, good point. If nothing else you reset the clock to zero, and that buys
you an awful lot of time even under the worst case scenario.

"instead of a relativistic projectile, they sent a starship,"

A starship is a relativistic projectile that bothers to slow down. If you're
going to smash a planet that acts up, you might as well just cut to the chase.
All even-remotely-physically-plausible forms of interstellar travel are also
intrinsically planet-busters, including the various exotic FTL drives that
hover on the edge of plausibility.

~~~
hugh3
_A starship is a relativistic projectile that bothers to slow down. If you're
going to smash a planet that acts up, you might as well just cut to the chase.
All even-remotely-physically-plausible forms of interstellar travel are also
intrinsically planet-busters, including the various exotic FTL drives that
hover on the edge of plausibility._

Sure, but they might not be complete dicks. They might not want to kill us
unless we're a threat to them.

The more I think of it the more unlikely the kill-everyone-immediately
strategy seems. Suppose you're Robinson Crusoe. You've been all alone on an
island for five years. One day you're out hunting and you see another human.
Do you pull out your gun and shoot him in the head before he can do the same
to you? Or do you take the calculated risk that he _isn't_ a homicidal quick-
draw champion?

~~~
jjs
That shouldn't be overlooked. A species that is social enough to cooperate and
build a civilization, and curious enough to develop science, might stay their
hand out of loneliness or curiosity.

 _OR_

Or perhaps this is a grim answer to Fermi's Paradox: the galaxy is quiet
because someone preemptively wiped out the competition a long time ago.

~~~
hugh3
_Or perhaps this is a grim answer to Fermi's Paradox: the galaxy is quiet
because someone preemptively wiped out the competition a long time ago._

Except us?

~~~
chc
I think the implication is that we're (possibly alone) among the first crop of
life to spring up since this hypothetical galactic holocaust.

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patio11
This whole issue is like Aztecs worrying that Quetyzcoatl is going to burn
their villages if he sees their smoke signals, in between the human sacrifices
and general non-white-Christianness which got them into trouble when an
advanced civilization they couldn't have predicted but which actually existed
knocked on the door.

I do not want to insult Quetyzcoatl by comparing likelihood of his existence
to that of space aliens. Evidence of winged serpent gods is lacking, but since
the Drake Equation means that anything which makes for a good sci-fi novel is
good enough to write a grant proposal for, I suppose I should cover my bases.

------
VengefulCynic
I find interesting to note that Shostak doesn't take the time to debate
Hawking on the potential dangers of extra-terrestrials but rather claims that
deliberately attempting contact poses no additional risks. I will certainly
claim no expertise on the subject of contacting extra- terrestrial life, I
will note that directed broadcasts will reach far more star systems than
background RF radiating off of the Earth, all else being equal.

------
ericb
I think our fears are unfounded. Development following an industrial
revolution is so fast compared to the time scales involved in interstellar
travel that we are unlikely to have anything of interest to a society even 500
years "older" than ours. It is somewhat akin to a three year old worrying
about a sixteen year old wanting their tricycle.

~~~
omgsean
I don't think the concern is about other societies wanting our tricycles, it's
about them wanting our water.

~~~
hugh3
Water? Water is one of the most common non-hydrogen, non-helium substances in
the universe. There's several Earth masses' worth of water in the Oort cloud
alone, and don't get me started on the interiors of Uranus and Neptune. The
piddly amount of water in Earth's oceans is worth nothing.

~~~
chc
Our water is much more accessible than the interior of Neptune. Even for a
species with relativistic technology, I doubt delving into a gas giant will be
completely trivial (kind of like the bottom of the sea is still a very
inhospitable place for us).

~~~
hugh3
Which is why I said "don't get me started" on them. Every solid body at or
past Jupiter orbit is, however, something like 30%+ water ice.

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VBprogrammer
You know, strange as this may sound, the length of a human life is but
nanoseconds when looked at on galactic scales, I think I could live with
having life cut short with the trade off that I'd die knowing the answer to
the question is there anyone else out there.

~~~
hugh3
The thing about having the Earth hit by a relativistic projectile is: you
wouldn't die knowing that. You'd just die.

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bombs
_Detecting this leakage radiation won't be that difficult. Its intensity
decreases with the square of the distance, but even if the nearest aliens were
1000 light years away, they would still be able to detect it as long as their
antenna technology was a century or two ahead of ours._

How? If radio waves travel at the speed of light and the first radio
transmitters were in operation in the late 1800's, this would mean that the
transmissions would be no further than 150 light years or so.

There are stars in this range, sure, but I'm interested in how antennas
outside of this range might be able to pick up the signal.

~~~
eavc
He means that the signal would still be detectable 1000 light years away.
You're right that we're a long time away from that being a possibility.

------
s_m
At the present rate of ecological calamity, I'd be more worried that aliens
_won't_ find us.

------
jbgoddard
I really can't take aliens seriously. But thanks for the laugh imagining
aliens watching I love lucy.

~~~
shasta
Someone should make an alien invasion movie where all the aliens are disguised
as characters from "I Love Lucy." A serious one.

~~~
stcredzero
Futurama already did a show where aliens invade because they want to find out
what happens an a show that's a lot like Ally McBeal.

