STEPHEN HAWKING is worried about aliens. The famous physicist recently suggested that we should be wary of contact with extraterrestrials, citing what happened to Native Americans when Europeans landed on their shores. Since any species that could visit us would be far beyond our own technological level, meeting them could be bad news.
Hawking was extrapolating the possible consequences of my day job: a small but durable exercise known as SETI, the Search for Extraterrestrial Intelligence.
Although we have yet to detect an alien ping, improvements in technology have encouraged us to think that, if transmitting extraterrestrials are out there, we might soon find them. That would be revolutionary. But some people, Hawking included, sense a catastrophe.
Consider what happens if we succeed. Should we respond? Any broadcast could blow Earth's cover, inviting the possibility of attack by a society advanced enough to pick up our signals.
On the face of it, that sounds like a scenario straight out of cheap science fiction. But even if the odds of calamity are small, why gamble?
For three years, this issue has been exercising a group of SETI scientists in the International Academy of Astronautics. The crux of the dispute was an initiative by a few members to proscribe any broadcasts to aliens, whether or not we receive a signal first.
In truth, banning broadcasts would be impractical - and manifestly too late. We have been inadvertently betraying our presence for 60 years with our television, radio and radar transmissions. The earliest episodes of I Love Lucy have washed over 6000 or so star systems, and are reaching new audiences at the rate of one solar system a day. If there are sentient beings out there, the signals will reach them.
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.
This makes it specious to suggest that we should ban deliberate messages on the grounds that they would be more powerful than our leaked signals. Only a society close to our level of development would be able to pick up an intentional broadcast while failing to notice TV and radar. And a society at our level is no threat.
The flip side is that for any alien society that could be dangerous, a deliberate message makes no difference. Such a society could use its own star as a gravitational lens, and even see the glow from our street lamps. Hawking's warning is irrelevant.
Such considerations motivated the SETI group at the International Academy of Astronautics to reject a proscription of transmissions to the sky. It was the right decision. The extraterrestrials may be out there, and we might learn much by discovering them, but it is paranoia of a rare sort that would shutter the Earth out of fear that they might discover us.
Seth Shostak is senior astronomer at the SETI Institute, and chair of the International Academy of Astronautics' SETI Permanent Study Group
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There Is No Big Reason To Be Afraid
Mon Jul 05 15:03:13 BST 2010 by Peter
Well from all races out there who would like to visit us?
If they are able to travel to our planet, then they must able to colonize other worlds as well, so they wont get here just for the colonization, other planets would be more nearby for their resource, its no practical to steal earths gold or water or whatsover there is enough of that everywhere. IS it practical to just kill any civilization who emerges in the unviverse no it isnt simple rules of logic dictate there is to much life out there (although not yet discovered).
also some other thing to think of, is it wise to visit us ?
no it isnt we are a species in conflict there is constant war on this planet, why risk a long travel near the speed of light to findout you endup in the middle of a war?
so it might be for most other species be wiser to hide from us until we have proven to be a more friendly species ourselves.
And if they are so advanced they would know us allready, cloacked scout satelites drones or things like that von neuman type scouts etc, they would know us but notmake contact because we are to dangerous to them
they wont risk damaging their hightec spaceship to our rockets / bullits etc, they are not crazy, thats us we are the crazy part of this unvierse, doing all kind of things that dont make sense (we're experts in that)
Very Casual And Misleading
Mon Jul 05 17:22:51 BST 2010 by Will
It beggars belief that a professional scientist can make such a casual statement as the following:
"Since any species that could visit us would be far beyond our own technological level, meeting them could be bad news."
Why make the assumption that such a species would have developed their means of travel through technology? In all likelihood, such a species would not operate within parameters that we can even comprehend.
We Are Entertainment For Them. . .
Mon Jul 05 20:07:42 BST 2010 by Ken
Any civilization that has developed interstellar travel would have no interest in our "resources," since they would be able to create any of them from energy. And our star is too weak for them to bother visiting to extract energy.
The only reason to come here (or to watch us) would be for the entertainment value.
As we switch from analog to digital broadcasting, it will become increasingly difficult to decode our transmissions, since they will look like noise (analog is trivial to decode). This is likely to be the case with any "alien" transmissions as well (unless they are purposefully directed toward us).
So I have to agree with the article and other posters. At this point, it makes no sense to panic about sending out signals. We've been doing it for far too long.
We Are Entertainment For Them. . .
Mon Jul 05 22:20:28 BST 2010 by Mal
I think ET's are probably observing us now as an anthropological project. An advanced species would have had to go through similar growing pains to the ones we are enduring at present, and would probably find us very interesting.
I dought however that they will make direct contact with us until we have overcome our problems, which is still a long way off, if ever.
As for ET's trying to dominate us, as is generally portrayed in SF stories, they simply couldn't have advanced beyond our current point without shaking off the primal aggression we continue to suffer & would have destroyed themselves long ago.
'Klingons simply don't advance far enough to build interstellar space craft, befor blowing themselves up.'
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