Article: Aliens need a lot more time to find us

Aliens need a lot more time to find us
20 January 2007
"SO, WHERE is everybody?" Nobel laureate Enrico Fermi reportedly quipped to fellow physicists in 1950, when discussing why we haven't seen any signs of alien civilisations if, as many believe, our galaxy is teeming with life. Now, a maths model may have an answer to Fermi's paradox.

Rasmus Bjørk of the Niels Bohr Institute in Copenhagen, Denmark, has calculated that eight probes - travelling at a tenth of the speed of light and each capable of launching up to eight sub-probes - would take about 100,000 years to explore a region of space containing 40,000 stars. When Bjørk scaled up the search to include 260,000 such systems in our galaxy's habitable zone, the probes took almost 10 billion years - three-quarters the age of the universe - to explore just 0.4 per cent of the stars (www.arxiv.org/astro-ph/0701238v1).

So, Bjørk's answer to the Fermi paradox: aliens haven't contacted us because they haven't had the time to find us yet.

He adds that the search could be optimised by visiting only those stars that harbour habitable planets, which could be identified by planet-finding missions such as NASA's Terrestrial Planet Finder. Bjørk is also "cautiously optimistic" about listening out for aliens with radio telescopes.

From issue 2587 of New Scientist magazine, 20 January 2007, page 15

Source: NewScientist
http://space.newscientist.com/articl...mg19325875.100

Comment:
Our television broadcasts of the 1950s have travelled over 50 light years thus far - aliens in that range will be judging us by such gems as 'Here's Lucy', 'The Honeymooners' and 'The Howdy Doody Show'.

Posted by
Robert Karl Stonjek

Maybe they are watching various science fiction flicks and know just how we
will treat them, especially if they land in Washington, D.C., or in a
trailer court in the Midwest. And, if they land in Japan, they'll have
Godzilla to contend with. Will E.

"WillE1" wrote in message
...

Maybe they are watching various science fiction flicks and know just how
we
will treat them, especially if they land in Washington, D.C., or in a
trailer court in the Midwest. And, if they land in Japan, they'll have
Godzilla to contend with. Will E.



On the other hand, since we already have all these terrible monsters on our
planet, they may consider this a suitable place to dispose of theirs. Thus
they'll send us a ship load of Godzillas etc.

Robert

You sure about that? I haven't seen any Godzillas lately. Just the
usual wackos and nutjobs...

Saul Levy


On Sun, 21 Jan 2007 07:05:40 GMT, "Robert Karl Stonjek"
wrote:

"WillE1" wrote in message
...

Maybe they are watching various science fiction flicks and know just how
we
will treat them, especially if they land in Washington, D.C., or in a
trailer court in the Midwest. And, if they land in Japan, they'll have
Godzilla to contend with. Will E.



On the other hand, since we already have all these terrible monsters on our
planet, they may consider this a suitable place to dispose of theirs. Thus
they'll send us a ship load of Godzillas etc.

Robert

"Saul Levy" wrote in message
...
You sure about that? I haven't seen any Godzillas lately. Just the
usual wackos and nutjobs...

Saul Levy


I assumed that they gained their impression of Earthlings through
electromagnetic trasmission, such as television. The rash of such movies
televised in the 1960s would lead them to a particular view of
earthlings....twilight zone etc.



On Sun, 21 Jan 2007 07:05:40 GMT, "Robert Karl Stonjek"
wrote:

"WillE1" wrote in message
...

Maybe they are watching various science fiction flicks and know just
how
we
will treat them, especially if they land in Washington, D.C., or in a
trailer court in the Midwest. And, if they land in Japan, they'll have
Godzilla to contend with. Will E.



On the other hand, since we already have all these terrible monsters on
our
planet, they may consider this a suitable place to dispose of theirs.
Thus
they'll send us a ship load of Godzillas etc.

Robert