- The main questions: Are we alone
or is there intelligent life elsewhere?
- Need to ask first: How could
we find out if it is out and there? How can we communicate?
Where Could Intelligent
Life Possibly Develop?
- First conditions: Existence
of extrasolar planets (we now know there are lots of those);
Environments suitable for life (life in general, we haven't found
those yet, but we have found planets with atmospheres, and there
are ideas for how to go further).
- Additional conditions: In addition
to life existing on a planet, what is the likelihood that it
develops into intelligent forms and civilizations?
- How many civilizations might exist
in our galaxy? Use the Drake equation to estimate it theoretically;
Optimistic result: As many as the average lifetime of a civilization
expressed in years; Carl Sagan estimated about 1 million in our
galaxy, one every 50 pc!
Communications and Contact?
- Detecting signals – SETI: Some
radio telescopes are listening (What was the 1977 "Wow!"
signal?); Our best bet is around 18-21 cm waves; Project Phoenix
was ended without a signal, but there are other searches; An
optical SETI telescope has started operating at Harvard, looking
for brief flashes of light.
- How can we reach out? Interstellar
travel? Takes far too long. Send out probes? Already done (Pioneer
10, Voyager); Send radio waves? In 1974 we broadcast a radio
message to space, and we're waiting; Also, we may be contributing
to future life elsewhere by leaking out our own, panspermia-style.
- Contact? No real evidence yet
of extraterrestrial presence on Earth (despite some relatively
SETI could succeed tomorrow, or it may be an endeavor for multiple
generations: We are a very young technology in a very old galaxy;
Our own leakage radiation outshines the Sun at many frequencies,
and we are detectable to others; When our use of the spectrum
becomes more efficient, it will be time to consider deliberate
transmissions and the really tough questions: Who will speak
for Earth? What will they say?
So far, though, the conclusion is: "We live in a quiet
neighborhood" (Peter Backus, Seti Institute).
page by luca bombelli <bombelli at olemiss.edu>,
modified 29 sep 2012
"This porridge is too hot," Goldilocks
So she tasted the porridge from the second bowl.
"This porridge is too cold."
So she tasted the last bowl of porridge.
"Ahhh, this porridge is just right!" she said happily.
And she ate it all up.
"Goldilocks and the 3 Bears" children's