Life in the Universe
(www.max3d.pl/galeria.php)"Damn it Jim, I'm a Doctor not a bricklayer." Bones McCoy
Would we recognize it ?
The Search for Extraterrestrial Intelligence (SETI)
The mission of the SETI Institute is to explore, understand and explain the origin, nature and prevalence of life in the universe.
This is not the BEM syndrome, but some guys actually make up SETI songs.
Life as we know it
Organic - Carbon based / Silicon (?) DNA / RNA
How do we make these molecules?
1950s - Urey and Miller mixed H2O, CH4, NH4 & H2 stimulated this w/ electric sparks
|BINGO! complex molecules that included amino acids
|The problem is that the Earth's early atmosphere probably wasn't like this SO....
|get all 5 essential compounds of the human gene
These match up w/ the Murchison meteorite & meteorites found in Antarctica
|"Primordial Soup" research continues
Other Solar Systems?
We look for
- wobbles (Doppler) in a star's orbit
Only found one by 1995 SS w/ 3 planets - 9 Earth masses it located around a Pulsar, found 2 more planets 1996, over 120 now
N = R* Fp Ne Fl Fi Fc L
- R* - rate of star formation
- Fp - stars w/ planets (or maybe ) and satellites
- Ne - # of planets on which life could survive per solar system
- archaebacteria - no O - use CO2 + H2 --> CH4 & they have different RNA
- "Goldilocks Effect" - .95AU to 1.5AU
- Fl - life arises
- Fi - intelligent life
- Fc - communication w/ other civilization - technology's =
- L - lifetime of a civilization
So if we are going to be optimistic
R* ~ 4 x 1011
Ne ~ 2
Fl ~ 1/3
Fi x Fc ~ 1/100
L ~ 1/107
(note we have only had radio telescopes for 50/ 4 x 109 yrs of Earth history)
Then N ~ 10 some estimates as high as 107
Even if they are out there - they are very far away!
N = 10 --> 10,000 LY apart (100,000 LY Milky Way)
N = 107--> 10 LY apart (assumes equal distance)
How do we talk to them?
Anybody want an old 300 channel receiver?-76k