Are we alone in the universe - Horizon BBC 1 9pm tonight

[Andy Hamilton]

Going to put the telly on for this in a bit

For fifty years, the Search for Extra Terrestrial Intelligence has been scanning the galaxy for a message from an alien civilisation. So far to no avail, but a recent breakthrough suggests they may one day succeed. Horizon joins the planet hunters who've discovered a new world called Gliese 581 c. It is the most Earth-like planet yet found around another star and may have habitats capable of supporting life. NASA too hopes to find fifty more Earth-like planets by the end of the decade, all of which dramatically increases the chance that alien life has begun elsewhere in the galaxy.

I would have thought it will be on iplayer if you miss it. Looks interesting though.

[Shirley]

Was it good Andy? Worth searching for on iplayer??

[Andy Hamilton]

Was it good Andy? Worth searching for on iplayer??

It was good if you like that sort of thing (which I do), makes you feel quite alone and due to the nature of the subject I think it asks more questions than it answers/

[old tree man]

i think in a universe that has boundrys beyond our comprehension it would be foolish of us to say that we are the only life that exists within it, the thought is totally exciting if not scary, lets hope that if there is "intelligent " life they can teach us to be less aggresive share the wealth of this beautiful planet and care for our fellow human and the wildlife we share it with.

Russ

[Shirley]

Beautiful words Russ!!

[mrsflibble]

Drake's Formula:

N = N* fp ne fl fi fc fL

The equation can really be looked at as a number of questions:

N* represents the number of stars in the Milky Way Galaxy

Question: How many stars are in the Milky Way Galaxy?
Answer: Current estimates are 100 billion.

fp is the fraction of stars that have planets around them

Question: What percentage of stars have planetary systems?
Answer: Current estimates range from 20% to 50%.

ne is the number of planets per star that are capable of sustaining life

Question: For each star that does have a planetary system, how many planets are capable of sustaining life?
Answer: Current estimates range from 1 to 5.

fl is the fraction of planets in ne where life evolves

Question: On what percentage of the planets that are capable of sustaining life does life actually evolve?
Answer: Current estimates range from 100% (where life can evolve it will) down to close to 0%.

fi is the fraction of fl where intelligent life evolves

Question: On the planets where life does evolve, what percentage evolves intelligent life?
Answer: Estimates range from 100% (intelligence is such a survival advantage that it will certainly evolve) down to near 0%.

fc is the fraction of fi that communicate

Question: What percentage of intelligent races have the means and the desire to communicate?
Answer: 10% to 20%

fL is fraction of the planet's life during which the communicating civilizations live

Question: For each civilization that does communicate, for what fraction of the planet's life does the civilization survive?
Answer: This is the toughest of the questions. If we take Earth as an example, the expected lifetime of our Sun and the Earth is roughly 10 billion years. So far we've been communicating with radio waves for less than 100 years. How long will our civilization survive? Will we destroy ourselves in a few years like some predict or will we overcome our problems and survive for millennia? If we were destroyed tomorrow the answer to this question would be 1/100,000,000th. If we survive for 10,000 years the answer will be 1/1,000,000th.

When all of these variables are multiplied together when come up with:

N, the number of communicating civilizations in the galaxy.


curtesy of SETI.

[QuakerBear]

From a religous point of view if we are alone, it makes me feel really special because of the concentration of effort gone to make us. If we're not alone it would make me feel really special for being part of such a varied creation. But then we're already part of a wonderful creation, even if I can't appreciate all of the maths that forms the basis of it .

Hhhmm.

If there is live out there I wonder what types it would include: gas beings, silicone based live forms, hive minds, inteligent fungus? Wow....

[MKG]

Well, you've all had a couple of months to think about it - your eight weeks older and wiser. You've probably realised by now that aliens do exist, they are living on earth, and they are all Ishers.

Live long and prosper.

[ina]

Well, you've all had a couple of months to think about it - your eight weeks older and wiser. You've probably realised by now that aliens do exist, they are living on earth, and they are all Ishers.

Live long and prosper.

We're all little green men and women...

[mrsflibble]

eh?












OOOOOOOOOOOOOOOH yeah. i get it now. too little sleep.

[ina]

OOOOOOOOOOOOOOOH yeah. i get it now. too little sleep.

I know the feeling. Just had to force myself out of bed - didn't get away from work before 3 - and need to do SOME shopping (farmers' market) before it's back to work at 2!