| Author |
Message |
    
Pine
flint knapper
Username: Pine
Post Number: 1285
Registered: 5-2003
| | Posted on Thursday, November 16, 2006 - 9:37 pm: |     |
Milky Way Shaped Life On Earth
A time of concentrated star formation about 2.4*10^9 years ago caused a huge increase in cosmic radiation reaching earth. This caused fluctuations in the biosphere's productivity.
quote:Most likely, the variations in cosmic radiation affected biological productivity through their influence on cloud formation. Hence, the stellar baby boom 2.4 billion years ago, which resulted in an extraordinarily large number of supernova explosions, had a chilling effect on Earth probably by increasing the cloud cover.
Cohen's Law: 'Unless you fail at more than 10% of the things you try, you aren't trying enough things.' |
Scott
flint knapper
Username: Scott
Post Number: 1622
Registered: 5-2003
| | Posted on Monday, November 20, 2006 - 2:19 am: | |
Thanks Pine.
Indeed supernova are probably responsible for life being wiped out on a lot of planets, not simply slowed down. Those supernovae were not close enough to do this 2.4 billion years ago.
I didn't realise the link between cosmic rays and cloud formation though!
So, God wanted to slow down the evolution of single celled organisms and wasn't in the area, being tied up elsewhere, so he caused a lot of supernovae in a stellar nursery a few billion years ago. Hey, isn't this evidence of God? 
Scott
~ ~ ~ ~ ~ ~ ~ ~
Ces gens, Jondalar, ils sourient. Ils me sourient. - Ayla |
Cavebear
cave painter
Username: Cavebear
Post Number: 3065
Registered: 9-2003
| | Posted on Monday, November 20, 2006 - 8:06 pm: | |
Pine, I think this shows that the universe is not so much "stranger" than we can imagine it be so much as it is "more complex" than we imagine it to be.
Astrologists were correct; the stars affect our lives. Not in the way they imagined, but in possibly stronger ways. I have read several times over the years of suggestions that supernovas can seriously damage life on Earth.
The star Sirius is 8.6 light-years from Earth. If it went supernova 8.59999 years ago, the effects could reach us tomorrow. And we wouldn't have a clue it was about to happen until it did happen. As best I understand it, it would be like a neutron bomb striking the entire surface of the Earth.
I had never read about a connection between farther supernovas and Earthly cloud formation, though. That is very interesting!
Thank you, Carl Sagan... |
Per
bear cub
Username: Per
Post Number: 36
Registered: 9-2003
| | Posted on Tuesday, December 05, 2006 - 3:51 pm: | |
I recently saw a Danish science program (Viden Om) with Dr Svensmark, where he explained the cloud fenomena. Waterwapor needs a surface to condensate onto in order to form a cloud, the perfect size being between 200nm. and 600nm. (nano meter) - if memory serves. There are a few surface fenomena that can provide those particles, but the majority are made from molecules syntesized from other molecules, already present in the atmosphere, and they are combined as a result of the cosmic rays. He explained it rather well, it's just my lousy memory, that's preventing me from giving you a more detailed picture - sorry. |
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