Milky Way Star Births May Have Influenced Life

eldavojohn writes "Space.com has an interesting article that speculates that the period when our galaxy was giving birth to stars resulted in huge fluctuations and impact on earth. From the article, 'Some 2.4 billion years ago when the Milky Way started upping its star production, cosmic rays — high-speed atomic particles — started pouring onto our planet, causing instability within the living. Populations of bacteria and algae repeatedly soared and crashed in the oceans.' Causes one to wonder what the probability for life arising on a planet is given that our own seemed to be in a very unique situation on many different counts."

Comments

Probability theory

[PhotoJim]

Even if the chances were one in a billion or one in a trillion, the sheer number of stars and planetary systems in the galaxy (and indeed the universe) make it entirely unlikely that there *isn't* life out there somewhere. Humans seem to want to be perceived as being special on both an individual and a collective level. We don't really want to accept being common or normal or average. There is life out there somewhere. We'll never find it because of the distances involved, but I am convinced it's there. I think we beat huge odds to get here, but there are still huge numbers of other civilizations that beat similar odds.

Re:Probability theory

[aliendisaster]

I don't see how Humans would cease to be special on a individual or collective level when we discover life outside of our own solar system.

Most people will agree that humans are still special even if we find an advanced civilization outside our solar system. However, the majority of Christians (and other religions) believe we were placed here by a supreme being in his likeness and the whole universe is ours and ours alone. The idea of another race of beings on another planet would basically shatter the definition of life created by the church.

Re:Probability theory

[Shakrai]

Most people will agree that humans are still special even if we find an advanced civilization outside our solar system. However, the majority of Christians (and other religions) believe we were placed here by a supreme being in his likeness and the whole universe is ours and ours alone. The idea of another race of beings on another planet would basically shatter the definition of life created by the church.

I think that most Christians (and other religions) could accept the concept of life beyond Earth without having their faith completely shattered. Hell, the Catholic Church is more or less accepting of evolution as a concept (though "guided" by God as they say). The Fundies might have a problem with it, but then, what don't they have a problem with?

A long time ago

[franksands]

2.4 billion years ago, cosmic rays travelled through space to create this first post.

Not too much different from other changes

[Josh Lindenmuth]

In general, any period of time where there is massive stress on a population would likely see rapid evolutionary changes. Whether it's volcanos, or asteroids hitting the planets, an ice age, or interstellar radiation, the effect is basically the same - an initial decimation of existing populations with amazing biodiversification thereafter.

Re:Not too much different from other changes

[Konster]

So....what's going to happen after Bush is out of office?

100 Billion

[Gotung]

To borrow a theme from Carl Sagan.
Estimations are that there are 100 Billion stars in our galaxy. Thats:

100,000,000,000 -- Let's say 1 in ten of those are in a good region of the galaxy (not a bunch of cataclysmic crap going on)
Thats: 10,000,000,000 -- Let's say 1 in ten of those have planets.
Thats: 1,000,000,000 -- Let's say 1 in ten of those have a planet in the stars habitable zone
Thats: 100,000,000 -- Lets say 1 in ten of those have adequate amounts of water
Thats: 10,000,000 -- Lets say on 1 in ten of those simple life arises.
Thats: 1,000,000 -- Lets say on 1 in ten of those complex life develops.
Thats: 100,000 -- Lets say on 1 in ten of those intelligent life develops.
Thats: 10,000 -- Lets say on 1 in ten of those advanced civilization pops up.
Thats: 1000

10,000,000 planets that foster life, and 1000 advanced civilizations.

I think the chances are pretty good. :P

Re:100 Billion

[CmdrGravy]

The trouble is that the Universe is maybe 17 Billion years old and although we have no figures on the length of time you can expect an intelligent species to survive for it's probably a small fraction of 17 Billion. It's likely that intelligent species will not have the capability for space travel or inter-stellar communication for their entire existence which cuts the percentage down further.

The rate at which a species can expand through the galaxy is likely to be quite an awful lot slower than the maximum speed of whatever craft they have developed so for us to ever be aware of anyone else in the Universe we'd have to have arrived in a similar time frame and be very close to them spacially. It's possible there may be a fantastic co-incidence and a probe or exploration vehicle come across us but really the universe is so huge both us and them would need huge blocks of inhabited space which would at some point need to intersect.

Re:100 Billion

[shma]

The problem is that there's no reason one of your 'one in ten' couldn't be '1 in a billion', in which case, you only have a one in a million chance of developing an advanced civilization per galaxy. For starters, there's no reason to believe that 10% of planets in stars habitable zones will have an adequate amount of water. In fact, we don't even know what a reasonable estimate of an adequate amount of water IS (certainly nothing more specific than "no more than what we have"). We have no way of knowing how likely it is that any kind of complex life forms from simple life, or intelligent life forms from complex life, simply because we've only had our own planet to study, and we're the only intelligent life on it.

And then there's the problem of coexistance. If advanced civilizations live only on average for a million years (still ~100 times longer than us, depending on your definition of 'advanced'), than the probability that two such civilizations would overlap is extremely tiny. Remember, our earth is over 4.5 billion years old, and life giving stars have been around for even longer.

Personally, I think the chances of finding other life in the galaxy are very low.

Insert God Jokes Here

[TubeSteak]

Humans seem to want to be perceived as being special on both an individual and a collective level. We don't really want to accept being common or normal or average.

As God once said to his pangalactic dominion: All Your Base Are Belong To Us.

Fermi Paradox

[benhocking]

Let's say 1 in 10 of those decide to start colonizing other star systems with generational ships. Where are they?

Rare Earth ? Think again...

[wikinerd]

what the probability for life arising on a planet is given that our own seemed to be in a very unique situation on many different counts

The probability of life appearing on a planet may be high, and our planet's situation may not be as unique as you think. I study Planetary Science at the Open University (UK) and the fact that they decided to couple lessons about the search for life in the, primarily geology-themed, planetology course has to say a lot about what scientists think of the Rare Earth Hypothesis.

It is, however, natural that some people think that Earth is unique, as it is the only living planet we know of. Sure, your first lemonade was unique, your first PC was unique, and your first GNU/Linux distro was also unique.