Giving a speech on why life most likely exists in the cosmos. Need Help.

[lifeinthecosmos]

Hey all,

 

I'm taking a speech class this quarter and for the persuasive speech, I submitted my topic as 'Why Life Most Likely Exists Elsewhere in the Cosmos'.

 

Whether it be microbial life or actual sentient life with comparable or greater intelligence, I'm not sure, but with the sheer size of our galaxy (400 billion stars) along with the size of the universe itself, filled with outrageous amounts of galaxies, the probability for at least some kind of independent development of basic microbial life seems great.

 

So, one of the main reasons for me is the fact that we evolved. We're the products of (roughly) 13.7 billion years of cosmic evolution. Therefore, seeing that we're already discovering significant amounts of extra solar planets, it seems that the development of planets is common (at least in our galaxy), which increases the chance for small, rocky worlds to be located in the goldilocks zone for various stars, increasing the chance for liquid water and, subsequently, microbial life to develop.

 

Furthermore, we've even recently discovered (rather roughly) some small planets that, seemingly, have water on their surface (wasn't there that news article a bit ago about the recent planet that they detected water on as well as the megaearth article?). I know the majority of the extrasolar planets are Jupiter-sized, but it's really just the fact that our current methods for planet searching are not technologically advanced enough to zoom in on comparatively small planets at incredible distances from our lonely point in the cosmos.

 

So, really, it's about the size of the cosmos, the fact that humanity has consistently tried to make it seem like we're the only ones on this grand cosmic stage, the fact that evolution simply begs us to consider that life evolved elsewhere in this enormous thing we call the universe...and... I guess that's about it. It just seems odd to think that we're the only ones.

 

However, I know there are some theories out there. Was it called the 'anthropic principle'? Something like this. The idea that the development of earth required too many variables to be perfect -- that the cosmic lottery requires so many 'numbers' to be right, it demands us to say the earth is the only planet hosting life in the cosmos. Not sure if I have the principle completely correct, but basically, it's saying that things like the alignment of the barrier planets (correct terminology?) is perfect to stop too many things from hitting earth, thus allowing it to develop life, etc etc.

 

How are those in the anthropic camp doing? How have things evolved?

 

Finally, this speech has to be between 5 to 7 minutes, so I'm just going to touch on the most fundamental reasons for why life (be it microbial or more developed) most likely exists in the cosmos. Crunch time is coming and I just haven't had the time to do all the independent research I wanted, so I was wondering if I could get some input here from people who've thought about it more. What would you consider the fundamental reasons, and perhaps, play devil's advocate, considering what might be strong arguments against the hypothesis.

 

Thanks all.

[Mr Skeptic]

Well as you know, the sheer size of the observable universe (and there could very well be an infinite universe but the observable part is limited), the number of stars, of habitable planets, all that is a good start. On Earth, life started almost as soon as conditions became tolerable for life, so that suggests that abiogenesis is not as difficult as might seem. There's also the theory that life arrived on earth via space traveling microbes, although that seems to be less popular nowadays.

 

The anthropic principle in my opinion is rather silly, since of course we live in a universe in which we can live in.

[vordhosbn]

To better express the hugeness of the cosmos, you can try to use a metaphor, so people can immagine it better.

Also, i think it's a good idea to present some types of extermophiles, to show how life can exist in very hostile environment.

Good examples are:

http://en.wikipedia.org/wiki/Deinococcus_radiodurans

http://en.wikipedia.org/wiki/Strain_121

http://en.wikipedia.org/wiki/File:Cryptoendolith.jpg

 

It seems life occupies almost every possible environment, where it can draw energy from...

Do you think that it could be possible for some kind of lifeforms to exist in stars... or the matter there is too "dynamic" to allow for any kind of organization?

[shakes]

You could always use the Drake equation, and demonstrate how new findings flush it out a bit. That ought to take up 5-7 minutes.

[ydoaPs]

You could always use the Drake equation, and demonstrate how new findings flush it out a bit. That ought to take up 5-7 minutes.

[shakes]

Yeah, an oldie but a goodie. Drake's equation is purely speculative, but any hypothesizing about exterrestrial life would be. Although scientifically useless it does have a value in that it helps define the parameters of the argument, which is all it was ever meant to do. And it's appealing to layman for it's simplicity.

[Mr Skeptic]

You could always use the Drake equation, and demonstrate how new findings flush it out a bit. That ought to take up 5-7 minutes.

 

Related to that, the Flake Equation:

[pioneer]

Life on earth is dependent on water. Water, in turn, is the second most abundant molecule in the universe, second only to hydrogen. Relative to atoms, the top four atoms of the universe are hydrogen and helium, then oxygen and carbon. Nitrogen is about number eight in relative abundance behind neon and iron. The universe has the basic materials for life at top of its atomic and chemical food chain.

 

The only key atom of life, that is not as abundant as the big four (H,O,C,N) is phosphorous. This atom is needed for DNA, RNA, ATP, etc., As such, based only on the abundance of atoms, one would expect proteins and possible enzymes to be orders of magnitude more common in the universe than genetic replicators. This is still possible but much less likely than proteins.

 

[ianhowson]

The first question we should ask is not 'Is there intelligent life in space?'.

The first question should be 'Is there intelligent life on earth?'