What are the chances of that?

[JOEYSHABADO]

There's a list going around of all the factors you need to put together to end up with human life on earth (gravity, the 'magic constants' etc/) Anyone have the list? ty.

[jake-the-peg]

This sounds like a modernisation of the Drake Equation which attempts to calculate the probability of intelligent life that we could communicate with:

http://www.planetarysystems.org/drake_equation.html

There is an issue regarding the so called "tuning" of certain constants to values necessary for life - however I think the current philisophical problem is with one particular constant - the cosmological constant who's tuning appears to vastly out-weigh all the others.

If you look up cosmological constant and tuning on Google you'll find an awful lot of stuff from sophisticated analysis to religious nuts - enjoy 

[JOEYSHABADO]

so u mean jake that the chances of the cosmo constant being just what it is, and not a little out which would not be any good, is much lower than the other constants?
Is there a good refutal of the idea of this probability?

[jake-the-peg]

Well the popular thing at the moment is the whoe concept of a <air quotes> multiverse </air quotes>

This idea is that our universe is only one of trillions upon trillions each with slightly different laws of physics the vast majority of which cannot end up with stable matter let alone life. We live in one of the very few that can produce life - if we didn't we wouldn't be here to observe it.

I don't like this because it takes us out of the realms of physics into philosophy there being absolutely no prospect of ever being able to prove it one way or another.

The basic underlying issue is that we just don't know how the various physical constants came to be set the way they were. It may be that there were other factors influencing them that we have no clue about - After all looking at a tree the chances of all those atoms and molecules coming together in just that way seem incredible - until you learn about evolution.   

Either way the religious community have the same problem. After all - who created God? "He's always been there" or "It's a mystery" are pretty pathetic answers      

[JOEYSHABADO]

Lots of probability in science, so I guess we can start from that and work out. Very unlikely for humans to exist as we do (from Gravity to the northern lights all being needed). But we do exist. So either it was designed, or there are lots of universes. The chances of this being the one universe and us having come about by chance are just so small, as to be rejectable.
So there were lots of universes, would be my better guess.
I'm gonna go back 500 years now in my time machine and explain human biological evolution to some scientists back then. I'm afraid they won't understand me, because they won't even know what genes are, or have any concept of how that could work. Similarly, I think we are trying to say 'We can't understand it now, with physics, so it must be a mystery, or outside our reach', whereas in fact we may discover something about fundamentals, or strings, or chance, or creation of universes, or the fabric of reality, that will make us understand these things.
What we need now, then, are 'fools': people who think differently from everyone else.

[JohnDTC]

i find the multiverse theory very plausible. & the fact is there is so much in physics we dont understand that philosophy has to play a part. there is no way yet to prove string theory, there are still disputes as to the nature of strings & how many dimensions they vibrate in. surely a lot of science begins as a theory without proof based on observation -a philsophy, which is then proved, explained & repeated in experiment, which then becomes science.

also, ALL science is based on probability & chance, scientific laws are really just an approximation of average results. logic says that if you ran at a solid brick wall you would break your nose &do yourself a mischief, but it is a scientific fact that is actually possible to run straight through it, with the all the atoms avoiding collision - the probability of it happening is infitesimally small, but it is possible.

[jake-the-peg]

You'd want to be very careful about "chance".

Say the probability of being born with blue eyes is 1 in 5 and the probability of being born blond is 1 in 10

Now what is the probability of being born with blond hair and blue eyes?