Special Conditions

I was talking in the last post on this topic about the improbability of the "information" required for life coming about by chance. However, there is something that needs to come first - that is the conditions need to be in place under which the appropriate chemical processes can take place in order to for that information to be encoded in some way and for some kind of living "thing" to be formed.

In other words we need the following:

• A mix of chemicals that supports the formation of molecules that could potentially combine to form a living thing (including encoding that "information").
• The right conditions for the chemicals to form themselves into those molecules and for those molecules to combine together into the living thing.
• Laws of physics and chemistry that support the very possibility of the formation of those molecules in the first place as well as their combination into that living something.

Let's look at these in a bit more detail...

Firstly, there's that mix of chemicals. A number of experiments have been done over the years to determine what the mix of chemicals and environmental conditions would need to be in order for the basic ingredients of life to be spontaneously synthesised. The most famous of these is known as the "Miller-Urey experiment" which was seen by some as "scientists creating life in the lab".

In reality, what they actually achieved was to generate monomers (amino acids). However, what was less well known and reported was the fact that they also generated a number of chemicals that would have prevented those monomers from combining to form polymers (which is what would really be needed to build some kind of cell or something like that). They also generated some other chemicals that would be likely to react with the very amino acids that had just been formed (thereby destroying them).

That was not the only such experiment, of course. There have also been other similar experiments using different mixes of chemicals and conditions. However, they have not been (as far as I can gather) particularly convincing either in terms of the molecules actually formed (in comparison to the actual molecules we find in living things) or in terms of the likelihood of that kind of environment actually being able to exist for any length of time on a planet like Earth.

That's not to say that there isn't some combination of chemicals and conditions that would work - maybe one of those is correct and we just haven't got the details thrashed out, or maybe we just haven't thought up the right mix yet. However, what is certainly true is that we would need very specialised and specific chemicals and conditions.

Which brings me to my next point: in order to have the right conditions, we would need a very specific planet on which to synthesize our living thing. For example, if the Earth were closer to the sun it would be too hot to have liquid water (a pre-condition for life as we know it). Similarly, if it were further away it would be too cold (water would freeze). Both of which would be a bit of a show-stopper for carbon-based life.

So, not only to we need to have the right mix of chemicals, but we need them to be on the right planet. Right chemicals but wrong planet? No life (bad luck). Right planet but wrong chemicals? No life. You need to have the right mix of chemicals with the right conditions on the right planet.

Finally there are the laws of physics. This one is, perhaps, a little less obvious at first, but the fact is that the laws and constants that govern how the universe works need to be "fine tuned" in relation to one another in order for it to be possible for chemicals to exist and combine in a way that makes life possible. For example, if gravity were a little stronger (and everything else stayed the same), anything that was complex enough to be life would be too heavy to move. We, for example would not be able to stand up, and (depending on how different) would be crushed by our own weight.

And gravity is only one of those things. There are all sorts of laws and constants that need to be in balance with each other or it becomes impossible for any kind of life to exist. Things like the size of atoms, the speed of light, the value of Pi, the charge held by electrons, the fact that when you apply a force to something it accelerates at a certain rate, etc. etc. If these things weren't all nicely in balance with each other then it would just not be possible for any conceivable kind of life to come into existence. In fact, a New Scientist article (24 May 1997, pg 39) suggested that the probability of all the laws and constants being balanced, by random chance, in a way that supports the existence of any kind of life is about 1 in 10²²⁹ (another one of those not-so-likely events like we had in the "Hello World" post).

So, in summary, quite apart from the probabilities involved in forming the information needed for life, there is the problem of the fact that we would need to have these very specialised and specific conditions. It's not something that could happen any old day on just any old planet in just any old universe. There are an awful lot of things that have to all be just right.

Note: This is part of a series of posts about why I believe in God. See my post "You Believe that Stuff???" for more info and links to the other related posts.