== Love God == Delight in Light ==

Sunday, March 09, 2008

Hello World

"How did life begin?"

At some point in the dim and distant past there was no life. Then something happened, and after that something, there was life.

The question is: What was that "something"? And what could have caused it? And, most critically, how likely (or unlikely) was it to have happened?

I'll sort of touch on the first two of those questions in a later post. For this one I want to constrain myself to talking about the last one.

There are various definitions of "life" (typically they talk about the ability to respire, reproduce, etc.). However, to me, when thinking about how life may have originated, a key consideration is information. For life to exist for an extended period (i.e. in order to be able to reproduce, eat, etc.) there needs to be information that is passed from one generation of that life to another (so that the life continues to the next generation).

In all life that we know of, that information is passed by genes (DNA and / or RNA). Genes are, in effect, a way of writing down information using an "alphabet" of 4 "letters". The "letters" are specific types of molecules - these are arranged in specific arrangements in the gene in order to code the information - just like letters are arranged in a certain order to encode information in writing (like this text you are reading right now).

Another place where information is often encoded is in computers. In this area, there are just two "letters" (0 and 1) which are arranged in specific orders to encode information.

Now, a couple of years ago, my brother-in-law and I were talking about how possible it would be to randomly generate a copy of Microsoft Word (I think we were using version 2000 at the time - licensed copies, I hasten to add!). The theory was that if you could randomly generate the relevant files, presumably you would be able to use it for free.

This hypothetical idea caught my interest, and I decided to have a go at working out the probabilities. However, rather than starting off trying to generate the whole of Word, I thought that (in the tradition of people learning to write programs) I would start with trying to generate the following simple Java program:

public class h
public static void main(String[] a)

To do that I made that assumption that I had another program that was capable of generating random 0s and 1s into a file of the correct length at a rate of 1000 attempts (i.e. complete files) per second. How long would it then take to generate that program?

I was surprised at the result.

I'm not sure what your estimate would be, but before I started, I had assumed that the answer would be in the order of 10s of years - i.e. if I set it off now, then I would get a result sometime in the next, say 20 to 50 years.

How wrong I was.

According to my calculations, I found that - get this - even if every atom in the known universe was itself a universe, and each atom in each of those universes was a computer generating 1000 files per second, it would still take about 5 billion billion years before I would be likely to generate a program similar to my simple "hello" program (never mind exactly the same as it).

That's quite a while. In fact, it's about a billion times as long as the earth is supposed to have been in existence (claimed to be around 4.6 billion years).

It also requires quite a few more computers than I have at my disposal at the moment.

So the long and short of it is we can forget about generating that program. And we can certainly forget about generating Microsoft Word which is vastly more complex than that.

This all lead me to think about the amount of information that would be required for the very simplest living thing. The answer was, at best, several times more than the amount of information in that program code (again resulting in vastly lower probabilities).

Something that improbable would, of course, normally not even be considered as an option. And I mean not even considered. Like - you would send me to the loony bin if I suggested it.

So, I ask myself, is it reasonable to consider it as a possibility for the origin of life?

Or, to put it another way: is it unreasonable to at least consider the possibility of an alternative explanation?

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.

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