Monday, January 05, 2009

Fine tunning the universe

It seems I’m starting a series on dispelling falsehood propagated to undermine science and promote religious dogma as the explanation for natural phenomenon despite the evidence. On future post I will talk about cosmic and stellar evolution and show that even if it cannot be completely observed, we have enough evidence to conclude in it’s existence or at least to know that our theories and hypothesis are adequate enough model of reality. In this post tho, I’ll talk about the idea that the universe is fine tune for the existence of life.

The argument goes roughly as such: if you change any one of a number of universal constant (such as the charge of the electron, the gravitational constant, the fine structure constant, the speed of light, etc.) life becomes utterly impossible in our universe. For example, elementary charge (the electric charge carried by an electron or a proton) was a little higher or lower, atoms would be unable to form, as electron would rapidly spiral into the nucleus or not be attracted enough to the nucleus to form an atom at all. At first glances a good argument for the design of the universe by some intelligence to eventually produce life.

Note, from the previous two posts you probably already guessed that this first glances is not the end all be all of this. First, let’s talk about something a little known fact, humanity exist. Surprising I know, but bear with my sarcasm for a second. Suppose that the particular set of constant we observe in the universe is one that allows the possibility of the human life is not the only one possible. Now, let’s have pure randomness determine every single constant in the universe. Given that only one set will produce humanity, the only set where humanity will be around to observe is the set we are in. Even if all the values are taken at random, if fact there is no reason that an infinite number of other space time with other fundamental constant do not exist, each one of those without humanity and as such without anyone to ask the question: “Why are all those constant at the right value for human life”. In short, the fact that we exist to ask the question: “how or why are those constant existing with those value” is not a valid reason to invoke an intelligence, pure, complete random luck could produce the exact same result without the need of a directing intelligence.

Now, I know that the previous argument isn’t going to be standing very strong with most people, and it is logical. It’s much easier to think that something was put there with a purpose in mind then to figure we are nothing special. This why I like this second argument better. You see the fine-tuning of the universal constants is a lie. The fact that if you change the value of only ONE constant life become impossible is true, however it is only true if you change ONLY ONE constant. You see there are many way to have an universe almost exactly like our own without using the exact same physical constant. To retake the elementary charge as an example, if in addition to a change in the elementary change you have slight change in the coulomb constant and in the strength of the weak nuclear force you can build another universe that should look a lot like our own. The fact is that our set or value for those universal constant is just one of many that allows for the possibility of matter and probably the possibility of life.

A third thing to consider is the other lie in the opening argument, that life becomes utterly impossible. It is only true in the meaning that life as we know and experience it as human being probably becomes impossible. Science-Fiction writers, dreamers and scientists have conceived form of life based on other chemistry and other biologies for years now, true that not the same as life based on other physical principles but given the challenge I’m pretty sure someone could conceive a way to create life out of a very alien universe. And if we can conceive a way for life to exist in such an alien place, there a good chance that if such a condition existed there would be life there. Cause you know, up to now, humanity has found life everywhere it didn’t expect life to be possible except outer space and other planets. And even there, they are mounting evidence that life could have/has/or will exist one day.

Think about this, scientists are seeing evidence that the condition of the small floating rock known as Mars were once fertile ground for the devoleppement of life. Scientist know of spores that could survive the vacuum of space and being irradiated with cosmic rays for thousand if not millions of years and still produce living organism if introduced in a adequate environnement.

One last thing about the fine tuning, it’s not that fine. While some universal constant values have a very narrow range that is favorable to life most can change quite a lot without any adverse effect on life. Take for example the distance from the Earth to the Sun varies by about 5 millions km twice in a year. The habitable zone around the sun is only about 120 millions km wide, with the Earth orbit around the middle slightly closer to the inside edge. To give you an idea that Earth is only 12 000 km wide, that means you could fit 10 000 other Earth in the habitable zone of our sun! And that only if life is impossible on Mars and Venus which would expend the habitable zone dramatically. So you see, the fine tuning isn’t that fine, it more like gross approximate tuning, or rough tuning, or well you know a your lucky if it works tuning.

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