Is Our World a "Fluke" of Nature?One of the most important scientific questions that we have not yet answered is : Why are we here? Or of even more importance: how did we get here? And, indeed, if you delve very deeply into the question you soon find that the odds against us being here are incredibly large. One of the major things that showed us this is known as the anthropic principle. It was put forward by Brandon Carter in 1973, and it has continued to cause controversy and confusion amongst physicists and astronomers ever since. It is simply stated as: If the fundamental constants of the universe were different – even by an infinitesimal amount – we would not be here. The earth might exist (or it might not), but it wouldn’t support life as we know it.
What do we mean by fundamental constant? It turns out that our universe has several of them and they include the mass and charge of the electron, the gravitational force (referred to as G), and various ratios between them.
A few of the questions we cannot answer are: Why is the mass of the proton exactly 1,835.153 times the mass of the electron? Furthermore, why is the mass of the electron what it is? In addition, there is the charge of the electron; it’s exactly equal, but opposite to the charge of the proton. Why does it have this charge? And inside protons are particles called quarks. Why do they have charges of 1/3 and 2/3 that of the electron? And why is the gravitational constant exactly equal to 6.6738 ´ 10 ̄ ¹¹?
We can’t answer these questions, but what is more important is that the anthropic principle says that if they were different – even by an infinitesimal amount – life would not exist on Earth. Life, in effect, is tuned to them. At the present time we have no idea why this is true. A number of well-known physicists, however, have speculated that when we finally get a " Theory of Everything" we will know the answer. Some have suggested that all we really need is a quantum theory of gravity (at least it would be a first step). But things look pretty bleak at the present time that we’ll achieve such a theory. Most of the work in this direction at the present time is going towards what is called " String Theory." According to this theory the universe consists of many more dimensions than the usual four that we observe – possibly 10 or 11. And these extra dimensions are curled up so we can’t observe them. The biggest problem with string theory, however, is that, unlike most theories, it doesn’t make predictions that we can check. In addition, the strings themselves are so tiny we’ll never be able to observe them.
So there appears to be a quandary. The anthropic principle seems to show us that life on Earth is a fluke of nature; in short, it predicts that only one in hundreds of trillions of stars have a planet that could support intelligent life. This appears to indicate that we are the only planet that contains intelligent in our galaxy. Furthermore, we know that reserves on our planet will only allow us to exist for a few thousand years more (with luck maybe a little more) then there will be no intelligent life in our galaxy.
But for years we have assumed (and it appears to be true) that if the conditions are just right on a planet of the right size in regard to temperature, proper atmosphere, proper energy sources and so on, that life (and even intelligent life) should arise. Furthermore, in recent years we have discovered a large number of planets in our neighborhood of space, and some have relatively ideal conditions for life (not as good as Earth, but reasonable). What does this mean?