While challenging the Platonic dream of theoretical physicists, the multiverse idea does explain one aspect of our universe that has unsettled some scientists for years: according to various calculations, if the values of some of the fundamental parameters of our universe were a little larger or a little smaller, life could not have arisen.
For example, if the nuclear force were a few percentage points stronger than it actually is, then all the hydrogen atoms in the infant universe would have fused with other hydrogen atoms to make helium, and there would be no hydrogen left. No hydrogen means no water.
…On the other hand, if the nuclear force were substantially weaker than what it actually is, then the complex atoms needed for biology could not hold together. As another example, if the relationship between the strengths of the gravitational force and the electromagnetic force were not close to what it is, then the cosmos would not harbor any stars that explode and spew out life-supporting chemical elements into space or any other stars that form planets.
The strengths of the basic forces and certain other fundamental parameters in our universe appear to be “fine-tuned” to allow the existence of life. The recognition of this finetuning led British physicist Brandon Carter to articulate what he called the anthropic principle, which states that the universe must have the parameters it does because we are here to observe it. Actually, the word anthropic, from the Greek for “man,” is a misnomer: if these fundamental parameters were much different from what they are, it is not only human beings who would not exist. No life of any kind would exist.
A Sidney-award-winning essay on physics in The Atlantic.
I am somewhat resentful that there is a universe out there where I am visiting my parents in San Diego rather than Ottawa.
3 Responses
This is the if my aunt had balls she’d be my uncle argument.
It’s not that (OK, it’s potentially not) the universe is fine tuned to allow for our erxistence, it’s that we exist simply because the universe has these paramaters.
To go from we exist because of the parameters to the statement that the parameters exist to make us is an error. Might be true, correct, but there ain’t no proof anywhere.
I’ve always agreed with Mike’s point. What strange and wondrous things might have arisen if the fundamental forces were calibrated a little differently? Perhaps even things intelligent enough to be uncomfortable with the notion that they couldn’t have existed if the fundamental forces had been as they are now.
The Anthropic argument would be a reason to like the multiverse, but it’s hardly sufficient.
If the nuclear force were weaker atoms might not hold together, but perhaps matter would assemble anyway in some other configuration. We might not be able to perceive it as such, but life could exist in radically different configuration.