Honest fine tuning?

[Chattiestspike2]

Well as I'm sure everyone else is, I'm pretty sure the universe isn't fine tuned for life because that would be rediculous BUT I did hear this interview between two NASA people who weren't creationist or intelligent design advocates. They were talking about some density of something at the start of the big bang which is currently calculated to be some 19 digit or something number of grams per something else. It was density. If the density was just one higher, the universe would collapse in on itself, and if it was just one less, it would keep on expanding forever and the only appearent configuration to allow the universe we have now is the current number that astronomers have calculated. I'm sorry that my terminology is so low but I just wanted to get my question out there. Does anyone else know about this? If so, what is your take on it?

My personal take is that I think they would be using the wrong intervals. I mean, I can argue that if my neck was 9.3x10^-15 light years longer, I wouldn't be able to support my head's weight. So does that mean the length of my neck was fine tuned for my survival? My question would be, what if you would decrease the density of that 19 digit number by .000001 would that make a difference? Maybe not. I dont know. Does anyone else have any insight? Or anything they can inform me on that I am missing?

 

[Ozymandyus]

Well as I'm sure everyone else is, I'm pretty sure the universe isn't fine tuned for life because that would be rediculous BUT I did hear this interview between two NASA people who weren't creationist or intelligent design advocates. They were talking about some density of something at the start of the big bang which is currently calculated to be some 19 digit or something number of grams per something else. It was density. If the density was just one higher, the universe would collapse in on itself, and if it was just one less, it would keep on expanding forever and the only appearent configuration to allow the universe we have now is the current number that astronomers have calculated. I'm sorry that my terminology is so low but I just wanted to get my question out there. Does anyone else know about this? If so, what is your take on it?

My personal take is that I think they would be using the wrong intervals. I mean, I can argue that if my neck was 9.3x10^-15 light years longer, I wouldn't be able to support my head's weight. So does that mean the length of my neck was fine tuned for my survival? My question would be, what if you would decrease the density of that 19 digit number by .000001 would that make a difference? Maybe not. I dont know. Does anyone else have any insight? Or anything they can inform me on that I am missing?

Anthropic principle. There could have been an infinite number of universes that did have those different variables, and thus could not support life. We find ourselves in this one because we could only find ourselves in a universe that could support life. The chances of the universe being 'fine tuned' for whatever sentient being that is exploring that universe is 100%. However, if you really look at the universe, 99.9999999999999% of it is completely uninhabitable by our particular kind of life. Seems pretty poorly tuned to me. I could certainly do better.

Perhaps there are other forms of life that can only exist in a rapidly expanding universe, or in a universe that has entirely different cosmological constants. Perhaps certain types of life can only exist inside a singularity: and they think it is weird that singularities seem to have the perfect configuration for them, designed just for them. It is the same mistake we humans are always making: we think that wherever we are is all there is, and all there could be. We used to think you could only live on one side of the earth. Or that we were the center of the universe. In this sort of thinking people are saying that our little part of the universe is representative of all that is or could be, and that our kind of life is the only kind of life.

 

[Aught3]

With probabilities you've always got to have something to compare it to. It is the relative probability that is most interesting. In the case of the early density (mass per volume) of the universe do we know by how much it could have varied? Or was its size and mass constrained by other considerations? Without the proper calculations fine tuning is a pretty uninteresting argument.

 

[Pulsar]

This is the so-called flatness problem. Like several other cosmological problems, it is solved by inflation theories, which automatically produce a 'flat' universe.

 

[Deleted member 619]

As always, it's cart before horse. The universe isn't fine-tuned for life. Life is fine-tuned for the universe, by virtue of arising under constants which allowed for it. In reality, if you ask the question 'could the constants we experience be any different', no physicist can give you a categorical answer. It has been worked out that, given a slight variance of the constants, that about 25% of plausible universe could give rise to life. It's also far from clear whether life can exist in ways other than that known to us, even under the constants we experience. Finally, the simple fact that you could remove one of the four (or is it 3, given that gravity is possibly not actually a force) fundamental forces and that would mean more stable isotopes, quite probably increasing the likelihood of life arising.

 

[Unwardil]

So in other words, the universe is the way it is because it has the properties that it does. If it had different properties, it would look different. That's really all these things are saying. There's an absolute butt load of things like that, the gravitational constant, the carbon fusion in red giant stars, they're all absolutely critical for the universe to form in the way that it has. Which is neat, but try to put any kind of reason into that and you're getting cause and effect backwards. They are that way because the universe is how it is.

 

[Deleted member 619]

^^^

Bingo! On the money.