its better than the alternative tho....

or how else do you explain the 'fine tuning'?.....

In what context are you referring to "fine tuning"? If you answer that, I may be able to explain what "fine tuning" is.

http://en.wikipedia.org/wiki/Fine-tuned_universe

I believe there is no need to account for the fine-tuning. If it hadn't happened, we wouldn't be here to ask the question. The best we can do is to assume that it happened through sheer chance. To ask why it happened is like asking why a fair coin landed on heads rather than tails. I see no reason for supposing that the fine-tuning was more than the chance outcome of a seriers of random events.

By the way, I appreciate your response to Dumb amateur astronomer's accusing me of arrogance.

no problem...

i would beg to differ on ''fine tuning'' ... as i understand it the universe or our part of it came into being as a quantum event with as we understand at present the constants masses forces getting their values ''at random''

we are here to ask the question so it did happen and the question asked !!

i like it as it suggests many many ''universes''



sheer chance is not very likely when you look at the odds...

i dont have them in front of me but its like the biggest number you ever saw!

i'll look them up if you like

damian 1727: i would beg to differ on ''fine tuning'' ..as i understand it the universe or our part of it came into being as a quantum event with as we understand at present the constants masses forces getting their values ''at random''. we are here to ask the question so it did happen and the question asked !!

dcl: I know of no reason for supposing that the "quantum event" occurred other than as a spontaneous event. The world is full of spontaneous events. Ancient peoples attributed such events to the actions of capricious gods, but modern people attribute them to sheer chance. I still say that if not for that event, we would not be here to argue about why it happened.

damian 1727: i like it as it suggests many many ''universes''

dcl: I see no reason for postulate other universes, presumably one corresponding to each of the infinity of other alternate events that could have happened but, as far as we are aware, didn't. Suppose that a mouse nibbled at the cheese in a mouse trapped and was caught. The trap could have been defective and allowed the mouse to enjoy its meal and go home to tell its family about it, but that doesn't imply that there is another entire universe in which this actually happened.

damian 1727: sheer chance is not very likely when you look at the odds...

dcl: The fact that it happened nullifies the odds against its happening.

damian 1727: i dont have them in front of me but its like the biggest number you ever saw!

dcl: I agree.

damian 1727: i'll look them [odds against the quantum event's having happened] up if you like

dcl: Don't bother. I agree that the number is horrendously large, but that fact implies nothing about the possible existence of that alternate universe as existing somewhere as a real universe. An alternate universe is only an idea, not something that actually exists. The very word "alternate" implies the actual occurrence of one of a number of possibilities and the nonexistence of all contrary possibilties.

dcl The fact that it happened nullifies the odds against its happening.


me huh ? i never understood this it makes no sense

i might win the lottery but the odds of me doing so are as they were..

and it also makes sense that if something happened once it could happen twice....or that big number we agreed on


we are not aware they did or did not

as i see it if quantum fluctuations in a void can do this then im sure they do
and as i see it fine tuning most certainly raises an eyebrow (!!) and i feel better with the very logical and beautiful explanation that is the multiverse

also on a completely personnel level i kinda take it as a an act of faith that the world is always far more complex and amazing than i could ever possibly imagine so i would not choose to limit myself to one universe if in fact i could have many for the same price

and it shuts (no it doesnt) the god squad up

damian1727, I agree. The chance against our Universe's having come into existence already fine-tuned for human life to arise was extremely high. It happened, the high probability against its happening notwithstanding.

If the universe by definition is 'everything', then what is the rationale for the term coined 'multiverse'. I never quite understood how that came about. Perhaps it is just semantics, but if we want to define 'universe' to mean all that is, then we should not refer to supersets of that. Granted it gets tedious to always say things like 'our observable universe' or 'all space-time that is causally connected'. I think if you allow existence of the concept of potentially disconnected spacetimes, then 'universe' as stated cannot be given the definition of 'all matter and energy' without a little refinement.

true dat

:P

damian1727, I just discovered that I committed a monstrous goof in my statement responding to your statement about fine-tuning of the Universe. By saying "high" when I meant to say "low", I said precisely the opposite of what I intended to say: a horrific example of careless forgetting to proof to assure that I was saying what I meant to say. Sorry, people. I meant to say that I agree with you that the probability of the Universe's coming into existence fine-tuned for human life to occur was highly IMprobable.

As for the term "multiverse", I want no part of it. I know of no evidence for there being more than the one Universe that we know, the "branes" of string theory notwithstanding.

jseats, I agree wholeheartedly with your rejection of the concept of multiverses. I see no useful purpose in speculating about the existence of universes other than the one we know unless there is a possibility of our being able to test for their existence. On the other hand, I do feel that it is important to distinguish the universe and the observable universe because they are drastically different, and it is often important to know which one is being referred to.

The universe is a big ball of wiggley-wobbley... timey-wimey... stuff.

dcl i may be wrong but i dont think jseats was saying that there was no multiverse per say he/she was saying that if we stick with the original definition of universe to mean EVERYTHING EVER .. including different space time bubbles and dimensions then your original deffinition ... all matter and energy... was oversimplistic

i think thats what he/she said



the multiverse is the simplest explanation for fine tuning

jseats said, "If the universe by definition is 'everything', then what is the rationale for the term coined 'multiverse'. I never quite understood how that came about. Perhaps it is just semantics, but if we want to define 'universe' to mean all that is, then we should not refer to supersets of that." This seems to me to be an argument against use of the term "multiverse" as being more inclusive than the term "universe".

He went on to say, "Granted it gets tedious to always say things like 'our observable universe' or 'all space-time that is causally connected'. I think if you allow existence of the concept of potentially disconnected spacetimes, then 'universe' as stated cannot be given the definition of 'all matter and energy' without a little refinement." This seems to me to be no more than an argument against saying "our universe" when one means "our observable universe".

he would call the multiverse .. universe.. as it means everything....

if you allow for disconnected spacetimes..(universes to us) then .....

nevermind

I believe that I failed to make it clear in my last remark that I am in agreement with jseats regarding ambiguity in the way the term "universe" is frequently used to refer to less than the entire Universe, the latter referring to everything, excluding nothing.

sooooooooo what i and many others term the multiverse you would would call universe?......?

and what would the word for the individual ''bubbles' be?

even tho you dont think they exist you would dtill need a word to tell me ~!!!!

lol

way to confuse ourselves!

when i say universe i mean the whole of space time that came into being 13.7 billion years ago

but i believe *scarey voice* there IS soOoO mucH mOreee....

As far as I know, there is no evidence for more than the single universe that we live in. Any speculation to the contrary is only that and is backed by no evidence whatever. I feel that such speculation remains sterile until at least some evidence has been found for it. Until individual bubble universes are found, I wouldn't worry about what to call them. If someone wants to believe in bubble universes, I'll be content to let him devise a name for them. When I say "universe", I, too, mean the whole spacetime that appears to have come into existence 13.71 billion years ago. I, too, suspect that there is much more to the Universe than we know about or can even guess at at present.

A lot of science or cosmology is based on the concept that "If it can happen here, it can happen somewhere else". Why not apply this to the universe itself?

The simple reason for the multiple universe idea is that it removes the fine tuning problem.

If this seems too speculative, consider that the fine tuning problem itself is really a philosophical question - you are asking why all the physical constants are at those particular values rather than other values - you are asking what mechanism defined those values - you are asking about the mechanism responsible for our universe being the way it is...

We now have a few contenders in cosmology that might take the time-line back further than the beginning of "our" universe, things like M-theory and Loop Quantum Gravity, but we have no way so far to test these ideas and they only take the "mechanism behind" question back along the time-line with them anyway.

"here" and "somewhere else" in the expression "If it can happen here, it can happen somewhere else" do not usually refer to locations in different universes. There is no basis for supposing that multiple universes would remove the fine-tuning problem. I am not asking why all of the physical constants have the values that they do. I think these values have the values that they do merely because we wouldn't be here to ask the question if they different, We shouldn't ask for causes when there were none. I'm not aware that M-theory and quantum gravity offer to take the time line back before the Big Bang.

Well, M-Theory proposes the possible existence of multi-dimensional membranes which interacted, causing our universe.

As for Loop Quantum Gravity, Abhay Ashtekar and Martin Bojowald have released papers stating that according to loop quantum gravity, the singularity of the Big Bang is avoided. What they found was a prior collapsing universe. Since gravity becomes repulsive near Planck density according to their simulations, this resulted in a "Big Bounce" and the birth of our current universe. These topics are an active research in loop quantum cosmology.

By the way, I wasn't implying that you were asking about the fine-tuning problem, that was bad wording on my part. I was just referring to the fine tuning problem in of itself. I agree with you regarding the lack of a need for a cause.