Alternate dimensions?

Question

If time reversed to the beginning of the universe just before the Big Bang and the universe started all over again, in the amount of time it took to become today, would anything be different or would the alter-me be sitting here typing this question also?

What makes me think this is that, although we have free choice to make decisions etc... surely, if the universe started again, everything would happen the same because that is how it happened the first time. Must it be impossible for the universe to pan out differently?

Answer 1

Although the Universe would probably look broadly similar to how it does now, I don't think you or I would be sitting here, nor would there be an Earth orbiting a sun. The reason being, that according to quantum mechanics, some things really are random, so they wouldn't happen quite the same way again (and to head off the obvious point by other posters, yes, quantum mechanics really is random, it's not just down to hidden variables we don't know -- there are experiments which show hidden variable theories cannot be right).

However, if the fundamental constants of physics are the same (the speed of light, and the Gravitational constant, for instance) then the Universe should look roughly similar - it would have stars, and planets, and galaxies in the same proportions as we see - just not the same ones. Would human life have evolved - its very difficult to say.

However, as there is no clear answer as to why the fundamental constants of physics have the values they do (without straying into the realms of metaphysics, such as "because god made them that way"), then maybe they could be different. Indeed, there is a view that there are already many other Universe, in a multiverse, where the constants are different. With different physical constants, our Universe would be a very different place. It may not even have survived this long - if gravity was stronger, it may have already collapsed in a big crunch. Or if it was weaker, matter would be so spread out that stars and planets could not form.

Where does free will come into this? Well, assuming that the Universe had developed similarly enough for there to be an alter-you, then because of quantum mechanics, you could never experience exactly the same conditions. And because of chaos, even a small change can have a huge difference (butterflies flapping their wings and all that). Am I suggesting that the randomness of quantum mechanics is the cause of the illusion of free will? Probably not - I think it is more complex than that, but as long as truly random processes exist, then things can always happen differently another time.

Answer 2

If it had exactly the same starting conditions then it would pan out excatly the same way. Any small variations and it could be dramatically different.

Free choice can only exist where there is no cause and effect. As far as I am aware everything in the universe has a direct cause and effect linage. So even though we think we have free choice the decisions we make are simply a result of things that have happened before.

When you wrote this question for example, you made a choice. If time was reveresed back to that point in time you would do exactly the same thing again because nothing would have changed in the build up to that decision.

I always wonder what the point of this predestined course the universe is on is all about. Why is it here in the first place. I think there is a purpose but no idea what it is.

Answer 3

Of course not, in fact the opposite is true, because yes, the basic physical laws would remain the same as well as the initial ingredients but it is the random inconsistencies that have caused the universe to become what it is today. Minor fluctations in the uniform homogenous state of the early universe are what caused the ancient black holes to form, which then lead to the formation of the spiral galaxies that we see now (this is too long to explain in detail). The same kind of random occurences also played their part in changing the universe ie: comets hitting masses out of orbit or crashing into planets and bringing organic matter to seed life on planets ect.

So even tho the basic laws of physics would form the underlying rules for the structure and development of the universe, it is the random occurences that would shape it, and because all of these factors are random, they would be different each time a big bang occured, thus resulting in a different universe.

Also, even one single different decision, like which way to walk to the bus stop, would lead to a completly different series of events, so imagine how many petty decisions all the billions of people past and present have made! Any difference would change the outcome of our reality,

Read about the chaos theory and it will explain how the tiniest difference can cause completly different outcomes.

So it is actually impossible for the universe to be the same no matter how many times we ´reversed´the big bang!

Answer 4

Lou B gave by far the best answer. This is why Einstein couldn't make any progress toward unifying the laws of physics. He just could not give up the idea that the universe was deterministic. He would not embrace the basic quantum principle until his last days, if then.

Some have extended the multiverse concept to absurd levels. They say a separate universe exists for each combination of indistinguishable quantum states. That makes for an unbelievably large number. There is, of course, no evidence for any multiverse or parallel universe.

Free choice is not an issue of physical determinism. It is governed by the part of man that isn't physical. The evidence is overwhelmingly in favor of free choice. The Bible and religious writings are all full of instructions and exhortations. Without free will, there would be no point to that.

The arguments and evidence are so strong that I would bet any amount of money against the scenario you described.

Answer 5

Events at the quantum level are indeed random. This means that if you have identical pre-big bang starting conditions, the universe would be completely different each time.

This also applies to time travel. If you sat and watched a radioactive substance emit a particle for example, then went back in time to watch it again, it might not emit the particle the second time around, even though it is the exact same event.
So events not only don't pan out if the starting conditions are they same, they don't even pan out the same if the very same event is witnessed by travelling back in time to watch it again.

Such is the bizarre world of quantum mechanics.

Answer 6

Sure. every choice that we make spins off another dimension. You choose to get a non-fat latte instead of an espresso. What happens is what's called 'the pants of time' where you have the time line running straight down. Then you make your choice (at the crotch). The time line splits, one side has you with the latte, the other has you with the espresso. So there are in fact an infinite amount of universes in what is commonly called the 'multivers'.

Answer 7

Affirmative. It is absolutely possible for the universe to pan out differently.

Answer 8

Nothing in nature is truly random, so given a known starting point and set of conditions, the same outcomes would still happen.

Answer 9

We are compelled to admit in one way or another that everything in our reality is objectively determined, as cause and effect. Even so there are plenty of variability regarding the details.

Answer 10

Absolutely!