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Comment by x3n0ph3n3 | Hacker News Reader

The big bang occurred _everywhere_.

This kind of brings up another point that is interesting about our universe. We're under the impression that every point in the universe is experiencing the same amount of distance from the beginning of the universe from that individual point's frame of reference. But this kind of makes time so fundamentally weird compared to the spacial dimensions. We assume no point in the universe is the center, for instance. And the topology of the universe would look fundamentally different if there were some spacial coordinate (of the three) upon which every point was "pinned." But isn't saying from every individual point's frame of reference the universe is the same age equivalent to making a central point within time at the beginning? aka the big bang, of course, but that also seems to imply something about the topology of the universe for eternity after the big bang, as well. It's got one complicated topology for sure.

Yeah, the time dimension is different from the space dimensions.

To mention the obvious: everything is constantly moving through the time dimension together, for unknown reasons. Nothing like that happens with space.

There was some ancient religion where their god or satan figure was responsible for time - literally the god/satan beings way of destroying the universe.

Wish we could figure out some better ways to experiment with time. Seems like it's very telling of what's really going on that it's so different.

But how would we know if all spatial dimensions were moving along a constant vector? We can't rely on redshit/blueshift if the medium of transmission itself is moving like everything else. The next question might be "moving in what, then?" but then why not abstractly ask the same about time.

This is a bit of a tangent, but the idea of "moving through time" always struck me as a little weird, because the concept of motion is dependent on time already. I like to think of things having a shape that exists along the time axis in addition to the spacial ones. The 4D shape of a thing is fixed, but captures within itself what we perceive as motion in 3D space.

To add to this: we are used to seeing explosions propagating across space and time. The Big Bang was an explosion of spacetime.

Why did it happen?

Good question, my understanding is that we frankly just don't know, it may be one of those things that we can't know, but that is getting awfully close to the realm of philosophy

> it may be one of those things that we can't know

This is true for anything we don’t know.

For the Big Bang, we know the intermediate problem: black holes. Gravity and quantum mechanics interacting at the same scale. The singularities there are accessible in a way the singularity of the Big Bang is not.

Nice try, I'd also like to know. But I am afraid no-one here will be able to answer you. But maybe we're lucky -- I'll monitor this thread.

We can never know the answer, because any possible cause was outside of our observable universe. Inside of our universe, time started at the big bang, so there was no 'before' and thus there was no cause, because the cause needs the time to be before the effect.

Well, if it's true the universe will start contracting at some point (which, some speculate, could happen sooner than we had thought[0]), and if a big crunch leads to a big bang, it is not impossible that this very moment - in the sense of these actual circumstances we're in - already happened an infinite number of times. (Still doesn't really answer the 'why?')

[0] https://www.independent.co.uk/space/universe-expanding-colla...

eeuugh, marketing thought it would make a splash and fucking sales wanted more people to talk at

Someone outside the universe hit "build" on their "universe sandbox generator". The sandbox is still loading from our perspective, although from their perspective perhaps it loads instantaneously.

I mean, obviously this is nonsense, but... I can't exactly disprove it.

It looks each epoch speaks about the universe in its own terms: as gods' creation, as a machine, as a computer, AI... So while there is no way to disprove the sandbox theory you presented, we can be 100% sure that at some point in time people will see it in a different way, and then it will change again and again. Sometimes I feel sad that there are so many mysteries of the universe and so few of them will be discovered during my lifetime.

I think one reason we want to discover more about the universe is because it gives us a sense of awe and a sense of powers greater than us. One useful trick if you're missing that is to take some mushrooms while you watch some space documentaries. Sure you don't really discover anything groundbreaking but it does open up the mind and you will definitely experience awe.

There's a book I read that specified that the universe could be "stateless" to an outside observer, yet the simple act of computing it allows us to exist.

I think that’s a modern way (or maybe techie?) way to think of the old adage that time is an illusion.

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