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Quantum Physics- Gravity

So if I understand correctly, according to Einstein, is time slowed by larger masses? ie. by a greater distortion of the spacetime continuum?

If so, at the time of the Big Bang when all matter existed in a supposed singularity of infinite density, shouldn't time have been infinitely slow? That is, shouldn't time have halted? In which case the Big Bang would not have occured at all because time would not move on from the point of the singularity. I don't get it :confused:

Reply 1

MeAndBubbles

Correct, Michio Haku, says time stops in a black hole.

I do not myself accept that time slows! As is know in this forum.

I find that some physicist 'go all the way' but some 'hold back', I think this depends on how bizarrely that particularly physicist wants to come across in the media.

My personal reading on it, the assumption is time slows as you approach c for the object doing the travelling!! But the weaker case is put forward in the media, that an observer sees that time is slower relative to his own time.

Reply 2

shinypenny

Well, think of it like this… the universe has always existed, but that doesn’t mean that time has too. You can't view time as one timeline, it’s relative, which means that it depends entirely upon your frame of reference. If you don’t have multiple reference frames, time just cannot exist. Essentially, time only began with the big bang, because it created the necessary multiple reference frames.

Einstein’s theory of general relativity itself (a pillar of the big bang theory) suggests that the big bang would have begun time because, in a singularity state (like what the universe was in just before the Big Bang), there is no time. The universe has literally existed for all time. If that makes sense.

Hard to know what this implies for the early universe eh?

Weeeeell, remember that space and time are interconnected. And since we know that mass creates warps in space, it therefore creates warps in time also. In other words, there is no absolute time or “correct" timeline. Which means that there is no correct spot to watch an event take place from.

Reply 3

div curl F = 0

General relativity does not hold inside black holes nor does it hold before the planck time (< 10^-44 seconds after the big bang), hence the need for a quantum theory of gravity to discuss these scenarios. GR works in almost every situation apart from these, it is doomed to fail hence the reason why physicists are searching for a more general theory which can describe GR and these problems in GR. Follow string theory, loop quantum gravity, super gravity and all the others.

Remember also that time runs slower for observers in deep gravitation wells, but they see time running as it always has done at the same rate, it only runs slow compared to an observer further out of the well. As an observer approaches an event horizon of a black hole, an observer looking at this will never see the other observer cross the event horizon when infact the observer would be long gone across the EH, this is the time dilation effect produced by energy/masses in GR.

Reply 4

Mehh

Okays....
We at present only have particle accelerators that can probe back to the Electro-weak epoch.

There is a branch of physics called High Energy Physics. These crazy people use powerful machines called Particle Accelerators to generate extremely high energy density events.
Now as the universe was very very young, it was very dense and very very hot. This means energy was in abundance.
A lot of the physics that you know today is low energy physics, where a lot of possible reactions have been 'frozen' out; there just isn't enough energy lying about to create a real W boson, so they appear not to exist.
But if we increase the temperature of the universe enough, these particles will just pop in and out of existance as readily as photons do.

Unfortunately the Electro weak epoch occured 10^-32s after the big bang.
So the answer to your question is that we really don't know.

One of the problems with this period of time is that we would have to develop a quantum theory of gravity, which was a strong player back that far in time. But at the ranges back then, so was quantum mechanics.

What you also need to know is that time only moves slower relative to an external observer in a gravitational field. But what is an external observer for the universe?