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Questions: clock stopping and what may of happened before time existed

posted 10 years ago by decegainer
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Why would the clock slow and then stop. With my limited understanding of physics and special relativity, I would think that the mechanical clock (absent any other forces) would continue to operate normally. Obviously the clocks on Earth or somewhere else would read a different time, but the mechanical clock should continue to keep time. I assume that the clock was just used to represent relative time, but I was not paying attention the whole time and I may of missed an explanation or something else regarding this idea.

The non-existence of God is an impossible negative proof. However, to say that some entity that is immune to the laws of physics could not have created anything "before time existed" does not make much sense. If such an entity did exist ("God"), as the creator, it would have created all of the natural laws we now understand, including time. I am not advocating any kind of belief in "God". I am just confused as to how Hawking believes that he is able to prove a negative by saying that nothing can exist in the absence of time.

[–] Furrerd 10 years ago

My degree is in physics and I went and reviewed Schwarzschild radius (the radius where light or matter can't escape) concepts .

First if the black hole is to small then the gravity forces between the top of the clock and bottom rip it to pieces so the black hole it heads into needs to be massive on the order of 30,000 suns which would be found within a galaxy center.
The mechanical clock would keep ticking. For the clock (or person holding the clock) they look at the person outside and see them slowing down and the person outside see the clock holder slowing down but their local time is unchanged. This is because photons of light is how the information is getting between the two observers and light travels at a set, unchanging speed.
When the clock is heading into the super massive blackhole all photons that would bounce from it's face and show the outside observer what time it says would bend back towards the black hole and it would appear to stop.

It's a failure of information transfer, not time stopping. And if the entire universe is within that radius then there are no outside observers. Just inside observers who are moving at similar speeds relative to each other all still experiencing time.

So this part of the episode appears to be incorrect. At least they shouldn't have used a black hole analogy. What happens to all matter in the Universe when it was compressed to a size less than a Schwarzschild radius (30 billion light years according to current estimates of the Universe mass/energy) is a debated section of modern cosmology. As the Universe was smaller then the total mass was much less as the negative mass/energy stored in space was equally smaller so wouldn't the Schwarzschild radius also have been smaller in the early seconds of the Universe?

I need to go back to school for what I have missed out on since 1990.

If the two observers had a means of communicating using entangled particles I wonder if they could compare time then?

"And what were you bobbleheads doing while I was just getting earf...ed by father time?"

[–] Furrerd 10 years ago

Here's a page that does a good jobs explaining falling into a black hole.
http://casa.colorado.edu/~ajsh/singularity.html

"And what were you bobbleheads doing while I was just getting earf...ed by father time?"