Recent content by dubsed

I have a question about a recent NASA article Titled http://www.nasa.gov/mission_pages/hubble/science/cosmic-expansion.html" . Is it safe to assume that when hypothesis talk about a low density bubble that they mean a density lower than expected? Meaning that they have taken into account...

From what I read in your book It looks like the CMB is used to determine curvature by looking for changes in the CMB at different positions in Earth's orbit (different angles). How good is the assumption is it that most of the differences in the data actually come from the CMB and not a closer...

How is a homogeneous infinite universe possible? Wouldn't that require the mass and energy in the universe to be infinite as well? Wouldn't an infinite universe also mean that statistically all things that could have already happened? In an infinite universe wouldn't you eventually reach a...

Can you explain or provide a link that explains how the CMB shows curvature? I thought the CMB only showed temperature variation which could be used to infer an initial matter distribution?

By spatially open vs closed do you mean finite vs infinite?

Please note that I am not trying to forward any type of personal theory. I am only trying to understand generally accepted physics. I have heard the universe described as the surface of a balloon. Inflating the balloon is the expansion of the universe and everything move away from...

Do we really need to argue semantics? You don't like that he says its flat at infinity. I don't like that you say it actually hits infinity. Saying that it is flat at infinity is the same as saying that (1/9) + (8/9) = 1

I think Dale's point is that it doesn't matter how far away you are, ignoring the possibility of falling into a closer massive body, if you have 0 kinetic energy and you do not fire any rockets you will eventually fall into the black hole. Though this does make me wonder, at a certain...

If space is not actually flowing into the black hole, then is it possible to give me another metaphor to help me better understand what is actually going on? I understand that no metaphor is perfect, the one that was given in the reading James gave me was as photons as canoes paddling against a...

Let me verbalize and see if I am starting to get this. Bob sees Alice frozen at the horizon not because she is there forever, but because the light she emitted/reflected eons ago has undergone so much time dilation that it takes light a very long time to reach Bob because it is fighting against...

I believe it was Susskind that was explaining it on the show. I have been reading the website you recommended and things are starting to become more clear.

Leonard Susskind was actually on the show I mentioned and was explaining the scenario. However he never said why Alice would not see the propeller slow down and show more detail. Hopefully learning more about the coordinate system you mentioned will shed some light.

Thank you for your help, this gives me some more to learn about before I ask more.

Dale, I really wasn't speaking about tidal forces, (at least that I know of). Actually, I considering the case you point out, with a very large black hole the gravitational gradient is still relatively flat at the event horizon. However, the time dilation gradient is very steep near the event...

Yes, but her propeller is in front of her, eg closer to the event horizon and thus experiencing a different time dilation. Or am I missing something?