Recent content by shalayka

Perhaps it might be helpful to consider that a modification of Newtonian dynamics (MOND changes the very foundation of acceleration, which is very strange) is not the same as a modification of the source of acceleration (MOG, CDM, which are still strange in a sense, but less "fudgy"). MOND in...

Do you know of an approach that makes sense for calculating the gravitational time dilation experienced by a test particle at the centre of a shell (of radius r)? My common sense says that the gravitational time dilation would be identical to the situation where the shell was changed into a...

How would one go about calculating (as a first-order approximation) the gravitational time dilation generated by multiple point sources? When generated by one point source (M = 1\cdot10^{25}, r = 1, t = 1), I've got it down to: \tau = t \cdot \sqrt{1 - \frac{2GM}{rc^2}} \approx...

Perhaps it can be summed up by an analogy of travel in a car: Fictitious force - A driver inside of a car is traveling along a rectilinear path. The car turns left (accelerates, changes direction), but the driver's body attempts to continue along the rectilinear path due to inertia. The driver...

Brick is a perfectly suitable analogy. It makes perfect sense in English. No worries.

I was referring to the fact that arguing the pros/cons of string theory with this person is tantamount to talking to a brick wall. Sorry, I assumed most people prefer not to waste their breath. My bad. There's no need to get defensive on anyone's behalf. My question had nothing to do with...

I find it odd that you say this, considering that Moffat and Brownstein's theoretical work on modified gravity relies on observations exactly like those seen in the Bullet Cluster collision. Not that I necessarily agree with their model, but still... I don't think the statement is entirely accurate.

You do realize who you're talking to, right?

http://motls.blogspot.com/2007/05/why-are-there-gravitons-in-string.html

The metre is a fraction of the distance that light travels in one second. Now that wasn't so hard, was it?

While not video, the book Galactic Dynamics (2008) is very helpful. It shows how the spirals and whatnot form due to something that looks like traffic jams. It's pretty cool stuff.

Perhaps it was because change is stress, and stress is something most people tend to avoid.

Why don't you ask him yourself when you die? I'm kidding. I don't really know if it's practical to question the things that others spend their time on, let alone Albert Einstein. Why don't you spend some time contributing to lattice QCD? I'm sure you could make some good contributions.

The \LambdaCDM model is something to look into. In it you will find that dark matter and luminous matter only make up about 1/4 of the required total energy needed to explain the apparent spatial flatness of the universe -- google for "angular size of microwave anisotropies". It's real science...

Let me guess... you believe that a static axisymmetric body rotating on its axis of symmetry emits gravitational waves? If so, try spinning a disc under water and see how well the disc's edge pushes the water out of the way. Doesn't work quite as well as a spinning stick, does it? PhD? My God...