Recent content by kaplan

No, it is not. As I said above, the event horizon can form and grows before there is any matter inside it at all. Your calculation is wrong. First, it only applies in static cases, not when matter is collapsing. And second, all it shows is that if the interior of the black hole had...

Actually no, it doesn't. Classical waves can reflect off wells or dips in a very similar way. For example, the sound waves inside a tube of a wind instrument (like a flute) partially reflect off an open end of the tube.

Maui, (as many people have told you) the above is simply not correct. In quantum mechanics, "superposition" refers to adding two or more states together (and multiplying by the appropriate normalization factor). But quantum states are elements of a vector space, and that means the sum of two...

It grows starting from r=0 at the center of the star (as you can clearly see in those diagrams you posted). The only odd thing is that it appears and starts to grow before the star has collapsed into a black hole. But that's fine - event horizons are not defined by local quantities. They...

Yes. There's no collapse (in the sense of a projection) in MW. Instead, there's a split. And yes, the split is deterministic. When you make a measurement and cause a split, one version of you obtains one result and the other version obtains the other. That's all there is, and no...

There are no random events according to the MWI. The Schrödinger equation is a differential equation, so the wavefunction of the universe evolves deterministically. There is no "Wn we end up in". We end up in all the worlds. You seem to have some basic misunderstandings of the MWI.

The difference between the worlds of the MWI and a single particle in a superposition is only that in distinct worlds of the MWI, macroscopic objects are in superpositions of states with macroscopically distinct properties ("Schrödinger's cat states"), instead of just particles being in states...

In thinking about this it's perhaps useful to revisit the basic EPR setup. There, you can think of the entangled state of the two particle as corresponding to two worlds: one where Alice has the particle with spin up and Bob has the particle with spin down, and another with the opposite...

No, that's not accurate. Referring to Fig. 1 of that paper, theory makes predictions regarding what Victor will see when he makes a measurement on the photons he receives. But Victor's measurement is within the future lightcones of both Alice and Bob's measurements, so there is clearly no...

"Simple" means "simple rules". Simple rules often lead to complex consequences. That's normal and expected. Newton's laws are very simple, but the chaotic dynamics of systems of many classical particles are extremely complicated. No, that's not the case - or rather it's the case only...

I'm not sure what you're getting at. Of course making a measurement affects the future lightcone of the measurement event - all events do. That's standard relativistic causality. Am I missing your point?

Renormalisation is a perfectly well-defined procedure, and it does not "blow up when it's used with high energies" - at least not in renormalisable field theories (hence the name). Not only that, we know experimentally that it works, because we've measured the runnings (the change of coupling...

You can dispute it all you want, but it's true. QCD is a good example. No, it's not. That's true. In fact we more than suspect, we know - because of gravity.

That's true - but the standard model does not have a Landau pole. Generally non-Abelian gauge theories are asymptotically free (or at least can be, depending on the matter content). It doesn't have a Landau pole. It could have had one if the Higgs were sufficiently heavy, but we now know...

The standard model would be valid to arbitrarily high energy scales if it wasn't coupled to gravity. In other words it's gravity that causes all the problems. How do I know gravity isn't a QFT? I don't, for sure - for example gravity (or really string theory) in asymptotically anti-de...