Recent content by Feynstein100

Thank you so much! This is exactly the explanation I was looking for. Why can't everyone be like you?

Hmm good point. I guess gases don't have "surfaces" to provide impact like liquids do. At that point, the liquid acts more like a solid than like a gas since vaporization upon impact is what happens when solids collide with other solids as far as I know. I'm using the Barringer Crater in Arizona...

Since you are so learned, I'd like to ask you a further question. On one end we have re-entry in air which causes objects to heat up and melt/vaporize. On the other hand we have re-entry in water which causes them to mostly just slow down. But both are fluids. The question is merely that of...

How insightful! I hadn't thought of that at all. Thank you for enlightening an ignoramus like myself with your profound grasp of physics. I am truly blessed to be in the company of such extraordinary minds.

As the title suggests, it just occurred to me that things don't burn up when entering the ocean as opposed to when entering the atmosphere. This seems counterintuitive because the explanation behind atmospheric burnup is usually attributed to friction. In that case, water should provide even...

And going back to my original question, why is this not a problem for the electron? If it indeed has zero size but non-zero mass, that would imply infinite mass density and thus infinite spacetime curvature, making the electron a singularity. Obviously that's not the case. So, why not? That's...

Yes, I am aware of this but what does this mean physically? To me, this seems no different than the instances where you solve a quadratic equation and get a negative value for distance/time. A mathematical artifact that doesn't correspond to physical reality.

You've lost me here. Doesn't the spacetime curvature of a region depend on the density of matter-energy in that region? As far as I know, the only way to get infinite curvature is to have infinite mass-energy density, which again implies zero size. I don't see how you can have one without the...

Hmm I don't understand. Any point in spacetime, by virtue of being in a 4D manifold, would have 4 co-ordinates, right? How can the singularity be closer to a moment in time? I mean, what does that even mean? That it doesn't exist in space but only exists in time? Again, I don't understand what...

As you no doubt have heard countless times, GR's prediction that a black hole should collapse to zero size is considered problematic because it would imply infinite density, which isn't physically possible. And yet, over on the other side in QM, electrons seem to be considered pointlike...

That's what Scihub is for :smile: That sounds reasonable but I see a contradiction. Because if that were true then charged black holes shouldn't have a magnetic field either, assuming that the charge, and thus the current generated by it are inside the event horizon

Assuming the black hole isn't a point and has some kind of internal structure, I'd estimate that the current loop resides internally, the same way it does in a neutron star, the sun or the earth.

That's a great analogy because everyone knows that bananas are yellow and no one would ask that, since it is self-explanatory. And even if they did, it wouldn't be that hard to answer that most fruits aren't yellow, but some, including bananas, are. [Mild insult deleted by the Mentors] My bad...

Thank you. So in that case, the question with the neutron star. If it goes from having a magnetic field to not having a magnetic field, how does that work? Does the magnetic field get radiated away as PeterDonis mentioned? That sounds interesting. I've never heard that before. How does that...

That doesn't really answer my question but thanks