geordief

Is this example(the event horizon of a black hole and a distant observer) any different qualitatively from a corresponding relationship btw any two frames of reference in that they equally do not share any sense of simultaneity . Is the former relationship just an extreme example of the latter?

OK ,so if we can substitute "energy " for "mass"(with the conversion factor,c^2) is there an intuitive way to understand why this energy causes a more or less proportional resistance to acceleration ? If we just consider a massive object like a proton would the energy be bound up in the constituent particles and the forces holding them together (the bonds)? -and so would also describe the "mass"... Maybe your last bit about expanding the equation to include massless particles would need its own thread?

An extremely big BH (maybe one that gobbled up all the others ,if that could happen) would have a curvature approaching zero at its EH,is what I was thinking

I note that both these seem to give rise to spacetime curvature What might be the apparent connection between them? Is mass a measure of some sort of concentration of the various fields? (If that means anything )

Is there any kind of a "sweet spot" between BHs with infinite curvature and zero curvature? Or are there any degrees of curvature that are more interesting in ways than others?

To tell the truth I am slightly disappointed that Trump actually tried to go to the Capitol as I had him down as a physical coward who would lead from the back. Maybe the source is the big Doh ,trying to big himself up?

Ah,yes.Actually I hadn't actually got round to looking at it but yes it would be the gravity wells depiction that I was after (but with the full-ish SR effects included -and "playable" ). I imagine that at some academic or research level such simulations might be in use but probably not for the general public. In the past Markus has shown me gravity simulations on a 2d level where there were settings that could be adjusted for mass and position but that was not quite what I had in mind now.

Carol Leonnig was pretty impressive.

Ok,thanks.

Well if the neutrino undergoes a change in flavour doesn't that imply some sort of internal mechanism?

Do different black holes exhibit different degrees of spacetime curvature (depending on their radius)? Might it be a requirement for a body to be massive that it have an inner structure of some kind?

Yes,that was loose language. I was really after the smallest known instance of mass . So it would be the neutrino? (which from memory was at one time considered massless) Is a black hole considered to be a massive object? I have read that it should be viewed as an extreme curvature of spacetime., Can it be both? Are mass and spacetime curvature somehow the same thing?

(Or maybe "What are the smallest objects with mass?") I think I may have seen that mass may be defined as a body's resistance to being accelerated. How would that apply to that smallest massive object? What would apply the force ? Another massive object? Does mass require another massive object to define itself?

Sadly the content of that link a bit old now (2007) and I can't get anything there to play. Actually,in any case I was more interested in proper 3d videos or virtual reality videos** if such exist (not that I have the facility to play them either) I get the impression that this kind of a thing might not be for the general public and perhaps used in university settings. If anyone has hands on experience with that sort of thing it would be interesting to hear. **perhaps "games" might be a better descriptor as I was imagining that there could b quite a few settings to play around with.

That would be originalist.

No,but the effect is similar.Is it not better that the appointment of Supreme Court Judges should be non partisan? The refusal to appoint Obama's pick felt like reverse packing to me.

Do all administations not try to pack the Court with their own picks. Any chance the Repubs will reap the whirlwind from this most transparent and seemingly unpopular episode? Will they be vulnerable in Red states now?

Thanks.We cross posted "simultaneously ".Will give that thread a butcher's

Edit:On reflection I see where this "model" falls down as I described it. Could it be improved by paring down the Solar system to just a few objects,say the Sun ,Earth and Jupiter as well as allowing for different frames of reference with their own clocks. Introduce a test object moving at relativistic speeds and compare how the movie plays out from the different frames of reference. Could it be a nice pedagogic tool?

Are you saying that that would just be pretty pictures but that it wouldn't show anything profound -and might actually be misleading,like the trampoline analogy? If you were to populate my 3d movie with an additional moving object (or a beam of light) wouldn't that object's trajectory be very realistic? Are there relativistic effects that this movie cannot capture?

Does the overturning of Roe v Wade bring the US legal system into further disrepute at a time it is most needed as a bulwark against the Big Lie and its attack on democracy in the States?

Yes,that is the sort of thing(I was looking for the way the different gravity wells joined up) It wouldn't be a problem to add the 3rd spatial dimension (and use 3d glasses) and to run a series of those still frames too get the time dimension, would it?

I just meant to simulate the map of curvature around and extending from the objects in the Solar system. I wasn't interested in actually seeing the objects themselves. Would that be possible?

https://www.newscientist.com/article/2325638-breast-cancer-is-more-likely-to-spread-during-sleep/ "Breast cancer is more likely to spread during sleep" A very interesting finding. A link to a pdf page in Nature in that that I can't seem to copy and paste....

Yes ,I only had in mind what would be practical (and enlightening for me) Is there anywhere that these spacetime graphs have been written down? Some sort of a graphic spacetime depiction of the Solar system at some particular time (say t=01/01/2000 at midnight) If there was then we could make adjacent snapshots (eg t=24 48 ,72 hours later etc ) and run the snapshots like a movie. Accuracy not important ,just maybe as a way of looking at spacetime events in a non local way?