PeterDonis's latest activity
-
PeterDonis replied to the thread Graduate Time evolution of a detected particle.If the potential in the box walls has only a finite width, yes. -
PeterDonis replied to the thread Undergrad Why does coordinate dependence violate homogeneity in spacetime intervals?.By analogy, "homogeneity of time" would mean invariance under time translations. And "homogeneity of space and time", which is what...
-
PeterDonis replied to the thread Undergrad Why does coordinate dependence violate homogeneity in spacetime intervals?.What source? Again, please give a specific reference. I'm not sure there's actually a difference, but without seeing the actual other...
-
PeterDonis replied to the thread Undergrad Why does coordinate dependence violate homogeneity in spacetime intervals?.Btw, I personally would argue that the statement I just quoted above, all by itself, is sufficient to establish that we must have ##ds =...
-
PeterDonis replied to the thread Undergrad Why does coordinate dependence violate homogeneity in spacetime intervals?.Ok, so their ##ds## and ##ds'## are describing the same infinitesimal spacetime interval in flat spacetime, just in two different...
-
PeterDonis reacted to Dale's post in the thread Graduate Using General Relativity to analyze the twin paradox with
Like.
A. Einstein. "The Foundation of the General Theory of Relativity". Annalen der Physik 354 (7), 769-822. (Translated version at... -
PeterDonis replied to the thread Undergrad Why does coordinate dependence violate homogeneity in spacetime intervals?.Which book? Where? Please give a specific book/chapter/section/page reference.
-
PeterDonis reacted to PeroK's post in the thread High School Understanding twin paradox without math with Like.
Another vital point about the paradox without acceleration is that it shows that differential ageing is fundamentally different from...
-
PeterDonis replied to the thread High School RocketGirl receives a radio message from Earth.@smaricic your latest post referencing Brian Greene's lecture on SR has been deleted, since its content makes clear that we all are...
-
PeterDonis replied to the thread High School RocketGirl receives a radio message from Earth.Thread closed for moderation.
-
PeterDonis replied to the thread Undergrad Momentum measurement and uncertainty.Thread closed for moderation.
-
PeterDonis replied to the thread Undergrad Momentum measurement and uncertainty.No, those boundary conditions are for a particle on a lattice, not a particle confined to a finite region.
-
PeterDonis replied to the thread Undergrad Momentum measurement and uncertainty.No, if the particle is confined in a box, the momentum eigenstates are different. You have to actually solve the Schrodinger Equation to...
-
PeterDonis replied to the thread Undergrad Momentum measurement and uncertainty.I think that's reasonably standard terminology, yes.
-
PeterDonis replied to the thread Graduate Time evolution of a detected particle.By no means. It could be bouncing back and forth within the confined space very fast. Or very slow. Or not at all.