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PeterDonis's Recent Activity

  1. PeterDonis replied to the thread I Two particle system, products and entanglement.

    If we assume that the two particles are distinguishable, then yes. (Here "distinguishable" really means "obeys Boltzmann statistics",...

    Apr 24, 2018 at 9:39 PM
  2. PeterDonis replied to the thread A Dark energy = cosmological constant, any problems with that?.

    No, you're not. If a rope is suspended on Earth, its point of suspension has nonzero proper acceleration whether the rope and the mass...

    Apr 24, 2018 at 7:06 PM
  3. PeterDonis replied to the thread I Electrons Emitting Photons And Ambient Light.

    Since this is a popular science book, not a textbook, its usefulness if you are actually trying to learn the science is limited. An...

    Apr 24, 2018 at 4:07 PM
  4. PeterDonis replied to the thread I Einstein-Bohr "photon box" debate and general relativity.

    This paper is by our own @Demystifier , who might want to comment.

    Apr 24, 2018 at 3:00 PM
  5. PeterDonis liked ZapperZ's post in the thread I Heisenberg Uncertainty vs Measurement Error.

    I could have sworn that I addressed this very issue many years ago....

    Apr 24, 2018 at 1:47 PM
  6. PeterDonis replied to the thread I Heisenberg Uncertainty vs Measurement Error.

    While it is true that the point under discussion in this thread originally came up in a previous thread, the discussion here can and...

    Apr 24, 2018 at 1:43 PM
  7. PeterDonis replied to the thread I Why doesn't a photon's mass increase to infinity?.

    This is not correct. The correct statement is that the concept of "experienced time" does not apply to photons. It only applies to...

    Apr 24, 2018 at 1:36 PM
  8. PeterDonis replied to the thread A Dark energy = cosmological constant, any problems with that?.

    I don't have my copy right now, but I'll take a look when I get a chance. If it's a place where the term "force" is used to mean...

    Apr 24, 2018 at 1:34 PM
  9. PeterDonis replied to the thread A Dark energy = cosmological constant, any problems with that?.

    Sorry, again you are mistaken. Please go back and read my exchange with @Bandersnatch again. In the case of tides on the Earth, the...

    Apr 24, 2018 at 12:34 PM
  10. PeterDonis replied to the thread I Two particle system, products and entanglement.

    Sort of. The notion of "degree of entanglement" allows for many more possibilities. For example, even in a two-photon system, you can...

    Apr 24, 2018 at 11:26 AM
  11. PeterDonis replied to the thread I Two particle system, products and entanglement.

    Once again, you need to be careful with your descriptions. What you are trying to describe here is two quantum systems: a two-photon...

    Apr 24, 2018 at 11:24 AM
  12. PeterDonis replied to the thread I Time-like KVF and Energy GR.

    There is certainly a formula: it's the one you quoted from Carroll, which actually ends up reducing to the one @Mentz114 gave you. But...

    Apr 24, 2018 at 10:53 AM
  13. PeterDonis replied to the thread A Dark energy = cosmological constant, any problems with that?.

    As a result of expansion, yes. But that happens regardless of whether there is dark energy; it's not due to any "transfer" of energy to...

    Apr 24, 2018 at 10:45 AM