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  1. J

    KSTAR recent result and breakeven

    Thanks for the references
  2. J

    KSTAR recent result and breakeven

    I assume this result was from a run with ordinary hydrogen, no deuterium or tritium. But I think the equivalent DT values are frequently calculated. Is this possible here? TIA again
  3. J

    B What is going on at LIGO/VIRGO?

    Why no new data? No news of any problems that I have heard. I'm both mystified and concerned. Jim Graber
  4. J

    B Why 50% of entangled photons pass through the polarizer?

    Thanks for the references. It is somewhat clearer to me now, particularly in the context of entanglement.
  5. J

    B Why 50% of entangled photons pass through the polarizer?

    So, please, what is the difference (in math and in words) between "the Photon is V-Polarized along axis X" and "if we measure the polarization along angle x the result will be V" ? Thanks jim Graber
  6. J

    Commercially Feasible Fusion Reactor

    https://thebulletin.org/iter-showcase-drawbacks-fusion-energy11512 An interesting and well done pessimistic assessment.
  7. J

    Chernobyl Interesting new paper on Chernobyl

    http://www.tandfonline.com/doi/full/10.1080/00295450.2017.1384269 According to this paper, two nuclear explosions and one steam explosion took place.
  8. J

    A Tension between recent dark matter results and Lux-Xenon?

    How much tension between recent AMS-02 80 Gev dark matter and Lux-Xenon negative results? Recent results ( Arxiv 1610.03840 and 1704.08258) suggest a WIMP dark matter particle near 80 Gev. See also https://phys.org/news/2017-05-possibility-cosmic-rays-due-dark.html If this particle really...
  9. J

    B Fusion reactor status?

    In addition to pB, there is also DHe3. Helion Energy plans to use this fuel
  10. J

    Tokamak News and Queries

    At one point they were supposed to be running with plain ordinary hydrogen now, leading up to deuterium and tritium next year. Have they even restarted the plasma runs? I am pretty sure they are done building (or rebuilding) the beryllium and tungsten based "iter like wall" Woops, Google says...
  11. J

    Tokamak News and Queries

    http://www.sciencemag.org/news/2016/09/stewart-prager-steps-down-director-princeton-plasma-physics-laboratory?utm_campaign=news_daily_2016-09-27&et_rid=17668404&et_cid=840230 There is more news on the NSTX-U problem this morning. it looks pretty bad. jim graber
  12. J

    Tokamak News and Queries

    http://www.pppl.gov/news/2016/09/pppl-director-stewart-prager-steps-down It appears that Stuart Prager is “stepping down” as director of PPPL. I wish him well. But in the announcement it refers to a “recent technical setback in the NSTX-U facility”. I had not heard previously of this set...
  13. J

    I The typical and the exceptional in physics

    https://arxiv.org/abs/1405.3483 Steven Weinberg Quantum Mechanics Without State Vectors In this paper, SW proposes a formulation of QM based solely on density matrices. Does this solve the problem? How is it similar or different to the AN formulation? TIA Jim Graber
  14. J

    B Is the wave function physical ?

    Oh Yes. I was thinking of the range, not the domain. Is that C^3N? Or Only R^3N? Or sometihng bigger and more complicated? TIA Jim Graber
  15. J

    B Is the wave function physical ?

    Is it R^3N or C^3N? And does this make a difference as far as realness or physicality?
  16. J

    I Delayed choice, pseudo-retrocausality, massive particles

    I did trace through the entangled but never simultaneously existing example. It does seem more or less obvious to me, but perhaps hard to prove. As far as I can remember, I have never seen anything published on this. Thanks for the reply., Jim Graber
  17. J

    I Delayed choice, pseudo-retrocausality, massive particles

    I would appreciate references for that Zigzag limit. TIA. Jim Graber
  18. J

    B Meaning of the word 'instantaneous'

    "And finally: entanglement of 2 photons does not require them to have interacted in the past. Nor to have interacted with anything that ever interacted in the past. Nor to have ever co-existed. Or even have existed in a common light cone. None of this is consistent with your mental picture of...
  19. J

    ITER Schedule

    I think it is June 17, but I do not know for sure.
  20. J

    B What is the Planck length?

    ""The Planck Length is so small that calculations show something vibrating within that length, would be so energetic it would become a black hole "" "sounds ridiculous to me." On the contrary, actually this (first quotation) is a slightly poetic version, but it is essentially true. For every...
  21. J

    ITER Schedule

    http://www.sciencemag.org/news/2016/04/updated-panel-backs-iter-fusion-project-s-new-schedule-balks-cost Here is the latest news on the ITER schedule.
  22. J

    ITER Schedule

    Oak ridge perspective on ITER: http://knoxblogs.com/atomiccity/2016/04/16/the-iter-decision/ There will be a House of Representatives hearing tomorrow (April 20) at 10:00 am Washington time. ITER Director General Bigot is expected to testify...
  23. J

    I Relation between QM and QFT

    What quantum mechanics (without collapse) predicts is that *everytime* you get half a silver atom in the first direction and another half of a silver atom in the second direction. That is the measurement problem. Best. Jim Graber
  24. J

    Are tracks in collision experiments proof of particles?

    I think all those thousands of people at CERN think that they work at a particle collider, and talk about particles all the time. Nevertheless, it is still possible that the wave picture or QFT could be more accurate than the particle picture (QM, or whatever you call it.) I think other posters...
  25. J

    When is the peak energy of gravitational radiation

    Just at the last instant before they merge. The energy increases during the inspiral, and decreases during the ringdown. The very brief in-between phase, sometimes called the "plunge" or the "merger" is when the peak occurs. Best, Jim Graber
  26. J

    A Shocker: PR Box is logically inconsistent

    I could be wrong, but I think it says that PR boxes are mathematically inconsistent, contrary to what was previously believed.
  27. J

    A Shocker: PR Box is logically inconsistent

    If correct, Uzan refutes Popescu and Rohrlich. To me this seems like a big deal. Super-Quantum, Non-Signaling Correlations Cannot Exist Pierre Uzan http://arxiv.org/abs/1602.01135 Comments?
  28. J

    How are mathematical concepts translated into illustrations

    Who made the first very well-known illustration of gravity that causes space-time to curve around massive objects? It is called Flamm's paraboloid, and dates back to 1916. You can see it here: https://en.wikipedia.org/wiki/Schwarzschild_metric There is also a reference to the original...
  29. J

    B Questions about recent paper on Entangled Histories

    Is it better to have multiple chronologies all going forward, or a "single" chronology going forward and backward in time?
  30. J

    An abstract long-distance correlation experiment

    Four steps on the road from not at all weird to completely weird: 1.) Classical communication 2.) Quantum communication. 3.) PRBox Communication. 4.)FTL communication.
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