Recent content by zefram_c

  1. Z

    QM says no observer, no existence

    To expand on the above comment, QM is more than capable to describe the time evolution of quantum objects, including interactions between objects or with externally imposed potential fields. In fact, it is actually deterministic in this manner: the wave function at any future time can be...
  2. Z

    Steve Asks: "Do Neutrinos Oscillate in Vacuum?

    The closest one can get to a 'pure vacuum' experiment is the measurements done on solar neutrinos - although of course such neutrinos have to pass through the Sun in order to reach us. You can look up the papers by the SNO or SuperKamiokande collaborations for that purpose.
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    News Separation of Church and State May God Bless the rest of us?

    Whether that was implied or not, speaking for myself, that's EXACTLY what I expect of elected officials - unless they were elected on the basis of their religion. The reason for that is as follows. A modern democracy is expected to guarantee certain basic rights to its citizens, among which...
  4. Z

    When electrons and positrons collide they produce 2 photons

    All that's required is a partial overlap of their wavefunctions to count as a "collision". Think of the positronium atom: in the ground state the electron's wave fcn vanishes at the positron "nucleus" and there is no "motion" as defined clasically - yet the system still decays.
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    News Plight of Terri Schiavo: Facts, Emotions, and Outcomes

    I've been following this case for the last while. I am not going to weigh in on the issue of what should or should not be done with Terri, but doesn't anyone see the larger implications of this? Isn't anyone bothered by the fact that Congress made an act that was targetted to deliberately...
  6. Z

    Understanding Uncountable Well-Ordered Sets: An Intuitive Explanation

    Thanks Hurkyl - after reading your response, I went back and checked. Turns out my understanding of well-ordering was incorrect; I now get the logic. The analogy gave me food for thought, so I will think on it for now and see if I can persuade myself that it works.
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    Understanding Uncountable Well-Ordered Sets: An Intuitive Explanation

    I can't get a good intuitive grasp on this set. Folland defines it as follows: My questions / problems with it are somewhat as follows: 1) I don't see how the set can be uncountable if any initial segment is countable. 2) How do we know that the element x0 used in the proof exists?
  8. Z

    What is the complete non-mathematical explanation for spin in particle physics?

    I don't know which paper that is, but I'm sure the context is more enlightening than just that quote. (Do they suggest why it is unsatisfactory, or how to improve upon it? There are valid and invalid reasons for saying that. I'm sure they don't just make that statement and move on.) Fair...
  9. Z

    Format hard drive / delete NTFS partition (Windows XP)

    You were misinformed. Fdisk can do it - that is, it can delete any partitions (even those it doesn't recognize, such as NTFS). Of course, it can only create FAT/FAT32.
  10. Z

    Understanding Neutron Decay in Elementary Particle Physics

    A "decay" in particle physics typically means a process where one initial particle is converted into other stuff. The term may be used liberally in some contexts; I don't know. Neutron has spin 1/2. There simply exists no mechanism within the SM to run (1.13). Of course, this means very...
  11. Z

    [canada] relevant fields in physics

    I have had a great physics education at UBC. We have plenty of good physicists in condensed matter, biophysics and laser physics, which are the most industry-related fields. Most departments will list the research interests (i.e. areas) of their faculty somewhere on their websites.
  12. Z

    Permanently block certain processes anti virus

    Aiiii. These kind of Windows viruses are a menace, and it looks like you got a cocktail of them, too. Why NAV can't delete them is as follows. An open process opens a file handle to its executable, so it can't be deleted while it's running. This has been a long-standing Windows policy that...
  13. Z

    Can Hybrid Atoms with Matter and Antimatter Nuclei Truly Exist?

    Unfortunately, that would not work either, since an anti-strange quark can still weakly interact with an up quark and form an electron/neutrino pair. Personally I don't think any nuclei of the proposed type can be formed.
  14. Z

    In an electrodynamic system, does the entropy of the field increase?

    If the electric field in a system is fully specified, the charge distribution is uniquely determined by Gauss' Law: \nabla \cdot E = \rho . So I don't see how you can have different microstates for a macrostate.
  15. Z

    Schools University of British Columbia

    I am currently a student at UBC, what do you need to know?
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