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Genady

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Everything posted by Genady

  1. It is not. Quantum mechanics prohibits this. No technology overcomes laws of nature.
  2. (1) There is a similar thread here: (2) Online it happens all the time. As soon as I touch a topic by reading or writing online, the ads and news related to the topic start flowing onto my screen.
  3. Here is why the total spin J for the sss baryon cannot be 1/2, AFAIU: The wavefunction for a baryon (a fermion) has to be anti-symmetric. In the ground state, this wavefunction is a product of the wavefunctions for spin * flavor * color. This product has to be anti-symmetric. Since all three quarks are of the same flavor, the flavor wavefunction is symmetric. Thus, the product of the wavefunctions for spin * color has to be anti-symmetric. Next, (Phy489_Lecture9a_2013.ppt (utoronto.ca)) Since the color wavefunction is anti-symmetric, for the product of wavefunctions for spin * color to be anti-symmetric, the wavefunction for spin has to be symmetric. The three 1/2-spin wavefunction is fully symmetric only in the case of all three spins being the same, i.e., J=3/2. It is not fully symmetric if one spin is different from the other two, i.e., if J=1/2. QED
  4. If you don't record all the necessary information, you cannot restore the original state. I claim that it is in principle impossible to collect all the necessary information. This makes your case implausible.
  5. I guess that the OP question is answered. As a personal OT note I wanted to mention that I don't have a positive vibe regarding Y. Ne'eman because he is rather familiar to me as a right-wing politician that he was when I lived in Israel.
  6. Yes, this is it. Any particle with a spin number s has 2s+1 possible spin values.
  7. IIUC, the spin quantum number of the particle is 3/2, which means that the z-component of the spin has 4 possible values, i.e., -3/2, -1/2, 1/2, and 3/2.
  8. @Bob Cross, Just to clarify my comment above. I meant to say in the first statement, "How do you know that the entire mind contents are recorded in the spatial locations of the neurons?".
  9. Genady replied to Genady's topic in The Lounge
    With a tiny little exception of sign language. (But it is not English. OT.)
  10. How do you know that the mind contents are recorded in the spatial locations of the neurons? I bet they are not. The neurotransmitter concentrations, release, absorption, and other molecular level mechanisms inside and outside of neurons are crucial as well. Moreover, how do you know that brain is not a quantum rather than classical computer? If it is, it is impossible in principle to record its state without destroying it.
  11. Genady replied to Genady's topic in The Lounge
    Perhaps it is so. I have a kind of screen in my mind, where a written text continually runs, and I read from it when I speak. So, I often make pronunciation mistakes.
  12. Genady replied to Genady's topic in The Lounge
    Isn't a concept the trigger for generating both the sound and the motor pattern of the word, among many other related aspects, such as visual images, emotions, memories, etc. ?
  13. Genady replied to Genady's topic in The Lounge
  14. Genady replied to Genady's topic in The Lounge
    To me, 'their' goes with 'they' while 'there' goes with 'here'. I didn't consider it a big challenge, I saw it rather as learning two very closely related sets of words: one, how to say it, another, how to spell it. Maybe it is in fact easier to ESL learners, as we learn speech and writing at the same time, while native speakers speak first and learn writing as an extension later.
  15. Genady replied to Genady's topic in The Lounge
  16. Genady replied to Genady's topic in The Lounge
    only native English speakers. Still ? I'm not sure how computer skills play into it.
  17. Genady replied to Genady's topic in The Lounge
    So, people who regularly make these word substitutions, (a) never knew the proper way, (b) forgot the proper way, (c) don't care ?
  18. Genady replied to Genady's topic in The Lounge
    But I did not. It is right here, a bit down the list:
  19. Genady replied to Genady's topic in The Lounge
    Reading such texts causes mental dissonance sometimes. For example, you read "who think their female ..." and you mentally construct a meaning, and then comes the next word and ruins it: "who think their female enough".
  20. Genady posted a topic in The Lounge
    As a non-native English speaker, I'd like to understand why so many native English speakers so often misuse words like their/ there/ they're?
  21. Food is an important element in building the human body.
  22. They have identical DNA, like homozygous twins, and the bodies are similar, but different. Especially, the brains. You can check many studies of homozygous twins. They help to distinguish between genetic vs. environmental effects on development.
  23. This is essentially correct. More generally, momentum is a 3-dimensional vector with a magnitude and a direction. When you sum several such vectors, you get a vector. In some frame, this final vector is 0. This is the frame we're talking about.
  24. You can consider any system of moving components in any reference frame. In any frame, the momentum of the system is a sum of momenta of the components. In some frame, this sum is 0. This is the "system's own" frame.

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