Recent content by kmm

  1. kmm

    I Are all symmetries in physics just approximations?

    Sounds interesting! Putting that on my 'to read' list.
  2. kmm

    I Are all symmetries in physics just approximations?

    Yes, perhaps I have overly romanticized the "laws of physics" as absolute things, fully capturing the nature of what they describe.
  3. kmm

    I Are all symmetries in physics just approximations?

    Interesting. Thanks for that, I will take a look at that paper.
  4. kmm

    I Are all symmetries in physics just approximations?

    I think the source of my confusion was in thinking of conservation of momentum and angular momentum as fundamental principles of reality, that must be exact regardless of any limits of our ability to measure those things; so that in principle, we could find that conservation of momentum and...
  5. kmm

    I Are all symmetries in physics just approximations?

    This is opening a new door for me to explore! I will be looking further into this. Thanks for the clarification!
  6. kmm

    I Are all symmetries in physics just approximations?

    I came across this video of Leonard Susskind saying that all symmetries in physics are approximations. Unfortunately, I don't have the links on hand, but I have come across other sources of physicists claiming that all symmetries are approximations. My confusion though is that it was my...
  7. kmm

    I Observing black holes in a finite time (in Earth's frame)

    I have spent a bit of time with Special Relativity and am just starting to learn General Relativity, so I still have a lot to learn but this thread was clarifying and made me aware of some false assumptions I was making. Thanks again!
  8. kmm

    I Observing black holes in a finite time (in Earth's frame)

    Another question is, does the fact that the formation of a black hole and the collision of two black holes entail a lot of dynamical processes mean that we can't apply standard gravitational time dilation to the process? I imagine that if two black holes are colliding and creating gravitational...
  9. kmm

    I Observing black holes in a finite time (in Earth's frame)

    Thank you for this clarification!
  10. kmm

    I Observing black holes in a finite time (in Earth's frame)

    I mentioned the gravitational waves observation, understanding that they are emitted outside of either black hole, since I assumed they shouldn't actually collide (in earths frame), since this would take infinite time. However, since the infinite time dilation only applies to an object falling...
  11. kmm

    I Observing black holes in a finite time (in Earth's frame)

    My understanding from General Relativity is that if as distant observers we watch a probe or any test mass approach a black hole, time dilation goes to infinity as the probe gets closer to the event horizon. This would imply that we would never observe a black hole form, or the collision of two...
  12. kmm

    I Confused about some notation used by Griffiths

    It turns out my problem was in making an embarrassingly simple mistake. I often have erroneously thought of numbers like ##a## or ##b^*## as merely real numbers or a real number with a factor of ##i## attached, and not like the complex number, ##z=x+iy##. With this in mind I was then able to...
  13. kmm

    I Confused about some notation used by Griffiths

    I’m not sure what lead you to this assumption that I didn’t try. I did try, and then came here when it was clear I was missing something. The previous comments gave me some clues of what I need to review, so I will be continuing to try.
  14. kmm

    I Confused about some notation used by Griffiths

    OK thanks. Well it looks like I need to just review complex numbers, because the factor of 2 and these relations aren't obvious to me.
  15. kmm

    I Confused about some notation used by Griffiths

    I worked out the expectation values of the components of a 1/2 spin particle. However, I'm confused about Griffiths notation for the x and y components. For the x component I got, ## \left< S_x \right> = \frac \hbar 2 (b^*a+a^*b)## which is correct, but Griffiths equates this to ##...
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