This account is temporarily suspended to cool down. The suspension period ends on Aug 24 at 17:32.
1 reputation
475175
bio website
location New York City
age 40
visits member for 2 years, 8 months
seen 11 hours ago

I do not participate on this site any longer, except to respond to comments regarding my own text, if that text is unavailable in another form. I do not accept the political moderation atmosphere here, it is not compatible with open science.


Oct
11
awarded  Nice Answer
Oct
11
awarded  Popular Question
Oct
7
awarded  Enlightened
Oct
7
awarded  Nice Answer
Sep
25
awarded  Necromancer
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13
awarded  Guru
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awarded  Good Answer
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awarded  Nice Question
Aug
24
comment Are gravitomagnetic monopoles hypothesized?
@BenCrowell: I gave a quick informal physicist's proof of positive mass in a question: it requires only the weak energy condition--- the positive mass is a requirement that distant black hole's area increase upon absorbing the configuration. A pure monopole is forbidden by positive mass, because it must have a mass, and therefore a regular mass. Birkhoff's theorem is not sufficient, nor are no-hair theorems, because a monopole field is not necessarily spherically symmetric, and it must not come with a horizon.
Aug
23
comment How can we deduce the relation $m = \frac{m_0}{\sqrt{1-\frac{v^2}{c^2}}}$ between relativistic mass and rest mass in special relativity?
@DImension10AbhimanyuPS: No, a continued fraction is when the infinite nesting is in the denominator--- yours is in the numerator. Expand out your formula, you will see.
Aug
23
comment How can we deduce the relation $m = \frac{m_0}{\sqrt{1-\frac{v^2}{c^2}}}$ between relativistic mass and rest mass in special relativity?
@DImension10AbhimanyuPS: Yes, that formula is correct, but it is not the sum of your infinite series--- you deluded yourself in the manipulations into thinking you got the right answer. The actual power series for ${1\over\sqrt{1-v^2}}$ is 1+v^2/2 + 3v^4/8 + 15v^6/48 and so on, the general term is (product of first k odd numbers)/(2^k k!). Your thing gives coefficients of 1/2^k, it is not the same power series (check it carefully). When you know what you're supposed to get in advance, and you are sure the argument is correct, it is easy to delude yourself, you don't check carefully enough.
Aug
23
comment Why is there a deep mysterious relation between string theory and number theory, elliptic curves, $E_8$ and the Monster group?
@DImension10AbhimanyuPS: With someone as young as you, people will just assume you don't know anything, so just make sure.
Aug
23
comment How would a Lagrangian be used to recover the Schrodinger equation?
Oh, then it should be a comment, not an answer. Once you know what the question is asking, then you give an answer.
Aug
23
comment Why does tachyon arise in bosonic string theory?
Oh, but then you shouldn't say "it's a misconception that ..." because then people think you are under the impression that RNS strings exist as theories. Ok, no worries, it's just miscommunication.
Aug
23
comment How can we deduce the relation $m = \frac{m_0}{\sqrt{1-\frac{v^2}{c^2}}}$ between relativistic mass and rest mass in special relativity?
@DImension10AbhimanyuPS: Ok, you know E= m + .5mv^2 to order v^2, why should the v^2 term suddenly change it's coefficient? If you went to order v^4, E = m + .5mv^2 - 1.5 mv^4, you could substitude the fouth-order expression for the mass in front of v^2, or in front of v^4 (maybe both). The issue is that the actual v^2 dependence is only a lowest order thing in v, it is intrinsically modified, not just the coefficient. It is hard to say why something isn't true. It just isn't. You should think about why you think it should be true, and figure out the mistake, because it gives the wrong answer.
Aug
23
comment Why is there a deep mysterious relation between string theory and number theory, elliptic curves, $E_8$ and the Monster group?
@DImension10AbhimanyuPS: ok, but you shouldn't write what I said, which is technically wrong--- E8 is not E6xSU(3), it's a simple group, but it has an embedded E6xSU(3) and fills in the off-diagonal parts with extra crud that's broken when you have SU(3) gauge fluxes which follow the holonomy of the manifold. The precise decomposition is described in detail in Green Schwarz and Witten, which has a nice description of E8.
Aug
23
comment Intuitive understanding of the irreps like Wigner-D matrix?
I explained it in my answer here: physics.stackexchange.com/questions/10403/… . The irreps are symmetric tensors of SU(2), and the D-matrices are just a particular basis for writing the symmetric tensor in terms of the number of "1" indices. When you're doing anything, it's always easier with the tensor representation, there is nothing to memorize then.
Aug
23
comment How does Boscovich's argument show that force must act at a distance?
@julianfernandez: The forces are not primarily electrical, but due to the increase in energy when the electron wavefunction clouds begin to overlap, due to the Pauli exclusion. This is obvious if you consider any sort of simple model of the situation, or even a complicated model, yet still everyone gets it wrong.
Aug
22
comment Combining metric tensors/curvature tensors
You can do this addition at weak field, so long as your coordinates make the metric nonsingular (rectangular coordinates as the unperturbed metric), and add the usually negligible corrections perturbatively.
Aug
22
comment Relative to the speed of light
To be precise, the light is travelling forward from A to B, but it is also going "up" in time in the moving frame, due to the "tilt" of the simultaneity lines in the moving frame. I can't explain without a picture, but you can see it in my answers to relativity questions--- you need to tilt the constant time line to explain why this happens. To see why, answer this: why is light moving backwards in the moving frame also moving at the speed of light as measured in the frame, same as light moving forward?