58,695 reputation
482200
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location New York City
age 41
visits member for 3 years, 4 months
seen 6 mins 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. I participate at physicsoverflow.org.


18m
comment Underground explosions due to plate tectonics and natural gas pockets
@Michael: It's difficult because the initial estimates are uncertain, and there is pressure below, so that the oil might be migrating from lower down from a larger reservoir, or continuously migrating from the mantle. It also depends on whether there is still a path for the hydrocarbons to migrate, it's a tough question. It would require a detailed way to estimate the length of time since the oil arrived from the mantle, and radioactive decay markers might be used for this, if you have some idea of what the radioactive signature of the mantle oil is. I don't know any more than anyone else.
22m
comment Is space unending?
@LarryHarson: Fields by definition are at a spacetime point. They don't move. The excitations move. The excitations move outward, and at the horizon, move outward at the speed of light as considered relative to the observer at the origin. But the fields themselves are defined on the interior, and can't move. It's a terminology issue, there is no actual question here regarding anything meaningful.
Dec
18
comment Underground explosions due to plate tectonics and natural gas pockets
@Michael: There's no such thing as non-abiotic oil, so you should just call it "oil". Nobody knows the answer to your question, because it isn't studied anymore, since the breakup of the USSR.
Dec
18
comment Is space unending?
@Michael: fields don't move.
Dec
4
awarded  Enlightened
Dec
4
awarded  Nice Answer
Nov
22
awarded  Nice Question
Nov
21
comment Will free-fall object into black hole exceed speed of light $c$ before hitting black hole surface?
@mike4ty4: The coordinates where the objects freeze are degenerate on the horizon, there is no paradox. The objects freeze because the coordinate time stops, not because their intrinsic velocity is slow. It requires knowing the metric form at a horizon, something you can work out for Rindler space easily, because it's just flat Minkowski space in disguise.
Nov
18
comment How long would it take to travel through a wormhole?
@mike4ty4: Do I ever give a citation for anything? It's easy to see for yourself.
Nov
15
comment What is a tensor?
@Physikslover: This is just the classical index definition. The process of finding invariants is by raising and lowering indices using the metric tensor (which is just the identity for Euclidean space, so you can ignore up and down position) and taking arbitrary traces by contracting indices. With a two-tensor, there are lots of invariants T^a_a, the trace, T_ab T_ab (sum of squares of all components--- the "length"), T_abT_bcT_ca (a cubic invariant that doesn't have a name) etc. There is one other invariant, the epsilon tensor, which is used to construct chiral invariants like the cross prod.
Nov
13
awarded  Nice Answer
Nov
12
comment Is the universe linear? If so, why?
Or, say, let's not.
Nov
12
comment Is the universe linear? If so, why?
@mike4ty4: A quantum computer which factors an arbitrary 10,000 digit number is sufficient to rule out all classical 10^140 bit computers even with extra miracles (like order 10^sqrt(n) factoring realized easily in nature), so that's the condition I choose for saying "quantum mechanics is experimentally proved to be exponentially large". That's enough for me to say that you've proven quantum mechanics is exact for all intents and purposes, since exponentially large alternatives are not particularly interesting to me personally.
Nov
12
comment Will a ball slide down a lumpy hill over the same path it rolls down the hill?
@Physikslover: NO, there is no difficult part. The no-slip rolling-ball constrained Maupertuis action is identical to the sliding ball Maupertuis action, up to an overall rescaling which doesn't affect the trajectory (the only difference is the time taken to traverse the trajectory). That's why it's trivial in the Maupertuis formulation. I worked it out (in my head, in two seconds) before posting.
Nov
11
comment Is the universe linear? If so, why?
@mike4ty4: The difference between a computer simulating a classical universe and a computer simulating all the details of a quantum universe is exponential, so a classical computer needs 10^140 bits, while a classical computer simulating a quantum computer simulating the universe needs 10^(10^140) bits, which is like the difference between a googol an a googolplex (except even bigger). If Quantum Computation is fundamental, not classical computation, this would still require 10^140 qubits, which is reasonable. The question here is which is the right computation model, CM/QM.
Nov
11
comment Is the universe linear? If so, why?
@mike4ty4: Theories don't work like that--- we still observe things that are consistent with Newton, does that mean there is no relativity? The idea is that it is possible QM could be superseded by a smaller alternative, which would make the universe less computationally demanding. There's no real reason it must be so, but there's no real reason it can't be so, except quantum mechanics is very hard to reproduce from such a thing, and it can't happen without massive nonlocality. If you see real Quantum Computation, this rules out small computer universes forever, so I don't care. Many worlds.
Nov
11
comment Will a ball slide down a lumpy hill over the same path it rolls down the hill?
@Physikslover: In case you are an English non-native speaker, the reference is a JOKE. There is NO REFERENCE, nor can there be, it's completely obvious, despite the lengthy arguments in other answers, because of the existence of the timeless action principle (Maupertuis principle). Arguments in Physics ARE NEVER MADE WITH A REFERENCE, they are made from first principles, and I did so. This is an IMMEDIATE corrolary of the principle of Maupertuis, not because I say so, but because IT IS, an anyone can check it in ten seconds of thinking.
Nov
10
comment Will a ball slide down a lumpy hill over the same path it rolls down the hill?
@Qmechanic: Do you still think the same stupid things, with the benefit of hindsight?
Nov
6
comment Why do covalent bonds form?
@KirkWoll: If you bring two classical polarizable atoms close, they don't attract. When you bring two quantum atoms close, they do, because the electrons can tunnel to the other atomic volume, reducing their energy. That's it. When they are really close, you get repulsion between the nuclei.
Nov
4
comment Is Stephen Wolfram's NKS, an attempt to explain the universe with cellular automata, in conflict with Bell's Theorem?
@agemO: I see. I'll write up something coherent. I never wrote it, because John Mattick has compiled the evidence well in 2001 (you can google Mattick RNA), and thinks similar things, although not with the computational point of view. The evidence is actually overwhelming by now, it's pretty much the only point of the enormous ENCODE project, to give this thesis scholarly weight.