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"I would never die for my beliefs because I might be wrong."

-- Bertrand Russell


Aug
16
comment Is dark matter really present around the sun?
Fair enough, I think every statement about dark matter should really be preceded by "we think that..." or "it is hypothesized that...".
Aug
16
comment Is dark matter really present around the sun?
I guess transparent matter would work, it just doesn't sound that ominous. ;)
Aug
16
answered Is dark matter really present around the sun?
Aug
9
comment what is wrong with the following argument about stokes law in compact universes?
I was just going to say that. It's easier to visualize with a closed curve on the surface of a sphere, thus dividing it in two regions. You have to determine an orientation along which to integrate over the curve and if you mean to enclose the other region, then the orientation w.r.t. to your previous choice must reverse.
Aug
7
comment Why is the probability that Kip could go back and kill his grandfather $10^{-10^{60}}$?
I don't know the detailed calculation. I suspect it can be found in "Gravitation" by Wheeler, Thorne and Misner. It must be based on the instability of wormholes. Wormholes have a very short lifetime and thus a probability must be associated with that lifetime.
Aug
7
revised Why is the probability that Kip could go back and kill his grandfather $10^{-10^{60}}$?
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Aug
7
comment On Bell's Inequality (Classical Intuition) and Quantum Mechanical Counter Intuition
It doesn't take care of it, since the local hidden variable theory leads to Bell inequalities which are incompatible with QM. Still don't see your point.
Aug
7
comment Why is the probability that Kip could go back and kill his grandfather $10^{-10^{60}}$?
Yes, but I think the point is that Hawking is envisioning time travel through a wormhole. That's the theory he's relying on. Thus, I suspect the probability is related to the probability of creating a stable wormhole capable of sending Kip Thorne back in time. Which would be a very low probability indeed.
Aug
7
comment Why is the probability that Kip could go back and kill his grandfather $10^{-10^{60}}$?
It must be based on some particular theory for the process that would take Kip back in time. I don't have my copy of "The Universe in a Nutshell" at hand, can you maybe quote the full paragraph in which the statement is made?
Aug
7
revised On Bell's Inequality (Classical Intuition) and Quantum Mechanical Counter Intuition
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Aug
7
comment On Bell's Inequality (Classical Intuition) and Quantum Mechanical Counter Intuition
I don't understand your question. Common sense intuition -- whatever that means but you seem to say Bell's inequality is what it means-- tells us that QM is wrong. Experiment tells us that common sense intuition is wrong. Science tells us that experiment is the arbiter here.
Jul
27
comment Why aren't we Boltzmann brains in an infinite universe?
I think this is philosophy more than physics. There's no physical answer other than: the most sensible hypothesis is that we are not Boltzman brains. And to then work from there.
Jul
16
comment How can I stand on the ground? EM or/and Pauli?
@ChrisGerig: I'm willing to concede your point. I'm no expert on the matter. But I can understand a reasoned argument, so please, instead of posting comments on a message that's nearly one year old, why don't you try to formulate your own reply with the necessary references? You're free to downvote my answer if it displeases you.
Jul
2
comment Is space unending?
The surface of the Earth has no boundaries, yet it is finite. Infinite and unbounded are different concepts.
Jun
29
revised Second Law of Thermodynamics, heat and quantum-level explanation
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Jun
29
answered Second Law of Thermodynamics, heat and quantum-level explanation
Jun
28
comment Negative and positive energy and Hawking
I suggest you drop question 2 if you insist that it's not a theological question. I'll just say that Hawking is a great physicist but a bad philosopher. The theories that Hawking describes can be treated in a mathematically rigorous way. For them to be able to say something about God, we'd need a precise mathematical formulation of God. Since there is no such thing, any conclusion about a theory in relation to God is worthless/meaningless.
Jun
18
accepted Wind Turbine Impact
Jun
18
comment Wind Turbine Impact
Great reply. What is your background, EnergyNumbers?
Jun
17
awarded  Student