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

-- Bertrand Russell


Jun
5
comment Why the heat flux vector at a point must be perpendicular to the temperature isothermal surface? Is it a definition or a deduction?
I don't see any equation (2-3) on page 65.
Jun
5
comment When we talk about speeds in relativity theory, where are they measured?
With respect to what are you measuring your velocity and the Earth's velocity? I think you still don't quite get it. Your question and assertions make no sense because you never define your reference system. Velocity is relative to a reference system.
Jun
4
revised Why the heat flux vector at a point must be perpendicular to the temperature isothermal surface? Is it a definition or a deduction?
added 210 characters in body
Jun
4
comment Why the heat flux vector at a point must be perpendicular to the temperature isothermal surface? Is it a definition or a deduction?
Your link doesn't seem to work.
Jun
4
comment Why the heat flux vector at a point must be perpendicular to the temperature isothermal surface? Is it a definition or a deduction?
It is not the original form of the law. But while vector calculus didn't exist in Fourier's time, Fourier was well aware that heat fluxes could flow through any side of my hypothetical box I was talking earlier. He would have had a $dQ/dt$ for each side, hence a vector.
Jun
4
comment Why the heat flux vector at a point must be perpendicular to the temperature isothermal surface? Is it a definition or a deduction?
See my edit, it addresses this issue.
Jun
4
revised Why the heat flux vector at a point must be perpendicular to the temperature isothermal surface? Is it a definition or a deduction?
added 133 characters in body
Jun
4
answered Why the heat flux vector at a point must be perpendicular to the temperature isothermal surface? Is it a definition or a deduction?
Jun
3
answered Why is the Big Bang the biggest explosion in the universe?
Jun
3
answered Having a problem about entropy, thermodynamics
Jun
3
comment Density of states of a photon gas in volume V and temperature T
Your formula also implies there are only two photons possible in your system. But the thing is photon systems can have an arbitrary number of them. Of course, taking into account quantization, for each frequency or momentum, only discrete multiples of the corresponding energy will be accessible. Also, you are making a computation for the microcanonical ensemble with fixed energy. They are asking for a canonical ensemble with fixed temperature. And since photon number is not fixed, it's even grand canonical.
Jun
3
comment Density of states of a photon gas in volume V and temperature T
To begin with, if $p$ is momentum, why is there an $\hbar$ in your first formula? One should have $E^2-p^2c^2=0$ for photons.
May
26
awarded  Nice Answer
Jan
27
comment Is Dr Quantum's Double Slit Experiment video scientifically accurate?
Maybe you could explain to me what the delayed choice quantum erasure changesto the problem? Because just saying it makes a difference doesn't quite cut it.
Jan
3
awarded  Nice Answer
Jan
1
comment Why is quantum entanglement so important?
I'm sure you're right about what he had in mind. But that should not be for us to guess.
Dec
30
comment Why is quantum entanglement so important?
Unfortunately, your example is not an example of entanglement. It's not even clear to me there are correlations involved. Antiparallel spins can be represented as: $|\uparrow\downarrow\rangle$.
Dec
9
awarded  Constituent
Nov
26
awarded  Caucus
Nov
12
awarded  Yearling