Recent content by PerpStudent

For clarificatiion: The stress energy tensor has a coefficient with specific dimensions. In order for the equation to be consistent, T, R and g must have dimensions to make the equation consistent. My understanding of the metric and curvature tensors is that they are geometrical and either have...

Thanks for your response. Newtons^-1 is the dimension of the coefficient of T. If the Ricci tensor has dimension of distance^2, would it not follow that T has dimension N(distance^2)?

The coefficient of the stress energy tesor in the GR equation reduces to 8π/Ν, where N = {"(Kg)m/s^2.} Is it correct to conclude that all the elements of the stress energy tensor must have the dimension of N = (Kg)m/s^2 since the curvature and metric tensors on the other side of the equation are...

According to the wikipedia article on virtual particles: . and: Yet, Hawking radiation is caused by the spontaneous creation of virtual particles -- as a consequence of the uncertainty principle -- that are separated by the event horizon and -- I guess -- become "real." Am I missing something?

What distiguishes real and virtual particles? Virtual photons, virtual gluons and virtual W particles are often referred to in discussing the interactions they determine. Why and when are they virtual? Why and when are they real?

This is great, thanks. Ignore the previous post.

OK, with Δx = Δy = Δz = 0, then τ = cΔt, which is a length. What does that mean?

Proper length is given by $$ L = \sqrt{\Delta x^2 + \Delta y^2 + \Delta z^2 - c^2\Delta t^2 }$$ So, when $$ \Delta x = \Delta y = \Delta z = 0 $$ there is no motion and $$ L = ic\Delta t $$ What does that mean, if anything?

Thanks for all the comments. It is quite amazing that the Lagrangian is so fruitful in ways that Lagrange could never have imagined. For example, I was just reviewing its application to quantum field theory. I am continually awed by the mathematical nature of the universe.

Thanks for your response. I see that the observed forces in the Casimir effect are consistent with the quantum theory of the harmonic oscillator. However, is there any experiment that demonstrates that the ground state of the energy for a particle cannot be zero? I understand that a zero ground...

I hope this is a coherent question: Solving the Schrödinger equation for energy eigenvalues for a harmonic oscillator leads to the ground state of the energy for a particle being ω/2. What is the experimental evidence that this is, in fact, the lowest achievable energy and that zero energy is...

Thanks for all the helpful comments.

Thanks, that's very helpful.

Yes, I am describing a PROTON, which is at rest at A, travels to B at .999c and is again at rest at B.

Intelligent protons are also skeptical. When at rest at A, it says to itself, hey, I'm 10 LY from B. Then after I accelerate it, it says, wow, now I'm only about .3 LY away from B so I'll get there in .3 years. After it gets to B and stops, it confirms that it traveled 10 LY, but it believes it...