Wednesday, March 29, 2017

measurement of the Planck-constant

could one use naturally occuring Planck-spectra for determining the Planck-constant? what would be a viable experiment and would the Sun or the CMB provide a better measurement?

Wednesday, March 22, 2017

40, 20, 10

imagine that one measures the 40 components of the Christoffel-symbol by observing geodesic motion: in what way are the 20 components of curvature fixed? and how does that determine the 10 components of the metric?

Wednesday, March 15, 2017

intuition from the geodesic equation

what would be your argument why the Christoffel-symbol $\Gamma^\rho_{\mu\nu}$ needs to be symmetric in the lower two indices $\mu$ and $\nu$?

Wednesday, March 8, 2017

Lorentz force and acceleration

please explain why the 6 entries of the Maxwell field tensor $F_{\mu\nu}$ determine 4 components of 4-acceleration, and how it is possible to infer all 6 entries from experimenting with a charge.

Wednesday, March 1, 2017

Christoffel-symbols and geodesic motion

why does one need 40 entries of the Christoffel symbol to determine the 4 components of 4-acceleration? can one, from observation of geodesic motion, infer all 40 components?