I'm trying to understand how we might sum over the metric (or vielbein) in a QG theory. So I'm looking at a simple (perhaps too simple) 0+1D action. Imagine a scalar field in 0+1D. The vielbein in 0+1D would be have one component $e(t)$. Also we know that $\det(e(t))=e(t)$ and $g^{00}(t)=e(t)^2$....

My physics textbook says, "The amount of force by which molecules attract each other when they are moved away from each other by a certain distance, is lesser than the amount of force by which molecules repel each other when they are moved closer to each other by the same distance." Why?

Assume a double slit experiment with electrons and no observer (light source). Can the wave-like behavior and resulting interference pattern be explained by the single electron that is being shot, doesn't really travel to the detector, but interacts with other electrons in the medium (e.g. air) b...

The speed of light is defined as $c=299,792,458m/s$, and a meter is defined as the distance that light travels in a $1/299,792,458=1/c$ of a second, but then we would have defined a meter in terms of the speed of light, but we also defined the speed of light in terms of a meter, seems a bit circu...

We can define the total energy of the electromagnetic field as: $$\mathcal{E}_{EM}= \frac{1}{2} \int_V \left(\varepsilon_0\boldsymbol{E}^2+\frac{\boldsymbol{B}^2}{\mu_0}\right)dV$$ which satisfies the conservation law: $$\frac{\partial\mathcal{E}_K}{\partial t} + \frac{\partial \mathcal{E}_{EM}}{...