Tagged Questions
3
votes
1answer
104 views
Negative energy and large-scale spacetime structure
I was reading an essay from Stephen Hawking's on the Space and Time warps and I was trying to make sense on some statements referring to the Casimir effect such as:
The energy density of empty ...
3
votes
1answer
131 views
Hamiltonians and Lagrangians, Euclidean and Hyperbolic: Are they related?
The Lagrangian of a system is the difference between its kinetic energy $T$ and potential energy $V$, and is relativistically invariant:
$L = T - V$
The Hamiltonian of the same system is the sum ...
0
votes
1answer
84 views
spacetime or only space? [closed]
I was thinking one day, if time doesn't exist and there is only space. I was trying to think about what other measurementunit could be instead of speed(m/s) and acceleration(m/s2) and I came to ...
2
votes
2answers
631 views
Proof that Energy Momentum Tensor of Scalar Field Theory satisfies Weak Energy Condition
It's a question on Sean Carroll's Spacetime and Geometry, where we are supposed to prove that the energy momentum tensor of scalar field theory satisfies Weak Energy Condition (WEC). The energy ...
2
votes
2answers
344 views
Does space have to be filled with charged particles to carry electromagnetic waves?
I'm a newbie here so have mercy.
I'm studying electromagnetic waves. This is the propagation of energy via the vibration of charged particles, as I understand it.
A charged particle could be like ...
