Question
Have you ever noticed that light is not actually required for playing quizbowl? To rectify this, answer the following about light, for 10 points each.
[10e] Light is a wave traveling in this field. This field can be described by a rank-2 antisymmetric tensor field F, or, more simply, by two vector fields symbolized E and B.
ANSWER: electromagnetic field [or EM field or EMF; accept answers that contain both electric AND magnetic fields; prompt on partial answer]
[10h] The stress-energy tensor of an electromagnetic field is symmetric and has this property, meaning that the energy density minus the pressures is zero everywhere. This property is written “T sub a sup a equals zero.”
ANSWER: traceless [or zero trace; accept any description stating that the trace is zero or vanishes]
[10m] The time-space components of the stress-energy tensor, times c, describe this 3-vector. This vector field can be used to calculate the direction and intensity of a light beam, though it may need to be time-averaged over a cycle.
ANSWER: Poynting vector [prompt on S]
<RA, Physics>
Summary
| 2023 ARCADIA at Imperial | Imperial | Y | 5 | 18.00 | 80% | 60% | 40% |
Data
| Cambridge A | Birmingham | 10 | 0 | 10 | 20 |
| Edinburgh | Oxford | 0 | 0 | 0 | 0 |
| Imperial A | Durham | 10 | 10 | 10 | 30 |
| Cambridge B | Imperial B | 10 | 10 | 10 | 30 |
| Warwick | Bristol | 10 | 0 | 0 | 10 |