Question
Nesvizhevsky et al. observed gravitationally bound quantum states in neutrons described by this adjective. For 10 points each:
[10h] Give this adjective describing neutrons with energies of less than 300 nanoelectron volts. Due to their low velocity, neutrons described by this adjective reflect off many materials at any angle of incidence, making them easy to store in traps.
ANSWER: ultra·cold neutrons [prompt on cold or very cold]
[10e] The trajectories of ultra·cold neutrons resemble this shape because they are highly affected by gravity. In the absence of air resistance, the trajectory of an object fired at an acute angle is this shape.
ANSWER: parabola [accept parabolic trajectories]
[10m] Experiments involving Larmor precession of ultra·cold neutrons have bounded the magnitude of this quantity. Polarization equals this quantity per unit volume, which is measured in debyes.
ANSWER: electric dipole moment [accept spontaneous electric dipole moment or neutron electric dipole moment; prompt on EDM or neutron EDM or nEDM, prompt on dipole moment or DM; prompt on P; reject “magnetic dipole moment”]
<Physics>
Summary
| 2025 ACF Nationals | 04/19/2025 | Y | 21 | 18.10 | 100% | 52% | 29% |
Data
| Chicago B | Virginia | 0 | 10 | 0 | 10 |
| Illinois B | Cornell B | 0 | 10 | 10 | 20 |
| Illinois A | Rutgers | 10 | 10 | 10 | 30 |
| Florida | Indiana | 0 | 10 | 10 | 20 |
| LSE | Ottawa | 0 | 10 | 10 | 20 |
| Michigan | WUSTL B | 0 | 10 | 0 | 10 |
| Minnesota | British Columbia | 10 | 10 | 10 | 30 |
| NYU | RIT | 0 | 10 | 0 | 10 |
| North Carolina A | Harvard | 10 | 10 | 10 | 30 |
| UC Berkeley B | Northwestern | 0 | 10 | 0 | 10 |
| Johns Hopkins | Ohio State | 10 | 10 | 10 | 30 |
| Virginia Tech | Stanford | 0 | 10 | 0 | 10 |
| Texas | Arizona State | 0 | 10 | 10 | 20 |
| Toronto A | Columbia B | 0 | 10 | 10 | 20 |
| Toronto C | Penn State | 0 | 10 | 0 | 10 |
| UC Berkeley A | Georgia Tech | 10 | 10 | 10 | 30 |
| Georgia State | UCF | 0 | 10 | 0 | 10 |
| Cornell A | Vanderbilt | 10 | 10 | 10 | 30 |
| Waterloo B | North Carolina B | 0 | 10 | 0 | 10 |
| Winona State | Chicago A | 0 | 10 | 0 | 10 |
| Iowa State | Yale | 0 | 10 | 0 | 10 |