A frame of reference relative to which a given body is at rest.
- ‘Soon afterwards it was realized that if the energy of a cosmic-ray proton exceeded 5 x 10 9 GeV then, in its rest frame, a typical cosmic-background photon would be Lorentz-boosted to gamma-ray energies high enough to excite the proton.’
- ‘This problem can also be tackled by saying that in the muon's rest frame the Earth's atmosphere appears length contracted, thus allowing a certain percentage of muons to arrive at the Earth's surface.’
- ‘The light of about 100 distant active galaxies was first corrected to the rest frame of our Milky Way and then added together.’
- ‘Thus our spacetime is more accurately modelled by a cone than by a cylinder, and the real universe, whether finite or infinite, has a preferred rest frame.’
- ‘Mach's principle, which is an important assumption of general relativity, postulates that the sum of all the mass in the universe offers the correct rest frame.’
We take a look at several popular, though confusing, punctuation marks.