1. In fact, the spring of the absorber is not massless.

2. All massless particles (particles whose invariant mass is zero) are elementary.

3. In particle physics, a massless particle is an elementary particle whose invariant mass is zero.

4. Finally, the quantum distribution of scalar massless particles in the accelerated frame of reference is computed.

5. Take the recent question of whether neutrinos, a type of near-massless subatomic particle, can travel faster than light.

6. On the contrary the “Iongitudinal” acoustical phonons, like the acoustical phonons in nonpolymeric crystals in general, remain comparable to the massless photons in the vacuum.

7. In an earlier paper, we constructed the genus-two Amplitudes for five external massless states in Type II and Heterotic string theory, and showed that the α′ expansion of the Type II amplitude reproduces the corresponding supergravity amplitude to leading order