PHYS 1750: SELECTED TOPICS in PHYSICS
LECTURE 40. Relativity
26.1. | The Principles of Relativity | ||
1. | The laws of physics cannot reveal a preferred frame | ||
a. Inertial frames of reference | |||
b. There is no absolute frame | |||
2. | The speed of light is the same in all inertial frames | ||
a. The emitter frame | |||
b. The detector frame | |||
26.2. | Consequences | ||
1. | Simultaneity | ||
2. | Time dilation | ||
a. Proper time Δto | |||
b. Δt = Δto / sqrt(1-v2/c2) = γ Δto | |||
c. True for real time, not just clocks | |||
26.3. | Length Contraction | ||
1. | Proper length Lo | ||
2. | L = Lo sqrt(1-v2/c2) = Lo / γ | ||
3. | Space travel and the twin "paradox" | ||
26.4. | The Addition of Velocities | ||
vab = (va + vb) / (1 + vavb/c2) | |||
26.5. | Relativistic Momentum p = γmv | ||
26.6. | Relativistic Energy | ||
a. Total energy E = γmc2 | |||
b. Rest mass energy Em = mc2 | |||
32.2. | General Relativity |