1 Tymor
52 Pennod
The Mechanical Universe - Season 1 Episode 42
If the speed of light is to be the same for all observers, then the length of a meter stick, or the rate of a ticking clock, depends on who measures it.
- Blwyddyn: 1985
- Gwlad:
- Genre: Documentary
- Stiwdio: PBS
- Allweddair:
- Cyfarwyddwr:
- Cast: