Inside Planet Earth [HD] (5 Of 10) Lunar Eclipse December 10 2011.mov. A Trip Through Spacetime. A Trip Through Spacetime See how space and time are in the eye of the beholder 1. Einstein understood that the speed of light never changes. All observers, no matter where they are or how fast they're moving, will measure the same speed of light. 2. Einstein realized that if the speed of light never changes, then two people moving at tremendous speeds relative to each other will experience TIME differently. Imagine a clock made of two mirrors. 3. 4. Watching from the crosswalk, you would see the clock within the cab ticking much more slowly. 5. Physicists call this effect TIME DILATION. 6.
If the cab driver and you at the crosswalk agree about the speed of light but disagree about measures of time, you must also disagree about measures of length. 7. Yet the cab driver measures this length as less than 10 feet. 8. Physicists call this effect LENGTH CONTRACTION. 9. To explore this phenomenon—special relativity in action—climb aboard our imaginary cab. Take a high-speed cab ride with Einstein. NOVA (PBS) - Hunting the Edge of Space - Part 2 (2010) How Large is the Universe? Astronomy 7B - Lecture 1 - sporadic slides - published at instructor request. HD) Cosmos (코스모스) - EP13 - Who Speaks for Earth? (누가 우리 지구를 대변해 줄까) BBC Space Episode 2 (Staying Alive) When art meets astronomy Watching the eclipse Astronomy Documentaries (Page 2)