difini..........tion

1. Geodesic: - A geodesic is the shortest or longest path between two nearby points.
2. Doppler Effect: - stars moving away from us will have their spectra shifted toward the red end of the spectrum and those moving toward us will have their spectra blue-shifted. This relationship between frequency and speed is called Doppler Effect.
3. Murphy’s Law: - Things always tend to go wrong.
4. The Uncertainty Principle: - curtain pairs of quantities, such as the position and velocity of a particle, can not both be predicted with complete accuracy.