Velocity vectors point in the same direction as displacement?

Photons with the highest energy have the longest period

Using a caesar cypher with an offset of three characters (a -> d, b -> e, z -> c), what would be the correct cypher text for the plain text "attack at dawn"?

The star nearest to our sun is proxima centauri, at a distance of 4.3 light-years from the sun. how far away, in km, is proxima centauri from the sun?