20210907 : Mars and speed of light
The speed of light is 299,792,458 m/s. Or roughly, as we learnt in school, 3x10^8 m/s. That's awfully fast. Incidentally, the fastest we can also communicate today. Can almost go around the whole earth once in a second. They are planning to colonise Mars sometime soon. They have many challenges. One of the main ones is communication. You see, it will take a little over 4 Seconds to send a message back or forth. But thats the best case scenario - when Earth and Mars are closest. When they are farthest, it will be over 16 minutes. There goes the concept of "instant" messaging folks there. It's a different problem that the Sun will be inbetween to communicate anything. Another interesting challenge is how to keep track of time. Mars doesn't rotate in its axis in 24 hrs. Days don't match. They have 2 moons- so there goes the concept of months. The earth revolves around the Sun almost twice in a mars year. So nothing cyclic matches. Yes, we can give earth time, but