Good Riddles

Question: There are two planes. One is going from New York to London at a speed of 600 MPH. The other is traveling from London to New York at a speed of 500 MPH.

When the planes meet which one will be closer to London?

Question: You see us everyday, but you never see us together. We appear everywhere but never are we together at the same place. Who are we?

Question: Why did the boy throw the butter out the window?

Question: I sit high glowing and watch the world go by, without me everything would seem dull and dangerous. What am i?

Question: I can be seen, I can be not. Thanks to me, you'll fall in love. I mostly am sweet, but once I were sour. You can receive me, you can't just buy me. You only can send me, or simply share me. What Could I be?