186 million miles per second.
thats travelling from the earth to our sun and then back to the earth in 1 second.
do that for 1 year and you have traveled 1 light year.

should have been 186 thousand miles per second.
sorry must have been either a brain fart ot alzheimers.
3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.