Dr. Neville Jones wrote: > To illustrate, what would happen on your train if the walls suddenly > disappeared? The air that was previously inside the carriage would be pushed > backwards, right? But Newton's laws of motion show us that the air molecules > outside the carriage would also be pushed forwards by those which were > previously contained within the carriage. Those that were outside have lost > energy in bringing the others "back into line." How is this energy loss made > up > again. With winds blowing all over the place, the friction and energy losses > would be enormous. The atmosphere, if it were rotating with the World would > soon slow down and stop - and the World would not be long after it. That last sentence is not true. According to the law of conservation of angular momentum if there were nothing else affecting the weather here on earth (like the sun, the moon and geothermal activity) then due to the friction between the atmosphere and the earth the whole system would settle down and once settled would just carry on rotating forever until some force stopped it. How can you say "But Newton's laws of motion show us..." and then go on to completely ignore them by claiming that there is some sort of drag in a vacuum? Regards, Mike.