This is a theoretical question: Say you bore a hole through earth, suck out all its air, and drop an object in one side. Let's say it takes 42 minutes for the object to come out the other side and come to complete stop (only to then drop back down, of course) Now let's say you drop an object twice as heavy, still 42 minutes right? Ok. Now say you bore a straight hole from Los Angeles to New York in this planet, put a completely frictionless track through that hole (I know, I know, bear with me) and stick a train on it in Los Angeles, letting gravity accelerate it. Will it arrive in New York in 42 minutes? Will it arrive from any point to any other point in 42 minutes? If so, we've got a pendulum there, right? Again, please approach this theoretically, oh and of course earth isn't spinning and is a perfect sphere.. What do you think, is this true?