Science Buddies: "Ask an Expert"

Hello, I am a person who likes to think about things- by all means not a scientist. But I was thinking, you know how a car is ran by small explosions, what if we came up with a different source of explosion. What I was thinking was something along the lines of splitting atoms. But I don't think that there is a small enough explosion, as well as not be radioactive.
Any thoughts on that? (lol I came back to this and all I could think of was Rick and Morty and their car that's ran by a multi verse. This idea of splitting atoms would like cars ran by little stars/suns.) Hmmm if this would be possible you would also have to take in account on how the 'star' would die. Wouldn't want cars to just be exploding all over the place.
Is it also possible for the split atom to be put back together. (this could be the on and off button of the car)
As well as, is there a way to wire magnets to hover above the ground? The movement forward (or backwards) would have to be a different power source but isn't getting something to float on its own the hard part?

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