Ann: Hi, this is Ann.
Jeremy: And Jeremy from NIU STEAM, and this is the Sound of Science on WNIJ.
Ann: Today’s question comes from Carl and he asks, will it ever be possible to travel through time?
Jeremy: Sure! I can do it right now. There, see?!
Ann: Um, see what? I didn’t see you do anything.
Jeremy: I just traveled 3 seconds into the future. It just took me 3 seconds to do it.
Ann: OK, I get it. You’re saying that we’re always travelling through time, into the future. But could we ever change how fast we’re travelling, or reverse direction and revisit the past?
Jeremy: The answer to the first part of that question is, yes. If objects are subjected to a large gravitational field, it will cause time to pass more slowly for them.
Ann: This is called Time Dilation, and it’s something we can actually measure. For example, everyone living here on Earth experiences about the same amount of gravity, so we all experience the same passage of time.
Jeremy: But astronauts in orbit experience much less gravity, so time passes just a bit faster for them. While they’re up there, they gain an extra 38 ms on us every day.
Ann: That means anything in orbit that has a clock in it needs to be set to run that much slower to compensate.
Jeremy: Otherwise, they would get ahead of the clocks here on earth, creating problems with our GPS and communications systems.
Ann: So we know gravity can warp spacetime. But can we warp it enough to actually travel backwards through time?
Jeremy: Some scientists think it might be possible, but it probably wouldn’t look anything like it does in the movies.
Ann: So, no hopping in a souped-up DeLorean and going back to fix up your parents in time for the big dance?
Jeremy: No, probably not. Of the scientists that take time travel seriously, many believe that if you could create a time machine here on earth, you would only be able to use it to travel back to a point in time after the device had been built.
Ann: So it’s like saying you can’t come back through a door that hasn’t been built yet?
Jeremy: Exactly. And since no one has built a working time machine that we know of, we probably won’t be able to go back and buy yesterday’s winning lottery ticket. Yet.
Ann: Great question Carl. Keep your questions coming to niusteam@niu.edu.
Jeremy: This has been the sound of Science on WNIJ.
Ann: Where you learn something new every day.
