How Traveling Back In Time Could Really, Physically Be Possible

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The idea of traveling back in time has long fascinated humans, such as in Back To The Future’s Delorean DMC-12. After decades of research, we may have hit upon a solution that’s physically possible. Image credit: Ed g2s of Wikimedia Commons.

And you don’t even need a Delorean at 88 MPH.

It’s one of the greatest tropes in movies, literature, and television shows: the idea that we could travel back in time to alter the past. From the time turner in Harry Potter to Back To The Future to Groundhog Day, traveling back in time provides us with the possibility of righting wrongs in our own past. To most people, it’s an idea that’s relegated to the realm of fiction, as every law of physics indicates that motion forward through time is an absolute necessity. Philosophically, there’s also a famous paradox that seems to indicate the absurdity of such a possibility: if traveling backwards through time were possible, you’d be able to go back and kill your grandfather before your parents were ever conceived, rendering your own existence impossible. For a long time, there seemed to be no way to go back. But thanks to some very interesting properties of space and time in Einstein’s General Relativity, traveling back in time may be possible after all.

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An illustration of the early Universe as consisting of quantum foam, where quantum fluctuations are large, varied, and important on the smallest of scales. Positive and negative energy fluctuations can create minuscule, quantum wormholes. Image credit: NASA/CXC/M.Weiss.

The place to start is with the physical idea of a wormhole. In our known Universe, we have tiny, minuscule quantum…