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Grandfather Paradox: Does This Halloween Costume Really Exist?

Posted: November 1, 2021

Each year for Halloween our resident content guru Prabir Mehta tries a different costume from the amazing world of science. His motto: the nerdier, the better!

In recent years he's done costumes like Schrodinger’s Cat and string theory, both pictured below. This year he wanted to make a costume about a theoretical physics term, so he decided to go with the grandfather paradox. (Look at the picture again ... get it?!)

As he was gathering materials and getting excited to create this year’s nerdy Halloween look, people kept asking what the term means so we thought we'd take a moment to explain.

Essentially, the grandfather paradox is an exercise for one’s mind. Here we go. What if you had a time machine and you went back in time and prevented your grandfather from ever having children (i.e. one of your parents). This would mean that you would have never been born and thus would have never been able to go back in time in the first place! 

This notion has been used in philosophy, physics ... and all three Back to the Future movies. Great Scott! Now it's ringing a bell, right?

Thinking about the grandfather paradox leads to other thoughts. Take, for example, the potential of parallel universes, where going back in time could create many future alternative realities. Ultimately it’s all just a thought experiment as it’s not able to be proven. No evidence, no fact. 

Nonetheless, Prabir thought it made for a pretty fun and inexpensive costume this year. Just a couple of paper boats hanging out along cardboard docks, two of them makes a pair of docks … or paradox. Add the classic old-age wig and beard easily procured at the store this time of year. A few dollars and a few moments later, voila: the grandfather paradox! 

As of yet, no future or past version has shown up to prevent Prabir from doing anything about this punny science costume but we'll be sure to share updates as those events transpire … or will we even be able to? Would you even know if that happened? So many questions held within this paradox! 

We hope everyone had a happy Halloween, and we look forward to sharing a costume and quick science lesson with you again next year!