The Flash‘s most famous move doesn’t have a name in the comics. When the hero needs to take out a foe quickly (duh), he engages the Speed Force, moves towards lightspeed, then unleashes a punch with “infinite” mass. It’s an awesome move, for sure. But is there science behind it?

In my latest Because Science, I’m finally taking a look at the IMP. (I started this show a little over two years ago, and you’ve been asking me to tackling this one since then.) Introduced in JLA #3 in 1997, the IMP was established in just a few panels packed with science. Wally West’s inner dialogue mentions everything from relativistic mass to blueshifting, and surprisingly, most of the science is spot on! However, the Infinite Mass Punch does not have infinite mass…it can’t.

According to everything we know about the universe, the speed of light is the speed limit. Full stop. Wally may be able to tap into the Speed Force to get around this, sure, but he doesn’t need to break the laws of physics to do what we see the IMP do. In fact, other Flash comics state that his relativistically increased mass isn’t infinite. It means nerds have been wrong for 20 years about the IMP, but that’s fine! The Flash’s fist doesn’t need infinite mass. To find out the real speed and mass of the IMP, check out my latest episode above.

Check out my last video on how much energy Galactus could get from eating the Earth, subscribe to this playlist to stay current with the show, buy a Because Science shirt (you know why), and follow me on Twitter to give me a suggestion for the next episode!