What if, instead of compressed air, we filled the cannon with liquid nitrogen? Could you live through the ordeal without getting frozen in the process? How far would you go? And how much would this cost you?
That is liquid nitrogen. It’s non-toxic, it has no smell and no color, and it boils at -196 °C (-320 °F). At this temperature, your body would instantly freeze. But for liquid nitrogen, it’s like a sauna.
If you got shot out of a real cannon, you’d fly out with gunpowder burns on your body, at the very least. To make it a safer trick, stuntmen use compressed air to push forward the platform they stand on inside the cannon. Basically, it’s a catapult masquerading as a cannon.
So, let’s fill this catapult with some liquid nitrogen. And in this scenario, you’d be like the cork in a champagne bottle.
Of course, we wouldn’t send you flying out of a liquid nitrogen cannon right away. For your safety, we’d perform some dummy tests first. We’d need to figure out how much liquid nitrogen we’d need, and calculate where to put a net to catch you safely. We don’t want this story to end up with you smashed all over the ground.
For this human cannonball to work, you’d need to be pretty thin. I don’t mean to tell you to lose some weight, but my calculations say that the lighter the person, the less force it takes to shoot them out of the cannon.
If you’re light enough, you’d only need 750 liters (165 gal) of liquid nitrogen. And if, on top of that, you heat up the cannon walls a bit, right before your launch, you can get by with only about 400 liters (88 gal) of the stuff. That’s still going to cost you about $1,000.
Theoretically, you’d fly a distance of about 60 m (200 ft), sailing 23 m (75 tf) up in the air, before landing in a net. At least, that’s the plan. After all the tests were done, everything would be good to go. Are you ready? I’m kind of worried about you.
You’d climb right into the cannon. It would be a snug fit, so hopefully, you’re not claustrophobic. As you stood there waiting, your assistants would heat the cannon slightly, but enough for you to break into a sweat.
From there, things would go pretty fast. The assistants would pour liquid nitrogen into the bottom of the cannon. Instantly, the liquid nitrogen would heat up and turn into gas. In a fraction of a second, the gas would expand and propel the platform you were standing on forward. A split-second later, you’d be flying at the speed of 112 km/h (70 mph).
But something’s not right. When we were testing the dummy, we kind of forgot about something. Liquid nitrogen is really cold. Before the cannon shot you out, the nitrogen would have to be stored in a sealed container at a temperature below -196 °C (-320 °F).
Once liquid nitrogen was poured into the cannon, you’d find yourself in a cloud of this gas all around you. Liquid nitrogen could be pretty deadly for humans. Because as it evaporates, it displaces the oxygen around it. And did I mention it’s insanely cold? You’d pass out and freeze if you stayed in that cloud long enough.
But luckily for you, our cannonball events would unfold too fast to cause any permanent damage to your body. Thanks to the Leidenfrost effect, the quick contact with liquid nitrogen inside the cannon wouldn’t instantly freeze your skin. The nitrogen wouldn’t even touch it, only hover above its surface.
If somebody hit you with a hammer after the stunt, your body wouldn’t shatter to dust. There would be no visible effects at all. Except the bruise from the hammer. But it would sting badly. Your whole body would be in sharp pain as you went flying towards the net. But hey, at least you’d still be alive.
You’d be accelerating rapidly. It would feel as if gravity just got nine times stronger. That could make you pass out on the flight. And if you didn’t pass out at this point, seeing the net would sure make you feel on edge. But you got lucky again as you dropped right into it. The net slowed down your velocity, and made the impact less intense. That didn’t cost you your life. But I wouldn’t do this again if I were you.
And if you like liquid nitrogen so much, you could try jumping into a pool completely filled with liquid nitrogen.
- “Liquid Nitrogen Cannon”. The Wonders Of Physics.
- “The Most Dangerous Profession: The Human Cannonball”. Blitz, Matt. 2014. Today I Found Out.
- “BBC News – ‘Head For Heights Required'”. 2020. news.bbc.co.uk.
- “Why Don’t Human Cannonballs Die When Shot Out of the Cannon?”. youtube.com
- “What is the Most Dangerous Part of Being a Human Cannonball?”. 2020. physicscentral.com.
- “Liquid Nitrogen Facts”. 2020. Thoughtco.
- “Density Of Liquid Nitrogen In 285 Units And Reference Information”. 2020. aqua-calc.com.