Skip to main content

It's National Physics Day!

Physics fans, rejoice! April 24th is National Physics Day, and physics enthusiasts across the country are celebrating with fun physics demonstrations, public lectures, and other science events.

But National Physics Day isn't new; revelers have celebrated physics on or around April 24th for the past 18 years, starting in 1995 at the University of Virginia. One year later, the National Science Foundation incorporated National Physics Day into their now defunct Science and Technology Week. Despite that program's end, National Physics Day has endured.

"It's always been focused on getting young children interested, and they're a fantastic audience," said Craig Dukes, a University of Virginia physicist who helped organize some of the first National Physics Days.

And how do you get the kids excited?

"The kids always like something that goes boom," said Dukes.

So in honor of National Physics Day, here's some awesome physics demonstrations to help you celebrate (including a couple that go boom!):

Imploding Train Car

This is a super-sized version of the imploding barrel demonstration you may see in a freshman physics class. The demonstrators boiled water in the tanker and then sealed off the tanker so that no gas could escape.

Before the tanker was sealed, the water vapor pushed all of the air out. Consequently, when the tanker was capped, the water vapor cooled back into a liquid and the pressure in the tanker plummeted. The difference between the low pressure in the tanker and the relatively high atmospheric pressure outside caused the tanker to implode with a bang.

Liquid Nitrogen Cannon

As liquid nitrogen expands into a gas, you can use it to propel projectiles.

Bubbles in Space

And here's one demo that's out of this world, literally!

Imploding drums, demos on beds of nails, and exploding balloons have been a hit at the University of Virginia's celebrations in past years, said Steve Thornton, a University of Virginia physicist who organized the first National Physics Day. Thornton has worked on National Physics Day since the beginning, and he has just started to hand the reins over to his colleagues.

So have some fun with physics this year, but remember to stay safe. Many physics demos, including the ones above, involve some risk, and kids should always be supervised by an adult.


  1. I love the bubble demo, is it easy to do and is there a guide available anywhere on how to do it and what is required?


  2. I love the bubble demo, is it easy to do and is there a guide available anywhere on how to do it and what is required?



Post a Comment

Popular Posts

How 4,000 Physicists Gave a Vegas Casino its Worst Week Ever

What happens when several thousand distinguished physicists, researchers, and students descend on the nation’s gambling capital for a conference? The answer is "a bad week for the casino"—but you'd never guess why.

Ask a Physicist: Phone Flash Sharpie Shock!

Lexie and Xavier, from Orlando, FL want to know: "What's going on in this video ? Our science teacher claims that the pain comes from a small electrical shock, but we believe that this is due to the absorption of light. Please help us resolve this dispute!"

The Science of Ice Cream: Part One

Even though it's been a warm couple of months already, it's officially summer. A delicious, science-filled way to beat the heat? Making homemade ice cream. (We've since updated this article to include the science behind vegan ice cream. To learn more about ice cream science, check out The Science of Ice Cream, Redux ) Image Credit: St0rmz via Flickr Over at Physics@Home there's an easy recipe for homemade ice cream. But what kind of milk should you use to make ice cream? And do you really need to chill the ice cream base before making it? Why do ice cream recipes always call for salt on ice?