In this video from Grenoble, France, two teams of people attempt to separate the halves of a metal ball. Spoiler: The ball wins.
There are no magnets involved, nor are the two sides of the ball locked to each other with any physical device. Instead, what you see here is a classic, hands-on physics demonstration that's been a crowd-pleasing favorite since 1654.
Magdeburg Hemispheres is the fancy name for the two halves of a hollow metal ball that you see in this video. You hold them together, hook them up to an pump, and suck out all the air from the cavity in between. What you're left with is a vacuum ... and a great way to show people the power of atmospheric pressure. At Skulls in the Stars, Greg Gbur explains:
All objects within the atmosphere are under constant bombardment from air molecules traveling every which way; this atmospheric pressure is not noticeable to us because our bodies have an internal pressure that matches and balances it.
When the hemispheres are first placed together, the air pressure within them balances the air pressure outside, and they are easily pulled apart. When air is removed from the interior of the hemispheres, however, there is no longer any force pushing outward: the atmospheric pressure outside dominates, pushing the hemispheres together and keeping them from being separated.
In the original Magdeburg Hemispheres demonstration, teams of horses couldn't separate the vacuum sealed ball.
I’ve had quite a few fun afternoons playing with dry ice from making spooky fog in the kitchen to exploding plastic bottles in the yard. But I’ve never had the opportunity to pour hot lava over dry ice. In this video, the lava is 1400 °C and the dry ice is -78C°. So cool! And […]
A Boston University team have developed an acoustic, 3D-printed metamaterial whose topology is such that it reflects 94% of human-audible sound; the researchers' demonstration involves inserting a ring of this stuff in a PVC pipe and blasting a speaker down one end: light and air emerges from the other end, but sound does not.
Are you super organized? You’re going to love the Genius Pack G4 and its seemingly limitless, well-placed compartments. Not that organized? You’re still going to love this piece of luggage because it’s so well thought out that it practically does the packing for you. We’ve all tried to stuff a piece of carry-on so full […]
Despite government legislation and improving caller ID technology, robocalls and scam artists are rampant on the phone lines – up to 35 billion a year in the US alone. They can be annoying at best and a financial threat at worst, but there’s a way to take security into your own hands. One good example […]
If you’re a Mac user, you thrive on simplicity. Everything in its place and a place for everything. Unsurprisingly, there’s a ton of great organizational apps out there for Mac, and now someone’s had the great idea to bundle them all together. Whether you’re running a demanding business or just getting through the day to […]