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.
TIL: Sharks are attracted to the sound of death metal. Apparently, the “dense tones” of it mimics the “low frequencies of struggling fish.” (Damn.) In 2015, a Discovery Channel crew — hoping to attract a large great white named “Joan of Shark” — dropped a speaker underwater and played some. Independent: Desperate to feature the […]
The mystery of the glorious fireball emitted by microwaved grapes (featured in my novel Little Brother) has been resolved, thanks to a paper in the Proceedings of the National Academy of Sciences in which Trent University researchers Hamza Khattak and Aaron Slepkov explain how they destroyed a dozen microwaves before figuring out that the grapes […]
The rise in a belief that the Earth is flat is bizarre and somewhat frightening, a repudiation of one of the most basic elements of scientific consensus. Texas Tech University psych researcher Asheley R. Landrum attended a 2017 flat earth convention and interviewed 30 attendees to trace the origins of their belief in a flat […]
What do Facebook, Twitter, YouTube and Google all have in common? Somewhere in their framework, they all use MySQL, that most versatile (and free!) of database management systems. And they’re not alone. If your company or the one you’d like to work for wrangles data (and who doesn’t?), they’re going to need someone with a […]
There’s a reason you’re hearing about the gig economy in every other business story these days. More than ever, people are finding income from more than one source. And if you find the right one, a side hustle can do more than just pad your pockets – it can allow you to finally get paid […]
High-def cameras are available to anyone and for much less than they were just a decade ago. Even the phones in our pockets can be used to shoot and edit short films. It’s never been easier to be a filmmaker, providing you have the technique. Enter the Film & Cinematography Mastery Bundle, an online boot […]