Showing 5 posts tagged balls
Because 2,000 ping pong balls and 30 middle-school teachers floating in “zero gravity” isn’t something you see everyday, the kids should watch (or rewatch!) this 2010 ScienceBob video. From northropgrumman.com:
Zero gravity flights are performed using a specially modified aircraft, an FAA approved aircraft called G-Force One. The maneuvers are conducted in dedicated airspace 100 miles long by 10 miles wide. Specially trained pilots fly the aircraft in a series of maneuvers called parabolas, or arcs, between the altitudes of 24,000 and 32,000 feet.
At the beginning of each parabola, the aircraft climbs at a 45-degree angle. At the “top” of the parabola, the aircraft is “pushed over” into a controlled descent that creates a temporary zero-gravity environment. The teacher flights include approximately 15 parabolas ranging from low-gravity environments typical of the moon (1/6th G) or Mars (1/3 G) to complete weightlessness. At the end of each “weightless” period, which lasts approximately 30 seconds, the aircraft is gradually pulled out of the descent, reestablishing a more normal gravity environment inside the plane.
Jason Allemann, who created these Lego mazes last year, built this beautiful and elegant Lego ball clock. The video shows how the rail system works with one ball being hauled up the chain every minute, then tipping the balance once enough balls have accumulated.
A playground ball finds stability in a saddle when the saddle is rotating at the proper speed.
Mechanical analog of a “Paul Trap” particle confinement—a ball is trapped in a time-varying quadrupole gravitational potential. A large saddle shape (attached to a plywood disk) is mounted on a multi-purpose turntable. The saddle shape is essentially a quadrupole gravitational potential. Rotation of this potential subjects the ball to an alternating repulsive and attractive potential, much like the time-varying electric quadrupole potential of a Paul Trap used in trapping single ions or electrons.
The plastic ball used here is about 25 cm in diameter and was purchased at a toy store. The saddle consists of many layers of fiberglass and was hand-made with help from Justin Georgi. The turntable is driven at about 110 rpm with a DC motor. We have observed this ball at this speed remaining stable for over 2 hours.
Dr. Roy Lowry of Plymouth University in the UK made science explosively exciting for his class by demonstrating how powerful (and loud) it can be when the pressure of cold, trapped Liquid Nitrogen, a liquified gas, is warmed in a bucket of water. Then he added 1500 Ping Pong Balls.
If that didn’t make sense, watch. He’ll explain it all. And then when you see him pour the balls in and run away (it’s dangerous!), cover your ears or turn down the volume, and let the science commence!
(Updated video link.)