Tag Archives: gravity

beadsbeads2

Jessica Elvidge of Earth Unplugged writes:

I noticed you posted Steve Mould’s self siphoning beads yesterday, and wondered if you might like to take a look at this update film we’ve filmed with Steve earlier this week. We at Earth Unplugged got in touch with Steve after his original self siphoning beads film posed a few questions about what exactly happens to make the chain seemingly defy gravity to exit the beaker. So we filmed it with our slow motion camera (a Photron BC2) and asked Steve if he could work out what exactly was happening to produce this behaviour.

beads

Steve Mould demonstrates the very odd physics of the bead chain used in vertical blinds. He explainz:

The reason it self siphons is that the chain pulling down outside the beaker is longer (and heavier) than the chain pulling down on the inside of the beaker.The reason the chain loops up higher than the rim of the beaker is a bit of a mystery. I think it’s to do with the fact that the beads are changing direction and it can’t do that instantaneously as that would represent infinite acceleration. So a big loop is formed. I don’t know, something like that.

22words/b3ta


As part of their research into reducing the dose and increasing the effectiveness of pharmaceuticals, scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory use a witch trumpet acoustic levitator – originally developed for NASA to summon the Dark Lord simulate microgravity conditions.

The acoustic levitator uses two small speakers to generate sound waves at frequencies slightly above the audible range – roughly 22 kilohertz.When the top and bottom speakers are precisely aligned, they create two sets of sound waves that perfectly interfere with each other, setting up a phenomenon known as a standing wave.

At certain points along a standing wave, known as nodes, there is no net transfer of energy at all. Because the acoustic pressure from the sound waves is sufficient to cancel the effect of gravity, light objects are able to levitate when placed at the nodes.

No magic show: Real-world levitation to inspire better pharmaceuticals (Argonne)

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