science demos

CNC Bender Ties Knots in Iron Pipe

This Nissin 3D bender is kind of like a PlayDoh Fun Factory, except it squirts out 1.25″ steel pipe instead of soft non-toxic-but-funny-tasting dough. Looks like much of the magic is in the bending-die head.

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The Alkali Metal Series, Reacting with Air and Water

If I understand the annotations on this, YouTuber ironnica’s only posted video, correctly, the footage was produced by a New Jersey educational media company in 1991, and the delightfully British narration more recently by somebody associated with the UK’s Open University. In any case, it is a perfectly concise, interesting, and entertaining demonstration of the increasing reactivities of the group I metals lithium, sodium, potassium, rubidium, and cesium.

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Showing Off Aluminum’s Natural Reactivity via Gallium Alloy

Showing Off Aluminum’s Natural Reactivity via Gallium Alloy

Very interesting vid from 16-year-old Hayden Parker, who impressed me greatly with his animated chemistry demonstrations at Maker Faire. Metallic aluminum can be dissolved in liquid gallium to create an aluminum-bearing alloy that is liquid at ambient conditions. Because it can flow in the alloy, the aluminum cannot form a stable passive oxide layer and will react violently with water, which nicely demonstrates the normally-hidden high natural reactivity of metallic aluminum.

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Laser Cutting Glow-in-the-dark Plastic

Laser Cutting Glow-in-the-dark Plastic

A few years back, before I worked for MAKE, I had some business cards laser cut and blogged about it. Every so often, somebody runs across them and e-mails asking for helping making their own. I always refer them to Angus Hines, who’s a good friend, a Maker Faire regular, and the best (and least expensive) CNC contractor I know. Recently, Angus was hired by Frank Anselmo Eco to laser-cut some business cards from glow-in-the-dark sheet plastic, which is a pretty cool idea, IMHO. But the reason it’s on MAKE is the sweet lights-out video Angus shot of the laser-cutting action; check out how the phosphorescent plastic continues to glow for several seconds behind each cut. [Thanks, Angus!]

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Tin Cans + Bucket of Sand = New Science

Tin Cans + Bucket of Sand = New Science

If you take two empty cans, one closed on the bottom and the other open (i.e. a tube), and turn them upside down, which will be harder to push into a bucket of sand? If, reasoning by analogy to liquids, you (like most people), said the closed one…well, you can sort of guess where this is heading: A closed can is, in fact, easier to push into a bed of sand than an open tube. Given the usual fine print. Adrian Cho explains over at ScienceNOW:

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