So-called “air batteries,” in which one of the reacting chemical species is atmospheric oxygen, are already widely employed, for instance, in hearing-aid batteries, which are commonly zinc-air cells with a piece of adhesive film that must be removed before use to allow atmospheric oxygen onto the cathode.
Scan a laser across a phosphorescent screen to create glowing, haunting images that slowly fade into blackness.
Love the articles in MAKE about cool science projects? Wish there was a mag dedicated to just science, stuff like biology, chemistry, physics, art+design, and math? Well the The Citizen Science Quarterly gang are raising money for their first run of 1000 magazines. Check out their Kickstarter video, you can see founder Jacob Schiach mock […]
Hoffman clamps are extraordinarily handy bits of lab kit. The screw is turned to compress a piece of flexible tubing between two bars, and may be thus be used to completely stop or simply to regulate flow of gas or liquid through such tubing. The screwing action of the Hoffman clamp allows adjustment of the rate of flow infinitesimally from full open to full stop. In amateur apparatus, a Hoffman clamp can often take the place of a glass or teflon stopcock, which is a much more sophisticated and expensive bit of apparatus. And they’re cheap!
Awhile back, I wrote about co-opting the awesome glue used to mount rear-view mirrors for hobby projects. An interested reader e-mailed me a couple weeks later asking if I knew how to remove a rear-view mirror button from a windshield, which I didn’t. Several people have reported that trying to forcibly remove the metal button from the glass can actually break a divot of glass out of the windshield. I was therefore not optimistic, but we talked a little about the idea of using an organic solvent combined with sharp lateral pressure parallel to the glass. She experimented a bit, and, what do you know, eventually succeeded! Here’s her report:
OK, so I spruced up the sublimely boring image accompanying this interesting question over at Popular Science with a picture of the thermite reaction. I couldn’t find a picture of burning plutonium. C’mon wikimedians! What’s taking so long?
The real answer, it turns out, is something like “at first it would be very exciting, and then it would be very boring.” Here’s a characteristically droll quote from my old quantum mechanics instructor, John Stanton:
This “50% sawdust” project from Israel’s Kulla design involves mixing equal parts sawdust and shredded plastic bags in a mold under heat and mild pressure to produce a composite chip-board type material that, reportedly, requires no other adhesives, binders, or other components. Lots of questions left to be answered, but an interesting start. [via Dude […]
