The copper earring you see here had already been glowing bright orange for half an hour when we took the photograph. There is no flame under it, no electric current through it. Underneath is a pool of volatile and highly flammable acetone, but the liquid is not on fire. So where is the heat coming from?
Last year, I stuck my hand in super-cold liquid nitrogen for the amusement of PopSci readers. My skin survived that demonstration, but I wimped out on a related experiment at the opposite extreme: dipping my finger into molten lead. That’s because the only time I’ve ever burned myself badly enough to need a doctor was while casting a lead plaque as a kid.
Among the most strictly enforced consumer-protection laws are those banning lead in toys. Lead is an insidious poison: It’s slow-acting and results not in immediately noticeable effects like rashes but in behavioral problems and a slightly lowered IQ. Even a very small amount of it is harmful. Yet a few decades ago, a lot of the most popular playthings were made from solid lead, including tin soldiers.
When you think of technology, you probably think of computers and jet engines and such. But there are other feats of engineering that are equally sophisticated, just less obviously so. Instant Kool-Aid, for example.
Oil and water don't mix: it's an old saying, but it's never more true than when you're talking about a pot of hot cooking oil and the moisture condensed on the surface of a frozen turkey. it's pretty incredible the amount of fire that simple combination can create.
Cooking oil is flammable, but it doesn't catch fire in a deep fryer because it never approaches the approximately 800°F required.
Running down the far-left column of the periodic table, the readily available alkali metals: lithium, sodium, potassium, rubidium and cesium—all generate potentially explosive hydrogen gas when they touch water. The strength with which they react with H2O goes up steadily in the order listed. Lithium just sizzles, whereas cesium explodes powerfully and instantly. You’d expect that to mean that cesium makes the biggest explosion, but it’s not the case.
For as long as I can remember, I've loved gunpowder. One of my fondest childhood memories is pulling down volume G of the encyclopedia and seeing the formula for this magic substance for the first time. Saltpeter, sulfur and charcoal, listed with exact percentages! That was heady stuff for a kid who had been forced to rely on collecting match heads for flammable material. But where to get the ingredients? I settled on hitting up pharmacists, telling one that my mom had sent me out to get saltpeter for canning, and a different one that she'd sent me out for sulfur and I didn't know why (because I couldn't think of a better cover story).
When you need to remove a tree stump, you have several options. Sissies call a tree service. Tough guys loop a chain around the stump, hook it to the bumper of their truck, and find out which one is stronger. Others use gunpowder to blow them up, though this is not advisable in most jurisdictions (unless your cousin is the sheriff and you let him watch). But my favorite method is to convert the stump itself into gunpowder and then burn it up. That is the secret behind how chemical stump remover works.
Pushing back the night with light of our own making was the first and greatest of humankind's achievements. What a thrill it must have been to discover that the setting sun no longer had to mean darkness and fear. We've come a long way since that first campfire, but it's just recently that technology has topped the most advanced form of open-flame light.