Reactions

Have you ever seen a drop of water navigate a maze? It’s possible thanks to the same phenomenon that lets you know if a griddle is hot enough for pancake batter. Water droplets that dance and skitter across a hot surface instead of boil away on the spot are experiencing the Leidenfrost effect. Understanding Leidenfrost — first described more than 200 years ago — helped engineers make more efficient steam engines. Today, scientists are using high-speed cameras to better characterize how superhot water behaves on metal surfaces. The investigation might lead to improvements in power generation.

Derby Day is around the corner, and with it comes big hats, horses with funny names, and bourbon. The latest episode of Reactions celebrates the chemical process of distillation that makes bourbon and other whiskey varieties possible. Since water and ethanol, along with tasty flavors, have different boiling points, they can be separated by carefully heating the mash that starts off every whiskey. Each distillery carefully protects their still design, engineered to create their signature liquor. The strongest flavors take aging, but might some innovative whiskey makers find a way to hack maturation time? Special thanks to District Distilling in DC! You can find more about them here: http://www.district-distilling.com/.

Tens of thousands joined the March for Science in Washington, D.C. We followed two groups of chemists to learn about what brought them here and the hopes that they’re leaving with. The views and/or opinions expressed in this video are those of the student participants and do not necessarily reflect the official policies or positions of their respective institutions or academic departments. More than 600 cities hosted satellite marches. Beyond our coverage in D.C., we’ve shared some footage from Berlin, Chicago, and San Francisco. Did you march? We want to see your footage. Share it with us on Twitter with @ACSReactions or on Facebook at https://www.facebook.com/SpeakingOfChem/ .

Sports drink commercials love talking about them, but what are electrolytes, why do we need them, and what happens if we don’t have enough? Electrolytes are salts that, once in our bodies, help our cells move water around. They also enable the nerve impulses that keep our hearts beating, our lungs breathing and our brains learning. But we can also lose them — for example, by sweating. Given all the ins and outs of electrolytes, should you reach for that bright orange sports drink after running around the block?

Did you know that thousands of precious paintings around the world are generating soap beneath their surfaces? Art conservators struggle with microscopic eruptions in masterpieces. A huge thanks to Rijks Museum conservator Petria Noble and independent conservation scientist Jaap Boon.

How do earthworms eat? If you’re enjoying some tasty food today that has at least one ingredient that was farmed somewhere, you probably owe a little thanks to earthworms. How is it that these detritivores – literally dirt eaters – turn what humans find inedible into beloved compost? After the biology and physics of swallowing and “chewing”, like us it’s all chemistry for digestion. But earthworms have an extra enzyme that allows them to munch through cellulose, the ultimate fiber of that makes tree bark a non-starter in human diets. Yet all this powerful chemistry means not everyone sees earthworms as the greatest creature to crawl – find out all the dirt in this video.

Bicycle day's just around the corner, but it's not what you think. This isn't a holiday honoring your favorite two wheeled, environmentally friend vehicle - it's about the day chemist Albert Hofmann first discovered the psychedelic effects of Lysergic Acid Diethylamide, or LSD-25. Today we're talking the chemical history of LSD, so get ready to turn on, tune in, but don't drop out... you might just learn something. Correction at 0:09 and 1:13: "Hoffman" should be spelled "Hofmann". We've added a correction (via annotation) -- we really regret missing this. Thanks to oildream for pointing this out.

We have a lot of confidence that we measure temperature accurately. But how do thermometers in the kitchen or doctor’s office work? Thanks to the laws of thermodynamics, thermometers respond to heat moving from hot to cold as a means of measuring temperature. Clever physical chemists and engineers have taken temperature tools from the simple, but still useful, lined glass thermometers to digital readouts. And you might be surprised to find out how Einstein took thermometers the distance.

Pasta noodles contain only three ingredients - eggs, water and flour. But how can you achieve a tasty result every time? Cooking pasta chemically changes how the proteins and starches interact, making the noodles sticky and springy. Therefore, what you do — or don’t do — to the cooking water can change the edible result. This video serves up four food-chemistry informed pasta pro-tips so you can serve up delectable al dente pasta instead of an unappetizing ball of overcooked noodles.

Supermarket tomatoes account for nearly 10% of produce sales in the U.S., but they taste terrible. What can be done to make them great again? A huge thanks to the tomato researchers Harry Klee and Jim Giovannoni who helped us with this episode’s science.

St. Paddy's Day is just around the corner, and so instead of celebrating with a glass of green beer, these year we decided to take a closer, chemical look into what makes redheads stand out from the crowd. It might surprise you to know that it's not just those fiery locks that make them stand out form the crowd.

There’s a new trend in agriculture called vertical farming. As humans learned to farm, we arranged plants outside in horizontal fields, and invented irrigation and fertilizer to grow bumper crops. But with modern technology and farmers’ cleverness, we can now stack those fields vertically, just as we stacked housing to make apartment buildings. Moving plants indoors has many benefits: Plants are not at the mercy of weather, less wilderness is cleared for farmland, and it’s easier to control the runoff of fertilizer and pesticides. But the choice of lighting can make or break the cost of a vertical farm and affect how long it might take for urban agriculture to blossom.

Cats love catnip, but that’s not why the catnip plant makes the kitty drug. It’s got its own merciless schemes… Find out what they are. If this episode leaves you wanting more chemistry goodness, check out the featured resources below.

Vegetables are chock-full of essential vitamins and minerals, but how should you eat them to get the most nutritious bang for your buck? Raw? Sauteed? Frozen? You might want to eat those fresh green beans right away, for one — flash-frozen green beans kept for months have up to three times more vitamin C than week-old beans kept in the fridge. And did you know that oil-based dressing and avocados can help you absorb more nutrients from that kale salad.

Online entrepreneurs will try to sell you bottled human pheromones, but do these even exist? Many thanks to Alla Katsnelson, who wrote a great lowdown on pheromone research. You should check it out. And while you’re sniffing around on the Internet, don’t forget to subscribe and share. But for heaven’s sake, don’t waste your money buying human pheromones online.