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For hand towels, astronauts get those little vacuum-packed pucks that you kind of have to unravel into a towel. But what happens when you actually put the towels to use?
Two Nova Scotia high school students, Kendra Lemke and Meredith Faulkner, submitted this experiment to Canadian Space Agency and got to see astronaut Chris Hadfield actually test it out on the ISS. The results are seriously extraordinary and you need to see them.
It seems like a weird past-time, magnetizing ants, but it has some practical purposes. At his blog, media engineer Andrew Quitmeyer explains how he mixed magnetic powder into insect-safe enamel paint, and what he was able to do with it.
The big benefit to something like this is that it could allow scientists to easily alter the populations of social insect groups. Each colony of ants functions, in many ways, like a single organism. So what happens to that hive mind if you remove all the ants doing one particular type of task? Instead of painstakingly picking out each worker with a pair of tweezers every time you want to try this, you could create a colony in which all the workers have had magnetic paint daubed onto their abdomens. Then, you could quickly and easily collect some of them, or all of them, using a magnet. Hunting ants with a tweezer once > hunting ants with a tweezer over and over and over.
Another, possibly less legitimate, use of the paint is demonstrated by Quitmeyer in this video. (Quitmeyer, for the record, is not a social insects researcher.) Using single painted ants in a population of unpainted ants, he plays around with the way colonies remove unhealthy members of their own community. When a magnetized ant starts flopping around erratically in response to a nearby magnet, nearby ants quickly react.
As Quitmeyer says in the video, this demonstration quickly passes from science into mad science (or, at least, YouTube science).
Thanks to Leah Shaffer!
The Joule Thief is a way of producing enough electricity to run small, but useful, electric lights using cast-off trash like pop-can tabs and "dead" batteries. It's especially handy in the Himalayas, writes inventor and Google Science Fair judge T.H. Culhane. There, electricity is a precious resource. But the components needed to build a Joule Thief are abundant, thanks to climbers and tourists who leave behind all sorts of surprisingly useful litter.
Last week, Culhane joined a G+ hangout sponsored by National Geographic and Girlstart to talk about the value in things we throw away and walk viewers through the construction of their very own Joule Thief. You can watched the video of the event, or read the instructions for building a Joule Thief at Culhane's blog.
The fact that the Joule thief allows one to run a 3V LED from a 1.5 or 1.2 Volt battery would itself be astounding, because it means you only need half the number of batteries to get the same light.
Some of you are thinking "wait, maybe it enables you to use a single 1.5 volt battery to light a 3V LED instead of the usual two, but doesn't it just make that battery last half as long? Great question, but the answer is that the Joule Thief, which works by building up and collapsing a magnetic field around the torus (which acts as an electromagnetic inductor) actually is more efficient than using a battery directly because it PULSES the energy to the LED. You see the lightbulb shining brightly, but in fact it is turning on and off very rapidly as the magnetic field of the inductor builds up and discharges again and again. That means that though the light appears to be on all the time it is actually turning on and off and saving energy because it isn't on all the time.
It turns out that the Joule Thief enables the battery to keep supplying electrons to the light long after the battery is normally considered DEAD. So the battery actually lasts much much longer than a normal battery. I've observed "dead" batteries working down to about 0.5 Volts. Normally a 1.5 V battery is considered dead when it reaches 1.0 volts. But the Joule Thief can "steal" the remaining energy much below that. And that got me thinking -- could I use other sources of between 0.5 and 1.0 Volts to run a 3V LED?
T.H. Culhane's post on The Joule Thief (includes instructions for making a Joule Thief with batteries and alternative electricity sources)
Is coffee bad for you or good for you? Does acupuncture actually work, or does it produce a placebo effect? Do kids with autism have different microbes living in their intestines, or are their gut flora largely the same as neurotypical children? These are all good examples of topics that have produced wildly conflicting results from one study to another. (Side-note: This is why knowing what a single study says about something doesn't actually tell you much. And, frankly, when you have a lot of conflicting results on anything, it's really easy for somebody to pick the five that support a given hypothesis and not tell you about the 10 that don't.)
But why do conflicting results happen? One big factor is experimental design. Turns out, there's more than one way to study the same thing. How you set up an experiment can have a big effect on the outcome. And if lots of people are using different experimental designs, it becomes difficult to accurately compare their results. At the Wonderland blog, Emily Anthes has an excellent piece about this problem, using the aforementioned research on gut flora in kids with autism as an example.
For instance, in studies of autism and microbes, investigators must decide what kind of control group they want to use. Some scientists have chosen to compare the guts of autistic kids to those of their neurotypical siblings while others have used unrelated children as controls. This choice of control group can influence the strength of the effect that researchers find–or whether they find one at all.
Scientists also know that antibiotics can have profound and long-lasting effects on our microbiomes, so they agree on the need to exclude children from these studies who have taken antibiotics recently. But what’s recently? Within the last week? Month? Three months? Each investigator has to make his or her own call when designing a study.
Then there’s the matter of how researchers collect their bacterial samples. Are they studying fecal samples? Or taking samples from inside the intestines themselves? The bacterial communities may differ in samples taken from different places.
Stanley Milgram's "Obedience to Authority" experiments are infamous classics of psychology and social behavior. Back in the 1960s, Milgram set up a series of tests that showed seemingly normal people would be totally willing to torture another human being if prodded into it by an authority figure.
The basic set-up is probably familiar to you. Milgram told his test subjects that they were part of a study on learning. They were tasked with asking questions to another person, who was rigged up to an electric shock generator. When the other person got the questions wrong, the subject was supposed to zap them and then turn up the voltage. The catch was that the person getting "zapped" was actually an actor. So was the authority figure, whose job it was to tell the test subject that they must continue the experiment, no matter how much the other person pleaded for them to stop. In Milgram's original study, 65% of the subjects continued to the end of the session, eventually "administering" 450-volt shocks.
But they weren't doing it calmly. If you read Milgram's paper, you find that these people were trembling, and digging nails into their own flesh. Some of them even had seizure-like fits. Which is interesting to know when you sit down to read about Michael Shermer's recent attempt to replicate the Milgram experiments for a Dateline segment. Told they were trying out for a new reality show, the six subjects were set up to "shock" an actor, just like in Milgram's experiments. One walked out before the test even started. The others participated, but had some interesting rationales for why they did it — and a simple ingrained sense of obedience wasn't always what was going on.
Our third subject, Lateefah, became visibly upset at 120 volts and squirmed uncomfortably to 180 volts. When Tyler screamed, “Ah! Ah! Get me out of here! I refuse to go on! Let me out!” Lateefah made this moral plea to Jeremy: “I know I'm not the one feeling the pain, but I hear him screaming and asking to get out, and it's almost like my instinct and gut is like, ‘Stop,’ because you're hurting somebody and you don't even know why you're hurting them outside of the fact that it's for a TV show.” Jeremy icily commanded her to “please continue.” As she moved into the 300-volt range, Lateefah was noticeably shaken, so Hansen stepped in to stop the experiment, asking, “What was it about Jeremy that convinced you that you should keep going here?” Lateefah gave us this glance into the psychology of obedience: “I didn't know what was going to happen to me if I stopped. He just—he had no emotion. I was afraid of him.”
J. Kenji Lopez-Alt, the chief creative officer at the Serious Eats Blog, is a mad kitchen-science genius. Here at BoingBoing, we've posted about his past experiments demonstrating that there's no reason to waste money on expensive cleavers; that foie gras isn't necessarily evil; and that McDonald's hamburgers will, in fact, rot (under the right conditions).
Now, just in time for your Thanksgiving planning, Lopez-Alt puts turkey brining to the test, running a series of trials comparing the meat-moistening results of various brining solutions, dry salt rub, tap water, and a plain control turkey breast. His conclusion: Don't bother with the brine. Not because it doesn't work — brined turkey does produce nice, moist meat. But because it also produces meat that's kind of soggy. You'll get nearly as good results, without the texture problems, out of dry salt.
I particularly enjoyed this part, where Lopez-Alt explains why the results of brining with water aren't any different from the results of brining with broth.
There are two principles at work here. The first is that to the naked eye, broth is a pure liquid, in reality, broth consists of water with a vast array of dissolved solids in it that contribute to its flavor. Most of these flavorful molecules are organic compounds that are relatively large in size—on a molecular scale, that is—while salt molecules are quite small. So while salt can easily pass across the semi-permeable membranes that make up the cells in animal tissue, larger molecules cannot.
Additionally, there's an effect called salting out, which occurs in water-based solutions containing both proteins and salt. Think of a cup of broth as a college dance party populated with cheerleaders (the water, let's call them the Pi Delta Pis), nerds (the proteins, we'll refer to them as the Lamba Lambda Lambdas), and jocks (the salt, obviously the Alpha Betas). Now, at a completely jock-free party, the nerds actually have a shot at the cheerleaders, and end up co-mingling, forming a homogenous mix. Open up the gymnasium doors, and a few of those cheerleaders will leave the party, taking a few nerds along for the ride. Unfortunately, those gymnasium doors are locked shut, and the only folks strong enough to open them are the jocks. So what happens when you let some jocks into that party?
Astronaut Don Pettit is a national treasure. He's been to space three times—once for a six-month stay on the ISS. On every mission, he's found time to make huge contributions to the public communication of science, including making a series of amazing "Science Saturday" videos and inventing (from spare parts he found lying around the ISS) a system to help the space station take clearer, sharper pictures of the Earth at night.
Pettit went to space with an international crew in December 2011 and is currently in space. This new video—where he demonstrates the way a small electric charge can manipulate the behavior of water droplets in microgravity—is a great addition to his oeuvre!
Thanks for Submitterating, James!