Viva la difference — and the difference is in the antennae. Mosquito antennae are lined with fine hairs called antennal flagellum, and the density of the flagellum differs from one sex to another. Males have many, many more antennal flagellum, turning their antennae into a pair of bushy bottle brushes. Megan Fritz, a post-doctoral student in the North Carolina State University department of entomology described them to me as the mosquitoes' mustache. Even though mosquitoes are tiny, the males' flagellum are prominently noticeable to the naked eye. Fritz can tell which mosquitoes are boys and which are girls, on sight.

Female Aedes aegypti do the biting. But they don't have nearly as many flagellum and, thus, their hearing is not nearly as finely tuned as that of male mosquitoes. That's because the men and the women are looking for different things.

Female mosquitoes are on the lookout for victims to bite. Like the males, they eat sugar. At the NCSU mosquito breeding facility, Megan Fritz feeds both males and females on sugar water. But, without regular meals of blood, the females lose their ability to reproduce. No blood, no baby mosquitoes. Unsurprisingly, then, female mosquitoes have special sensory abilities that allow them to find and procure blood.

Males, on the hand, are primarily interested in finding females. And that's where those thick flagellum come in. Turns out, the flagellum are integral to the mosquitoes' ability to hear. Specifically, all those flagellum help male mosquitoes hear the very, very, very quiet sounds of female mosquitoes buzzing around. Sound waves make the flagellum move. That movement is carried through the antenna to a special organ that helps the mosquitoes actually make sense of the motion. Called Johnston's organ, it can tell males how fast the wings of nearby mosquitoes are beating and it can help them distinguish male from female, and species from species.

Further reading:

In this short video, Jane shows how to use the Sukie Button Factory to make fabric-covered buttons (also known as badges). The kit comes with a sheet of fabric and 25 metal snap-together buttons.

I invented the Monkey Couch Guardian, and wrote a how-to so you can build one, too.

Combine an Arduino with a proximity sensor, and make an obnoxious device to discourage cats and other fur-shedding pets from jumping on beds and couches. This project will also introduce you to the SPDT relay, a fundamental component of hobbyist electronics projects.

But do I really have to go easy on the tilt-shift filter, Casey?

Make:Projects just posted complete instructions for making your own Most Useless Machine. It's the simplest version yet, and is sure to bring a smile to the face of anyone who tries it.

Last year I saw a video of the "Leave Me Alone Box" built by Michael Seedman. Flip its switch on, and an arm reaches out of a door to turn the switch back off. To paraphrase The Terminator, that's what it does, that's all it does, and it will not stop until its circuit is dead.

I had to have one of my own, so I made one. Seedman's design uses a microcontroller to run two servomotors: one to open the lid, and another to push the switch. This makes for an impressive performance, but seemed too complicated, and actually, his circuit remains powered even when the box is idle.

For existential purity, I wanted a super-simple machine that really turned itself off. So I came up with a single-motor design controlled by a 555 timer chip, with a curved arm that both lifts the lid and flips off the switch. I called it the "Most Useless Machine" and posted it on Instructables along with a YouTube video of the box in action. The project soon went viral, attracting millions of viewers, thousands of comments, and many builds and design variations. Whew!

Along the way, Instructables member Compukidmike came up with an even simpler version that dispenses with the 555 circuitry entirely by using a gearmotor and two switches. The resulting project, presented here, is the ultimate in technology for its own sake, a minimal assemblage of parts that, through its one meaningless act of defiance, speaks volumes.

How to Build the Most Useless Machine

You can buy a kit for $30

In 2007, my husband and I were privileged enough to take a month off and travel around Europe. Given that we spent most of our time in Western Europe, there really wasn't a whole lot of cultural confusion, with a few notable exceptions*. Chief among them, the squat toilets we stumbled across at a very inconvenient moment in Italy. "Inconvenient moment" here defined as "actually having to use the bathroom."

My friend Frank Bures is a travel writer and he understands the squat toilet problem all too well. Frank is, after all, somebody who has traveled extensively in places where squat is all you got. In a piece from 2006, he shares some hard-earned advice on squat toilets. How I wish I had read this before my venturing into small towns in coastal Italy.

Dr. Jane Wilson-Howarth is probably the world’s foremost expert on excretion, a real Buddha of Bowel Movements, and she’s not afraid to get into the details. “My technique when I’m teaching volunteers about to go abroad,” said the author of How to Shit Around the World from her UK office, “is that when you’re learning, you need to take everything off below your waist: socks, shoes, pants, underwear. Then squat over the toilet. Pour water over your bum, and with your left hand, just whittle away with your fingers and try to dislodge any lumpy bits while pouring water. And that’s actually not too unaesthetic, because any mess that goes onto your fingers comes off in the water.”

What to do: Most important: Cultivate the right mindset. Relax, pretend like you’ve been doing this for years. Remember, using your hand is (according Wilson-Howarth) actually more hygienic, not less, than using toilet paper. “You get good bacteriological cleaning with just rubbing your hands together with soap under running water four times,” she says, and cites a study which says you don’t even need soap. “It can be ash or mud, just rubbing your hands together under water with some kind of washing agent. Even dirt from the river bank will give you good bacteriological cleaning.”

Read the rest at WorldHum

I spent last weekend in the Harvard Forest, participating in hands-on science experiments as part of the Marine Biological Laboratory's science journalism fellowship. The goal was to give us an inside look at what, exactly, scientists actually do. When you're reading a peer-reviewed scientific research paper, where did all that data come from?

Sometimes, it comes from a swamp.

On Saturday, we walked into the Forest's Blackgum Swamp to take core samples out of the muck. There was no standing water in this swamp, at least not when we visited. But I wouldn't call the ground "solid", either. Instead, it was more like a moss-covered sponge. With every step, the ground beneath me would sink and smoosh. In some of the lower patches, that meant a shoe-full of water. In other spots, it was just a disconcerting sensation.

Taking core samples involves a little machine that's like a cross between a shovel and a straw. Made of heavy, solid metal, it has an extendable handle on one end. At the other, there's a hollow, cylindrical chamber that can be opened and closed by turning the handle counterclockwise. You drive the chamber into the ground, turn the handle, and then pull it back out. Once everything is back on the surface, you can open the chamber and see a perfect cylinder of earth, pulled up from below. That cylinder is removed from the chamber, wrapped in plastic wrap, labeled, and put in a long wooden box. Then you do all of that again, in 50 centimeter increments, until you hit stone. We got to about 475 centimeters—15 feet deep. By that point, you'll have collected 1000s of years of layered sediment.

This is not as easy as it sounds.

Second, as you get deeper, it becomes harder and harder to pull the coring tool back out of the hole. First off, there's the handle. Each extension adds weight and unwieldiness. Then, there's the swamp itself—water-saturated mud that forms a suction around the coring tool. By the end, it took three people to remove the tool from the ground—two to pull it out, and one to catch the comically tall handle as it emerged from the Earth. When the tool came out of the ground, it came with a gush of water, like we'd just struck oil, and indescribably hilarious squirpple-plushhh-blurp sound.

In this series of photos, you can see journalist Eric Niiler, one of my co-fellows in the program, push the coring tool into the ground and begin to take it back out. Bear in mind, this is early in the process. The handle was MUCH longer than this by the end.

In these final two shots, Harvard Forest director David Foster and scientist Rich McHorney open the cylindrical chamber and move a fresh core from the tool to a plastic wrap sheath.

Video Link

Read the rest of my series of dispatches from the Harvard Forest

Check out all the wonderful things people send us over at Submitterator.

I stumbled across this randomly on YouTube today and had to share. The first 3/4 of the video are a chemistry experiment breakdown of what goes into a glow stick and what each of those ingredients is meant to do. But what makes me LOVE it is that, at the end, all of this coalesces into a fine explanation of the difference between light-absorbing dyes and fluorescent dyes. Come for the glow-stick "how to", stay for the better understanding of how light works and how it influences what you see!

Video Link

This custom silver ink, developed by materials researchers at the University of Illinois, Urbana-Champaign, allows you to draw working circuits out on paper. It's extremely cool, and the video shows you step-by-step how they make it. Bonus: This ink provides an actual reason to use cursive.

Video Link (Via Aaron Rowe)]]> http://boingboing.net/2011/10/17/how-to-make-silver-ink-that-conducts-electricity.html/feed 25 http://boingboing.net/2011/07/26/how-to-build-a-burning-man-theme-camp.html http://boingboing.net/2011/07/26/how-to-build-a-burning-man-theme-camp.html#comments Tue, 26 Jul 2011 18:12:00 +0000 Dean Putney http://boingboing.net/?p=110787 Photo by Ian Norman

My friend John Mills has been integral in running the Duck Pond – one of the larger and more well-organized Burning Man theme camps – since 2005. Those who have been to Burning Man probably know this camp as the one with the giant slip 'n' slide and the radio tower with a yellow duck on top.

This year John is unable to attend, so he's focused his energy into helping the community by writing an extremely detailed account of how their camp works and how to run your own. I helped John edit this post, and as a total Burning Man outsider I was amazed at how much work and thought goes into throwing a week-long party in the desert. Even if you're not interested in Burning Man, I think you'll find this insider's perspective on the culture and innovation behind the event extremely interesting.

Building a Burning Man theme camp]]> http://boingboing.net/2011/07/26/how-to-build-a-burning-man-theme-camp.html/feed 21