Dr. Augustine Fou's Online Scrapbook

Friday, May 31, 2013

Apple Juice: How to Charge Your Phone With Pocket Change and Fruit

Source: http://gizmodo.com/apple-juice-how-to-charge-your-phone-with-pocket-chang-510129312

Apple Juice: How to Charge Your Phone With Pocket Change and Fruit

Arthur C. Clarke wrote that "any sufficiently advanced technology is indistinguishable from magic," but he was wrong. It's easy to tell the difference—technology works. For example, "remote-viewing" mentalists claim they can see events far away, yet they fail every test. In fact, remote viewing is simple: It's called TV.

Another example that recently circulated online was a fake video of someone charging his iPhone by jamming the end of a USB cable into an onion. How do I know it was fake? First, you need contacts made of two different metals, and second, you can't get enough voltage out of a single vegetable. What makes the ruse so disappointing is that it is possible to charge an iPhone this way, if you do it right.

Theodore Gray, the author of Popular Science's monthly column, "Gray Matter," is convinced that when kids and adults are introduced to science in its most exciting form, they, too, will get hooked. In his newest book Mad Science²: Experiments You Can Do At Home, But Still Probably Shouldn't, Gray wants to spark that curiosity with visually spectacular experiments that illustrate the principles, the beauty, and the power of science.

Why It Works

A regulation vegetable battery, made by sticking strips of zinc and copper into a potato, generates about half a volt. The electricity comes from the oxidation of zinc; the vegetable is just an elecrolyte (conductive barrier), and the copper completes the circuit. Stacking alternating layers of vegetables, zinc, and copper is like wiring batteries in series, each set adding its voltage to the total.

After some 10 volts' worth of teary-eyed onion peeling, I decided to switch to apples using a fruit corer to cut out the apple rods and a cheese slicer to cut them into disks. Pennies with the copper plating sanded off on one side made a handy source of copper and zinc layers in one.

Apple Juice: How to Charge Your Phone With Pocket Change and Fruit

About 150 of these, arranged into six parallel batteries of 25 apple/zinc/copper layers each, yielded enough power to charge an iPhone, but only for about a second. (Much larger zinc plates and whole slices of apple would have provided more power for longer.) Around 200 of the layers went into one three-foot long apple battery, delivering much higher voltage. I was able to create a visible, and potentially fatal, spark with this battery. Yes, in the right configuration, you can electrocute yourself with an apple.

How I Did It

This was one of the most involved demonstrations I've done, due to the need to produce a couple hundred half-sanded pennies. Post-1982 pennies are made of copper-plated zinc, so if you sand off the copper plating on one side of them, and combine them with solid copper pre-1982 pennies, you have both metals needed to create a battery.

I mounted a short iron water pipe, whose inside diameter was just about the same as a penny, up against a small vertical belt sander, leaving a gap between the end of the pipe and the sanding belt that was just a bit thinner than a penny. Then I filled the pipe with a stack of pennies, and pressed them up against the running belt with a plunger. Each penny in turn was sanded down until it was thin enough to fit through the gap, at which point the moving belt threw the penny out of the machine, allowing the next one to advance into position. It worked surprisingly well as an automatic penny sander, plopping out a sanded penny every few seconds.

Apple Juice: How to Charge Your Phone With Pocket Change and Fruit

I first thought of using onions because I figured I could core them with a fruit coring tool (basically a very thin-walled metal tube with a sharpened edge, which you can use to cut plugs out of fruits), and then the layers would separate into lots of individual disks. Unfortunately onion didn't work very well, I think becasue each layer has a sort of membrane on one side that doesn't conduct electricity very well. So I switched to using apples instead, and had to manually slice the cores into disks.

Apple Juice: How to Charge Your Phone With Pocket Change and Fruit

With about two hundred sets of alternating penny/apple disks connected in series (stacked inside a clear plastic tube) the battery produces enough voltage (over 100V) to actually be dangerous. To charge an iPhone I had to rearrange the battery into six stacks of about 20 apple/penny slices each, with the six stacks connected in parallel to incrase the current capacity. Even so it charged the phone for literally about one second, just long enough for it to come on and display the charging symbol

Real Danger Alert: This experiment could damage your iPhone if done improperly.

In his new book, Mad Science²: Experiments You Can Do At Home, But Still Probably Shouldn't, science enthusiast Theodore Gray illustrates the awesome power of science with illuminating behind-the-scenes tours of the potential of the world around us. His (often dangerous) experiments are sure to capture the imaginations of students and anyone interested in science or just plain old cool stuff.

Scientists Revived 400-Year-Old Plants That Could Help Us Live on Mars

Source: http://gizmodo.com/scientists-revived-400-year-old-plants-that-could-help-510691491

Scientists Revived 400-Year-Old Plants That Could Help Us Live on Mars

A recently uncovered, perfectly preserved, 400-year-old plant specimen might be the answer to our increasingly important colonization of other planets—and the preservation of the human race as a whole.

You probably already know that human stem cells hold a vast, wildly exciting potential—both in terms of furthering our understanding of the human body and in saving countless lives. But did you know plants have their very own version of the industrious little cells, called bryophytes, that could prove just as important in saving humanity? That's exactly what scientists have found, and what's gotten them so excited.

Lead by Catherine La Farge, a team of researchers from the University of Alberta was exploring mosses around the Teardrop Glacier in the Canadian arctic archipelago when they discovered that portions of the (now rapidly receding) glacier were tinted an incongruous green. After taking the sample plant material back to her lab, the team ground up the specimens, placed them in potting soil, and watched with awe as they successfully regenerated from their 400-year-old parent material.

Scientists Revived 400-Year-Old Plants That Could Help Us Live on Mars

As the glacier recedes at an astonishing rate of 3 to 4 meters per year since 2004, scientists have gained access to an increasing amount of centuries-old plant life frozen in time. Every discovery up until now, though, has been flora of the vascular variety. But it's this non-vascular sort that, though often overlooked, holds the key to understanding our past and our future.

What's a Bryophyte?

Vascular plants are primarily defined by the existence of a xylem and a phloem, or in other words, the parts that suck up water and nutrients and send them shooting throughout the rest of the plant. Non-vascular plants, as all you keen observers may have already guessed, don't have this system—they're a far more simple breed. Made to freeze and dry out, they're able to survive in conditions that vascular plants, what with their fancy leaf and stem tissue needing "water" and "food" all the time, could only dream of.

Scientists Revived 400-Year-Old Plants That Could Help Us Live on Mars

Bryophytes, which fall into this latter category, have to reproduce asexually since they often don't have access to water, which is key to fertilization. And because of this, depending on its environment, a single bryophyte cell can essentially reprogram itself to grow as an entirely different plant. But that's not even the exciting part. As La Farge explained:

This has been known forever by biologists who deal with bryophytes. Because if a moose goes through a forest, it might pick up moss in its toes and carry that material somewhere else. So when the plant tissue drops, it will be able to reestablish itself in its new environment and thrive.

It's as if you could drop a lion in the ocean and have it grow gills.

So... What's the Big Deal?

As glaciers retreat and a greater variety of plant life surfaces, it's essentially like peeling a blanket back over a perfectly preserved portion of the past. Dormant, yes—but alive nonetheless. And that's what makes this discovery so incredible. The knowledge that it's even possible for plant life to survive in such extreme conditions opens the door to a deeper understanding of this robust group's cell biology. Which in turn, could very well pave the way towards us figuring out how the hell we're going to grow plants on other planets—oh, say Mars, for instance.

Because unquestionably, before we can even begin to fantasize about sending people into the red abyss, we're going to need to test whether or not plants can survive in those kinds of conditions—harsh light, dryness, freezing, etc. And now it seems like we may have found just the plant for the job. Eschews water? Check. Ability to reproduce simply and all by its lonesome? Check. Doesn't mind the cold? Double check. Not to mention the fact that it can morph into other plants.

Scientists Revived 400-Year-Old Plants That Could Help Us Live on Mars

Which is part of the reason why bryophytes represent the second largest lineage of land plants in terms of diversity—10,000 different species diverse, to be exact. And various, disparate strains will happily live side-by-side; they don't compete in the way vascular plants do. Rather, they bunch as close together as possible, which allows them to retain the moisture that facilitates their entire biological life cycle. So there's a reason you'll always see moss growing in tufts. And though they might be virtually microscopic as single organisms, there's still plenty about them to find fascinating—especially if you're a bryophyte enthusiast like La Farge. As she explained to us:

It's mind boggling, because normally you walk through a forest, and you see green moss on a rock. So you might think oh, that's a nice moss and move on. But you never stop to think about what that green actually represents. How diverse is it? How many species are we really considering here? I mean, when you're up in the high arctic, if you pick up just a small packet, say a letter envelope size, you can often get 15 different species of bryophytes in one letter-size collection. It's pretty amazing.

The Next Stage

There's still many other organisms that could be lying peacefully under the still-frozen glacier. Scientists knew that fungi, yeast, and bacteria were all able to survive in ice, and they also knew that both vascular plants and mosses could live on the top of a glacier. But this is the first time we've really considered the possibility that the stuff peeking out from underneath the glacier just might be alive. Frozen specimens, then, won't necessarily be considered dead on arrival, leaving researchers with plenty of work ahead of them.

La Farge is particularly interested in moving into the lower latitudes, where the even more rapidly shrinking icecaps are exposing even older glimpses of past life. And all of this will only enhance our newly illuminated understanding of basic life systems—something we're going to need when we start planting biodomes on other planets.

Of course, tests like that may still be quite a ways off. But at least now, we have plenty of reason to hope. [Proceedings of the National Academy of Sciences of the United States]

Images via Catherine La Farge