Make: Online: Science Archives

Science Archive: Science

July 2, 2009

Metallurgical eye candy

An alloy of 1.3% copper, 0.3% magnesium, and 0.3% manganese in aluminum, etched with potassium permanganate and lye.

So I woke up this morning all pumped up to blog about metallography. If you don't already know, metallography is a type of scientific microimaging that involves mirror-polishing metal surfaces and then etching them with various reagents to reveal their microstructures, which are often of breathtaking beauty.

"Griffith Cannon Flash," by Dr. Frederick E. Schmidt, from the iron of a cannon used at Gettysburg.

Unfortunately, there aren't a lot of these images online. ASM International, the big metallurgical professional society, has a large online database of metallographs, but it's locked away behind a members-only paywall. Except for a couple of skimpy .PDFs (2007, 2008), even the winners of their annual International Metallographic Contest seem to go largely unpublicized.

Which is a shame, not only because the images themselves are so beautiful, but because they could inspire a whole culture of amateur and artistic metallographers that does not, as far as I can tell, presently exist. Which fact also surprises me, by the way, because the equipment and techniques of metallography are very accessible to amateurs, especially relative to other modern methods of materials analysis.

"Grain structure in CC cast 3304 aluminum alloy," by Elana Naez.

If you know of anyone who's making metallographs as a hobby or as a means of personal artistic expression, please drop me a link in the comments.

Explaining voltage on FMCG

In this clip from FMCG, Ken responds to Jeri's capacitor deconstruction with his own very visual (and very mechanical) demonstration of how voltage is generated and how you can build a simple capacitor, with aluminum foil and plastic, to generate charge mechanically and dump it into the cap (analogous to how a Wimshurst machine works).

I love how this was inspired by Jeri's demo and how the two of them are having a Net-carried, seemingly casual conversation, marveling over the miracles of science. I don't know about you, but this sort of thing makes me strangely happy.

BTW: Jeri's capacitor demo is cool too, but unfortunately, the sound craps out at the end.

FMCG

July 1, 2009

Some recent FMCG vids

Our pal Jeri Ellsworth and her crew of restless USTREAM-ing hackers are at it again, exploring light polarization, sparking ions, and reversing time.

The Fat Man and Circuit Girl

June 30, 2009

How-To: Make pyrophoric iron

A former chemistry teacher of mine provided a great definition of "pyrophoric:"

[It] means that if you playfully squirt some at your lab mates, they will burst into flame.

In other (less amusing) words, a "pyrophoric" substance is one that ignites spontaneously on exposure to air.
Pyrophoric iron, however, isn't as dangerous as that makes it sound, especially in small quantities.

Basically, the oxidation of iron is so vigorous that it can cause very finely divided iron metal to become incandescent. Amazing Rust has a great tutorial on how to prepare finely divided iron by thermolyzing iron oxalate, a yellow powder that can, in turn, be prepared by a simple reaction between two common chemicals.

June 28, 2009

AIDG: water solutions

AIDG is a NonGovernmental Organization (NGO) that helps provide low technology solutions to help address environmental and health needs to people living in communities without great access to the systems that many of us consider requirements.

Here are a few of their water-based initiatives:

Solar Hot Water:

XelaTeco, with support from AIDG's wonderful interns, recently installed a solar water heating system and water tower for La Guarderia, a childcare center in Llanos del Pinal, Guatemala. La Guarderia was started by two non-profit organizations, Pop Wuj and Jóvenes Juntos, who saw the need for daycare and after school homework assistance in a community plagued by poverty, domestic violence and alcoholism.
Jóvenes Juntos requested the hot water system to promote healthy hygiene practices amongst the children served by center, particularly in the cold winter months. The presence of hot water is expected to reduce the occurrence of skin ailments, such as scabies and other rashes. This segment of the project was funded by AIDG.

Ram Pump:

As the water runs downhill from the source to the ram pump, it gains force and velocity. When this velocity reaches a determined point, the water closes a valve in the ram pump known as the "impulse" or "waste" valve. The force of the water against the now closed impulse valve causes pressure to build inside the pump. The water sends high-pressure shock waves in all directions (the "water hammer," or "ariete" in Spanish, from which the pump gets its Spanish name, "Bomba de Ariete"). These shock waves open another valve, the delivery check valve, and water squirts through reaching altitudes of up to ten times greater than the vertical distance from the water's source to the pump. An air vessel installed in the pump acts as a kind of regulator which keeps the flow at the top steady, instead of delivered in bursts, as the pump internally functions

Sand Filtration:

Properly managed sand filters remove 96%-98% of water borne pathogens such as E. Coli and Giardia, producing a positive significant impact on the health of target users. The greatest effect is expected for young children, who are extremely susceptible to diarrheal diseases caused by exposure to contaminated water. Diarrheal disease causes approximately 2 million deaths per year among children in developing countries.

The World Health Organization has some good documentation on sand filtration technology.

To find out more about AIDG, check out their blog and their photos.

June 27, 2009

Prototyping Thermatron, flame-controlled synth

Lorin Parker of Electric Western (creator of the Phantastron) puts fire to work controlling sound -

The THERMATRON is essentially a voltage controlled oscillator and wave shaper controlled by the action of a flame. This is possible because electricity can be conducted through a flame. This is not a new discovery, in fact the electrical properties of flame have been known for hundreds of years and well studied. For example, many hot water heaters have a sensor that detects flame by sensing the current inserted through the gas flame (if the gas flame goes out, the current does not reach the sensor and the heater knows that the flame is out).

Check out the project's post for a much deeper explanation of the Thermatron's funciotnality and flame conduction in general.

June 25, 2009

Thinking of building a solar still?

Build It Solar has a great collection of solar DIY projects, including stills, cookers, food driers, and water heaters. But the gem of their solar-distillation collection, for my money, is this paper, from 1985, by Horace McCracken and Joel Gordes. It's unformatted ASCII and black-and-white GIFs, but it provides a better review of the various designs of solar stills, and the theory that informs their design and operation, than anything else I've found in the tubes.

From the pages of MAKE:

If you're interested in all things solar, be sure to check out Parker Jardine's Solar Power System Design in MAKE 14.

More:

June 23, 2009

Library of strange compounds

George Pendle wrote the highly-recommended Strange Angel: The Otherworldly Life of Rocket Scientist John Whiteside Parsons, the biography of rocket pioneer Jack Parsons (whom I profiled in MAKE, Volume 13). In Saturday's Financial Times, George writes about the Materials Library at King's College, London.

Deep in the bowels of a brutalist concrete building on the Strand, long shelves are packed - crammed, really - with some of the world's strangest substances, from the past, present and sometimes, it seems, the future. Take Aerogel: the world's lightest solid consists of 99.8 per cent air and looks like a vague, hazy mass. And yet despite its insubstantial nature, it is remarkably strong; and because of its ability to nullify convection, conduction and radiation, it also happens to be the best insulator in the world. Sitting next to the Aerogel is its thermal opposite, a piece of aluminium nitride, which is such an effective conductor of heat that if you grasp a blunt wafer of it in your hand, the warmth of your body alone allows it to cut through ice. Nearby are panes of glass that clean themselves, metal that remembers the last shape it was twisted into, and a thin tube of Tin Stick which, when bent, emits a sound like a human cry. There's a tub of totally inert fluorocarbon liquid into which any electronic device can be placed and continue to function. The same liquid has been used to replace the blood in lab rats, which also, oddly enough, continue to function.

A library of the world's most unusual compounds [via Boing Boing]

June 17, 2009

Coin shrinking with high voltage in slow motion

Recently Hackerbot Labs was invited by Intellectual Ventures to demonstrate their Maker Faire Editor's Choice Award-winning high voltage coin shrinker in front of a Vision Research Phantom 100k fps high-speed camera.

Discharging about 10 kV (15,000 joules!) from enormous 300 µF capacitors the team at Hackerbot Labs "Turn half dollars into quarters! Turn quarters into dimes! Turn dimes into little semi-molten balls of metal!" with their custom built apparatus through a process known as "Magnaforming".

Passing current through a coil of wire produces a magnetic field. In this case, with so much current, the magnetic field produced is gigantic: the coil becomes a magnificently powerful electromagnet.

The creation of a magnetic field in the coil-now-magnet induces a circling current to flow around the coin sitting inside the coil. This current in the coin also produces a magnetic field (i.e., the coin becomes another electromagnet). The kicker is that the coin's magnetic field and the coil's magnetic field point in opposite directions, so the coin and the coil repel each other furiously.

This repulsion creates forces which overcome the strength of the metal; the coil is expanded out and explodes, and the coin is pushed in and shrunk.

Some interesting facts were gathered as a result of the demonstration:

Filmed at 100,000 fps, the coin will shrink in just 30-40 microseconds

The coin will have shrunk prior to the coil exploding

A loud 135 dB shockwave is produced as the coil explodes

When shrinking the edge of the coin moves at about 400 mph

High Speed Coin Shrinking [via Intellectual Ventures]

June 12, 2009

Students enjoy MAKE, build styrofoam speakers

David Veloz Jr., an engineer at the Naval Surface Warfare Center, told us about a unique class he was teaching over the summer. His company conducts an outreach program for local high school students who show an interest in science and math. David was teaching them about his job and electronics in general.

Thinking that his class sounded like a worthwhile effort, we were happy to send some copies of MAKE out to his students. Afterward, David was kind enough to send us some photos of his class reading the issue, along with this nice note:

I've been meaning to get back to you guys, attached are some photos of the class reading their magazines. They absolutely loved them! I tried not to bore them too much, so I kept my bit short and quickly got them started on their project (Styrofoam speaker). We talked about magnetism, magnetic fields, and current, it was fun for everyone! A handful of the kids finished after our 2.5 hrs were up (we went over). They said that it was the best class!

During the class, David helped the students build the styrofoam plate speaker from MAKE, Volume 12, and gave away a couple of multimeters as prizes. What a great way to teach young people about the world of making!

You can still pick up a copy of MAKE, Volume 12, and other back issues of MAKE in the Maker Shed.

Record-vying transatlantic robot submarine at sea

The Scarlet Knight, named for sponsoring Rutgers University's mascot, is a cruise-missile-shaped autonomous ROV that was launched off the New Jersey coastline on April 27. If all goes according to plan, the Rutgers team will recover it off the westernmost coast of Spain right around Christmas day. That happy event would mark the first successful underwater crossing of the Atlantic by an unmanned vehicle. At the mission website, you can track the robot's position using Google Earth, monitor her battery status, and follow the team's navigation blog.

June 11, 2009

Endless sustainable power at the sea floor

"Benthic microbial fuel cell" is propeller-head code for the following very interesting fact: If you bury a metal plate a few centimeters beneath the ocean floor, and elevate a parallel plate a few centimeters above the ocean floor, the potential between them (due to ongoing microbial metabolism in the sediment) is enough to generate useful power. 800mV is a typical figure, but if I understand correctly, the current is directly related to the area of the plates, so the amount of power available by this method is theoretically only limited by the size of the plates you can install. Mark Nielsen is a doctoral candidate at Oregon State University under Dr. Clare Reimers, an expert in the field. This page at the OSU website provides a nice general overview of the concept and of Mark's work in particular.

June 10, 2009

Teaching mirrors new tricks

Andrew Hicks, a mathemagician at Philadelphia's Drexel University, has lately made headlines with one of those head-slappingly simple, brilliant, OMG-why-didn't-I-think-of-that sort of projects: He makes mirrors. Not the run-of-the-mill flat mirrors most of us use every day for identifying vampires, but totally unorthodox, heretical, downright blasphemous mirrors with convoluted surfaces that do tricks I didn't even know mirrors can do--like reflecting things the right way 'round! New Scientist has some nice photos, and PhysOrg the story.

In the Maker Shed: The Ballistic Bundle

Announcing our new bundles available exclusively in the Maker Shed. William "Bill" Gurstelle is an award-winning writer, licensed engineer, bestselling author and professional speaker (not to mention MAKE Magazine contributing editor and producer on Make: television). We like the guy, we like the way he thinks. We think you'll like him too, which is why we've created the Ballistic bundle.

The Ballistic Bundle includes:

Backyard Ballistics $16.95 value
Whoosh! Boom! Splat! $16.95 value
Make Vol. 3 $14.99 value
Barrage Garage Vol. 1 DVD $19.99 value

All for the discounted price of $48. That's an amazing 46% off the price if you purchased these items individually. Take advantage of this amazing deal before it's too late.

More about the Ballistic bundle in the Maker Shed

June 6, 2009

Ultraminimalist lab-stand lamp

I made this minimalist table lamp from three ready-made components: 1) a burner tripod lab stand from The Science Company, 2) a 5" globe incandescent light bulb, and 3) a socket extension cord from the hardware store. It works and looks great, and the total cost is about $20 US. The 5" globe light bulbs are also available as compact fluorescents (CFLs), rather than incandescents, which doubles the unit price but probably saves money in the long term due to the radically increased lifetime and efficiency of CFL bulbs.

June 4, 2009

h+ Summer issue

h+ Magazine is edited by MAKE contributor R.U. Sirius. While it's not exactly a DIY magazine in the conventional sense, it's about making the future and about robotics, biohacking, brain-machine interfacing, space colonization, and other topics that may be of interest to MAKE readers. They have a digital magazine edition, a downloadable PDF version, and will soon offer a print edition as well.

h+ Summer Edition

June 3, 2009

Theo Gray on why "safety" is overrated

The most awesome Theo Gray, author of the I-can't-recommend-it-highly-enough Mad Science, has a post on Powell's Books blog about his book and the dangers it contains (the subtitle is "Experiments You Can Do at Home -- But Probably Shouldn't"). He writes:

Is it irresponsible to write a mass-market book that describes how to do dangerous science experiments? It used to be very common. I have books from the early 1800s through the mid 1900s that would make your hair stand on end. One 1930s book from none other than the Popular Science Press includes the recipe for Armstrong's mixture, a friction-sensitive explosive notorious for blowing hands off while it's being mixed.
But that's ancient history now. Books of home science, and even classroom chemistry at the high school level, are filled with baking soda and vinegar science. The Dangerous Book for Boys, for example, is completely devoid of danger.

Surely recommending only perfectly safe experiments is a good thing, isn't it?

Is Science As Important As Football?

Hunting strange waves with hacked circuits

The Electromagnetic waves sent out by modern living can make for some decidedly eerie soundscapes - and some very interesting exploration. Radiolariax uses a variety of devices to listen in on the otherwise unheard -

The hunt for weird radio signals and other electromagnetic waves with small, cheap modified radios, cassette players, walkie-talkies, dictaphones, babyphones, pc speakers,... and simple circuits.

Check out the collection of devices used and relevant audio samples on the signal and wave hunting site.

May 28, 2009

The siren song of Gnathonemus petersii

OK, so, it's not exactly a song. It's more like a clicky, morse-codey, geiger-countery sort of buzz. Nonetheless, it is generated by an electric fish, and you can hear it yourself just by wiring a piezoelectric earphone across the water in your fish tank. Provided, of course, that said water contains said electric fish. If that seems like too much work, then you can just download the sound from here. While you're at it, read all about the details of the so-called "Elephant Nose Fish" and its so-called "electric organ." I'm not making any of this up.

May 26, 2009

The importance of being stupid

UVA Microbiologist Martin A. Schwartz has a wonderful article in the Journal of Cell Science about the importance of what he calls "productive stupidity:"

I'd like to suggest that our Ph.D. programs often do students a disservice in two ways. First, I don't think students are made to understand how hard it is to do research. And how very, very hard it is to do important research. It's a lot harder than taking even very demanding courses. What makes it difficult is that research is immersion in the unknown. We just don't know what we're doing. We can't be sure whether we're asking the right question or doing the right experiment until we get the answer or the result. Admittedly, science is made harder by competition for grants and space in top journals. But apart from all of that, doing significant research is intrinsically hard and changing departmental, institutional or national policies will not succeed in lessening its intrinsic difficulty.

Second, we don't do a good enough job of teaching our students how to be productively stupid - that is, if we don't feel stupid it means we're not really trying. I'm not talking about `relative stupidity', in which the other students in the class actually read the material, think about it and ace the exam, whereas you don't. I'm also not talking about bright people who might be working in areas that don't match their talents. Science involves confronting our `absolute stupidity'. That kind of stupidity is an existential fact, inherent in our efforts to push our way into the unknown. Preliminary and thesis exams have the right idea when the faculty committee pushes until the student starts getting the answers wrong or gives up and says, `I don't know'. The point of the exam isn't to see if the student gets all the answers right. If they do, it's the faculty who failed the exam. The point is to identify the student's weaknesses, partly to see where they need to invest some effort and partly to see whether the student's knowledge fails at a sufficiently high level that they are ready to take on a research project.

The importance of stupidity in scientific research [Thanks, Arwen!]