Ever since I was a kid I've loved playing with magnets. They're just so amazing! Remember those nifty, magnetic Scottie Dogs you could buy? Often one was black and the other was white but sometimes they were the same color. You could set them up on the table and push one away with the other until the loose one flipped around and the two joined together with a dull snap. Or how about using a magnet underneath the table to move a paperclip around the tabletop? That was always fun. I still like playing with magnets. When I worked in the Dino and Fossils gallery here at the museum, I carried a magnet with me and would demonstrate the magnetic properties of iron ore, especially the very magnetic mineral, magnetite.
I've been watching some videos lately about magnets and magnetism, and an oddball magnetic liquid called ferrofluid, which you can make in your kitchen. Anyway, I've gathered some videos here to share with our Buzz audience. The first (above) is about the strongest magnet in the world! The next is a levitation demonstration using neodymium magnets, followed by a couple videos utilizing ferrofluid, and ending with instructions on how to make your own at home.
Courtesy Mark RyanIt's Earth Science Week and this year's celebration centers around maps and mapping and their importance in geology and other earth sciences. Then on Saturday, October 19th from 1-4pm, the Science Museum of Minnesota is celebrating National Fossil Day with some special fossil-related exhibits throughout the museum. This year's theme is Paleozoic life, which is exactly the types of fossils commonly found in the southern half of Minnesota. Unfortunately, the official National Fossil Day website is closed due to the US government shutdown that continues, but that shouldn't stop anyone from celebrating fossils. Join us Saturday for some fossil fun.
Courtesy Wikimedia - en:User:Fir0002Eden Steven, a physicist at Florida State University is developing ways to possibly conduct electricity using spider webs and carbon nanotubes.
A carbon nanotube is a one-atom thick sheet of carbon that’s been rolled into a tube. A nanotube’s diameter is at least 10,000 times smaller than a strand of human hair. Carbon nanotubes are strong and have been found to conduct electricity and heat.
Florida State University reports Steven used just a drop of water to attach powdery carbon nanotubes onto spider silk. He gathered the spider silk himself, using a stick to gather webs outside his lab.
The experiment has drawn much national attention. “It turns out that this high-grade, remarkable material has many functions,” Steven said of the silk coated in carbon nanotubes. “It can be used as a humidity sensor, a strain sensor, an actuator (a device that acts as an artificial muscle, for lifting weights and more) and as an electrical wire.”
Steven wanted to investigate eco-friendly materials and was especially interested in materials that could deal with humidity without complicated treatments and chemical additives.
“Understanding the compatibility between spider silk and conducting materials is essential to advance the use of spider silk in electronic applications,” Steven wrote in the online research journal Nature Communications. “Spider silk is tough, but becomes soft when exposed to water. … The nanotubes adhere uniformly and bond to the silk fiber surface to produce tough, custom-shaped, flexible and electrically conducting fibers after drying and contraction.”
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Courtesy Public domain via WikipediaWe've all seen images and films of atomic bomb tests performed by the US government during the mid-20th Century: typically a brilliant flash of light followed rapidly by a mushroom cloud expanding outward and high into the sky. But that's not the only images to come out of the Atomic Age. Scientists were eager to gather as much information as they could about every aspect of fission and fusion, and used several means to glean as much as they could from those thermonuclear tests. The mechanical shutters in conventional cameras just weren't fast enough to photograph the very early moments of an atomic blast which occurred in a matter of nano-seconds. So scientists devised the rapatronic camera, an imaging devise that used three polarized lenses and a Kerr cell to capture the earliest moments of a nuclear reaction. Two of the polarized lenses were turned 90 degrees to each other with a third polarized lens turned at the diagonal and sandwiched between them. A Kerr cell is made up of liquid-suspended electrodes and rotates the light polarization when an electric field is applied (Kerr effect), allowing for super-rapid turning of lens orientation to record some amazing images.
Tired of the constant din and bustle of modern life? Is the noise of screaming children or the neighbor's yapping miniature collie turning you into a nervous nelly? Maybe what you need is a place where you can go for some real top-notch peace and quiet.
That place could very well be the special anechoic chamber located at Orfield Laboratories right here in the Twin Cities. The chamber, which is hidden behind two vault doors, has 3.3-foot-thick fiberglass sound-deadening fiberglass acoustic wedges covering all of its flat surfaces, so instead of bouncing off the walls, ceiling, and floor as in a traditional room, any sounds are absorbed. I'm talking absorbed almost completely - the double-walled steel and concrete room is, in fact, 99.99 percent absorbent. That's a lot of quiet! Humans can't detect any sound registering below 0 dBA, and the Orfield chamber has a decibel rating of −9.4 dBA! The space is so soundproof it's listed in the Guinness Book of World as the "Quietest place on the planet."
Of course, there are some side effects to being thrust into utter silence. One is that the sounds inside your own body, your breathing, stomach gurgles, and of blood rushing through your veins become quite pronounced. "In the anechoic chamber, you become the sound," says lab president and founder Steven Orfield.
Be aware that it's not that easy being in a totally silent environment. The longest anyone has been able to withstand the sensory deprivation of the chamber is 45 minutes. And even short spells of dead silence can trigger hallucinations. The brain just doesn't like being deprived of sensory input.
Orfield's anechoic chamber has been used by several industries, including Harley-Davidson, Whirlpool, and airlines to test product sound levels, and by NASA to test the ability of astronauts to function in the extreme silence of space where, as they often say, no one can hear you scream.
Courtesy NISE NetworkWhen things get really really small (nanoscale small), they behave completely differently! For example, gold at the nanoscale can look purple, orange, or red; static electricity has a greater effect on nanoparticles than gravity; and aluminum (the stuff your benign soda cans are made of) is explosive at the nanoscale!
If you want to experience some of these nanoscale phenomena first-hand, check out whatisnano.org, or download the DIY Nano app. The website and the app were both created by the Nanoscale Informal Science Education Network (NISE Net for short), and have videos and activity guides, complete with instructions and material lists, so you can do some nano experiments at home! The app was a Parents' Choice award winner for 2012, and was featured in Wired Magazine's review of apps. Definitely worth a look!
Have fun exploring nanoscale properties!
Courtesy Photo and graphic by author plus Wikimedia CommonsThis is a perfect post for Halloween. A really scary story involving quantum physics. Let me begin by saying that this stuff is absolutely mind-boggling. I’m not even sure I can explain it. Albert Einstein himself – the bravest theoretical physicist there ever was - called it “Spooky action at a distance”, that’s how much it scared him. What’s even more disturbing is that scientists now are reporting that this spooky action has gotten even spookier! I’m talking back-from-the-dead-zombie spooky! Let me feebly try to explain.
One dark and stormy night there were two sub-atomic particles – photons, let’s say – that are joined together like a two-headed freak show turtle. Wait, probably a bad analogy – how about this: like a set of identical twins? That works. Think of twins, Larry and Ralph. They’ve interacted with each other since birth, acting exactly the same way no matter where they were. If Larry ate a cheeseburger for lunch, Ralph had one, too. Anyway, in the world of quantum mechanics, this joining of two particles is called entanglement.
At quantum levels all rules of physics are thrown out like a rotting pumpkin on All Saints Day. As I understand it, particles don’t really exist in one particular spot or state on the time-space continuum –but rather in all their probable states at the same time. It has to do with a deal called superposition, and is all about probability. Which means until they’re measured or observed in some way, they live in a constant state of uncertainty. Once one of them gets measured, and a value is placed on it, the uncertainty is eliminated, and at that point it locks into some sort of “existence”. I think so anyway. But – and this is a really big but – just by measuring it, the particle dies. Or it’s state of uncertainty dies– I’m not sure which. Something gets killed. Does this make any sense? Not to me, but I’ll continue anyway.
So, with an entangled pair of particles, things get kind of weird. When two particles are entangled – i.e. physically interacting - with some sort of correlation (or anti-correlation), – that interaction remains no matter where they are located in relation to each other. You measure a value in one of the entangled particles, you can be certain the other particle instantly has the same value. In a correlated pair, if you see that one particle has an up spin, you’ll know right away the other has an up spin, too. In a normal world analogy, if you see Larry bobbing for apples at a party tonight, you’ll know Ralph is somewhere with a wet head.
This theory has been successfully tested several times on pairs of entangled photons separated by 80 some miles. It would matter not a whit if they were separated by a 100 billion lightyears, some unexplained force tying them together, would give the same results.
Now here comes the really scary part. Quantum physicists are now predicting that the same kind thing can happen when the two entangled particles don't even exist at the same time. This is called an entanglement swap. It involves removing a particle from one entangled pair, and using it to create a new pair with another particle removed from a different entangled pair. I know. Blah, blah, blah. But let’s see if I can help you (and me) understand.
Let’s start with an entangled pair of photons, our old pals “Larry and Ralph” again. You decide to measure Larry’s spin. It’s a down spin. So far so good. But unfortunately, your measurement leaves his twin Ralph, all alone. “You’re dead to me!” Ralph screams! And Larry is dead because you gave him a value (his spin). Ralph now wanders about by himself (with the same down spin as Larry of course). This is called disengagement. A little later, you create another entangled pair of photons, this time named “Jane and Sally”. They’re not very happy– always bickering, always fighting over whether they’re actually particles or packets of waves – you know, the usual photon sibling stuff. Anyway, after a while they become disengaged (somehow evidently without measuring and killing one – I’m confused here). Anyway, Jane leaves in a huff and eventually ends up hooking up with the very lonely Ralph. They’ve now done the old entanglement swap.
This leaves us with one dead photon, Larry, and one abandoned photon, Sally. They come from two different disengaged pairs and couldn’t be more unrelated. But, thanks to the screwy world of quantum mechanics Larry has somehow returned from the dead and is suddenly now entangled with Sally. They are an entangled pair. Sally wasn’t even alive when Larry died! But now she’s stuck in a paired entanglement with a stupid zombie. Now that's frightening. I’m sure Einstein is spinning in his grave.
If my telling of this bizarre quantum tale hasn’t scrambled your brains, or made the hairs on the back of your neck stand up, you can try to learn more at the below links.
SOURCES AND LINKS
New Scientist story
Scientific American story
Niels Bohr – the genius responsible for this stuff
Schrodinger’s Cat A cat's both dead and alive until you look inside the box.
Courtesy ksoAs a happy accident, scientists from the University of Manchester learned that graphene (sheets of carbon atoms arranged in a honeycomb crystal lattice, just one atom thick – think chicken wire) can repair itself spontaneously. Graphene is a semi-metal that conducts electricity very easily. It has potential uses in not only electronics, but also DNA sequencing, desalination, and it has been found to be a great antimicrobial.
The Manchester researchers were originally trying to understand how metals react with graphene, which will be an important part of incorporating it into everyday electronic devices. They found, much to their dismay, that some metals actually damaged graphene’s structure by punching holes in its neatly-arranged lattice. This is not a good thing if you’re trying to create a graphene-based device. However, quite unexpectedly, the graphene started to mend itself spontaneously, using nearby loose carbon atoms! As stated by the Scientific Director at the Daresbury Laboratory, Dr. Quentin Ramasse, this could mean the “difference between a working device and a proof of concept with no real application.” It also means that graphene just jumped to the top of my “baller carbon allotropes” list.
Courtesy Alex WalkerResearchers from Rice University have rethought the battery. Typically, batteries are made up of 5 layers: a positive and negative electrode, each with a metal current collector, and a polymer separator. These layers are manufactured in sheets and then rolled into cylinders. Rice researchers realized that each of these layers were available, or could be created, in sprayable form. They used lithium titanium oxide and lithium cobalt oxide for the anode and cathode, existing metallic paints and carbon nanotube mixtures for the current collectors, and a chemical hodge-podge with a very lengthy name for the separator layer. The result is an ultra thin (a fraction of a millimeter thick) lithium ion battery.
In their first experiment, researchers sprayed each consecutive layer onto nine bathroom tiles, topped with a solar cell. The resulting batteries were able to power 40 LEDs for six hours.
In its current state, this method is too toxic to be used outside a controlled environment, but with a little tweaking, a safe alternative will be found. At that point, any surface could be a battery!
Courtesy Fabian OefnerEver wonder what adding watercolor to ferrofluid might look like? Yeah, me neither. But photographer Fabian Oefner did, and this is the result – cool, psychedelic, maze-like images!
Ferrofluid is a colloidal liquid that’s made up of nanoparticles of iron, suspended in a fluid (usually water). Because it’s basically liquid iron, it becomes magnetized when exposed to a magnetic field, and ends up looking like a spiky mound. What Fabian did to create these cool images was to inject watercolors into a magnetized puddle of ferrofluid. The nanoparticles of iron then rearrange themselves into channels and pools to accommodate the paint, creating these colorful labyrinths. I highly recommend watching the video that demonstrates this process – it’s mesmerizing!