Stories tagged Physical Science
Electricity from Viruses: Berkeley Lab scientists generate electricity using viruses.Courtesy Courtesy ksoScientists from the Berkeley Lab have developed a way to generate electricity from viruses! Their method is based on the piezoelectric properties of the virus, M13 bacteriophage. Piezoelectricity is the charge that accumulates in certain solids when a mechanical stress is applied to them (squeezing, pressing, pushing, tapping, etc.) The scientists realized that the M13 virus would be a great candidate for their research because it replicates extremely rapidly (no supply problems here), it’s harmless to humans (always a good thing), and it assembles itself into well-organized films (think chopsticks in a box). It was these films that they layered and sandwiched between gold-plated electrodes to create their nearly paper-thin generator. When this postage stamp-sized generator was tapped, it created enough electricity to flash a “1” on a liquid crystal screen.
The potential here is that someday we could put these super-thin generators in any number of places, and harness electricity by doing normal, everyday tasks like walking or closing doors. I propose putting them in the shoes of marathon runners and then have cell phone charging stations along the route. Nothing is more maddening than waiting all day in the rain to get an action shot of your runner, only to find that your battery has since died by the time your slow-poke reaches the finish line. There’s always next year.
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World's smallest giraffe: Scanning electron microscopy (SEM) image depicting a baby giraffeCourtesy Image courtesy of the Materials Research Society Science as Art Competition and Shaahin Amini and Reza Abbaschian, University of California RiversideMaterials science is the study of the relationship between the structure of materials at the atomic or molecular scales and their properties at the macroscale. Materials scientists do a lot of monkeying around at super small scales, and the Materials Research Society (the organization that brings together materials scientists from academia, industry, and government) has given them a creative outlet. At each of their annual meetings, MRS includes a Science as Art competition, where any registered meeting attendee can enter an image they have created. The images are pretty amazing in their own right, but when you think about the methods, medium, and scale used to create them, it's truly mind-boggling! Here are some of the best entries from past meetings, and some video versions of selected works as well.
Smear campaign: climate scientist relates his own experience from anti-science attackCourtesy CECAR - Climate and Ecosystems Change Adaptation R (adapted by Mark Ryan)Several months back there was a lot of hoopla revolving around the so-called "Climategate" scandal. Climate scientists' emails were hacked, posted online and taken out of context as they were disseminated around the internet and through the news channels. Some researchers were charged with manipulating climate data to bolster their own point of view, and indignant investigations were launched against them. As the story fermented in the media, the blogosphere, and political circles, it grew into an over-inflated bag of hot-air. But, eventually, the truth prevailed, and those accused were exonerated by the facts. Michael Mann, a climate change researcher at Pennsylvania State University, was one of key figures in the "scandal", and has written (both here and in a new book) about his experience dealing with the kind of smear campaign that was hurled his way. He terms it the "scientization" of politics. It's involves some of same anti-science tactics used by the tobacco industry and creationists: mainly to cast doubt on the facts, and fabricate controversy where there is none.
This article describes the results of a study conducted by the Australian Government, which says some Australians “may be raising their risk of skin cancer by avoiding sunscreen due to unfounded fears over nanoparticles.” The article went on to say that one third of the people surveyed had heard or read about the possible risks of nanoparticles, and that 13% of these people would be less likely to use sunscreen. At first, this seemed like a very interesting finding – people would rank nanoparticles higher than skin cancer on their personal risk meters! But as I examined the article a little more, I realized I have a few issues with the way it presented the results. 
A Discrete Request for Regulation: The Hoff is on board.Courtesy Friends of the Earth Australia
First, the article makes it sound as if survey-takers were faced with the question, “would you rather risk getting skin cancer or use a sunscreen with nanoparticles in it?” In actuality, they were simply asked if they would be less likely to use a nanoparticle-based sunscreen, given the risks they’d heard about. I realize it is implied that if you don’t use sunscreen your chances of getting skin cancer increase, but when taking a survey, you’re probably just answering the question at hand: Would you be less likely to use a product that you’ve heard could by risky. These answers are also coming from a survey that repeatedly mentions the “possible risks of using sunscreen with nanoparticles” in various questions. It seems to me that hula hooping could start to sound risky by the end of a survey like that. “Have you heard or read about the possible risks of hula hooping? If you have heard or read about the possible risks of hula hooping, do the stories make you any less likely to hula hoop in general? Agree or Disagree: 1.) Hula hooping is risky to my health. 2.) Hula hooping is more risky to my health than not hula hooping 3.) I am scared to hula-hoop.” Ok, I exaggerate a little, but the way a survey is presented has an effect on the answers people provide.
I get that they’re trying to highlight the fact that some people perceive nanoparticle-based sunscreens as dangerous, and that’s an interesting finding- not because they would stop using sunscreen, but because the current weight of evidence suggests that the nanoparticles in sunscreens don’t penetrate the skin - they’re harmless to humans. Which brings me to my point that perhaps a more telling result of the study is the high number of people who said they didn’t know if nanoparticle-based sunscreens are risky, and needed more information before deciding whether to use them. The fact that some people perceive nanoparticle-based sunscreens as dangerous when the current scientific evidence suggests otherwise, supports the idea that people just don’t know enough about nanoparticle-based products.
Now, I’m not suggesting that all nanoparticle-based products are safe, across the board. I’m also not trying to downplay people’s concerns about this relatively new technology. In fact, I think a healthy dose of caution is a good thing when it comes to new technologies. I just think that fear comes from not knowing, and people’s concerns could be alleviated if they had more information. What is concerning is that the information isn’t exactly available. There are no regulations on nano products (though the FDA appears to be working on it), companies are not required to label their products as containing nanoparticles, and there are no standards in defining what a nano product is. What I am suggesting is that maybe we should be demanding that information from the likes of industries, governments, policy makers, etc, instead of focusing on the few that perceive nanoparticles as risky.
The point of the study was to figure out the public’s perception of sunscreens that contain nanoparticles, and I think it did. It showed that the public doesn’t know enough about it to make any real/informed decisions.
What’s your take? How do you feel about nanoparticles being used in products you rely on every day? What do you think about regulating this technology? Creating standards for it? Do you think these regulations and standards would stifle scientific progress, or protect our health? What do you think about hula hooping?
As a physical science teacher, one of my jobs is to teach my students how to measure like scientists. This includes, but of course is not limited to, distance with a ruler and mass with a balance. That is why I like to do a lab with the density blocks very early in the year. You use the rule to measure the length, width, and height of the blocks (in this case they're cubes, but hopefully sometime the Resource House will get some non-cube blocks) to calculate volume. They get practice using the triple beam balance finding mass. Finally they get to calculate density and put the blocks in order by density. A fun and engaging way to learn about the importance of measurement. Oh yeah, it's totally free too (thanks Resource House).
The Moon: According to a recent study, it's two moons in one.Courtesy Mark RyanA new study published in Nature proposes that our Moon once had a companion satellite that it eventually accreted in a celestial collision. Planetary scientists, Erik Asphaug, of the University of California, Santa Cruz, and Martin Jutzi of the University of Bern in Switzerland devised computer simulations that show how it could have happened.
According to present lunar origin theory, four and half billion years ago, while the Earth’s system was forming, gravitational forces attracted a Mars-sized object that collided with the early Earth. The collision - more of a glancing blow than a direct hit - tossed terrestrial material into space that coalesced into our Moon. But during the period of coalescence – perhaps for tens of millions of years - a smaller companion moon (about 1/3 the size of the larger moon) would have been visible in Earth’s primitive sky. Geologically speaking, the mini moon’s existence would have been short-lived. The system was unstable, and sooner or later the moonlet’s orbit would decay and it would be pulled either into Earth’s mass or into that of the larger satellite.
Computer simulations set up by Asphaug and Jutzi reconstruct the latter taking place. The researchers propose that the dominant moon was still in a semi-molten state when its smaller companion collided with it at a sub-sonic speed. Being smaller, the doomed moon would have cooled faster and would have been more solidified, but the collision was hardly devastating. It’s low impact speed made it more like a clump of mud being lobbed against a wall. There wasn’t enough force in the collision to punch through, but just enough to make it stick.
More evidence: lunar composition differences
During NASA’s Apollo lunar program in the late 60s and early 70s, astronauts collected several samples of rock from the near side landing sites. The rocks brought back proved rich in potassium (K), rare earth elements (REE) and phosphorus (P) – hence the acronym. These elements, which are scarcer on the Moon’s dark side, crystallize very slowly in cooling magma, and remain molten until the entire mass of magma solidifies. So according to the researchers, when the collision occurred, it was enough to push much of the still molten magma - and the KREEP along with it - to the near side, and leave a pile of mountainous terrain on the far side.
I find this all pretty fascinating. The hypothesis answers several questions that have been puzzling lunar scientists for several years, and fits well into what we observe now. Of course we only see the Moon’s near side. Gravitational forces keep much of the far side hidden from us except via photography and lunar probes (Why that is can be learned here).
SOURCE and LINKS
Story in Scientific American
Story on Weather Space.com
Apollo Lunar Program
Sometimes we here at Nano Headquarters grow weary of reading and attempting to decipher scientific papers in ways that make them easy to understand.
Take, for example, this sentence:
“The as-prepared gold particles showed good catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol by excess NaBH4, and a surface-enhanced Raman scattering (SERS) study suggested that the gold nanoparticles exhibited a high SERS effect on the probe molecule Rhodamine 6G.”
Here’s what we were able to immediately comprehend:
“The as-prepared gold particles showed good BEEEEEEEP for the reduction of BEEEEEEEP to BEEEEEEEP by excess BEEEEEEEP, and a surface-enhanced BEEEEEEEP BEEEEEEEP BEEEEEEEP study suggested that the gold nanoparticles exhibited a high BEEEEEEEP effect on the probe molecule BEEEEEEEP BEEEEEEEP”
On days like this, we like to practice what we call "selective avoidance" and seek out pretty images instead. Pretty nano-related images, mind you – but pretty images nonetheless. They soothe our bleeding brains. And so, for your BEEEEEEEP-free pleasure, we offer you this here compendium of pretty nano images:
Pretty!: Pollen GrainsCourtesy Dartmouth Electron Microscope Facility
NOVA - The Art of Nanotech
Remember our friends over at NOVA who made the nanorrific Making Stuff series? This here slideshow was a little buried treasure accompanying it. The images are originally from the Materials Research Society - Science as Art competition. We’re a little partial to the Starry Night knockoff. Van Gogh would be impressed. And if not, then we wouldn’t have wanted to be his friend anyway because apathy gets boring fast and huffy, stuffy artists are tedious.
Sciencescapes Speaking of the Science as Art competition – here are a few more images from competitions in years past. From likenesses of spaghetti and meatballs to a decaying Santa to a creepy Pac-Man to a dotted-dude walking off a cliff to his ultimate doom, there’s a little something here for everyone.
Also Pretty!: Water Droplet on Nasturtium LeafCourtesy Stephan Herminghaus
International Science and Engineering Visualization Challenge
A video from the National Science Foundation wherein they invite us to “discover the artistry behind the 2010 International Science & Engineering Visualization Challenge winners as they explain the processes, techniques and thoughts behind their entries.” SPOILER ALERT: The very first fellow we meet tells us right out that there’s “no message” to his work. Awesome.
Silver Saver – nanotech in art preservation Think that the old, old artifacts you see in museums just stay that way because they’re in a fancy, climate-controlled case? Think again!
Equally Pretty!: Silicon NanomembraneCourtesy S. Scott, University of Wisconsin-Madison
NISE Net Viz Lab All the pretty, pretty pictures you’ve seen in this post thus far are from the NISE Net Viz Lab. And guess what? They’re in the public domain! That means you can use them however you like without going through all sorts of crazy legal hoops! Whee! Just remember to give credit where credit it due – ‘cause we’re pretty sure you don’t have a scanning electron microscope at home.
SPECIAL NOT-NECESSARILY-NANO BONUS:
The Periodic Table Printmaking Project We could look at these for DAYS. In fact, we have. Take the Periodic Table of the elements, mix in a few block-print makers, and what do you get? Some seriously killer prints that provide visual intrigue for such favorites as Promethium and Fluorine. We will admit to getting a little googley-eyed over these.
Okay kids, stop swooning. Back to work.
Science FridayCourtesy Science Friday Today,
"Fleas are admirable jumpers -- a talent that humans have recognized for thousands of years, according to engineer Greg Sutton. Yet, until this week, exactly how fleas propel themselves wasn't understood. Sutton and Malcolm Burrows, of the University of Cambridge, filmed fleas jumping, analyzed flea anatomy, made mathematical models and cracked the flea leap mystery. It's not in the knees."
Quest for the best optical display
Better resolution displaysCourtesy Yutaka Tsutano
I have been waiting for the new iPod Touch. I want a display screen so sharp, it looks like a photograph. The "retina display" creates an image out of pixels that are only 78 nanometers. How small is that? Well, more than 300 of these pixels are packed in each inch. Supposedly this is the limit for human perception, or as some fanboys might say, "It doesn't get any better than this!"
Plasmonic nanoresonators
University of Michigan researchers can do better, though, Their paper in Nature Communications titled, Plasmonic nanoresonators for high-resolution colour filtering and spectral imaging explains how pixels of only 10 microns can be produced.
Such pixel densities could make the technology useful in projection displays, as well as wearable, bendable or extremely compact displays, according to the researchers.
How does it work?
The resonators are kind of like a light filter. Two nano thin layers of metal selectively allow light to pass through small sets of slits. The slit spacing determines which wavelength of light makes it through the slits.
Red light emanates from slits set around 360 nanometers apart; green from those about 270 nanometers apart, and blue from those approximately 225 nanometers apart. The differently spaced gratings essentially catch different wavelengths of light and resonantly transmit through the stacks. LinuxForDevices.com
These displays are simpler, use fewer parts, are more efficient, and should be cheaper to make. I am not going to wait, though.
Aurora borealis above Lake Harriet in Minneapolis, MN: The white streak visible in the lower right of the timed exposure is an aircraft taking off from the Minneapolis-St. Paul airport.Courtesy Mark RyanOld Sol could be stirring up the atmosphere this evening with a display of northern lights (aurora borealis). Scientists have recorded a significant burst of plasma shooting from the Sun’s surface that could mean we earthlings are in for a light show tonight or early Wednesday morning. The solar wind particles are headed right toward us, and when they reach the Earth’s magnetic field they’ll interact with atoms of nitrogen and oxygen in the atmosphere and - hopefully - produce glowing sheets and fingers of green, red, blue, or even yellow in a wonderful display in the northern skies. The southern hemisphere experiences the same phenomenon but down there it’s known as the aurora australis (southern lights).
Lately, here in the Twin Cities, the air has been supersaturated with humidity so I don’t know how crisp a view we’ll get but it could be worth stepping outside tonight to see what’s up.
SOURCE and LINKS
CNN.com report
Univ. of Alaska’s Geophysical Institute Aurora Forecast page
Michigan Tech’s Aurora page
Solar flares
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