Courtesy Birck Nanotechnology Center, Purdue University
Lasers, now used in CD and DVD players and to read prices at the checkout counter, were first developed about fifty years ago. They work by resonating light between two reflectors. They cannot be made smaller than half a wavelength of light, though (about 200 nanometers).
Researchers have now figured a way to force a sphere of only 44 nanometers to emit laser light (more than 1 million could fit inside a red blood cell). These nano-lasers are called spasers which stands for "surface plasmon amplification by stimulated emission of radiation".
When light is pumped onto the sphere, the surface coating generates a form of radiation called surface plasmons.
To act like lasers, they require a "feedback system" that causes the surface plasmons to oscillate back and forth so that they gain power and can be emitted as light.Plasmon resonances are capable of squeezing optical frequency oscillations into a nanoscopic cavity to enable a true nanolaser
This new area of technology sometimes called nanophotonics or nanoplasmonics will enable better microscopes, smaller computer memories, faster computer circuits that use light instead of electrons, and many more yet to be imagined applications.
Solar cells produce less than 1/1000 of the Earth's electricity. This is mainly because they are expensive and are made from rare, hard to obtain materials.
An IBM research team, managed by David Mitzi, is working on photovoltaic cells that are made from common materials.
The new solar cells are also cheaper to manufacture, using a “printing” technique that uses a hydrazine solution containing copper and tin with nanoparticles of zinc dispersed within it. The solution is then spin-coated and heat treated in the presence of selenium or sulfur vapor. PhysOrg
This new material, called kesterite, was 6.8% efficient in 2009. IBM increased the efficiency to 9.8% and is planning to increase the efficiency above 11 per cent, which is equal to or better than the traditional solar cells.
Abstract of published paper: High-Efficiency Solar Cell with Earth-Abundant Liquid-Processed Absorber Advanced Materials
Courtesy JGordonHeyo, Buzzketeers. Any Starketeer Treketeers out there?
Yes? Well check this bit of fun science out: a Professor at Johns Hopkins says that traveling at near-light speeds in a space ship (as folks often do in science fiction) would have the delightful effect of almost instantly killing everyone on board.
Aw, whoops. Did I say "fun"? I meant the opposite of fun.
See, it'd obviously be no good to run into a big chunk of rock while flying around super fast in outer space, but (fortunately) big chunks of rock are really pretty rare way out in space. That's not the problem. The problem is the tiny stuff. The really, really tiny stuff.
Here on Earth, each cubic centimeter of air has about 30 billion billion atoms in it. (That's right—two "billions.") In outer space, however, each cubic centimeter of space might have 2 atoms in it. Two lonely, harmless little hydrogen atoms, drifting around, looking for friends. That low-density of matter is no problem for a low-speed ship—it'd just zoom right through them—but for a ship approaching the speed of light, they could be a huge problem, according to this professor.
Because the ship would be going so fast, the hydrogen atoms would "appear highly compressed, thereby increasing the number of atoms hitting the craft." There's something here about Einstein's special theory of relativity here, but, you know, blah blah blah.That stuff is complicated. I think if it like going running on a buggy night—if you run fast through a cloud of bugs, more of those bugs are going to hit you, and harder. (The moral there being: run with your mouth closed, and run slowly, especially if you're naked.)
So, because so many of the hydrogen atoms are hitting the ship, and because the ship is going so fast, it would be like turning a giant particle accelerator on the ship (except, in this case, the ship is being accelerated into the particles, not the other way around, but the effect is the same). It would be like getting hit with approximately the same amount of energy as if you stepped into the beam of the Large Hadron Collider. Even with a 4-inch-thick aluminum hull, 99% of the hydrogen would blast through the ship as radiation, frying the electronics and killing the crew in seconds. Sad.
You can't wrestle a particle beam, Kirk.
Still, maybe there are some Trekkies and physicists out there who can make us all feel a little better about this? The Johns Hopkins professor clearly knows a ton about radiation, but maybe he's not such an expert on space, or about the physics of Star Trek. I'm certainly not. Don't they warp space on that show? So that they aren't traveling though billions of miles of space (and all that dangerous hydrogen), but are skipping from one spot to another? Something like that? Help me out here. The image of Spock dying of radiation poisoning (again) makes me cry salty tears.
A controversial battle to flood 500 sq km of rain forest in order to provide clean energy for 23 million Brazilian homes appears to be over. The creation of the Belo Monte Dam is expected to begin in 2015 and is rumored to cost around $17 billion. When it is completed, Belo Monte would be third largest hydro-electric dam in the world.
Brazil's environment minister Carlos Minc has stated that those who win the bidding process to building contract and operate Belo Monte will have to pay around $800 million to protect the environment and meet 40 other conditions. EuInfrastructure.com
Lives of up to 40,000 natives who extract from the river most of what they need for food and water could be affected. The biodiversity within the area to be flooded would definitely be effected. Does the ever increasing need for electricity justify these hydro-electric projects? Over the next decade at least 70 dams are said to be planned for the Amazon region.
Courtesy Lauras512Yeah, I’ll tell you what it can’t do: it can’t get that stink out of my freakin’ mittens.
But, besides that, tobacco is an interesting plant, and useful for a lot more than giving us cancer and temporary good feelings. Currently, some scientists are thinking that tobacco might be able to give us electricity-producing solar panels too.
It all started one sunny afternoon, when two scientists were lying in an open patch in a tobacco field, holding hands and watching the occasional cloud drift by.
“Isn’t tobacco great?” asked the first scientist.
“Yes,” sighed the second. She had just woven a bracelet from tobacco leaves, and was feeling like there couldn’t be a better plant in the world.
“But, really,” the first continued. “It’s really great.”
“Yes…” said the second, wondering where her colleague was going with the thought.
“Like, it sits here all day, just being tobacco…” started the first scientist.
“Which is great,” interrupted the second scientist.
“Which is great,” agreed the first scientist. Then she went on. “And it’s so good at sitting here, absorbing the sun… I wonder… I wonder…”
“Wonder what?” asked the second scientist, propping herself up on one elbow to look at the other scientist.
“Well, I wonder if we couldn’t use tobacco’s sunlight-gathering abilities to make, you know, solar cells. For electricity.”
The first scientist let herself sink back on to the ground, brushing dirt from the arm of her white lab coat. “You’re drunk,” she said.
“No! Well… maybe a little,” admitted the first scientist. “But I think it could work. Tobacco has evolved to have its chromophores—its sunlight-gathering molecules…”
“I know what a chromophore is,” said the second scientist.
“To have its chromophores very efficiently spaced out in its cells,” the first scientist went on. “If we could just figure out a way to make tobacco produce more chromophores, we could extract them from the plant, and coat solar cells with them. It could be a cheap, environmentally friendly way to make solar panels!”
“But how are we going to entice tobacco to produce more chromophores? By asking politely?” pointed out the second scientist.
“Yeah…” The first scientist frowned. “Yeah, I suppose you’re right. Never mind.”
In the warm air of the sunny tobacco patch, the suggestion was soon forgotten, and the first scientist drifted off to sleep. The second scientist played with the new tobacco bracelet on her wrist, and wrinkled her nose as a gentle gust of wind blew dust through the surrounding plants. She sneezed.
“Wait a second!” The second scientist shook the first scientist awake, looking excited. “What if we infected the tobacco with a virus?”
“What?” asked the first scientist sleepily, having all but forgotten about the idea.
“We could engineer a tobacco virus that would cause the plants to make more chromophores!” She gestured at the field around them. “We could just spray it on the field, like… like… like a giant sneeze!”
The first scientist jerked upright and gripped the second scientist’s shoulders tightly, her expression so intense it was frightening. The green of the tobacco all around them reflected in her eyes, giving her a Bruce Banner-ish, pre-hulk out look. The second scientist shivered.
“You,” whispered the first scientist, “are… a… genius!”
And that’s pretty much how it all went down.
This sort of thing takes time, though, so we shouldn’t expect the big tobacco/solar power juggernaut to get off the couch any time soon. Tobacco’s natural chromophore arrangement makes chains of molecules that could be ideal for absorbing light on solar panels, but they haven’t been made to produce electric current just yet. Once that gets figured out, however, it could lead to cheaper solar cells, with some biodegradable components. (On the other hand, they would likely have a shorter lifespan than other types of solar panels, but, hey, who doesn’t like throwing stuff away now and again?)
It’s not that I necessarily want them all exterminated, or anything. It’s just that mollusks, with their tentacles and beaks and pseudopodia and large brains, freak my Schmidt out. And I tend to live under a “you’re either with us or against us” credo, and mollusks obviously aren’t “with us.” (They aren’t with me, anyway. Frankly, most things aren’t.)
But I get by. I know that there are mollusks out there, doing… I don’t know what. Probably something utterly horrible. But we leave each other alone, and more or less leave it at that. It’s a workable arrangement.
Now and again, however, a mollusk stretches its squishy neck out and, by its very existence, makes cracks in the already fragile JGordon/Mollusca peace. It’s like the cold war, really—if one side does something strange, or develops a fantastic new piece of technology, the other side gets a little nervous. So, naturally, I’m a little cagey about this news:
Are you kidding me? I’m all, “I think I’ve got chronic anxiety!” and this lousy slug is like, “That’s too bad. Also, I feed myself with sunlight.” I can’t even get groceries because my car battery died (there’s a very scary tree near my bus stop, so that’s out), and this little jerk is a phototroph. If I had laser eyes, or something, the situation would be a little more balanced, but last time I checked I didn’t have laser eyes.
I have to give it to the slug, though—it’s a pretty neat trick. Early in its approximately one-year-long lifecycle, the slug eats some photosynthetic algae. From that point on, the slug is photosynthetic; it feeds itself by using sunlight to convert CO2 and water into sugar, just like plants do. What’s more, the photosynthesis isn’t being performed by algae inside the slug (some organisms, like lichen contain algae, which feeds them). The slug itself has genes for photosynthesis, and the photosynthesizing genes from the algae are just required to kick-start the slug’s own abilities. And then, BAM, a photosynthetic animal.
The leaf-shaped slug, which lives in salty swamps in Eastern Canada and grows to be about an inch long, is remarkable not only for its photosynthetic abilities, but also for something unique in the process written above. Getting those kick-starting genes from the algae requires gene transfer. Passing genes from one species to another is a rare and complicated thing, but some microscopic, single-celled organisms have been known to do it. This is the first time gene transfer has been observed between two multi-cellular organisms (the slug and the algae, of course).
Aside from being, well, just sort of weird, the slug’s gene transferring abilities might turn out to be useful in the future of gene therapy, where new genes are inserted into cells to combat diseases. A practical application whatever transferring mechanism the slug and algae use is a long way off, though. And, anyway, I’ll be damned if I ever use anything that came from a mollusk.
Electric cars, hydrogen cars… algae cars? Scientists and policy makers are researching ways to reduce carbon dioxide and other greenhouse gas emissions associated with automobile use. One promising fossil-fuel alternative may be a biofuel made from algae.
Some varieties of algae are as much as 50% lipids (oil). This oil can be removed from the algae and converted into biofuel in a way that is similar to how vegetable oil is converted into biodiesel. Compared to other biofuel crops, such as corn and soybeans, algae require less space and grow 10 to 20 times faster. What sets algae apart even more is that they can help us remove certain pollutants from the water.
Courtesy Lee Nachtigal
The Institute on the Environment at the University of Minnesota, Twin Cities is funding a project to model how to grow algae on a scale large enough for biofuel production. Researchers at Dr. Roger Ruan’s lab grow algae in sewage plant discharge. Their idea is to build algae farms next to wastewater treatment plants so the algae can remove nitrates and phosphates from the water before it is released into rivers. Too many nitrates and phosphates are harmful to rivers, but these nutrients are good for algae. The algae also capture carbon dioxide released by the treatment plants when they burn wastewater sludge.
UMN Center for Biorefining
Why the growing interest in algae fuel? One reason is the Environmental Protection Agency’s National Renewable Fuel Standard (RFS) program. This program mandates that fuel producers derive a certain amount of fuel from renewable sources. Current standards require that 12.95 billion gallons of transportation fuel be from renewable sources. By 2022, this amount is set to triple to 36 billion gallons. RFS
There is a lot of talk about different renewable energy sources and it is difficult to decide which options are the best to pursue. Even if algae fuel never makes it to the gas pumps, it is encouraging to consider a renewable fuel that is less resource intensive and can actually help improve water quality. I would be interested to hear if anyone thinks algae are “fuel for thought.”
Researchers now hope that by scanning brainwaves, early recognition and treatment might be possible. Autism spectrum disorders, which includes Aspergers, is now being found in about one per cent of the (US) population.
In the current study, published in the journal Autism Research, Dr Roberts used a magnetoencephalography (MEG), a scanner that detects magnetic fields in the brain.
The children with ASDs had an average delay of 11 milliseconds (about 1/100 of a second) in their brain responses to sounds, compared to the control children. Telegraph.co.uk
Courtesy ksoTalk of nuclear power has been brought back into the spotlight, especially after the discovery of Iran’s uranium enrichment plant last September. A solution to the debate about whether countries should even have the capability of enriching uranium (the process required for attaining both nuclear energy and nuclear weapons) was posed more than 50 years ago by President Eisenhower. Eisenhower suggested that various countries should allocate uranium from their stockpiles for peaceful pursuits (i.e. nuclear energy). At the time it wasn’t received very well, but a recent BBC article reported that this vision has been renewed. As of November of last year, the United Nation’s International Atomic Energy Agency (IAEA) successfully negotiated with Russia to store 120 tonnes of nuclear fuel in a plant in Angarsk (a city in the south central-ish part of Russia). In 2010, similar arrangements are said to be made with Kazakhstan. The idea is to get developing countries that are thinking about using nuclear energy in the future to join in this program, eliminating their need to enrich their own uranium.
All of this got me thinking about how nuclear energy actually works. It turns out that nuclear power plants are not that different from regular coal-burning power plants. Both plants heat water to produce pressurized steam. This steam then drives a turbine, which spins a generator to produce electricity. The only difference between the plants is how the water is heated. Coal-burning plants…well, burn coal (fossil fuels) to produce the heat, while nuclear plants rely on nuclear fission. This is where nuclear power gets really cool!
So atoms are made up of protons, neutrons, and electrons; protons are positively charged, neutrons carry no charge, and electrons are negatively charged. Atoms have an equal number of protons and electrons (making the atom, itself, electrically neutral), but the number of neutrons can vary. Atoms of the same element with a different number of neutrons are called isotopes. The isotope of uranium that is needed for nuclear fission, and therefore, nuclear energy, is Uranium-235. This isotope is unique because it can undergo induced fission, which means its nucleus can be forced to split. This happens when a free neutron runs into the nucleus of U-235.
Courtesy wondigamaU-235 absorbs the neutron, becomes unstable, and breaks into two new nuclei. In the process, two or three neutrons are also thrown out. All of this happens in a matter of picoseconds (0.000000000001 seconds)! The neutrons that are released in this reaction can then go and collide with other on-looking U-235 atoms, causing a huge chain reaction (much like this). The amount of energy released when this happens is incredible- a pound of highly enriched uranium has about the same energy as a million gallons of gasoline. This energy comes from the fact that the products of the fission (the two resulting nuclei and the neutrons that fly off), together, don’t weigh as much as the original U-235 atom. This weight difference is converted directly into energy. It’s this energy that is used to heat the water that creates the steam, which turns the turbine that spins the generator, that produces power in the nuclear reactor that Jack built.
On the plus side, with nuclear power there wouldn’t be a reliance on fossil fuels. Nuclear power plants are cleaner because they don’t emit as much carbon dioxide as traditional coal-burning and natural gas plants. However, there are some downsides as well. Mining uranium is not a clean process, transporting nuclear fuel creates a risk of radioactive contamination, and then there’s the whole issue with what to do with the still-dangerous nuclear waste once the fuel has been used up.
Whether or not we should increase our nuclear power program is still debatable, but one thing I do know is that the science behind it is fascinating!
Courtesy toolmantimHere’s an article about a paper airplane virtuoso who’s trying to break the world’s record (held by himself) for keeping a hand-launched paper plane in the air. Engineer Takuo Toda of Japan not only wants to beat his old record of 27.9 seconds – set last April in Hiroshima – he’s also set his sights on achieving the nearly impossible - breaking the 30 second barrier. Actually, the record time of 27.9 seconds should require an asterisk in the record books since it was set using a paper plane with tape on it. The paper-only airplane record – using a single sheet of uncut paper - is 26.1 seconds, and Toda holds that one, too. This guy seems to be the undisputed king of paper airplanes, but I'm sure somebody out there can show him a thing or two. Check out some of the links below and maybe it can be you.
MORE ABOUT PAPER AIRPLANES
More about paper airplane aerodynamics
Build your own paper airplane (by former record holder Ken Blackburn
Build the best paper airplane
How to build 10 paper airplanes with animated instructions no less
Even more paper airplane designs