Archive for the ‘O is for Optics’ Category

Will the Mystery of Dark Matter be Unlocked in 2012?

Thursday, May 20th, 2010

Photo via flickr by NASACoLab

There’s another reason to watch what happens in 2012: Neutrino mass will be measured by The Karlsruhe Tritium Neutrino Experiment in Germany, in the quest for the missing link to understanding dark matter, the undetectable matter (so far) that makes up about 25 per cent of the matter in our universe.
There are many theories of what dark matter consists of. We do know that around twenty to twenty-five per cent of all matter is dark, while less than one per cent emits light. The current paradigm is that of ‘cold’ dark matter: heavy particles that were already collecting together before the primordial plasma turned into hydrogen and helium. These would then move towards the collections of dark matter, which explains the current structures of galaxies and clusters. However, despite many attempts, the particle in question has never been identified.

In a recent report, physicist Theo M. Nieuwenhuizen suggests that neutrinos could be the missing link. Neutrinos are uncharged particles, such as those created during the nuclear fusion processes in the sun. Their role in ‘cold’ dark matter is considered to be negligible, partly because the neutrino mass has never been determined. Nieuwenhuizen now concludes that this is indeed light, but not super-light: 1.5 electron volts or three millionths of the electron mass. He obtained this information by studying data from a cluster of galaxies, where there is a great deal of dark matter present, as well as a large amount of hot gas. Nieuwenhuizen formulated a new theory for this purpose, based on Newton’s laws and quantum mechanics, but also virial equilibrium (a state in which all speeds are approximately the same). He then used this theory to determine the mass of the dark matter particle and even the temperature of the gas. The dark matter forms a quantum structure in the centre of the cluster that is a couple of light years in diameter: the largest known.

Up until a few years ago, it was believed that neutrinos were left-handed (like a top that spins to the left), and that anti-neutrinos were only right-handed. This theory leads to 9.5 percent dark matter; much more than is anticipated from neutrinos, but less than the estimated twenty to twenty-five per cent. It is possible to explain twice as much dark matter if right-handed neutrinos and left-handed antineutrinos are also normally present. However, this assumption requires changes to be made to the standard model of elementary particles. The lepton number (an indication of the number of subatomic, elementary particles) is therefore violated. This means that it must be possible for two neutrons to disappear simultaneously without the release of neutrinos. This therefore leads to nineteen per cent ‘hot’ dark matter and also the need for a new explanation for structure formation in the early universe. A definite answer on the theory will be obtained in 2012, when neutrino mass will be measured by The Karlsruhe Tritium Neutrino Experiment in Germany.

via Insciences Org

In a conversation recorded in 2007, artist Hiro Yamagata questioned what else the neutrino may carry:

We base everything we think, capture thought in 3D. There is something we call zone, area, territory, or another world or this other world we talk about so many things explain, but we don’t know. For example neutrino, the most weakest power from the edge of the cosmos. They go through Earth to the edge of the cosmos. They journey, travel. The neutrino is the most weakest power and their frequency travel. But the neutrino particles we know people capture now the neutrino. Might neutrino carry something else with each particle, for example? We don’t know. We call the focus of neutrino here. Now we capture the neutrino, but not only neutrino. There’s a neutrino carry something else together, stick on, or time-wise, field-wise, we don’t know where the neutrino come, how it comes through your body. We don’t know. Just basic we capture it now, the neutrino now, but we don’t know. 2.7% we know about light. 99% we don’t know what’s going on the light or all the knowledge of the light. How they put on the 2.7%, even that number we don’t know. So there are so many where light come from: original light, meta particle, or proton between the electron; one of the particle of the electron, they are hitting the light and releasing like gravity, they come to light. All light like that.

Invisibility Cloak Generates Virtual Images

Monday, April 26th, 2010

Photo via flickr by pfv

In a new twist from the liquid invisibility cloaks Sptnk reported here, researchers have designed a material that not only makes an object invisible, but also generates one or more virtual images in its place. Because it doesn’t simply display the background environment to a viewer, this kind of optical device could have applications that go beyond a normal invisibility cloak. Plus, unlike previously proposed illusion devices, the design proposed here could be realized with artificial metamaterials.

The team of engineers, Wei Xiang Jiang, Hui Feng Ma, Qiang Cheng, and Tie Jun Cui from Southeast University in Nanjing, China, describes the recently developed class of optical transformation media as “illusion media.” As they explain in a new study, any object enclosed by such an illusion medium layer appears to be one or more other objects. The researchers’ proposed device is designed to operate at microwave frequencies.

“The illusion media make an enclosed object appear like another object or multiple virtual objects,” Cui told PhysOrg.com.  “Hence it can be applied to confuse the detectors or the viewers, and the detectors or the viewers can’t perceive the real object. As a result, the enclosed object will be protected.”

But as the researchers explain, illusion media is similar to an invisibility cloak, except for one main difference. In a perfect invisibility cloak, there are almost no scattering electric fields, so that the illusion space is only free space. In illusion media, on the other hand, the material creates scattered electric field patterns that generate virtual images. Any detector located outside the illusion medium layer will perceive the electromagnetic waves as if they were scattered from a virtual object.

“Generally speaking, different objects will generate different scattering patterns under the illumination of electromagnetic/optical waves,” Ciu explained. “Hence a detector can perceive an object according to its scattering pattern. Our illusion media will change the scattering patterns of the enclosed object to make it appear like another object or multiple virtual objects.”

via PhysOrg.com

Can Light Run Our Electronics?

Thursday, November 5th, 2009

Photo via flickr by Dead Air

“If you open up almost any electronic gadget, you will see various elements that are operating using electric circuitries,” explains scientist Nader Engheta.  “Many of them have different functionalities, such as inductors, capacitors, resistors, transistors, and so forth. These well-known elements have been around for decades. But what if you could bring these concepts to the nanoscale, and what if they could operate with light instead of electricity?”

Engheta, a scientist at the University of Pennsylvania, along with Andrea Alů, believes that it is possible to create a nanoscale circuit board that has the potential to be useful in communications.

There are three main advantages of using optical nanoparticle circuit boards, Engheta says. First of all, being able to further miniaturize various communications devices would ensure that technology continues to evolve. “We are moving toward having more and more information compacted into a smaller volume.” The second advantage is that using optical frequencies would provide more bandwidth. Finally, there is a very real possibility that nanoscale circuit boards, properly constructed, would use less energy. “We have to look more into this possibility, but it is quite likely that optical nanoparticle circuit boards would be low energy in nature,” Engheta insists.

One of the biggest challenges to realizing this type of nanoscale circuitry is that it is difficult to form the structures needed at such a small size. So far, Engheta and Alů have only used computer simulations to test their ideas related to nanoscale circuit boards.

via PhysOrg.com

Light from Nano Butterfly Wings

Thursday, October 22nd, 2009

Photo via flickr by Photoholic1

A team of researchers from the State University of Pennsylvania (USA) and the Universidad Autónoma de Madrid (UAM) has developed a technique to replicate biological structures, such as butterfly wings, on a nano scale. The resulting biomaterial could be used to make optically active structures, such as optical diffusers for solar panels.

Insects’ colors and their iridescence (the ability to change colors depending on the angle) or their ability to appear metallic are determined by tiny nano-sized photonic structures which can be found in their cuticle. Scientists have focused on these biostructures to develop devices with light emitting properties that they have just presented in the journal Bioinspiration & Biomimetics.

“This technique was developed at the Materials Research Institute of the State University of Pennsylvania and it enables replicas of biological structures to be made on a nanometric scale”, Raúl J. Martín-Palma, lecturer at the Department of Applied Physics of the UAM and co-author of the study explains.

The researchers have created “free-standing replicas of fragile, laminar, chitinous biotemplates”, that is, copies of the nano structures of butterfly wings. The appearance of these appendices usually depends more on their periodical nanometric structure (which determines the “physical” color) than on the pigments in the wings (which establish the “chemical” color).

Martín-Palma points out that the structures resulting from replicating the biotemplate of butterfly wings could be used to make various optically active structures, such as optical diffusers or coverings that maximize solar cell light absorption, or other types of devices. “Furthermore, the technique can be used to replicate other biological structures, such as beetle shells or the compound eyes of flies, bees and wasps,” the researcher says.

The compound eyes of certain insects are sound candidates for a large number of applications as they provide great angular vision. “The development of miniature cameras and optical sensors based on these organs would make it possible for them to be installed in small spaces in cars, mobile telephones and displays, apart from having uses in areas such as medicine (the development of endoscopes) and security (surveillance),” explains Martín-Palma.

via Science Daily

Low-intensity Light Controls Cells

Monday, August 31st, 2009

Photo via flickr by istargazer

Scientists at the University of Central Florida have shown that light energy can gently guide and change the orientation of living cells. The ability to optically steer cells is slated to be a major step in guiding stem cells to the areas of the body that need help.

Research results were presented at the 2009 Conference on Lasers and Electro-Optics / International Quantum Electronics Conference. The discovery was led by Aristide Dogariu, an optical scientist at the College of Optics and Photonics, and Kiminobu Sugaya, a stem cell researcher at the College of Medicine’s Burnett School of Biomedical Sciences.

Long-term implications include the possibility of altering the shapes of cells and preventing malignant tumors from spreading throughout the body.

“Actin rods are constantly vibrating, causing the cells to move sporadically,” Sugaya said. The researchers demonstrated that low-intensity polarized light can guide the rods’ motion to ever-so-slowly line up and move in the desired direction.

“Stronger light would simply kill them,” Dogariu said. “We wanted to gently help the cells do their job the way they know how to do it.”

A time-lapse video shows that after more than two hours of exposure to light with specific characteristics, a group of stem cells migrates from a seemingly random mix of shapes, movement and sizes to a uniform lineup.

via Science Daily

O is for Optics

Saturday, May 9th, 2009

If there has been one constant in the world, it’s that nothing travels faster than the speed of light. However, according to physicist Joao Magueijo, the speed of light in the “early” universe was faster, in fact, 60 orders of magnitude quicker than its present recorded speed of 3 x 106 meters/second. And if this heretical idea is true, then not only would there be implications for future space travel, but Einstein was wrong. Coincidingly, scientists have recently been able to stop light in its tracks. The hope, of course, is to revolutionize information transfer to deliver rapid, extreme connectivity with optical computing. Meanwhile, the notion that DNA strands can be converted into fiber optic cables is underway, and researchers at Kiel University, according to Journal Science, have shown that since DNA has a high-degree of photostability, light may be the answer for diagnostic testing for future gene repair. And while Mystery Schools advocate DNA activation, upgrading our dormant 12 strands for the advancement of human consciousness, light therapy, or laser-light cellular photo-repair for anti-aging is also now considered chic. Then there’s the idea that full-spectrum light invigorates our bodies, providing heath benefits, which was the basis behind the work of Dr. John Ott, and more currently, the light installation, Polaria, where artists Bruce Gilchrist and Jo Joelson of London Fieldworks captured the 24-hour daylight of Greenland to create an interactive virtual daylight chamber that used sensors to biomonitor a body’s physiological response. As photochemists develop polymers that can change shape when activated by photons, and scientists vie to develop edible optics for food safety measures that will serve to detect harmful bacteria, like e-coli, in our spinach, it’s safe to say that light is, indeed, a dazzle.