Posts Tagged ‘oscillation’
Video: New Liquid Pistons Made of Magnetic Droplets Could Power Self-Focusing Lenses
Researchers at Rensselaer Polytechnic Institute embedded drops of ferrofluid, a liquid infused with magnetic nanoparticles, into a thin substrate that was submerged in water. Then they exposed the device to a magnetic field to make one of the droplets vibrate back and forth (up or down in the image above), which caused its partner to oscillate in a mirror pattern. This ballet displaces teeny amounts of liquid, moving it from one chamber to another, according to Amir H. Hirsa, a mechanical engineering professor at Rensselaer. The piston is superfast, allowing micro-scale devices with cycling speeds in the kilohertz range.
The liquid piston has no moving mechanical pieces, so it never suffers wear and tear, according to a Rensselaer news release. The droplet duo could be used in a wide array of devices that require reliable resonator action, like an implantable chip that slowly pumps drugs from one chamber to another, Hirsa said.
What’s more, the droplets’ shape constantly changes as they vibrate, so if you pass light through them, they function as a lens that automatically changes its focal length. Hirsa and colleagues took some video from these liquid lenses and they say its quality is comparable to a typical computer web cam. You would need special software to filter out the blurry frames, but Hirsa says it could work for handheld electronic devices as well as potential replacement eye lenses. So instead of a cool pair of frames, you could wear magnets on your head to fine-tune your vision.
Other involve trapping light at different wavelengths to produce a high-definition display. This device would instead focus light to obtain a sharp picture.
The droplets’ speed and vibration strength can be controlled by changing the strength of the magnetic field, according to Rensselaer.
The liquid piston is described in the journal .
[]
Fermilab Experiment Hints At Existence of Brand-New Elementary Particle
A fourth neutrino could help explain dark matter
Working with Fermilab's MiniBooNE experiment — the first part of the larger planned Booster Neutrino Experiment — physicists found evidence for a fourth flavor of neutrino, according to a published in Physical Review Letters. This means there could be another particle we didn’t know about, and that it behaves in a way physicists didn’t expect.
Neutrinos have been mystifying physicists since they were first theorized decades ago. They are one of the building blocks of matter, and to the best of our knowledge, they come in three varieties, called flavors: electron neutrinos, muon neutrinos and tau neutrinos. Oscillation is what happens when neutrinos turn from one flavor to another; an electron neutrino might turn into a muon neutrino, and then turn back again. How often they do this tells physicists about the infinitesimally small differences in their masses. Neutrino mass is important because it may lead us to physics beyond the Standard Model. And that is exactly what seems to have happened.
Examining three years’ worth of MiniBooNE data, researchers detected more oscillations than would be possible if there were only three flavors. The simplest explanation is that there’s another flavor, and that it is “sterile,” meaning it does not interact with the weak nuclear force; it only interacts via gravity, which makes it really hard to detect. Incidentally, the same holds for dark matter. Sterile neutrinos could therefore help explain dark matter, which makes up most of the universe, according to William Louis, a scientist at Los Alamos National Laboratory, who is quoted in a news release about the MiniBooNE findings.
MiniBooNE was built to confirm some odd results from a decade ago at a scintillation detector in Los Alamos, which had also found faster-than-anticipated oscillations. When Fermilab physicists tried the experiment with a beam of neutrinos, they could not replicate the Los Alamos scintillator’s results. But when they tried it with antineutrinos instead, they found what they were seeking — antineutrinos oscillated into electron antineutrinos faster than expected. This is odd because it violates the symmetry principle, which holds that antiparticles’ behavior mirrors that of their regular-matter counterparts. The fact that it didn’t work with a neutrino beam is also weird, according to Byron Roe, a physics professor at the University of Michigan.
Now that MiniBooNE has confirmed these results, physicists might want to build the full-sized BooNE to prove it once and for all.
Researchers Devise the First Experimental Test of Controversial, Confusing String Theory
String theory elegantly reconciles the otherwise competing rules of quantum mechanics and general relativity. It’s the most widely accepted unified field theory, but it remains controversial. It basically posits that electrons and quarks are not objects, but one-dimensional strings, whose oscillation gives them their observed qualities. The most fun element of string theory is the requirement that the universe has about a dozen dimensions, rather than the usual four (length, width, height and time).
M-theory, the dominant version of string theory, holds that the universe is made up of unfathomably small slices of a 2-dimensional membrane, wriggling in 11-dimensional space.
These bizarre ideas are widely accepted by many theoretical physicists, but the problem is that they can’t be tested — how do you examine an 11th dimension? The field has suffered a backlash in recent years partly for this reason, as some scientists say a theory is not a theory if its predictions can’t be studied in a lab.
Well, now they can, according to of the theoretical physics department at Imperial College London. He is lead author of a paper to be published tomorrow in Physical Review Letters, which explains how string theory math can be used to predict quantum entanglement.
Duff said he was at a conference in Tasmania when a colleague presented some mathematical formulas describing entanglement of multiple quantum bits. The equations looked familiar. Upon returning home, Duff checked his notebooks from a few years earlier, and realized the formulas were the same as those he developed to use string theory to describe black holes.
This is completely unexpected, he said. There is no obvious reason why the insanely complex mathematics underlying string theory can also be used to predict the behavior of entangled quantum systems.
“This may be telling us something very deep about the world we live in, or it may be no more than a quirky coincidence,” he said.
Either way, it’s useful, he added. Using string theory math, Duff predicted the pattern that would occur when four quantum bits are entangled with each other. This can be measured in a lab, and the results will demonstrate whether string theory actually works.
Right now, the best hope for string theory tests comes from CERN’s Large Hadron Collider, which is designed to find the tiniest elementary particles that make up matter. It’s theoretically possible that LHC experiments will uncover supersymmetric particles — one element of string theory — or bounce a graviton into a higher dimension, which could help prove M-theory. But testing the fuzzy math that predicts these behaviors will be much easier.
Are We Living Inside a Black Hole?
But an Indiana University professor has a new theory, reports New Scientist: that exists in another universe. Specifically, a black hole that rebounded, somewhat like a spring.
Some fairly mind-blowing physics is involved here, but the gist is that Nikodem Poplawski of IU-Bloomington used a modified version of Einstein’s general relativity equation set that takes particle spin into account.
Including this variable makes it possible to calculate torsion, part of the geometry of space-time. It also gets rid of the black hole singularity, a phenomenon that general relativity cannot explain.
In a published earlier this year, Poplawski said when the density of matter reaches epic proportions, torsion counters gravity. This prevents matter from compressing indefinitely to a singularity of infinite density. Instead, matter rebounds like a spring, and starts expanding again.
In Poplawski's , his calculations show that space-time inside the black hole expands to about 1.4 times its smallest size in as little as 10-46 seconds -- two orders of magnitude faster, for lack of a better word, than the Planck time. This brisk bounce-back could have been what led to the expanding universe that we see today.
But here's the real kicker: as Poplawski says, we may not be living in our universe at all; we might be living inside a rebounded black hole that exists in a different universe.
We could tell by measuring the preferred direction of our universe. A spinning black hole would have imparted some spin to the space-time inside it, which would violate a law of symmetry that links space and time. This might explain why neutrinos oscillate between their antimatter and regular-matter states.
[]