Equations reveal the rebellious rhythms at the heart of nature

Equations reveal the rebellious rhythms at the heart of nature: Physicists Dmytro Iatsenko , Professor Peter McClintock, and Professor Aneta Stefanovska, have reported a far more general solution of the Kuramoto equations than anyone has achieved previously, with some quite unexpected results.

One surprise is that the oscillators can form "glassy" states, where they adjust the tempos of their rhythms but otherwise remain uncoordinated with each other, thus giving birth to some kind of "synchronous disorder" rather like the disordered molecular structure of window glass. Furthermore and even more astonishingly, under certain circumstances the oscillators can behave in a totally independent manner despite being tightly coupled together, the phenomenon the authors call "super-relaxation".

Proteins 'ring like bells'

Proteins 'ring like bells': Using modern laser spectroscopy, the scientists have been able to measure the vibrational spectrum of the enzyme lysozyme, a protein that fights off bacteria. They discovered that this enzyme rings like a bell with a frequency of a few terahertz or a million-million hertz. Most remarkably, the ringing involves the entire protein, meaning the ringing motion could be responsible for the transfer of energy across proteins.

The experiments show that the ringing motion lasts for only a picosecond or one millionth of a millionth of a second. Biochemical reactions take place on a picosecond timescale and the scientists believe that evolution has optimised enzymes to ring for just the right amount of time. Any shorter, and biochemical reactions would become inefficient as energy is drained from the system too quickly. Any longer and the enzyme would simple oscillate forever: react, unreact, react, unreact, etc...

Hypnotic Art Shows How Patterns Emerge From Randomness in Nature | Science | WIRED

Hypnotic Art Shows How Patterns Emerge From Randomness in Nature | Science | WIRED: Turing called this the reaction-diffusion process, meaning that it’s driven by reactive molecules that can diffuse between cells. He called these molecules “morphogens”...

...a team of scientists based at Brandeis University reproduced the system Turing envisioned...

If Turing’s theory was right, then the population of cells would ultimately assume one of six different patterns...

In fact, this is mostly what the team found — they saw five of the six predicted patterns; but they also found a seventh pattern that Turing had not predicted....

Ultracold Big Bang experiment successfully simulates evolution of early universe | UChicago News

Ultracold Big Bang experiment successfully simulates evolution of early universe | UChicago News: These excitations are called Sakharov acoustic oscillations, named for Russian physicist Andrei Sakharov, who described the phenomenon in the 1960s. To produce Sakharov oscillations, Chin’s team chilled a flat, smooth cloud of 10,000 or so cesium atoms to a billionth of a degree above absolute zero, creating an exotic state of matter known as a two-dimensional atomic superfluid.

Then they initiated a quenching process that controlled the strength of the interaction between the atoms of the cloud. They found that by suddenly making the interactions weaker or stronger, they could generate Sakharov oscillations.

The universe simulated in Chin’s laboratory measured no more than 70 microns in diameter, approximately the diameter as a human hair.

Super-accurate atomic clock doubles up as quantum sim - physics-math - 08 August 2013 - New Scientist

Super-accurate atomic clock doubles up as quantum sim - physics-math - 08 August 2013 - New Scientist: Electrons' behaviour inside solids can be physically modelled using networks of atoms cooled to trillionths of a degree above absolute zero...

...she and her colleagues have stumbled upon a way to mimic quantum behaviour in a system several orders of magnitude warmer: an atomic clock...

Rey says that the strontium atoms in the ground state can be used to simulate spin-down electrons, and the excited atoms, spin-up electrons. Tracking the emergence and details of the interactions between the atoms could then shed light on the nature of the quantum interactions between electrons in magnets.

Neutrino shape-shift points to new physics - physics-math - 20 July 2013 - New Scientist

Neutrino shape-shift points to new physics - most experiments measure the rate of neutrino oscillation by starting with one neutrino type and seeing how many of them disappear by the time the particles reach a detector, rather than seeing the transformed neutrino arrive anywhere...
They have detected a total of 28 electron neutrinos, when fewer than 5 would be expected if the neutrinos were not oscillating. Odds that the result is a fluke are less than one in a trillion...
Now that we have seen the muon neutrino morph into the electron neutrino in normal matter, physicists can run the T2K experiment with a beam of anti-muon neutrinos. Subtle differences in the way neutrinos and antineutrinos oscillate could have skewed the ratios of matter and antimatter production in the early universe...

Slowing down microwaves in a chip

Slowing down microwaves in a chip: The circuit holds a microwave cavity, which looks like a miniature S-shape conductor (see image on right), and a nano-mechanical oscillator (see image below), a tiny vibrating string, which is positioned inside the micro-cavity. A signal that reaches the micro-cavity is reflected around the interior boundaries of the cavity thousands of times. In this way it stays within the device for a short period. The nano-mechanical oscillator allows the cavity to hold the wave even longer. In this way, the two technologies combine to "hold" the wave for several milliseconds...

...More precisely, in practice when a signal arrives in the circuit an additional strong microwave (pump) is used to help to boost the power of the oscillations produced naturally by the nanomechanical oscillator. A reciprocal phenomenon subsequently occurs: the oscillations, which were driven by the microwave, reciprocally provoke a change in the microwave signal itself.

Existential blow for ghostly quantum supersolids - New Scientist - New Scientist

Existential blow for ghostly quantum supersolids - New Scientist: ...they sealed the glass with a thin layer of epoxy resin and inserted the helium through a very thin tube. This meant only a tiny fraction of the helium could become a bulk solid – and so any speeding up due to quantum plasticity would be negligible.

Chan and Duk Kim found that this set-up completely eliminated the changes in oscillation rate that they had originally observed. "We didn't see anything at all," says Chan. That suggests that all of the speeding up in the original experiment must have been due to bulk helium forming a quantum plastic, not supersolidity as originally claimed in 2004.

Physicists create first-ever mechanical device that measures the mass of a single molecule

Physicists create first-ever mechanical device that measures the mass of a single molecule: The device which is only a couple millionths of a meter in size consists of a tiny, vibrating bridge-like structure. When a particle or molecule lands on the bridge, its mass changes the oscillating frequency in a way that reveals how much the particle weighs...

To do so, the researchers analyzed how a particle shifts the bridge's vibrating frequency. All oscillatory motion is composed of so-called vibrational modes. If the bridge just shook in the first mode, it would sway side to side, with the center of the structure moving the most. The second vibrational mode is at a higher frequency, in which half of the bridge moves sideways in one direction as the other half goes in the opposite direction, forming an oscillating S-shaped wave that spans the length of the bridge. There is a third mode, a fourth mode, and so on. Whenever the bridge oscillates, its motion can be described as a mixture of these vibrational modes.
The team found that by looking at how the first two modes change frequencies when a particle lands, they could determine the particle's mass and position, explains Mehmet Selim Hanay, a postdoctoral researcher in Roukes's lab and first author of the paper. "With each measurement we can determine the mass of the particle, which wasn't possible in mechanical structures before."

First Atomtronic Radio Broadcasts Matter Waves

First Atomtronic Radio Broadcasts Matter Waves: Their atomtronic circuit generates an oscillating atom current that emits matter waves in which atoms carry energy through space.
The heart of their device is an atomtronic transistor--an optomagnetic trap with three compartments that can hold a Bose Einstein Condensate of rubidium atoms cooled almost to absolute zero...
Caliga and co initiate their atomtronic transistor by filling the source compartment with rubidium atoms. This process is like charging a capacitor: it produces a chemical potential that pushes atoms through the device, just as electric potential drives electrons.
They then lower the barriers to allow atoms to tunnel into the gate. Of course, the atoms can tunnel back again, which leads to the oscillation.
The atoms are also able to tunnel from the gate to the drain and out of the device. This is the matter wave emission.

Light Bends by Itself

Light Bends by Itself: In the late 1970s, physicists... discovered that a so-called Airy waveform, a wave describing how quantum particles move, can sometimes bend by a small amount...

...imagine light emitted from a wide strip—perhaps a fluorescent tube or, better, a laser whose output has been expanded. By carefully controlling the initial position of the wave peaks—the phase of the waves—at every step along the strip, it is possible to make the light traveling outward interfere constructively at only points on a curve and cancel out everywhere else. The Airy function, which contains rapid but diminishing oscillations, proved an easy way to define those initial phases—except that the resultant light would bend only up to about 8°.

Now physicists Mordechai Segev and colleagues at Technion, Israel Institute of Technology, in Haifa say they have a recipe for making light self-bend through any angle, even through a complete circle. The problem with the Airy function, says Segev, is that the shape of its oscillations specify the right phases only at small angles; at angles much greater than 8°, the shape becomes a crude approximation... After laborious mathematics and guesswork, the researchers found solutions to Maxwell's equations that precisely describe the initial phases required for truly self-bending light...

How to create multiple frequencies of light simultaneously

How to create multiple frequencies of light simultaneously: When the high-frequency optical laser beam hits the semiconductor material — in this case, gallium arsenide nanostructures — it creates an electron-hole pair called an exciton. The electron is negatively charged, and the hole is positively charged, and the two are bound together by their mutual attraction.

“The very strong, low-frequency free electron laser beam rips the electron away from the hole and accelerates it...”

“As the low-frequency field oscillates, it causes the electron to come careening back to the hole.” The electron has excess energy because it has been accelerated, and when it slams back into the hole, the recombined electron-hole pair emits photons at new frequencies — up to 11 in their experiment.

Could primordial black holes be dark matter?

Could primordial black holes be dark matter?: “A small, primordial black hole would be the size of an atom but have the mass of an asteroid,” he points out. “Its strong gravitational field, as it cut through the sun, would squeeze it, then release, and cause the sun to oscillate before ultimately settling down.”
The idea is to measure the oscillation, and determine what would cause it. “Shravan Hanasoge wrote a program to help us with a simulation to see what the sun would look like if a primordial black hole passed through. The smallest mass detectable is 10^21 grams,” Kesden continues.

Engineers use short ultrasound pulses to reach neurons through blood-brain barrier

Engineers use short ultrasound pulses to reach neurons through blood-brain barrier: Up until now, scientists have thought that long ultrasound pulses, which can inflict collateral damage, were required. But in this new study, the Columbia Engineering team show that extremely short pulses of ultrasound waves can open the blood-brain barrier -- with the added advantages of safety and uniform molecular delivery -- and that the molecule injected systemically could reach and highlight the targeted neurons non invasively...
Konofagou and her team have designed a focused ultrasound method that can target only the area of the hippocampus that is affected in early Alzheimer's. In this study, they administered microbubbles to enhance the intended mechanical effect, and a high-field MRI to detect and map the area of BBB opening as well as quantify the permeability of the opened BBB...
The blood-brain barrier has been shown to recover within the range of three hours to three days depending on the aforementioned parameters used...

GPS in the head? Rhythmic activity of neurons to code position in space

GPS in the head? Rhythmic activity of neurons to code position in space: The research scientists showed that cells in the entorhinal cortex, which is important for spatial navigation, oscillate with individual frequencies. These frequencies depend on the position of the cells within the entorhinal cortex. "Up to now people believed that the frequency is modulated by the interaction with neurons in other brain regions", says Yoshida. "However, our data indicate that this may not be the case. The frequency could be fixed for each cell. We may need new models to describe the contribution of rhythmic activity to spatial navigation."

Scientists discover new water waves

Scientists discover new water waves: By precisely shaking a container of shallow water, researchers have observed wave behavior that has never been seen before. In a new study, Jean Rajchenbach, Alphonse Leroux, and Didier Clamond of the University of Nice-Sophia Antipolis in Nice, France, have reported the observation of two new types of standing waves in water, one of which has never been observed before in any media...
“These waves are both strongly localized, and stationary,” Rajchenbach told PhysOrg.com. “Until now, two main classes of water solitary waves had been described: propagative solitons (the famous 'Korteweg de Vries’) and envelope solitons (described by the nonlinear Schrodinger Equation), consisting of a large wave packet enveloping a large number of arches of 'carrier' waves. The observed waves belong to a different category of solitary waves.”

Soft-Drink Cans Focus Sound Waves to a Point, Beating Diffraction Limit: Scientific American

Soft-Drink Cans Focus Sound Waves to a Point, Beating Diffraction Limit: Scientific American: The group generated audible sound from a ring of computer speakers surrounding the acoustic 'lens': a seven-by-seven array of empty soft-drink cans. Because air is free to move inside and around the cans, they oscillate together like joined-up organ pipes, generating a cacophony of resonance patterns. Crucially, many of the resonances emanate from the can openings, which are much smaller than the wavelength of the sound wave, and so have a similar nature to evanescent waves.

To focus the sound, the trick is to capture these waves at any point on the array. For this, Lerosey and his team used a method known as time reversal: they recorded the sound above any one can in the resonating array, and then played the recording backwards through the speakers...

Normal waves scatter efficiently, so they disappear quickly. However, the evanescent-like waves are less efficient at scattering, and take roughly a second to make it out of the can--a prolonged emission that allows the build up of a narrow, focused spot...

How to Switch Off Friction In Nanomachines - Technology Review

How to Switch Off Friction In Nanomachines - Technology Review: Shake the surface (or the tip) and this immediately raises the tip out of this minimum, allowing it to explore the energy landscape. This is equivalent to smooth sliding, or at least smoother sliding. Vanossi and co study the relationship between the friction and vibrations of various different frequencies and amplitudes.

So the vibration dramatically reduces friction. In fact, it essentially allows friction to be switched on and off.

But Vanossi and co have another interesting result. They say that once the oscillations have overcome stick-slip friction, they can help to maintain motion. In effect, the tip can ride the oscillations, like a surfer rides ocean waves.

Physicists Dispute Table-Top Relativity Test: Scientific American

Physicists Dispute Table-Top Relativity Test: Scientific American: The debate comes down to whether a fundamental atomic oscillation, based on the rest mass of a cesium atom, can be used as a clock. The table-top setup relied on an atom interferometer, which tracked the offset in oscillations, or phase difference, of the cesium atoms as they flew on paths of marginally different heights. But Blanchet's team argue that the phase difference between any two atoms due to the fundamental oscillation will always be zero, and therefore could never be used to detect a gravitational redshift.

They say that the Berkeley researchers were instead using their interferometer as an accelerometer to measure a different aspect of general relativity: the universality of free fall. That is no less interesting in its own right, but it has already been tested to greater levels of precision.

If A Primordial Black Hole Hits The Sun...� - Technology Review

If A Primordial Black Hole Hits The Sun...� - Technology Review: The likelihood is that a primordial black hole with mass of an asteroid or comet (about 10^21 g) would pass straight through the Sun, generating a small puff of X-rays in the process. Such a burst would be less even than the background rate of X-rays, so it would be impossible for astronomers to see.

Instead, Kesden and Hanasoge say that the collision would generate supersonic turbulence that would set the Sun ringing like a bell. Today, they calculate what these oscillations would look like.