Watch a singularity form in a stretchy soap film - physics-math - 28 May 2014 - New Scientist

Watch a singularity form in a stretchy soap film - physics-math - 28 May 2014 - New Scientist

A black hole in a bath: Big physics on a bench-top - physics-math - 10 March 2014 - New Scientist

A black hole in a bath: Big physics on a bench-top - physics-math - 10 March 2014 - New Scientist

Supersymmetry...  One of its central predictions is that there should be more than one Higgs particle... they might have found some clue as to where those extra particles might be – in superfluid helium-3... The discovered Higgs weighs in at around 125 gigaelectronvolts (GeV). Studying the spectrum of excitations in the superfluid helium suggests Higgs particles should also exist at energies of 210 GeV and 325 GeV. These possibilities are not excluded by results collected so far at the LHC...

By concentrating laser light into a very small spot within a waveguide made of a glass block, he can temporarily change the refractive index of the glass so that it slows down subsequent laser pulses and ultimately repels them. "What makes these analogue experiments so powerful is that from a photon or a water wave's perspective, it has no way of distinguishing whether it is crossing the event horizon of a real black hole or is in a waveguide under some weird constraints," he says.

RAMBO allows high-magnetic-field experiments on a tabletop

RAMBO allows high-magnetic-field experiments on a tabletop: "We can literally see the sample inside the magnet," Kono said. "We have direct optical access, whereas if you go to a national high magnetic field facility, you have a monster magnet, and you can only access the sample through a very long optical fiber. You cannot do any nonlinear or ultrafast optical spectroscopy...

Kono's group built the system to analyze very small, if not microscopic, samples. A sample plate sits on a long sapphire cylinder that passes through the coil's container and juts through one end of the magnet to place it directly in the center of the magnetic field.

The cylinder provides one direct window to the experiment; a port on the other side of the container looks directly down upon the sample. The coil is bathed in liquid nitrogen to keep it cool at around 80 kelvins (-315 degrees Fahrenheit). The sample temperature can be independently controlled from about 10 K to room temperature by adjusting the flow of liquid helium to the sapphire cylinder.

'Accelerator on a chip' demonstrated

'Accelerator on a chip' demonstrated: ...electrons are first accelerated to near light-speed in a conventional accelerator. Then they are focused into a tiny, half-micron-high channel within a fused silica glass chip just half a millimeter long. The channel had been patterned with precisely spaced nanoscale ridges. Infrared laser light shining on the pattern generates electrical fields that interact with the electrons in the channel to boost their energy.

Ultracold Big Bang experiment successfully simulates evolution of early universe

Ultracold Big Bang experiment successfully simulates evolution of early universe: Physicists have reproduced a pattern resembling the cosmic microwave background radiation in a laboratory simulation of the Big Bang, using ultracold cesium atoms in a vacuum chamber at the University of Chicago...


It turns out that under certain conditions, a cloud of atoms chilled to a billionth of a degree above absolute zero (-459.67 degrees Fahrenheit) in a vacuum chamber displays phenomena similar to those that unfolded following the Big Bang, Hung said.

"At this ultracold temperature, atoms get excited collectively. They act as if they are sound waves in air," he said. The dense package of matter and radiation that existed in the very early universe generated similar sound-wave excitations, as revealed by COBE, WMAP and the other experiments.

The synchronized generation of sound waves correlates with cosmologists' speculations about inflation in the early universe. "Inflation set out the initial conditions for the early universe to create similar sound waves in the cosmic fluid formed by matter and radiation," Hung said.

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.

First Toy Multiverse Created in a Laboratory, Say Physicists

First Toy Multiverse Created in a Laboratory, Say Physicists: Cobalt is ferromagnetic so the nanoparticles tend to become aligned in a magnetic field. In fact, if the density of nanoparticles is high enough, the field causes them to line up in columns. When this happens, the nanocolumns form a metamaterial which is mathematically equivalent to a 2+1 Minkowski spacetime...


The secret here is to keep the density of nanoparticles just below the threshold required to form nanocolums. That’s just over 8 per cent of the fluid by volume in this case. When that happens, natural variations in the density cause nanocolumns to form in small regions of the liquid. In effect, tiny universes are leaping in and out of existence. Smolyaninov and co can even “see” these universes by their effect on polarised light passing through the fluid.

That’s a fascinating result that demonstrates the potential of self-organisation to create metamaterials.

How to Measure Quantum Foam With a Tabletop Experiment

How to Measure Quantum Foam With a Tabletop Experiment: Bekenstein's goal is to move the block by a distance that is about equal to the Planck length. His method is simple: zap the block with a single photon.

The photon carries a small amount of moment and consequently pushes the block as it enters the glass, giving it some momentum.  As the photon leaves the block, the block comes to rest.

So the result of the photon's passage is that it moves the block a small distance.

Bekenstein's idea is that if this distance is smaller than the Planck length, then the block cannot move and the photon cannot pass through it.

So the experiment involves measuring the number of photons that pass through the block. If the number is fewer than predicted by classical optics, then that proves the existence of quantum foam.

How to model a white hole in your kitchen sink

How to model a white hole in your kitchen sink: When a stream of tap water hits the flat surface of the sink, it spreads out into a thin disc bounded by a raised lip, called the hydraulic jump… More recently, physicists have suggested that, if the water waves inside the disc move faster than the waves outside, the jump could serve as an analogue event horizon. Water can approach the ring from outside, but it can't get in.

"The jump would therefore constitute a one-directional membrane or white hole," wrote physicist Gil Jannes and Germain Rousseaux of the University of Nice Sophia Antipolis in France and colleagues in a study on ArXiv Oct. 8. "Surface waves outside the jump cannot penetrate in the inner region; they are trapped outside in precisely the same sense as light is trapped inside a black hole."

How To Build A Black Hole Laser - Technology Review

How To Build A Black Hole Laser - Technology Review: Their idea is to create a black hole next to a white hole so that their event horizons are separated by just a few hundred micrometres and create a small cavity. Then they show that when light is fired into this cavity, it is reflected off the white hole horizon onto the black hole horizon, back to the white again and so on...
Their real triumph, however, is in showing how such a device could be made in the lab...
...a very intense beam can create a huge gradient in the refractive index. This gradient can be so steep that it behaves like an event horizon. In fact, a single pulse can create black hole horizon at its leading edge and a white hole horizon at its trailing edge.

Physicists Recreate 'End Of Time' in Lab - Technology Review

Physicists Recreate 'End Of Time' in Lab - Technology Review: Metamaterials can be made to behave like ordinary space with two dimensions of space and one of time. But they can also be made to behave like other types of spaces, with two dimensions of time and one of space, for example.

Smolyaninov points out that an interesting situation occurs when these two materials are place end on. If a time dimension is perpendicular to a space dimension, it simply hits a dead end. In other words, time runs out...

So what happens at the end of time? Smolyaninov says that the electromagnetic field simply diverges, which is something of an anticlimax...

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.

Ship in Bottle, Meet Rogue Wave in Tub - ScienceNOW

Ship in Bottle, Meet Rogue Wave in Tub - ScienceNOW: That equation has several weird solutions, including one with the basic properties of a rogue wave. Discovered in 1983, the so-called Peregrine solution consists of a single peak that suddenly emerges out of a smoothly varying wave train (a so-called sine wave) by sucking energy out of it, zipping along for a while, and then disappearing back into the sine wave. In October 2010, experimenters produced an optical version of that wave with light.

Now, mathematician Amin Chabchoub and physicist Norbert Hoffmann at the Hamburg University of Technology in Germany and physicist Nail Akhmediev of Australian National University in Canberra have produced a Peregrine rogue wave in a water tank 15 meters long, 1.6 meters wide, and filled to a depth of 1 meter.

Metamaterial Reveals Nature of Time and the Impossibility of Time Machines - Technology Review

Metamaterial Reveals Nature of Time and the Impossibility of Time Machines - Technology Review: Metamaterials can help researchers study this problem because it is possible to manipulate them so that space-like dimensions become time-like. Smolyaninov describes how to create a material in which the the x and y directions are space-like while the z-direction is time-like.
The way light moves in this space is exactly analogous to the behaviour of a massive particle in a (2+1) Minkowski spacetime, which is similar to our own universe. So the pattern of light propagation inside this metamaterial is equivalent to the "world lines" of a particle in a Minkowski universe.
Smolyaninov says that a Big Bang event in the metamaterial occurs when the pattern of light rays expands relative to the z-dimension, or in other words, when the world lines expand as a function of time. This establishes a cosmological arrow of time...
Their system is made using specially shaped plastic strips placed on a gold substrate. And the light rays are actually plasmons that propagate across the surface of the metal while being distorted by the plastic strips...

Simulating tomorrow's accelerators at near the speed of light

Simulating tomorrow's accelerators at near the speed of light: A team of researchers led by Jean-Luc Vay of Berkeley Lab’s Accelerator and Fusion Research Division (AFRD) has borrowed a page from Einstein to perfect a revolutionary new method for calculating what happens when a laser pulse plows through a plasma in an accelerator like BELLA. Using their “boosted-frame” method, Vay’s team has achieved full 3-D simulations of a BELLA stage in just a few hours of supercomputer time, calculations that would have been beyond the state of the art just two years ago...
The boosted-frame method, first proposed by Vay in 2007, exploits Einstein’s Theory of Special Relativity to overcome difficulties posed by the huge range of space and time scales in many accelerator systems. Vast discrepancies of scale are what made simulating these systems too costly...
Vay’s team showed that using a particular boosted frame, that of the wakefield itself – in which the laser pulse is almost stationary – realizes near-optimal speedup of the calculation. And it fundamentally modifies the appearance of the laser in the plasma. In the laboratory frame the observer sees many oscillations of the electromagnetic field in the laser pulse; in the frame of the wake, the observer sees just a few at a time.

Wave-generated 'white hole' boosts Hawking radiation theory: research

Wave-generated 'white hole' boosts Hawking radiation theory: research: Placing an airplane wing-shaped obstacle in the path of the flowing water created a region of high-velocity flow which blocked surface waves, generated downstream, from traveling upstream. The obstruction simulated a white hole, the temporal reverse of a black hole.
The shallow surface waves divided into pairs of deep-water waves, analogous to the photon pairs featured in Hawking's theory. Like in black holes, they showed that the analog would also emit a thermal spectrum of radiation.

Physicists create sonic black hole in the lab

Physicists create sonic black hole in the lab: The researchers created the sonic black hole in a Bose-Einstein condensate made of 100,000 rubidium atoms slowed to their lowest quantum state in a magnetic trap. This cold cluster of atoms acts like a single, large quantum mechanical object. In order to transform this condensate into a sonic black hole, the scientists had to find a way to accelerate some of the condensate to supersonic speeds so that the condensate would contain some regions of supersonic flow and some regions of subsonic flow.

The scientists achieved this acceleration by shining a large-diameter laser on the condensate in such a way as to create a steplike potential and a harmonic potential. When the condensate crosses the “step” in the steplike potential, the condensate accelerates to supersonic speeds. The scientists demonstrated that the condensate could accelerate to more than an order of magnitude faster than the speed of sound.

New Scientist TV: How to trap a supernova in a jar

New Scientist TV: How to trap a supernova in a jar: "'The solution is stable until it is triggered' says Stephen Morris of the University of Toronto. 'We do this triggering at the bottom of a small tube that you can see in the bottom of the video. This is something like a fuse. The reaction proceeds as a front up the tube until it enters the much larger main vessel. Then it billows out as a plume. All over the surface of the plume, at a thin front, like a flame front, the reaction is happening. All the fluid motion is generated by the reaction itself.'"

Fahrenheit -459: Neutron stars and string theory in a lab

Fahrenheit -459: Neutron stars and string theory in a lab: Duke physicist John Thomas made the viscosity measurements using an ultra-cold Fermi gas of lithium-6 atoms trapped in a millimeter-sized bowl made of laser light. When cooled and placed inside a magnetic field of the correct size, the atoms interact as strongly as the laws of quantum mechanics allow. This strongly interacting gas exhibits "remarkable properties," such as nearly frictionless fluid flow, Thomas said.

Black Holes In The Bathtub - Science News

Black Holes In The Bathtub - Science News: "The Canadian team with the water-based black hole analog now sees the radiation in the form of water waves. Another team observes photons emitted from a black hole analog in glass. Yet another has created a black hole in ultracold gas that could be probed for the signal in the form of sound. These lab-made emitters of Hawking radiation share one required feature with their astrophysical counterparts — a point of no return, analogous to the black hole’s outer boundary, or event horizon...
These and other analog systems may help solve a lingering problem in Hawking’s original proposal. His model suggested that radiating light could have wavelengths shorter than the Planck length, supposedly the shortest length allowed by quantum mechanics. If light could have such short wavelengths, and thus really high frequencies, one photon could carry more energy than contained in the entire universe — clearly fishy. Hawking had wanted to eliminate this possibility, but he couldn’t make his equations work without it."