Researchers Using Quantum “Squeezed Light” to Image The Insides of Cells
Conventional optical imaging is limited by the process of diffraction, the way light spreads out when it passes an object. The amount of diffraction depends, in part, on natural uncertainties in the position of the photons. Physicists think of this uncertainty as quantum noise.
In recent years, however, they’ve have worked out how to minimise the amount quantum noise by carefully manipulating the way photons are created. They call the resulting photons “squeezed light” and there has been no little excitement over their potential to beat the conventional diffraction limit in all kinds of applications.
One obvious use is in cellular imaging where squeezed light offers biologists a clear advantage for exploring cellular processes. Various groups have used squeezed light to make pioneering measurements inside cells. But the process of imaging to reveal spatial variations in the structure of a cell, has so far eluded them.
(via First Quantum-Enhanced Images of a Living Cell | MIT Technology Review)
IBM Makes Stop-Motion Animation using individual Atoms as Pixels
IBM moved the molecules using two of its own scanning tunnelling microscopes. It’s a huge machine that weighs two tons, operates at minus 268 degrees Celsius and magnifies atoms—placed on a copper surface—by 100 million times. The machine moved around 5,000 carbon monoxide molecules to create the movie. Each time the molecules were arranged in the right way, the IBM team rendered a still image to create each of the 242 frames. In those frames, you can only see one atom or pixel because you look at it from above. It took roughly 10 days of 18-hour shifts to get each frame right.
The machine itself is operated via a standard computer and the atoms are manipulated by a super sharp needle that can “feel” atoms. The needle can be used to physically attract atoms and molecules (using an electrical current) on the surface and then pull them into a particular location. This process makes a unique, scratchy sound called an “atomic short” which indicates to researchers how far the atoms have moved.
This is important because atoms can’t be filmed while they are being moved, so the sound is a critical indicator for the research team to assess whether the atom has been moved to the right slot. The noise is created as the atom is dragged between two binding sites—when it finds itself between two positions like this, the current changes, and this generates the sound that researchers play through speakers as an aural guide.
(via IBM makes stop-motion film using atoms as pixels | Ars Technica)
New Technique Uses Metamaterial “Hoses” To Transmit Magnetic Fields Over Distance
Electromagnetic waves can travel over long distances without interruption. But magnetism, the field that attracts or repels objects, only works at close range.
A team of Spanish and German researchers… have developed a “magnetic hose,” capable of transferring a magnetic field across long distances in any direction they want… This new method would amplify those fields, allowing magnetic fields to still propagate far away from the magnetic dipole that generates them. It requires a metamaterial magnet-amplifier.
Carles Navau and his fellow researchers think of magnetic fields like any other electromagnetic wave, only with an infinite wavelength. So theoretically, these waves could be controlled like other electromagnetic waves, with amplifiers and transformers. A magnetic hose made of concentric rings of metamaterials could transmit, for lack of a better word, the magnetic field. A tube about 10 times longer than it is wide would transmit 90 percent of a magnetic field, they say.
(via Metamaterial Can Squirt A Magnetic Field Through A Hose | Popular Science)
Meet Sonny White: The NASA Scientist Who Claims to Be Building a Warp Drive
White leads me to his office, which he shares with a colleague who is looking for water on the moon and then takes me down the hall to Eagleworks.
As we walk, he tells me about his quest to open the lab, which he frames as “a long arduous process of trying to find ways for advanced propulsion to help human space exploration.” He speaks with a slight drawl, a product of many years spent in the South—first at college in Alabama and then 13 years in Texas.
White shows me into the facility and ushers me past its central feature, something he calls a quantum vacuum plasma thruster (QVPT). The device looks like a large red velvet doughnut with wires tightly wound around a core, and it’s one of two initiatives Eagleworks is pursuing, along with warp drive. It’s also secret.
When I ask about it, White tells me he can’t disclose anything other than that the technology is further along than warp drive. A 2011 NASA report he wrote says it uses quantum fluctuations in empty space as a fuel source, so that a spaceship propelled by a QVPT would not require propellant.
White’s warp experiment is tucked into the back corner of the room. A helium-neon laser is bolted onto a small table pricked with a lattice of holes, along with a beam splitter and a black-and-white commercial CCD camera. This is a White-Juday warp field interferometer, which White named for himself and Richard Juday, a retired JSC employee who is helping White analyze the data from the CCD.
Half of the laser light passes through a ring—White’s test device. The other half does not. If the ring has no effect, White would expect one type of signal at the CCD. If it warps space, he says “the interference pattern will be starkly different.”
When the device is turned on, White’s setup looks cinematically perfect: The laser is bright red, and the two beams cross like light sabers. There are four ceramic capacitors made of barium titanate inside the ring, which White charges to 23,000 volts. White has spent the last year and a half designing the experiment, and he says that the capacitors will “establish a very large potential energy.”
Yet when I ask how it would create the negative energy necessary to warp space-time he becomes evasive. “That gets into … I can tell you what I can tell you. I can’t tell you what I can’t tell you,” he says. He explains that he has signed nondisclosure agreements that prevent him from revealing the particulars. I ask with whom he has the agreements. He says, “People come in and want to talk about some things. I just can’t go into any more detail than that.”
Researcher Calls for a Moratorium on Nanotech Patents
Joshua Pearce is a professor at Michigan Technological University, and he very explicitly argues for taking an open-source and open-access approach to nanotechnology research. But he also goes well beyond that, calling for a patent moratorium and a gutting of the law that governs tech transfers from government-funded university research.
At stake, he argues, is the growth of a field that could be generating trillions of dollars of economic activity within a few years. Pearce’s viewpoint may seem like a radical overreaction, but there are technical reasons that nanotech might be more prone to patent troubles than other fields.
Though often portrayed in science fiction as having something to do with tiny robots, nanotechnology is actually based on the premise that the familiar properties of materials in the world around us can be radically altered when those same materials are structured on nanometer length scales…
Normally, the natural properties of a material aren’t patentable. But in this case, there is often a well-defined innovation, in the form of a manufacturing process that is needed to create specific nanomaterials. And slight tweaks to the process can often have significant influences on the properties of the end product…
Pearce has found that there are over 1,600 US patents that mention single-walled carbon nanotubes. Intel has one that covers any with a diameter of less than 50nm; Rice University holds one for any material that is over 99 percent pure nanotube.
The nightmare faced by anyone attempting to innovate in that space should be obvious, but in case it wasn’t, Pearce cites an example where a small nanotech company faced legal fees that were a substantial fraction of its assets, and another where a jury hit a company with damages that were nearly twice its total value.
(via Stallman’s got company: Researcher wants nanotech patent moratorium | Ars Technica)
Sonic ‘Bullets’ Could Destroy Tumors Better
Ordinary ultrasound sends sound waves into a material. Those waves bounce back to the source, where a computer analyzes the signal and creates an image. But the images can be fuzzy, since the waves are traveling back and forth through a material and getting dispersed. Sonar is similar. A submarine typically uses it to “ping” its surrounding. But again, the sound waves get dispersed through the water and may be scattered further by particles or small fish suspended in it. It’s similar to how headlights scatter in the rain, making it more difficult to see.
In the case of the Cal Tech’s innovation, rows of tiny steel spheres are arranged rows and columns to form a cube shape. The sound waves travel through the balls, emerging as a pulse at the end of the array. The pulse of sound is concentrated and therefore has more power than the conventional ultrasound, which emits sound waves in a continous flow. More power results in a higher resolution image.The Cal Tech team devised a technique that overcomes the challenges of dispersal and provides sharper images. Their innovation works in a way similar to the Newton’s Cradle toy, in which a row of metal balls hang from strings. If you pull back on a ball at one end and allow it to swing and collide with the row of balls, the energy passes through all of the balls and gets transferred to the one on the opposite end, causing it to swing up.
Daraio told Discovery News that because it’s possible to control the sound energy this way, it’s possible to make a kind of ultrasound machine that wouldn’t suffer from the scattering and wave diffraction problems that ordinary ultrasound does. The same is true of sonar. Because the pulse of sound is short, rather than continuous, sending a high-power pulse through tissue would be safer to do. When treating tumors this way, more energy could be sent at one time, with tighter focus.
(via Sonic ‘Bullets’ Could Destroy Tumors Better | Discovery News ht singularitarian)
Chinese Researchers Achieve Quantum Teleportation at Macro Scale
So by entangling two photons, for instance, physicists have demonstrated the ability to transmit quantum information from one place to another by encoding it in these quantum states—influence one of the pair and a change can be measured in the other without any information actually passing between the two. Researchers have done this before, between photons, between ions, and even between a macroscopic object and a microscopic object.
But now Chinese researchers have, for the first time, achieved quantum teleportation between two macroscopic objects across nearly 500 feet using entangled photons…
The two bundles of rubidium atoms that served as sender and receiver are more or less analogs for what we hope will someday be our “quantum Internet”—a system of routers like the ones we have now that, instead of beaming information around a vast network of fiber optic wires, will send and receive information through entangled photons.
So in a way, this is like a first proof of concept, evidence that the idea works at least in the lab. Now all we have to do is figure out is how to build several of these in series so they can actually pass information from one to the other. To do that, we only have to somehow force these quantum states to exist for longer than the hundred microseconds or so that they last now before degrading. Sounds easy enough.
Quantum Photonics: Researchers Develop Technique to Transmit Data As Twisted Streams of Light
In terms of these quantum states, photons possess two distinct polarization orientations, along with a theoretically infinite number of helical wave forms, in which the photons rotate around the direction they’re moving. The latter have garnered a lot of interest, as they could potentially carry a lot more data than other optical methods.
Possible applications include quantum computing, improved fiber optic communication, point-to-point data transfer across free space, and microscopy.
Researchers have now developed a way to produce twisted light beams using silicon chips, the starting point for compact, efficient optical communication.
Xinlun Cai and colleagues shaped photons using a microscopic, ring-shaped grating, which sent twisted light out in a specified pattern. Each ring was small enough to be fabricated into integrated circuits, and capable of emitting multiple vortexes of light simultaneously. The same type of chip could also serve as a receiver for twisted light, and manipulate waves that transit through it.
(via Fabbing a chip that could encode data in a twisted vortex of light | Ars Technica)
If the Universe Is Really Just a Simulation, There Are Ways We Could Tell
The problem with all simulations is that the laws of physics, which appear continuous, have to be superimposed onto a discrete three dimensional lattice which advances in steps of time.
The question that Beane and co ask is whether the lattice spacing imposes any kind of limitation on the physical processes we see in the universe.
…What they find is …that the lattice spacing imposes a fundamental limit on the energy that particles can have. That’s because nothing can exist that is smaller than the lattice itself.
So if our cosmos is merely a simulation, there ought to be a cut off in the spectrum of high energy particles. It turns out there is exactly this kind of cut off in the energy of cosmic ray particles... This cut-off has been well studied and comes about because high energy particles interact with the cosmic microwave background and so lose energy as they travel long distances.
But Beane and co calculate that the lattice spacing imposes some additional features on the spectrum. …the cosmic rays would travel preferentially along the axes of the lattice, so we wouldn’t see them equally in all directions.
That’s a measurement we could do now with current technology. Finding the effect would be equivalent to being able to to ‘see’ the orientation of lattice on which our universe is simulated.
In a nutshell, if you look closely enough, the universe would look as if you were drawing diagonal lines on a 1-bit display.
(via The Measurement That Would Reveal The Universe As A Computer Simulation - Technology Review)
