Physicists at the Delft University of Technology, Netherlands, have achieved a milestone that might soon revolutionize the world of quantum computing, quantum physics, and perhaps shed new light on the mystery of the dark matter in our universe. Experimenting with nanoelectronics, a group led by Prof. Leo Kouwenhoven has succeeded in detecting the elusive Majorana fermion in the laboratory, without the need for a particle accelerator.

Majorana fermions might be the sole component of the dark matter in our Universe

The find is the culmination of decades of research. First theorized by Italian physicist Ettore Majorana in 1937 by building on the work of Erwin Schrödinger and Paul Dirac, the Majorana fermion emitted too weak a signal to be spotted within most materials. Recently, however, theoretical physicists have suggested that some exotic materials might circumvent defects and impurities found elsewhere and allow for the detection of this elusive particle.

Building on this knowledge, Kouwenhoven connected indium antimonide nanowires to a circuit with a gold contact at one end and a slice of superconductor at the other, and then exposed the circuit to a moderate magnetic field. Measurements of the electrical conductance of the nanowires showed a peak at zero voltage that is consistent with the formation of a pair of Majorana particles.

Conceptual close-up of the Majorana nano-device

This special kind of fermion has the unique property of being its own antiparticle. An antiparticle is defined as a subatomic particle having the same mass as a given particle, but opposite electric or magnetic properties – for instance, the antiparticle of a negatively-charged electron is a positively-charged positron. The unique properties of Majorana fermions generate an interesting behavior whenever two particles interact.

Elementary particles come in two kinds: bosons, such as photons, and fermions, such as electrons. Besides having different charge and spin properties, they also behave quite differently when two particles of the same kind interact with each other.

When two bosons trade places, there is no change in their quantum mechanical state, and they become interchangeable; when two normal fermions trade places, the sign of their mathematical "wavefunction" changes from positive to negative with each switch, returning to their original state after two switches. Majorana fermions, on other hand, "remember" their previously taken path.

This property makes Majorana fermions a very strong candidate for use in quantum computers. While we’ve seen a number of developments in quantum computing in recent years, from qubits in semiconductors to manipulating quantum informationthrough electrical fields, one longstanding issue is that the qubits – "quantum bits," the basic unit of information in a quantum computer – are unstable and highly sensitive to external influences.

Not so with this particle, which promises to be unaffected by external influences (even though, it should be pointed out, it’s not yet entirely clear whether qubits created in this manner will be long-lived enough to be used in that way).

More broadly, the "memory" of these particles could be a crucial factor that will enable researchers to more effectively crack some of the long-standing mysteries of quantum mechanics once and for all, helping to investigate the behavior of other particles.

Also, as some researchers suggest, the particles may play a crucial role in cosmology – a proposed theory assumes that the mysterious dark matter, which is thought to form around 73 percent of our Universe, is composed entirely of Majorana fermions.

The video below illustrates the process by which Kouwenhoven’s team managed to isolate the fermions.

Is dark matter in danger? A few days after scientists said there’s no dark matter near our sun, a team of researchers in Germany now says there’s no dark matter in our galactic neighborhood. The team found a vast structure of globular clusters and satellite galaxies surrounding the Milky Way in a smooth, evenly distributed pattern. Most models of galactic distribution and evolution require the gravitational effects of dark matter, but in this model, it doesn’t seem to exist.

Cluster of galaxies Galaxies in this image, left to right: Upper inner left, NGC 3193; middle, NGC 3190; upper right (2 o’clock), NGC 3187; lower right (4 o’clock), NGC 3185.

Examining a wide range of astronomical source data, the team assembled what they’re calling a new picture of our cosmic neighborhood. Companion galaxies, star clusters and loose gases are all properly aligned with the galactic disk, according to the team, led by Marcel Pawlowski at the University of Bonn.

This newly-discovered organizational structure is huge — it starts around 33,000 light years from the center of the Milky Way, and reaches 1 million light years. As the companion galaxies and clusters move about the Milky Way, they shed material like stars and gas, which forms long tails around their cosmic trajectories. These trailers also follow the galactic plane, the researchers say. Something is responsible for this organization, but the German team says it isn’t dark matter. They have a few ideas, including that the Milky Way collided with another galaxy 11 billion years ago, and the current companions are just debris following the galactic gravitational field.

“We were baffled by how well the distributions of the different types of objects agreed with each other,” said Pavel Kroupa, professor of astronomy at the University of Bonn, in a news release.

Dark matter is said to make up 23 percent of the mass-energy of the universe, much more than regular, baryonic matter that we can see. Its existence is inferred partly by its effects on galaxy distribution and galaxy cluster evolution. But the Milky Way’s satellite galaxies don’t trace a dark matter pattern, Pawlowski said in a blog post. He also notes that nobody has been able to find a dark matter particle yet, despite a slew of efforts around the world in all sorts of interesting configurations. Maybe they’re not finding it because it isn’t there?

Here’s the problem, though: Galaxy rotations (among other phenomena) cannot be explained by existing physics without something like dark matter. It fits the equations so well, it’s become pretty much accepted theory. But if we can’t find it — and if the structures that are supposed to help prove its existence can’t do that, either — then we’ll have to come up with something else.

“Our very understanding of space-time and matter are now at stake,” Pawlowski said.

A real-world demonstration of a thought experiment conducted at the University of Vienna, has produced a result that is somewhat befuddling to people with what the lead researcher calls a "naïve classical world view." Two pairs of particles are either quantum-entangled or not. One person makes the decision as to whether to entangle them or not, and another pair of people measure the particles to see whether they’re entangled or not.

Four Particles

The head-scratcher is: the measurement is made before the decision is made, and it is accurate. "Classical correlations can be decided after they are measured," says Xiao-song Ma, the writer of the study. Entanglement can be created "after the entangled particles have been measured and may no longer exist."

The finding can be integrated into potential quantum computers, one hopes. Causality, clearly, is a quaint, irrelevant concept.

First, it’s important to know that the big bang wasn’t an explosion of matter into empty space—it was the rapid expansion of space itself. This means that every single point in the universe appears to be at the center. Think of the universe as an empty balloon with dots on it. Those dots represent clusters of galaxies. As the balloon inflates, every dot moves farther away from every other dot. The space between clusters of galaxies expands, like the rest of the universe, at an accelerating rate. (Gravity keeps the clusters themselves the same size.)

Edwin Hubble first observed this phenomenon in 1929, when he noticed that the light from distant galaxies shifted to the red end of the spectrum, as though it had been stretched as it traveled through space. By measuring the wavelengths of the light, Hubble observed that galaxies were expanding away from each other at a rate proportional to their distance from one another.

In the beginning, the universe was a single point. Where was that? It was, and still is, everywhere. Scientists even have proof: Light from the big bang, in the form of cosmic radiation, fills the sky in every direction.

As Earth humans begin to seriously consider sending missions to icy worlds like Europa and Enceladus, one of the necessary concerns has to be protection of the environment where such a mission would land. It would be a shame to arrive on a fascinating alien world only to immediately seed it with Earth microbes, carelessly infecting the local ecosystem, ruining the unique scientific opportunity and possibly incurring the wrath of the local alien ruler.

Enceladus and its Plumes of Water

A new assessment by the Space Science Board looks at which destinations are most in need of protection from microbes — Europa, Enceladus, Titan, and Triton, it concludes — and sets out a series of protocols for deciding how and where best to assess and deal with the risk.

COSPAR [Committee on Space Research] guidelines require that less than 1 in 10,000 missions will deliver a single viable microbe that is able to grow on a solar system destination, i.e., a 10^-4 probability of contamination per mission flown. Failure to meet this mandated objective could impose requirements for more stringent cleaning or terminal bioload-reduction procedures comparable to that employed by the Viking missions. In extreme cases, satisfying planetary protection requirements might require spacecraft redesign or cancellation of an entire mission.

We generally think of electrons as fundamental building blocks of atoms, elementary subatomic particles with no smaller components to speak of. But according to Swiss and German researchers reporting in Nature this week, we are wrong to think so. For the first time, the researchers have recorded an observation of an electron splitting into two different quasi-particles, each taking different characteristics of the original electron with it.

Using samples of the copper-oxide compound Sr2CuO3, the researchers lifted some of the electrons belonging to the copper atoms out of their orbits and placed them into higher orbits by manipulating them with X-rays. Upon placing them in these higher–and higher-velocity–orbits, the electrons split into two parts, one called a spinon that carried the electron’s spin with it, and another called an obitron that carried the electron’s orbital momentum with it.

Spin and orbit are–at least as our basic understanding goes–attached to each particular electron. So the fact that they have been separated is pretty significant. And while researchers have thought for a while that this kind of separation could be theoretically achieved, they’ve had a hard time proving it empirically until now. It’s a reminder that at the quantum level there are still things that more or less mystify us.
But that’s not all it is. This particular observation of an electron splitting could have big-time implications in the field of high-temperature superconductivity. Understanding the way electrons can decay into quasi-particles could improve our overall understanding of the electron and how it moves, and thus help us figure out new ways of moving electrons–or electricity–around in bulk without losing large amounts of it as waste.

If biomimicry is the instance of technology emulating nature, then this must be something like the opposite: researchers at Kobe University have built a computer out of crabs. Placed within a geometrically constrained environment, swarms of soldier crabs can be effectively used to emulate logic gates. In other words, researchers have replicated the fundamental workings of a computer–with crabs.

The crabs in question, soldier crabs, live in large groups in lagoon environments (not to be confused with Shanghai hairy crabs, which live in a vending machine). When they move they swarm, with no real discernible leader. Crabs near the edges of the group exhibit serious leadership qualities, keeping the group together and moving in a direction as a cohesive body. Crabs in the interior of the group go with the flow, following their neighbors who are following their neighbors who are following the leaders at the edges.

But, interestingly, the soldier crabs also rotate regularly. Leader crabs at the edges cycle back into the interior, and interior crabs rotate to the outside, into leadership roles. All this happens without discussion of course. The direction and speed the crabs travel is often dictated by outside stimuli, such as the shadow of a crab-eating bird being cast on the group. But they more or less move as a unit, regardless of which crabs are in charge at any particular time.

When two swarms of crabs meet in motion, they tend to compromise by merging and continuing on in a direction that is the sum of the two swarms’ velocities, and this is where the computing comes in. The researchers built a system of channels in an environment that funnel the crabs along, like electrons flowing through a computer (they are prodded along by a fake bird shadow that is cast from overhead). Using a group of 40 real soldier crabs, the researchers tried to cajole the group into acting like a logic gate.

They found they could build a very reliable OR logic gate–where one or two swarms are merged into a single path. Creating the AND gate–one that requires the crabs to all swarm down one of three paths–was more difficult, but the researchers think they can improve its rate of success by altering the environment to be more friendly to the crabs.

All that means that, technically, you could build a classical computer using the presence or absence of a swarm of crabs to represent 1s and 0s. Which doesn’t impact you at all, since it would be kind of silly to actually build a working computer that works in such a way. But isn’t it cool that you could?

Yesterday–at least in the northeast U.S.–was a picture-perfect, sun-shiney day. But as many of us took a few extra minutes at lunch to soak up one of the first nice spring days of the season, the sun overhead was in the midst of some serious violence. At roughly 1:45 p.m. EDT yesterday, a huge and beautiful eruption took place on the east limb of our local star, sending a massive prominence looping out into space.

The explosion unleashed a rather large coronal mass ejection (CME), those sometimes-menaces that threaten satellites, astronauts and terrestrial electronics, though the CME was not pointed toward earth. So instead of a space weather warning, we get this: beautiful imagery and footage of this M1 class (that’s like a medium) solar flare and prominence captured by NASA’s Solar Dynamics Observatory. While it was quite pleasant here on the Earth yesterday, click play below to see just how crazy things were getting on the surface of the sun.

A start-up in Seattle has created the ‘Textspresso,’ a coffee machine that accepts and prepares specialized coffee orders via text message and will soon also print directly onto the coffee’s top layer of cream.

When Seattle-based start-up, Zipwhip, wanted to show off its new cloud texting platform, it needed a way to demonstrate just how useful it could be. Most companies might talk data points, like how fast its platform broadcasts or how its product offers a service no one else does. Instead, Zipwhip got a little creative and built the "Textspresso" coffee maker, a machine that accepts and brews specialty coffee orders via text message so the beverage is ready once a person arrives to pick it up.

So why would you need to order coffee through text message? Well, if you’re standing right by the machine, you wouldn’t. If you’re away from the device though – like on your way to the office or in the bathroom – you can send out a text to make sure a hot cup of joe is waiting for you when you get there. After receiving the text order, a mechanical arm automatically picks up a mug from a warming tray and carries it to the espresso maker. The machine then serves whatever drink was ordered and the arm delivers the mug back to the heating tray to wait for its owner.

The machine itself was constructed and programmed in-house by Zipwhip from scratch after the office decided to ditch its old drip brewing machine for a much fancier espresso maker. Once the hardware was in place, the company worked out the movement scripts for the mechanical arm by having employees test different motions using an Xbox 360 controller. For now, the machine can only accept simple orders ("coffee," "latte," "espresso double," etc.). Zipwhip is also refusing to reveal what phone number the Textspresso uses to avoid getting flooded with hundreds of random orders (and no, it’s not the one listed on its screen).

As an added touch, the machine will soon also incorporate an edible ink printer that can actually print directly onto the coffee’s top layer of cream. Zipwhip plans to have it print the company logo along with the phone number that ordered the drink, so that people don’t mix up the orders after they’re made.

Unfortunately, Zipwhip only built the Textspresso in order to demonstrate their cloud texting platform, which allows text messages to be sent and received between computers and Android devices. Since revealing its creation though, the company has been flooded with questions about how to build one and has now stated that it intends to publicly release the designs for the machine later on.

The first human eggs grown from human stem cells could be fertilized with human sperm cells later this year, potentially revolutionizing fertility treatment for women. This could be one more step on the path toward reproduction sans human interaction — in this case, a potential parent wouldn’t even need to donate her eggs. But it could also turn stem cells into an infinite loop, of egg cells into embryos into stem cells, and on and on, in a fractal-like repetition of reproduction.

In February, there were  a study involving Japanese women whose reproductive stem cells were donated because they were undergoing gender reassignment surgery. Researchers at Massachusetts General Hospital were able tocoax these ovarian stem cells into becoming immature human egg cells, which were then incubated in mice so they’d have the proper ovarian structures. Now these same scientists, working with a team at Edinburgh University, want to fertilize them.

After sperm implantation, the scientists would watch the blastocysts develop into embryos for two weeks — the legal limit — and determine if they’re viable. Then these embryos would either be frozen or "allowed to perish," according to the independent. The tests would validate the stem-cell-derived human eggs, more properly called oocytes, and serve as an early indicator of whether they could someday be used to eradicate infertility.

Stem-cell derived oocytes could replenish the stocks of women undergoing menopause, or they could be used to allow infertile women to reproduce. The Independent goes so far as to mention an “elixir of youth,” wherein women of any age are full of stem-cell derived oocytes, remaining fertile and youthfully healthy forever.

This potential stem cell-based embryo construction still faces some hurdles — reproductive biologists are applying for a license to the Human Fertilisation and Embryology Authority in the UK. But if it’s approved, the eggs could be fertilized this year, according to the Independent.

Stem cells hold such great promise because they can differentiate into any cell, potentially replacing neurons, islet cells, kidney cells and more. But this research conceivably turns stem cells into an infinite supply of cellular material. The stem cell eggs would obviously most likely be used to help women conceive a child, but it’s not a huge leap to much more frightening scenarios: Stem cells turned into human egg cells, which could be fertilized to grow embryos, which would contain more stem cells, which could in turn be harvested …. and so on, as self-contained stem cell factories. It will be interesting to see how the UK authority interprets the possibilities.