Lifeboat Foundation

What would happen if an electric current no longer flowed, but trickled instead? This was the question investigated by researchers working with Christian Ast at the Max Planck Institute for Solid State Research. Their investigation involved cooling their scanning tunnelling microscope down to a fifteen thousandth of a degree above absolute zero. At these extremely low temperatures, the electrons reveal their quantum nature. The electric current is therefore a granular medium, consisting of individual particles. The electrons trickle through a conductor like grains of sand in an hourglass, a phenomenon that can be explained with the aid of quantum electrodynamics.

Flowing water from a tap feels like a homogeneous medium – it is impossible to distinguish between the individual water molecules. Exactly the same thing is true about electric current. So many electrons flow in a conventional cable that the current appears to be homogeneous. Although it is not possible to distinguish individual electrons, quantum mechanics says they should exist. So how do they behave? Under which conditions does the current not flow like water through a tap, but rather trickles like sand in an hourglass?

For the first time ever, laser physicists have recorded an internal atomic event with an accuracy of a trillionth of a billionth of a second.

When light strikes electrons in atoms, their states can change unimaginably quickly. Laser physicists at LMU Munich and the Max Planck Institute of Quantum Optics (MPQ) have now measured the duration of such a phenomenon – namely that of photoionization, in which an electron exits a helium atom after excitation by light – for the first time with zeptosecond precision. A zeptosecond is a trillionth of a billionth of a a second (10−21 s). This is the first absolute determination of the timescale of photoionization, and the degree of precision achieved is unprecedented for a direct measurement of the interaction of light and matter.

When a light particle (photon) interacts with the two electrons in a helium atom, the changes take place not only on an ultra-short timescale, but quantum mechanics also comes into play. Its rules dictate that either the entire energy of the photon is absorbed by one of the electrons, or the energy is distributed between them. Regardless of the mode of energy transfer, one electron is ejected from the helium atom. This process is called photoemission, or the photoelectric effect, and was discovered by Albert Einstein at the beginning of the last century. In order to observe what occurs, you need a camera with an incredibly fast shutter speed: The whole process, from the point at which the photon interacts with the electrons to the instant when one of the electrons leaves the atom, takes between 5 and 15 attoseconds (1 as is 10–18 seconds) as physicists have worked out in recent years.

Continue reading “A Zeptosecond Stopwatch for The Microcosm” »

What would happen if an electric current no longer flowed, but trickled instead? This was the question investigated by researchers working with Christian Ast at the Max Planck Institute for Solid State Research. Their investigation involved cooling their scanning tunnelling microscope down to a fifteen thousandth of a degree above absolute zero. At these extremely low temperatures, the electrons reveal their quantum nature. The electric current is therefore a granular medium, consisting of individual particles. The electrons trickle through a conductor like grains of sand in an hourglass, a phenomenon that can be explained with the aid of quantum electrodynamics.

Flowing water from a tap feels like a homogeneous medium — it is impossible to distinguish between the individual water molecules. Exactly the same thing is true about electric current. So many electrons flow in a conventional cable that the current appears to be homogeneous. Although it is not possible to distinguish individual electrons, quantum mechanics says they should exist. So how do they behave? Under which conditions does the current not flow like water through a tap, but rather trickles like sand in an hourglass?

The hourglass analogy is very appropriate for the scanning tunnelling microscope, where a thin, pointed tip scans across the surface of a sample without actually touching it. A tiny current flows nevertheless, as there is a slight probability that electrons “tunnel” from the pointed tip into the sample. This tunnelling current is an exponential function of the separation, which is why the pointed tip is located only a few Ångström (a ten millionth of a millimetre) above the sample.

A new approach to a once-farfetched theory is making it plausible that the brain functions like a quantum computer.

The mere mention of “quantum consciousness” makes most physicists cringe, as the phrase seems to evoke the vague, insipid musings of a New Age guru. But if a new hypothesis proves to be correct, quantum effects might indeed play some role in human cognition. Matthew Fisher, a physicist at the University of California, Santa Barbara, raised eyebrows late last year when he published a paper in Annals of Physics proposing that the nuclear spins of phosphorus atoms could serve as rudimentary “qubits” in the brain—which would essentially enable the brain to function like a quantum computer.

Atoms, photons, and other quantum particles are often capricious and finicky by nature; very rarely at a standstill, they often collide with others of their kind. But if such particles can be individually corralled and controlled in large numbers, they may be harnessed as quantum bits, or qubits — tiny units of information whose state or orientation can be used to carry out calculations at rates significantly faster than today’s semiconductor-based computer chips.

In recent years, scientists have come up with ways to isolate and manipulate individual quantum particles. But such techniques have been difficult to scale up, and the lack of a reliable way to manipulate large numbers of atoms remains a significant roadblock toward quantum computing.

Now, scientists from Harvard and MIT have found a way around this challenge. In a paper published in the journal Science, the researchers report on a new method that enables them to use lasers as optical “tweezers” to pick individual atoms out from a cloud and hold them in place. As the atoms are “trapped,” the scientists use a camera to create images of the atoms and their locations. Based on these images, they then manipulate the angle of the laser beams, to move individual atoms into any number of different configurations.

Continue reading “Scientists set traps for atoms with single-particle precision” »

On October 5th 2016, Ranga Dias and Isaac F. Silvera of Lyman Laboratory of Physics, Harvard University released the first experimental evidence that solid metallic hydrogen has been synthesized in the laboratory.

It took 495 GPa pressure to create. The sample is being held in the cryostat in liquid nitrogen.

Atomic metallic hydrogen, if metastable at ambient pressure and temperature could be used as the most powerful chemical rocket fuel, as the atoms recombine to form molecular hydrogen. This light-weight high-energy density material would revolutionize rocketry, allowing single-stage rockets to enter orbit and chemically fueled rockets to explore our solar system. To transform solid molecular hydrogen to metallic hydrogen requires extreme high pressures.

Continue reading “Co-discover of Metallic Hydrogen wrote paper on metallic hydrogen for rockets” »

Physicists have come up with a new model that they say solves five of the biggest unanswered questions in modern physics, explaining the weirdness of dark matter, neutrino oscillations, baryogenesis, cosmic inflation, and the strong CP problem all at once.

The new model, called SMASH, proposes that we only need six new particles to reconcile all of these gaps in the standard model of physics, and the team behind it says it won’t be that hard to test.

The model has been developed by a team of French and German physicists, and they say it doesn’t require any major tweaks to the standard model — just a few new additions.

Continue reading “This New Hypothesis Claims to Solve 5 of the Biggest Problems in Physics” »

In a study led by the University of Leeds, scientists have solved one of the most challenging and long-standing problems in atmospheric science: to understand how particles are formed in the atmosphere.

The research paper, published online today in the journal Science, details the first computer simulation of atmospheric particle formation that is based entirely on experimental data. The research was made possible thanks to a sophisticated laboratory called CLOUD, based within the research facility CERN in Switzerland.

The lead scientist on the study, Professor Ken Carslaw from the School of Earth and Environment at the University of Leeds said: “This is a major milestone in our understanding of the atmosphere. The CERN experiment is unique, and it has produced data that seemed completely out of reach just five years ago.”

In Brief:

• Using an advanced supercomputer, scientists came up with a profile for dark matter, concluding that it may be made of axions of a specific type.
• With this new information, the race is on to be the first to prove the existence of dark matter particles.

Understanding what dark matter is has proven to be amazingly difficult. Of course, one might expect this from a thing that is, for all intents and purposes, entirely invisible. Scientists have come to the conclusion that dark matter exists by observing the way gravity behaves—either our model of gravity is in need of an update, or dark matter exists. The latter is the most likely conclusion.