Lifeboat Foundation

Japanese scientists were able to prove that rare earth elements are made by looking at the spectra of light coming from neutron stars that were colliding.

For the first time, Japanese scientists have found evidence that rare earth elements are indeed made when two neutron stars merge. The Astrophysical Journal just published the specifics of the scientists’ discoveries.

The first verified incidence of this process, GW 170,817, occurred in 2017.

Continue reading “Rare earth elements are created during neutron star mergers, study confirms” »

Imagine you are at a museum. After a long day admiring the exhibitions, you are exiting the museum. But to be able to get out, you will need to exit through the gift shop. The layout of the gift shop can be set up in several ways. Maybe you can take a short and direct path to the exit, maybe there are long winding corridors stuffed with merchandise you need to pass through. If you take the longer path, you are more likely to lose more of your money before you get outside. The scientists at the CMS collaboration have recently observed a similar phenomenon in high-energy heavy ion collisions, as those illustrated in the event display.

The life of the tiniest particles making up ordinary matter — quarks and gluons — is governed by the laws of quantum chromodynamics. These laws require quarks and gluons to form bound states, like protons and neutrons, under normal conditions. However, conditions like in the early universe, when the energy density and temperature far exceeded those of ordinary matter, can be achieved in giant particle accelerators. In the Large Hadron Collider at CERN this is done by colliding lead nuclei that are accelerated close to the speed of light. In these conditions, a new state of matter, called the quark-gluon plasma, is formed for a tiny fraction of a second. This new state of matter is special, since within the volume of the matter, quarks and gluons act as free particles, without the need to form bound states.

Figure 1: A schematic presentation of a non-central (left) and central (right) heavy ion collision. The outlines of the ions are presented by dashed lines, while the overlap region in which the quark-gluon plasma is produced is colored in orange. The red star shows a position where two quarks might scatter, and green and blue arrows are alternative paths the scattered quark can take to escape the quark-gluon plasma.

Conventional light sources for fiber-optic telecommunications emit many photons at the same time. Photons are particles of light that move as waves. In today €™s telecommunication networks, information is transmitted by modulating the properties of light waves traveling in optical fibers, similar to how radio waves are modulated in AM and FM channels.

In quantum communication, however, information is encoded in the phase of a single photon – the photon €™s position in the wave in which it travels. This makes it possible to connect quantum sensors in a network spanning great distances and to connect quantum computers together.

Researchers recently produced single-photon sources with operating wavelengths compatible with existing fiber communication networks. They did so by placing molybdenum ditelluride semiconductor layers just atoms thick on top of an array of nano-size pillars (Nature Communications, “Site-Controlled Telecom-Wavelength Single-Photon Emitters in Atomically-thin MoTe 2 ”).

Axions that decay into photons could account for visible light that exceeds what’s expected to come from all known galaxies.

If you could switch off the Milky Way’s stars and gaze at the sky with a powerful telescope, you’d see the cosmic optical background (COB)—visible-wavelength light emitted by everything outside our Galaxy. Recent studies by the New Horizons spacecraft—which, after its Pluto flyby, has been looking further afield—have returned the most precise measurements of the COB yet, showing it to be brighter than expected by a factor of 2. José Bernal and his colleagues at Johns Hopkins University in Maryland propose that this excess could be caused by decaying dark matter particles called axions [1]. They say that their model could be falsified or supported by future observations.

Comparing COB measurements to predictions provides a tool for testing hypotheses about the structure of the Universe. But measuring the COB is very difficult due to contamination by diffuse light from much nearer sources, especially sunlight scattered by interplanetary dust. Observing from the edge of our Solar System, New Horizons should be unaffected by most of this contamination, making the measured excess brightness a tool for improving our understanding of galaxy evolution.

So-called relativistic jets of energetic particles are stunning, destructive spectacles, and this one was “unprecedented.”

Water that simply will not freeze, no matter how cold it gets—a research group involving the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) has discovered a quantum state that could be described in this way.

Experts from the Institute of Solid State Physics at the University of Tokyo in Japan, Johns Hopkins University in the United States, and the Max Planck Institute for the Physics of Complex Systems (MPI-PKS) in Dresden, Germany, managed to cool a special material to near absolute zero temperature.

They found that a central property of atoms—their alignment—did not “freeze,” as usual, but remained in a “liquid” state. The new quantum material could serve as a model system to develop novel, highly sensitive quantum sensors. The team has presented its findings in the journal Nature Physics.

Massachusetts Institute of Technology (MIT) researchers are building swarms of tiny robots that have built-in intelligence, allowing them to build structures, vehicles, or even larger versions of themselves.

The subunit of the robot, which is being developed at MIT’s Center for Bits and Atoms, is called a voxel and is capable of carrying power and data.

“When we’re building these structures, you have to build in intelligence,” MIT Professor and CBA Director Neil Gershenfeld said in a statement. “What emerged was the idea of structural electronics — of making voxels that transmit power and data as well as force.”

IT WAS March 2018. The atmosphere at the annual meeting of the American Physical Society at the Los Angeles Convention Center was highly charged. The session had been moved to the atrium to accommodate the crowds, but people still had to cram onto the balconies to get a view of the action.

Rumours had it that Pablo Jarillo-Herrero, a physicist at the Massachusetts Institute of Technology, had something momentous to report. He and his colleagues had been experimenting with graphene, sheets of carbon just a single atom thick that are peeled from the graphite found in pencil lead. Graphene was already celebrated for its various promising electronic properties, and much more besides.

Here, Jarillo-Herrero showed that if you stacked two graphene sheets and twisted, or rotated, one relative to the other at certain “magic angles”, you could make the material an insulator, where electric current barely flows, or a superconductor, where current flows with zero resistance. It was a staggering trick, and potentially hugely significant because superconductivity holds promise for applications ranging from quantum computing to nuclear fusion.

Bohr’s model of the atom is kind of crazy. His collage of ideas mixing old and new concepts was the fruit of Bohr’s amazing intuition. Looking only at hydrogen, the simplest of all atoms, Bohr formed the image of a miniature solar system, with a proton in the center and the electron circling around it.

Following the physicist’s way of doing things, he wanted to explain some of his observed data with the simplest possible model. But there was a problem. The electron, being negatively charged, is attracted to the proton, which is positive. According to classical electromagnetism, the theory that describes how charged particles attract and repel one another, an electron would spiral down to the nucleus. As it circled the proton, it would radiate away its energy and fall in. No orbit would be stable, and atoms could not exist. Clearly, something new and revolutionary was needed. The solar system could only go so far as an analogy.

To salvage the atom, Bohr had to invent new rules that clashed with classical physics. He bravely suggested the implausible: What if the electron could only circle the nucleus in certain orbits, separated from each other in space like the steps of a ladder or the layers of an onion? Just like you can’t stand between steps, the electron can’t stay anywhere between two orbits. It can only jump from one orbit to another, the same way we can jump between steps. Bohr had just described quantum jumps.