Quantum Questions

Scientists break record for highest-temperature superconductor: Experiment produces new material that can conduct electricity perfectly

University of Chicago scientists are part of an international research team that has discovered superconductivity–the ability to conduct electricity perfectly–at the highest temperatures ever recorded.

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Using advanced technology at UChicago-affiliated Argonne National Laboratory, the team studied a class of materials in which they observed superconductivity at temperatures of about minus-23 degrees Celsius (minus-9 degrees Fahrenheit)–a jump of about 50 degrees compared to the previous confirmed record.

Though the superconductivity happened under extremely high pressure, the result still represents a big step toward creating superconductivity at room temperature–the ultimate goal for scientists to be able to use this phenomenon for advanced technologies. The results were published May 23 in the journal Nature; Vitali Prakapenka, a research professor at the University of Chicago, and Eran Greenberg, a postdoctoral scholar at the University of Chicago, are co-authors of the research.

One hundred years ago, Einstein’s theory of general relativity was supported by the results of a solar eclipse experiment. Even before that, Einstein had developed the theory of special relativity — a way of understanding how light travels through space.

Particles of light — photons — travel through a vacuum at a constant pace of more than 670 million miles per hour.

All across space, from black holes to our near-Earth environment, particles are being accelerated to incredible speeds — some even reaching 99.9% the speed of light! By studying these super fast particles, we can learn more about our galactic neighborhood. 

Here are three ways particles can accelerate:

1) Electromagnetic Fields!

Electromagnetic fields are the same forces that keep magnets on your fridge! The two components — electric and magnetic fields — work together to whisk particles at super fast speeds throughout the universe. In the right conditions, electromagnetic fields can accelerate particles at near-light-speed.

We can harness electric fields to accelerate particles to similar speeds on Earth! Particle accelerators, like the Large Hadron Collider and Fermilab, use pulsed electromagnetic fields to smash together particles and produce collisions with immense amounts of energy. These experiments help scientists understand the Big Bang and how it shaped the universe!

2) Magnetic Explosions!

Magnetic fields are everywhere in space, encircling Earth and spanning the solar system. When these magnetic fields run into each other, they can become tangled. When the tension between the crossed lines becomes too great, the lines explosively snap and realign in a process known as magnetic reconnection. Scientists suspect this is one way that particles — for example, the solar wind, which is the constant stream of charged particles from the Sun — are sped up to super fast speeds.

When magnetic reconnection occurs on the side of Earth facing away from the Sun, the particles can be hurled into Earth’s upper atmosphere where they spark the auroras.

3) Wave-Particle Interactions!

Particles can be accelerated by interactions with electromagnetic waves, called wave-particle interactions. When electromagnetic waves collide, their fields can become compressed. Charged particles bounce back and forth between the waves, like a ball bouncing between two merging walls. These types of interactions are constantly occurring in near-Earth space and are responsible for damaging electronics on spacecraft and satellites in space.

Wave-particle interactions might also be responsible for accelerating some cosmic rays from outside our solar system. After a supernova explosion, a hot, dense shell of compressed gas called a blast wave is ejected away from the stellar core. Wave-particle interactions in these bubbles can launch high-energy cosmic rays at 99.6% the speed of light.

Giant lasers crystallize water with shockwaves, revealing the atomic structure of superionic ice

Scientists from Lawrence Livermore National Laboratory (LLNL) used giant lasers to flash-freeze water into its exotic superionic phase and record X-ray diffraction patterns to identify its atomic structure for the very first time—all in just a few billionths of a second. The findings are reported today in Nature.

In 1988, scientists first predicted that waterwould transition to an exotic state of matter characterized by the coexistence of a solid lattice of oxygen and liquid-like hydrogen—superionic ice—when subjected to the extreme pressures and temperatures that exist in the interior of water-rich giant planets like Uranus and Neptune. These predictions remained in place until 2018, when a team led by scientists from LLNL presented the first experimental evidence for this strange state of water.

Now, the LLNL scientists describe new results. Using laser-driven shockwaves and in-situ X-ray diffraction, they observe the nucleation of a crystalline lattice of oxygen in a few billionths of a second, revealing for the first time the microscopic structure of superionic ice.

Richard P. Feynman an astounding theoretical physicist and professor

∆ Quantum mechanics & particle physics

∆ Quantum electrodynamics (QED) for which he shared a Nobel Prize

∆ Superfluidity of liquid helium  

The diagram above is of a vector boson fusion producing a Higgs boson. Feynman developed this method of representing particle interactions which have been important to the understanding of work in particle accelerators such as the Large Hadron Collider.

The following is a wonderful video of Feynman talking about light

Oregon scientists drill into white graphene to create artificial atoms: Patterned on a microchip and working in ambient conditions, the atoms could lead to rapid advancements in new quantum-based technology

By drilling holes into a thin two-dimensional sheet of hexagonal boron nitride with a gallium-focused ion beam, University of Oregon scientists have created artificial atoms that generate single photons.

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The artificial atoms - which work in air and at room temperature - may be a big step in efforts to develop all-optical quantum computing, said UO physicist Benjamín J. Alemán, principal investigator of a study published in the journal Nano Letters.

“Our work provides a source of single photons that could act as carriers of quantum information or as qubits. We’ve patterned these sources, creating as many as we want, where we want,” said Alemán, a member of the UO’s Material Science Institute and Center for Optical, Molecular, and Quantum Science. “We’d like to pattern these single photon emitters into circuits or networks on a microchip so they can talk to each other, or to other existing qubits, like solid-state spins or superconducting circuit qubits.”

This Is Why Quantum Field Theory Is More Fundamental Than Quantum Mechanics

“But the motivation for quantizing the field is more fundamental than that the argument between those favoring perturbative or non-perturbative approaches. You need a quantum field theory to successfully describe the interactions between not merely particles and particle or particles and fields, but between fields and fields as well. With quantum field theory and further advances in their applications, everything from photon-photon scattering to the strong nuclear force was now explicable.”

What’s wrong with quantum mechanics? It might surprise you to hear that the answer is, “it isn’t quantum enough.” The enormous differences between the quantum and the non-quantum Universe are so striking, as we replace:

* continuous matter with discrete particles, * ideal points with dual-nature wave/particle quanta, * and observable properties like position and momentum with quantum mechanical operators containing an inherent uncertainty. But it’s still not enough. For one, the original (Schroedinger) equation of quantum mechanics doesn’t play nice with relativity, but even the relativistically invariant versions don’t describe reality fully. Why not? Because only the particles are quantized in quantum mechanics. To reveal the full behavior, you need to quantize their fields and interactions, too.

For decades, astronomers searched the cosmos for what is thought to be the first kind of molecule to have formed after the Big Bang. Now, it has finally been found. The molecule is called helium hydride. It’s made of a combination of hydrogen and helium. Astronomers think the molecule appeared more than 13 billion years ago and was the beginning step in the evolution of the universe. Only a few kinds of atoms existed when the universe was very young. Over time, the universe transformed from a primordial soup of simple molecules to the complex place it is today — filled with a seemingly infinite number of planets, stars and galaxies. Using SOFIA, the world’s largest airborne observatory, scientists observed newly formed helium hydride in a planetary nebula 3,000 light-years away. It was the first ever detection of the molecule in the modern universe. Learn more about the discovery:

Helium hydride is created when hydrogen and helium combine. 

Since the 1970s, scientists thought planetary nebula NGC 7027—a giant cloud of gas and dust in the constellation Cygnus—had the right environment for helium hydride to exist. 

But space telescopes could not pick out its chemical signal from a medley of molecules. 

Enter SOFIA, the world’s largest flying observatory! 

By pointing the aircraft’s 106-inch telescope at the planetary nebula and using a tool that works like a radio receiver to tune in to the “frequency” of helium hydride, similar to tuning a radio to a favorite station…

…the molecule’s chemical signal came through loud and clear, bringing a decades-long search to a happy end.

The discovery serves as proof that helium hydride can, in fact, exist in space. This confirms a key part of our basic understanding of the chemistry of the early universe, and how it evolved into today’s complexity. SOFIA is a modified Boeing 747SP aircraft that allows astronomers to study the solar system and beyond in ways that are not possible with ground-based telescopes. Find out more about the mission at www.nasa.gov/SOFIA

I think Voyager 1 would be just past the event horizon, but slightly less than halfway to the bright ring.

How to Understand the Image of a Black Hole | Veritasium

We are about to see the first image of a black hole, the supermassive black hole Sagittarius A* at the center of the Milky Way galaxy. But what is that image really showing us? This is an awesome paper on the topic by J.P. Luminet: Image of a spherical black hole with thin accretion disk Astronomy and Astrophysics, vol. 75, no. 1-2, May 1979, p. 228-235 https://ve42.co/luminet

For more follow | 4 your brain |

2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today we look at helium.

Discovery

Helium was first discovered by French astronomer Jules Janssen in 1868 when observing the spectral lines of the Sun during a solar eclipse. He initially thought the unidentified line was sodium, later concluding it was an element in the sun unknown to Earth.

In March 1895, Sr William Ramsey, a Scottish chemist, isolated helium on Earth for the first time by treating a mineral called cleveite with mineral acids. He was initially looking for argon, but noticed his spectral lines matched that of Jules Janssen’s.

Helium was discovered when Jules Janssen was observing the solar eclipse spectra.

Helium is a colourless, non-toxic and inert gas. It is the second lightest and second most abundant element in the universe.  

Applications

Helium is often used for cryogenic (cooling) purposes. Liquid helium has a temperature of -270°C or 4K, which is only 4°C above absolute zero. It is utilised for cooling super conducting magnets.

Helium is used to cool superconducting magnets used in MRI. Image: Pixabay

Super conducting magnets have applications in imaging such as nuclear magnetic resonance (NMR), used for analysing molecules, and magnetic resonance imaging (MRI), a medical imaging device. These techniques are important for scientific research and medical diagnostics.

Helium can also be used a pressurising gas for welding and growing silicon wafer crystals, or as a lifting gas for balloons and airships.

Helium is also used in airships and balloons. Image: Pixabay

Squeaky voices

A commonly known use of helium is to fill balloons often found at parties and events. When people breathe in the helium gas from these balloons, their voice changes.

As helium is much less dense that nitrogen and oxygen, the two gases that make up regular air, sound travels twice as fast through it. When you speak through helium, the timbre or tone of your voice is affected by this change, causing it to appear higher in pitch.

Why is helium so important? Video: SciShow

Unfortunately, helium is a non-renewable resource, and reserves are running out. There is currently no cheap way to create helium, so industries need to be vigilant when using it, and we may see less helium balloons in the future.