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Comment by Dr. Krishna Kumari Challa on August 13, 2021 at 7:10am

Newtonian physics for babies

Comment by Dr. Krishna Kumari Challa on August 13, 2021 at 6:34am

Combining classical and quantum systems to meet supercomputing demands

Quantum entanglement is one of the most fundamental and intriguing phenomena in nature. Recent research on entanglement has proven to be a valuable resource for quantum communication and information processing. Now, scientists from Japan have discovered a stable quantum entangled state of two protons on a silicon surface, opening doors to an organic union of classical and quantum computing platforms and potentially strengthening the future of quantum technology.

One of the most interesting phenomena in quantum mechanics is "quantum entanglement." This phenomenon describes how certain particles are inextricably linked, such that their states can only be described with reference to each other. This particle interaction also forms the basis of quantum computing. And this is why, in recent years, physicists have looked for techniques to generate entanglement. However, these techniques confront a number of engineering hurdles, including limitations in creating large number of "qubits" (quantum bits, the basic unit of quantum information), the need to maintain extremely low temperatures (<1 K), and the use of ultrapure materials. Surfaces or interfaces are crucial in the formation of quantum entanglement. Unfortunately, electrons confined to surfaces are prone to "decoherence," a condition in which there is no defined phase relationship between the two distinct states. Thus, to obtain stable, coherent qubits, the spin states of surface atoms (or equivalently, protons) must be determined.

Recently, a team of scientists  recognized the need for stable qubits. By looking at the surface spin states, the scientists discovered an entangled pair of protons on the surface of a silicon nanocrystal.

Proton entanglement has been previously observed in molecular hydrogen and plays an important role in a variety of scientific disciplines. However, the entangled state was found in gas or liquid phases only. Now, researchers have detected quantum entanglement on a solid surface, which can lay the groundwork for future quantum technologies.

The scientists studied the spin states using a technique known as "inelastic neutron scattering spectroscopy" to determine the nature of surface vibrations. By modeling these surface atoms as "harmonic oscillators," they showed anti-symmetry of protons. Since the protons were identical (or indistinguishable), the oscillator model restricted their possible spin states, resulting in strong entanglement. Compared to the proton entanglement in molecular hydrogen, the entanglement harbored a massive energy difference between its states, ensuring its longevity and stability. Additionally, the scientists theoretically demonstrated a cascade transition of terahertz entangled photon pairs using the proton entanglement.

Takahiro Matsumoto et al, Quantum proton entanglement on a nanocrystalline silicon surface, Physical Review B (2021). DOI: 10.1103/PhysRevB.103.245401

https://phys.org/news/2021-08-worlds-combining-classical-quantum-su...

Comment by Dr. Krishna Kumari Challa on August 13, 2021 at 6:21am

Dendrimers: The tiny tentacles shown to evade our immune response

Tiny synthetic particles known as dendrimers avoid detection by our immune system and could help develop a new way to deliver drugs into the body without triggering a reaction.

The dendrimer is a chemically-created molecule with tentacles branching out in a highly-symmetrical structure around a central core. The research describes how dendrimer tentacles arranged incredibly closely to each other—less than one nanometer apart—avoided detection by the complement system, part of our immune system.

Our immune system is equipped with many tools to recognize and eliminate invaders. For example, our blood contains sensors belonging to a family of defense system known as the "complement system," which recognizes unique patterns expressed by invaders such as bacteria and viruses. Binding of these sensors to pathogens alarms the immune system and triggers an immune response. These sensors are termed "complement pattern-recognition (CPR)" molecules.

CPR can sense surface patterns that are regularly repeated so close to each other, for instance in 2–15 nanometer ranges—a distance, which is at least 5000 times thinner than the thickness of a typical sheet of paper.

The international team discovered however, that the CPR could not sense patterns repeated closer to each other, for instance, at 1 nanometer or less.

At a nanoscale level, the team grew tiny particles known as dendrimers which are shaped like trees with many branches—or tiny tentacles. The number of tentacles exponentially increases with dendrimer size and the tentacles are positioned less than 1 nanometer from each other. The ends of tentacles are where regular patterns appear. Depending on chemical structure of these patterns, they found that these dendrimers could escape detection by the CPR radar.

Dendrimers offer us the ability to deliver drugs to diseased sites where inflammation is a major problem such as in conditions like atherosclerosis, cancer, macular degeneration  and rheumatoid arthritis.

Lin-Ping Wu et al, Dendrimer end-terminal motif-dependent evasion of human complement and complement activation through IgM hitchhiking, Nature Communications (2021). DOI: 10.1038/s41467-021-24960-6

https://phys.org/news/2021-08-dendrimers-tiny-tentacles-shown-evade...

Comment by Dr. Krishna Kumari Challa on August 12, 2021 at 1:05pm

Can you Stand On Liquid Mercury?

Comment by Dr. Krishna Kumari Challa on August 12, 2021 at 11:46am

At the ions' relativistic speeds, the virtual particles can behave like real photons. Thankfully, there's a way physicists can tell which electron-positron pairs are generated by the Breit-Wheeler process: the angles between the electron and the positron in the pair generated by the collision.

Each type of collision - virtual-virtual, virtual-real and real-real - can be identified based on the angle between the two particles produced. So the researchers detected and analyzed the angles of over 6,000 electron-positron pairs generated during their experiment.

They found that the angles were consistent with collisions between real photons - the Breit-Wheeler process in action.

"We also measured all the energy, mass distributions, and quantum numbers of the systems. They are consistent with theory calculations for what would happen with real photons.

"Our results provide clear evidence of direct, one-step creation of matter-antimatter pairs from collisions of light as originally predicted by Breit and Wheeler."

The argument could be very reasonably made that we won't have a direct first detection of the pure, single photon-photon Breit-Wheeler process until we collide photons approaching the energy of gamma rays.

Nevertheless, the team's work is highly compelling stuff - at the very least, it shows that we are barking up the right tree with Breit and Wheeler.

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.127.052302

Part 3

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Comment by Dr. Krishna Kumari Challa on August 12, 2021 at 11:45am

At the RHIC, ions are accelerated to relativistic speeds - those that are a significant percentage of the speed of light. In this experiment, the gold ions were accelerated to 99.995 percent of light speed.

This is where the magic happens: When two ions just miss each other, their two clouds of photons can interact, and collide. The collisions themselves can't be detected, but the electron-positron pairs that result can.

However, it's not enough to just detect an electron-positron pair, either.

That's because the photons produced by the electromagnetic interaction are virtual photons, popping briefly in and out of existence, and without the same mass as their 'real' counterparts.

To be a true Breit-Wheeler process, two real photons need to collide - not two virtual photons, nor a virtual and a real photon.

part 2

Comment by Dr. Krishna Kumari Challa on August 12, 2021 at 11:45am

Physicists Detect Strongest Evidence Yet of Matter Generated by Collisions of Light

According to theory, if you smash two photons together hard enough, you can generate matter: an electron-positron pair, the conversion of light to mass as per Einstein's theory of special relativity.

It's called the Breit-Wheeler process, first laid out by Gregory Breit and John A. Wheeler in 1934, and we have very good reason to believe it would work.

But direct observation of the pure phenomenon involving just two photons has remained elusive, mainly because the photons need to be extremely energetic (i.e. gamma rays) and we don't have the technology yet to build a gamma-ray laser.

Now, physicists at Brookhaven National Laboratory say they've found a way around this stumbling block using the facility's Relativistic Heavy Ion Collider (RHIC) - resulting in a direct observation of the Breit-Wheeler process in action.

But what do accelerated ions have to do with photon collisions? Well, we can explain.

The process involves, as the collider's name suggests, accelerating ions - atomic nuclei stripped of their electrons. Because electrons have a negative charge and protons (within the nucleus) have a positive one, stripping it leaves the nucleus with a positive charge. The heavier the element, the more protons it has, and the stronger the positive charge of the resulting ion.

The team used gold ions, which contain 79 protons, and a powerful charge. When gold ions are accelerated to very high speeds, they generate a circular magnetic field that can be as powerful as the perpendicular electric field in the collider. Where they intersect, these equal fields can produce electromagnetic particles, or photons.

"So, when the ions are moving close to the speed of light, there are a bunch of photons surrounding the gold nucleus, traveling with it like a cloud.

part 1

Comment by Dr. Krishna Kumari Challa on August 12, 2021 at 11:38am

The 'Second Brain' in Your Gut Might Have Evolved Before The Brain in Your Head
The enteric nervous system (ENS) in our gut operates a lot like other neural networks in the brain and the spinal cord – so much so that it's often called the 'second brain'. Now a new study has revealed more about how exactly the ENS works.
Using a recently developed technique combining high-resolution video recordings with an analysis of biological electrical activity, scientists were able to study the colons of mice, and in particular the way that the gut moves its contents along.

One of the key findings was discovering how the thousands of neurons inside the ENS communicate with each other, causing contractions in the gastrointestinal tract to aid the digestive process. Up until now, it wasn't clear how these neurons were able to join forces to do this.

"Interestingly, the same neural circuit was activated during both propulsive and non-propulsive contractions.

The team found large bunches of connecting neurons firing to propel the contents of the colon further down the gut, via both excitatory (causing action) and inhibitory (blocking action) motor neurons.

The discovery means the ENS is made up of a more advanced network of circuitry, covering a wider section of the gut and involving a greater amount of different types of neurons working in tandem than had previously been thought.

Another important finding is that this activity is significantly different from the propulsion that's seen in other muscle organs around the body that don't have a built-in nervous system, such as lymphatic vessels, ureters, or the portal vein.

"The mechanism identified is more complex than expected and vastly different from fluid propulsion along other hollow smooth muscle organs," the researchers explain in their paper.

The team says it backs up the hypothesis that the ENS is in fact the 'first brain' rather than the second one – suggesting that it may have evolved in animals a long time before our actual brains took their current form.

https://www.nature.com/articles/s42003-021-02485-4

https://www.sciencealert.com/we-have-a-brain-like-system-in-our-gut...

Comment by Dr. Krishna Kumari Challa on August 12, 2021 at 10:30am

A glucose-COVID-19 hypothesis

In normal conditions, the lungs have the necessary immune defense to contain SARS-CoV-2 and avoid spread of the infection. If elevated, glucose impairs this primary defense system making ideal conditions for the SARS-CoV-2 to invade the pulmonary cells and spread into the rest of the body.

Comment by Dr. Krishna Kumari Challa on August 12, 2021 at 10:23am

Lichens may one day detoxify the air in your home

When smoke from fires darken the skies as they did last summer, hunkering down indoors makes good sense. But on most days throughout the year, the air we breathe indoors carries far more pollutants than outdoor air. Exposure is highest in crowded homes where space is a luxury, leading the EPA to rank indoor air quality as one of the top five public health concerns.

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Skull birth defect detailed in cell-by-cell description

Contrary to the popular song, the neck bone is actually connected to one of 22 separate head bones that make up the human skull. These plate-like bones intersect at specialized joints called sutures, which normally allow the skull to expand as the brain grows, but are absent in children with a birth defect called craniosynostosis. A new study in Nature Communications presents a detailed cellular atlas of the developing coronal suture, the one most commonly fused as a consequence of single gene mutations. 

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Humans will always have oxygen to breathe, but we can't say the sam...

There is nothing more fundamental to humans than the availability of oxygen. We give little thought to the oxygen we need, we just breathe, but where does it come from?

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Study says 'blue hydrogen' likely bad for climate

Use of "clean" hydrogen has been seen as a viable and environmentally benign energy alternative, but a study released Thursday said it could lead to higher greenhouse gas emissions than coal.

Touted as clean, 'blue' hydrogen may be worse than gas, coal

"Blue" hydrogen—an energy source that involves a process for making hydrogen by using methane in natural gas—is being lauded as a clean, green energy to help reduce global warming. But Cornell and Stanford University researchers believe it may harm the climate more than burning fossil fuel.

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Is your mobile provider tracking your location? This new technology...

Right now, there is a good chance your phone is tracking your location—even with GPS services turned off. That's because, to receive service, our phones reveal personal identifiers to cell towers owned by major network operators. This has led to vast and largely unregulated data-harvesting industries based around selling users' location data to third parties without consent.

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