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Comment by Dr. Krishna Kumari Challa on March 13, 2021 at 9:16am

Three Ways Quantum Physics Affects Your Daily Life

Quantum physics is all around us. The universe as we know it runs on quantum rules, and while the classical physics that emerges when you apply quantum physics to enormously huge numbers of particles seem very different, there are lots of familiar, everyday phenomena that owe their existence to quantum effects. Here are a few examples of things you probably run into in your everyday life without realizing that they're quantum:

Toasters: The red glow of a heating element as you toast a slice of bread or a bagel is a very familiar sight for most of us. It's also the place where quantum physics got its start: Explaining why hot objects glow that particular color of red is the problem that quantum physics was invented to solve.

"quantum hypothesis" (giving the eventual theory its name) that the light could only be emitted in discrete chunks of energy, integer multiples of a small constant times the frequency of the light. For high-frequency light, this energy quantum is larger than the share of heat energy allotted to that frequency, and thus no light is emitted at that frequency. This cuts off the high-frequency light, and leads to a formula that matches the observed spectrum of light from hot objects to great precision.

So, every time you toast bread, you're looking at the place where quantum physics got its start.

Fluorescent Lights: Old-school incandescent light bulbs make light by getting a piece of wire hot enough to emit a bright white glow, which makes them quantum in the same way that a toaster is. If you have fluorescent bulbs around-- either the long tubes or the newer twisty CFL bulbs, you're getting light from another revolutionary quantum process.

Computers: While Bohr's quantum model was undeniably useful, it didn't initially come with a physical reason as to why there should be special states for electrons within atoms. That didn't come for almost ten years, but once the idea got locked it, it turned out to be the basis for the most transformative technological revolution of the last century.

So, every time you turn on your computer (say, to read a blog post about quantum physics), you're exploiting the wave nature of electrons, and the unprecedented control of materials that allows. It may not be the sexy kind of quantum computer, but every modern computer needs quantum physics to work properly.

https://www.forbes.com/sites/chadorzel/2018/12/04/three-ways-quantu...

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Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 12:18pm

Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 11:41am

I ain't afraid of no ghosts: people with mind-blindness not so easily spooked

People with aphantasia – that is, the inability to visualise mental images – are harder to spook with scary stories, a new UNSW Sydney study shows.

The study, published today in Proceedings of the Royal Society B, tested how aphantasic people reacted to reading distressing scenarios, like being chased by a shark, falling off a cliff, or being in a plane that’s about to crash.

The researchers were able to physically measure each participant’s fear response by monitoring changing skin conductivity levels – in other words, how much the story made a person sweat. This type of test is commonly used in psychology research to measure the body’s physical expression of emotion.

According to the findings, scary stories lost their fear factor when the readers couldn’t visually imagine the scene – suggesting imagery may have a closer link to emotions than scientists previously thought.

Researchers found the strongest evidence yet that mental imagery plays a key role in linking thoughts and emotions.

Aphantasia affects 2-5 per cent of the population, but there is still very little known about the condition.

A UNSW study published last year found that aphantasia is linked to a widespread pattern of changes to other cognitive processes, like remembering, dreaming and imagining.

https://royalsocietypublishing.org/doi/10.1098/rspb.2021.0267

https://researchnews.cc/news/5578/I-ain-t-afraid-of-no-ghosts--peop...

Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 11:37am

Sonolithography: In‐Air Ultrasonic Particulate and Droplet Patterning

Sonolithography is based on the application of acoustic radiation forces arising from the interference of ultrasonic standing waves to direct airborne particle/droplet accumulation. Sonolithography is capable of rapidly patterning micrometer to millimeter scale materials onto a wide variety of substrates over a macroscale (cm2) surface area and can be used for both indirect and direct cell patterning.

Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 11:31am

Membrane around tumors may be key to preventing metastasis

For cancer cells to metastasize, they must first break free of a tumor’s own defenses. Most tumors are sheathed in a protective “basement” membrane — a thin, pliable film that holds cancer cells in place as they grow and divide. Before spreading to other parts of the body, the cells must breach the basement membrane, a material that itself has been tricky for scientists to characterize. Now MIT engineers have probed the basement membrane of breast cancer tumors and found that the seemingly delicate coating is as tough as plastic wrap, yet surprisingly elastic like a party balloon, able to inflate to twice its original size. But while a balloon becomes much easier to blow up after some initial effort, the team found that a basement membrane becomes stiffer as it expands. This stiff yet elastic quality may help basement membranes control how tumors grow. 

The fact that the membranes appear to stiffen as they expand suggests that they may restrain a tumor’s growth and potential to spread, or metastasize, at least to a certain extent.

The findings, published this week in the Proceedings of the National Academy of Sciences, may open a new route toward preventing tumor metastasis, which is the most common cause of cancer-related deaths.

Now scientists can think of ways to add new materials or drugs to further enhance this stiffening effect, and increase the toughness of the membrane to prevent cancer cells from breaking through

https://news.mit.edu/2021/membrane-tumors-metastasis-0308

Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 11:25am

Antarctic detector spots cosmic antineutrino

A huge neutrino detector in the Antarctic ice sheet might have seen the first evidence of a rare neutrino-interaction process called the Glashow resonance.

The IceCube Neutrino Observatory, buried in the deep ice near the Amundsen–Scott South Pole Station, observes eye-wateringly powerful neutrinos produced by sources such as active galactic nuclei and supernovae. The observatory detected a shower of secondary particles that look likely to have been caused by a collision between an electron antineutrino travelling close to th.... If confirmed by more observations, the finding provides further confirmation of the standard model of particle physics, proves the existence of cosmic antineutrinos and opens the door to a better understanding of the wild stuff going on in the cosmos.

https://www.nature.com/articles/d41586-021-00486-1?utm_source=Natur...

Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 11:15am

Physicists measure smallest gravitational field yet

Physicists in Austria have measured the gravitational field from the smallest ever object: a gold sphere with a diameter of just 2 mm. Carried out using a miniature torsion balance, the measurement paves the way to even more sensitive gravitational probes that could reveal gravity’s quantum nature.

The latest work, in contrast, uses a gold sphere with a mass of just 92 mg as its source. Markus Aspelmeyer and Tobias Westphal of the Institute for Quantum Optics and Quantum Information in Vienna and colleagues positioned this mass a few millimetres away from another tiny gold sphere with about the same mass located at one end of a 4 cm-long glass rod. The rod was suspended at its centre via a silica fibre, while a third sphere at the far end of the rod acted as a counterbalance.

Such “torsion balances” have been used for more than 200 years to make precise measurements of gravity. The idea is that the source mass pulls the near end of the bar towards itself, causing the suspending fibre or wire to rotate. By measuring this rotation and balancing it against the stiffness of the wire, the strength of the gravitational interaction can be calculated. The fact that the bar moves horizontally means it is less exposed to the far larger gravitational field of the Earth.

A major challenge with such experiments is screening out noise. Aspelmeyer and colleagues did this by placing the balance in a vacuum to limit acoustic and thermal interference, while also grounding the source mass and placing a Faraday shield between it and the test mass to reduce electromagnetic interactions. In addition, they mainly collected data at night to minimize ambient sources of gravity. This is important because the gravitational attraction of the source mass is equivalent to the pull of a person standing 2.5 m from the experiment or a Vienna tram 50 m away.

To generate signals above the remaining noise, the researchers used a bending piezoelectric device to cyclically move the source towards and away from the test mass. Doing this at a fixed frequency (12.7 mHz) allowed them to look for a corresponding variation in the rotation of the balance – which they measured by bouncing a laser beam off a mirror below the silica fibre.

After repeating this process hundreds of times over a 13.5-hour period and then converting the time-series data into a frequency spectrum, Aspelmeyer and colleagues identified two clear signals above the background. These were the principle oscillation at 12.7 mHz and, at 25.4 mHz, the second harmonic generated by the gravitational field’s nonlinear variation in space. As the researchers point out, both harmonics were well above the resonant frequency of the oscillating balance and below the frequencies of readout noise.

https://www.nature.com/articles/s41586-021-03250-7.epdf?sharing_tok...

https://physicsworld.com/a/physicists-measure-smallest-gravitationa...

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Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 11:04am

Part 2 - extreme hot planets

In our study, we used publicly available data, taken by the Hubble Space Telescope, to obtain the eclipse spectrum of this planet.

We then used open-source software to extract the presence of molecules and found there were plenty of metals (made from molecules). This discovery is interesting as it was previously thought that these molecules would not be present at such extreme temperatures – they would be broken apart into smaller compounds.

Subject to the strong gravitational pull from its host star, Kelt-9 b is “tidally locked”, which means that the same face of the planet permanently faces the star. This results in a strong temperature difference between the planet’s day and night sides. As the eclipse observations probe the hotter day-side, we suggested that the observed molecules could in fact be dragged by dynamic processes from the cooler regions, such as the night-side or from deeper in the interior of the planet. These observations suggest that the atmospheres of these extreme worlds are ruled by complex processes that are poorly understood.

Kelt-9 b is interesting because of its inclined orbit of about 80 degrees. This suggests a violent past, with possible collisions, which in fact is also seen for many other planets of this class. It is most likely that this planet formed away from its parent star and that the collisions happened as it migrated inwards toward the star. This supports the theory that large planets tend to form away from their host star in proto-stellar disks – which give rise to solar systems – capturing gaseous and solid materials as they migrate toward their star.

https://theconversation.com/how-can-some-planets-be-hotter-than-sta...

Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 11:03am

How can some planets be hotter than stars? We’ve started to unravel the mystery

Data from the Kepler mission has shown that large, gaseous exoplanets can orbit very close to their star – rather than far away from it, as is the case in our Solar System, causing them to reach temperatures exceeding 1,000K (727°C). These have been dubbed “hot” or “ultra-hot” Jupiters.

But how can hot, gaseous planets form and exist so close to their star? What kind of extreme physical processes happen here? Answers to those questions have large implications in our understanding of exoplanets and solar system planets. In our recent study, published in The Astrophysical Journal Letters, we have added another piece to the puzzle of planet formation and evolution.

The hottest exoplanet known so far is Kelt-9 b, which was discovered in 2016. Kelt-9 b orbits a star that is twice as hot as our Sun, at a distance ten times closer than Mercury orbits our star. It is a large gaseous exoplanet, with a radius 1.8 times that of Jupiter and temperatures reaching 5,000K. For comparison, this is hotter than 80% of all the stars in the universe and a similar temperature to our Sun.

In essence, hot Jupiters are a window into extreme physical and chemical processes. They offer an incredible opportunity to study physics in environmental conditions that are near impossible to reproduce on Earth. Studying them enhances our understanding of chemical and thermal processes, atmospheric dynamics and cloud formation. Understanding their origins can also help us improve planetary formation and evolution models.

To find out, we need to learn more about exoplanet compositions by observing their atmospheres.

There are two main methods to study exoplanet atmospheres. In the transit method, we can pick up stellar light that is filtered through the exoplanet’s atmosphere when it passes in front of its star, revealing the fingerprints of any chemical elements that exist there.

The other method to investigate a planet is during an “eclipse”, when it passes behind its host star. Planets also emit and reflect a small fraction of light, so by comparing the small changes in the total light when the planet is hidden and visible, we can extract the light coming from the planet.

Both types of observations are performed at different wavelengths, or colours, and since chemical elements and compounds absorb and emit at very specific wavelengths, a spectrum (light broken down by wavelength) can be produced for the planet to infer the composition of its atmosphere.

Comment by Dr. Krishna Kumari Challa on March 12, 2021 at 10:58am

Using softened wood to create electricity in homes

A multi-institutional team of researchers has found that it is possible to use a type of fungus to soften wood to the point that it could be used to generate electricity. In their paper published in the journal Science Advances, the group describes their process and how they tested it.

As the world works its way toward cleaner energy-producing systems, scientists seek novel approaches to producing electricity. One possibility is the use of piezoelectric devices that generate electricity by harnessing movement such as footsteps. In this new effort, the researchers have noted that much energy is wasted when people walk around. And while some have attempted to harness some of that energy with devices designed for shoes or legs, the researchers with this new effort wondered if it might be possible to add piezoelectrics to the floor to make use of that energy.

In studying the kinds of wood that are used to make floors, particularly in homes, the researchers noted that they do not have much give—a necessary component of an energy-harvesting system. To solve that problem, they found that applying a type of white rot fungus to pieces of balsa wood for a few weeks sped up the decaying process in a useful way. It made the wood spongier, which translated to give. When stepping on the wood, the researchers could feel it depress. They also found that after the wood returned to its former shape when pressure was removed.

To test their idea, the researchers treated a wooden veneer with the fungus and then added a piezoelectric device, which sent the power it produced through a wire attached to an LED light. The wood was then placed on a floor where people could walk on it. Each time they did so, the light came on. The researchers note that the amount of electricity generated was just 0.85 volts but the system could very easily be scaled up to include all the flooring in a home, generating enough electricity, perhaps, to power certain devices.

Jianguo Sun et al. Enhanced mechanical energy conversion with selectively decayed wood, Science Advances (2021). DOI: 10.1126/sciadv.abd9138

https://techxplore.com/news/2021-03-softened-wood-electricity-homes...

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