Physics Buzz

Imagine a world where everyone is right-handed. The world may not look different, but eventually, the question might arise: Why is no one left-handed? In the world of the molecules that make up the bodies of living things like DNA and RNA, this is a real question—and astrophysics researchers think they might have an answer.

Molecules that have two different structures that are mirror images but can’t be superimposed possess chirality—or handedness. Our hands are good visual representations of chirality: When you stack your hands, back of hand to palm, it’s apparent that, while being mirror images, they can’t be superimposed as your thumbs jut out to the sides. While molecules have the option of being left- or right-handed, biomolecules such as amino acids, RNA, and DNA only occur in one form in nature. DNA, for example, is only ever a right-handed helix, sugar molecules are also right-handed, while amino acids are the lefties of the biomolecular world.

These preferences each biomolec…

The essence of the perfect slice of sourdough bread is in the air right now. It is even on your hands. The heart of the sourdough is the starter, a fermented culture of flour and water. The sour flavor of the dough comes from lactic acid bacteria (LAB) who live in relative harmony and competition with yeasts. The starter (also called “levain” or “mother”) is the source of all of the good qualities of sourdough bread: the tang, the spongy texture, and the nutritional properties.

Although yeasts are commonly associated with baking and other fermentations, the forgotten heroes are the LAB who generally outnumber yeasts by 100:1 in the starter1. The initial mixture of flour and water makes an excellent home for LAB with an initial pH of 5.0-6.2 - which is more acidic than water - and rich in carbohydrates for the bacteria to consume. In these favorable conditions, lactobacillus species, such as L. sanfanciscensis, flourish and outcompete other types of bacterias. Lactobacillus are used i…

Combatting the COVID-19 pandemic has become an international challenge and charge. It has highlighted the positive consequences of science operating on a global scale. It has shown how answers can be found quickly when scientists share results at unprecedented speed and research becomes increasingly open-access. It has shown that we must rely on scientists from a wide array of expertise to understand — and eventually control — this virus. We need epidemiologists, virologists, biologists, engineers, data scientists, and statisticians. We also need physicists in the mix.

Here at Physics Buzz, we’ve previously explored how artificial intelligence has helped us fight pandemics. But I also wanted to know: how has physics research aided in the fight to combat this pandemic? How does physics research overlap with other sciences — including epidemiology, medicine, virology, among others — to uncover new knowledge about COVID-19? What is the role of physics in our pandemic response?

A quick se…

What happens when you focus one of the world’s most powerful lasers on a spot so tiny it can be hidden by a human hair?

Using the J-KAREN-P laser at the Kansai Photon Science Institute (KPSI) in Japan, a team led by researchers from the National Institutes for Quantum and Radiological Science and Technology (QST) in Japan investigated this extreme situation. As they report in the American Physical Society’s journal Physical Review Letters, the experimental results reveal a fundamental limit that’s key to optimizing the next generation of ultra-high-intensity lasers.

“[S]tate-of-the-art high-power laser facilities can produce extreme conditions like no other on earth,” explains Nicholas Dover, a postdoctoral researcher at QST and lead author of the new research paper. “To be precise, there is no other method we know of to concentrate as much energy into such a small space and time.”

This extra-concentrated energy can potentially be used for a wide assortment of technological, medi…

We’ve all wished for weightlessness at some point in our lives—that fantastical quality that powers the magic of flying broomsticks and fuels our fascination with space travel. Although we’re a long way from floating down the street, physicists have developed ways to mitigate the effect of gravity, from carefully aligning sound waves to mimicking free fall in reduced-gravity aircraft. But Kosuke Shibata and his colleagues at the Gakushuin University say they’ve developed a new tool for levitation: beams of light.

It might sound rather Star Trek-esque, but the physics is real. Light can be described mathematically as a wave of electric and magnetic fields moving through space, and when a strong light source like a laser shines on an atom, the changing electric field interacts with the electric charges contained within the atom’s protons and neutrons. If done just right, the resulting force can precisely cancel out that of gravity, allowing the atoms to levitate.

While a similar techniq…

The electromagnetic spectrum, an assortment of energy wiggling throughout space and time, is overwhelmingly underappreciated in our lives. There is no combination of existence that could happen without it. To celebrate the role that light plays in our lives, our ecosystem, and the operation of the universe, UNESCO declared March 16th as the International Day of Light, a day to celebrate “ vital role of light and light-based technologies in science, culture and art, education and sustainable development”. Across the world, citizens are planning events to celebrate light in all of its forms.

Everywhere around us are waves, whether we can see them or not. Out of all the waves traveling through space, we can only see a fraction. On earth, we’re only seeing ~44% of the radiation coming from the sun! Even so, scientists estimate that we can differentiate up to 10 million colors in the visible spectrum.

Everything we can see in this universe is detected through waves, with wavelengths far s…