Physics Buzz

One night in late April, my husband happened to look out the window and noticed, passing over our valley in southwest Montana, a string of around 30 mysterious lights—too fast to be aircraft and apparently too numerous to be satellites.

The next day, a string of emails lit up a local listserv. People who’d observed the lights were wondering what they’d seen, and readers who knew what they’d seen were quick to respond: This was Starlink, a network of satellites intended to deliver high-speed broadband Internet to areas of the globe where such connectivity is currently costly, unreliable, or inaccessible. Deployed by SpaceX, the aerospace company founded by busy tech entrepreneur and would-be Martian Elon Musk, the network will ultimately consist of thousands of satellites and, according to its website, is projected to provide worldwide coverage by 2021.

The company got closer to that goal last week. On June 3, just four days after NASA astronauts Bob Behnken and Doug Hurley traveled t…

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…