Physics Buzz

Ultrasound is a powerful tool for looking inside the body. The scans see through layers of tissue to reveal pumping hearts, developing fetuses, troublesome blood clots, and injured muscles. They are relatively low-cost, portable, and have few side effects. Patients aren’t exposed to ionizing radiation or confined in a small space. They are, however, slathered in goo.
Most of the time, having a body part temporarily coated in a cold, sticky substance and then pressed on by a technician is a small price to pay for an accurate diagnosis. But in some situations, like when it’s necessary to image a wound, this contact can be painful. That’s one of the downsides of ultrasound technology. Another is that some results can be influenced by the amount of pressure applied by the technician–it’s a very “hands-on” technique, especially compared to other types of medical imaging.

In new research published in the journal Light: Science & Applications, a team of researchers from the Massachusett…

Daniel Harris prefers Cinnamon Toast Crunch, but he’s spent a lot of time talking about Cheerios lately. And cleaning them up. The cleaning up is thanks to his 1-year-old daughter, but the talking is courtesy of his latest physics research project. Harris is a professor at Brown University who studies fluids and how they interact with solid objects. He doesn’t study breakfast cereal per se, but even cereal follows the laws of physics.

It turns out that one of the same physical interactions that governs the behavior of the last few Cheerios in a bowl of milk also enables water-walking insects to climb onto land and tiny particles to self-assemble into small but functional machines. The better we understand these forces, the better position we’re in to harness them in designs for next-generation robots, medical devices, environmental sensors, and other technological advances.

With this in mind, a team composed of Harris, undergraduate student Ian Ho, and former postdoc Giuseppe Pucci …

The human body can be a little pessimistic, constantly hoarding any excess nutrients just in case things go south. From an evolutionary perspective, this makes sense—when you don’t know where your next meal is coming from, being able to hang onto your resources can make the difference between life and death. Cells on the other hand, have long puzzled researchers with their tendency to throw away essential chemicals without any apparent regard for the future.

“The chemicals in a cell can basically be classified into two groups: metabolites and proteins,” explains Jumpei Yamagishi, a first-year graduate student at the University of Tokyo. As cells take in nutrients, such as sugars, fats, and proteins, they use the comparatively small metabolites, like amino acids, as intermediaries to break down the nutrients and release the energy stored in their chemical bonds. Without metabolites, the cells can quite literally starve to death in a sea of abundance—yet they persist in releasing the es…

“Strike while the iron is hot” is a well-known adage meant to inspire immediate action. Researcher Juan Carlos Nieto-Fuentes is spreading a slightly different message: Strike and the iron is hot.

Nieto-Fuentes is a researcher at the University Carlos III of Madrid in Spain studying what happens to metal objects during high-speed collisions. The more we know about how metal responds to such impacts, the better equipped we are to design vehicles that can protect passengers in a crash, armor that can shield soldiers from enemy strikes, and metal structures that can withstand shocks. One of those responses is generating heat.


In research recently published in the American Physical Society’s journal Physical Review Letters, conducted while Nieto-Fuentes was working at the Israel Institute of Technology (Technion),
Nieto-Fuentes and a team that includes colleagues from Technion and the Nuclear Research Center Negev (NRCN) in Israel made a surprising discovery that could help us better unde…

According to the Guinness Book of World Records, the largest blown free-floating soap bubble currently stands (the record, the bubble has since popped) at 96.27 m3 (that’s a whopping 5.7 m diameter!). To put that in context, a bubble that size could hold an entire Volkswagen Beetle. In terms of the longest bubble, the world record stands at 32 meters, that’s longer than a basketball court! One could even say its..unbeleivabubble.

As large as these bubbles are, they somehow maintain a wall thickness of only a few microns - that’s one one-hundredth the thickness of a sheet of paper. So why can such fragile bubbles grow to such large sizes? A team of physicists at Emory University is working on it.

While at a conference in Madrid, physicist Justin Burton was walking the streets when he came across street performers blowing massive soap bubbles. Upon returning home his sister bought him a bubble wand. Burton wondered, what kind of natural forces yield such large bubbles, and how can they…

When Fan Xu needs a break from his mechanics of soft materials research at Fudan University, he likes to visit the campus’s lotus pool for a calming breath of fresh air. When you’re a physicist, though, sometimes a short break can backfire—in Xu’s case, leading to an 18-month study of thin biological tissue.

It all started when he observed something curious in the growth of the lotus plants. “I noticed that the leaves had different shapes depending on whether they had a water foundation,” he says. “The lotus leaves floating on the water had a flat shape with wrinkles around the margin, while for leaves growing up above the water they have a global deformation, like a cone shape.” While there are a host of factors influencing the growth of a lotus leaf, including genes, Xu wondered what effect the water substrate had on leaf growth and whether he could explain the various shapes from a physics perspective.

“The basic idea is very simple,” he says of their work, recently published in Ph…