Physics Buzz

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. The J-KAREN-P (Japan-Kansai Advanced Relativistic ENgineering Petawatt) laser at KPSI. Credit: QST. “[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 spac

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. Figure 1. Astronaut David Scott experiences weightlessness in a C-135 aircraft. Image credit: NASA 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 res

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 fa

UUltrasound 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 Massachus

If you’re on the receiving end of a snapping shrimp’s attack, prepare to be stunned. Also known as pistol shrimp, these little crustaceans shoot lethal rounds at predators and prey at highway speeds—a direct hit can be outright fatal or shock the recipient into submission. It’s not just the force of the attack that’s stunning though, it’s the sound. Snapping shrimp are among the noisiest creatures in the ocean. Left: Researcher Ashlee Lillis holds a microphone to tank of snapping shrimp. Right: A snapping shrimp, note the large snapping claw. Credit: Woods Hole Oceanographic Institution. “They are hardly ever seen, and very cryptic in their habitat, but their sounds are ubiquitous,” says to Ashlee Lillis, a scientist leading the coral conservation activities in the US Virgin Islands for The Nature Conversancy. As a PhD student Lillis studied the soundtrack of the ocean and its impact on marine larvae. “I was fascinated by the most common biological sound in all of the recordings