Atoms in a gas can seem like partiers at a nanoscopic rave, with particles zipping around, pairing up, and flying off again in a seemingly random fashion. And yet physicists have come up with formulas that predict this behavior, even when the atoms are extremely close together and can tug and pull on each other in complicated ways. The environment within the nucleus of a single atom seems similar, with protons and neutrons also dancing about. But because the nucleus is such a compact space, scientists have struggled to pin down the behavior of these particles, known as nucleons, in an atom’s nucleus. Models that describe the interactions of nucleons that are far apart broken down when the particles pair up and interact at close range. Now an MIT-led team has simulated the behavior of protons and neutrons in several types of atomic nuclei, using some of the most powerful supercomputers in the world. The team explored a wide range of nuclear interaction models and found, surprisingly,
Researchers at Helmholtz Zentrum München and the Technical University of Munich (TUM) have developed the world’s smallest ultrasound detector. It is based on miniaturized photonic circuits on top of a silicon chip. With a size 100 times smaller than an average human hair, the new detector can visualize features that are much smaller than previously possible, leading to what is known as super-resolution imaging. Since the development of medical ultrasound imaging in the 1950s, the core detection technology of ultrasound waves has primarily focused on using piezoelectric detectors, which convert the pressure from ultrasound waves into electric voltage. The imaging resolution achieved with ultrasound depends on the size of the piezoelectric detector employed. Reducing this size leads to higher resolution and can offer smaller, densely packed one or two-dimensional ultrasound arrays with improved ability to discriminate features in the imaged tissue or material. However, further reducing t