Everyone has heard the sound of the crack of a whip, at least in movies or TV serials like “El Zorro: The man with the whip” (1954). A shock wave is created by the supersonic motion of the tip of the whip in the air . Whipping is a typical fluid instability of an accelerating […]
Science news with bad titles usually attract a lot of attention. A recent example is “The sound of an atom has been captured” ]. Laypeople must know that atoms do not emit sound. Quantum acoustics study the propagation and the interaction of phonons, the analogues in sound to photons in light. An atom cannot emit […]
The most widely used metaphors for nuclear fusion reactors are the recreation of the Sun on Earth and the controlled explosion of a hydrogen bomb. In both cases, the first thing that comes to mind is the need for high-performance radiation-resistant materials to contain the fusion reaction. The selection and design of new materials that […]
Biomedicine • Materials • Neurobiology • Physics • Physiology
Human brain has about 85 billion neurons. Each neuron forms thousands of chemical and electrical synapses with other neurons. To record the synaptic activity of each neuron in the brain an intracellular probe with a millivolt scale is required. Glass electrodes are widely used, but they are fragile and they have high impedance. An intracellular […]
Entanglement is a fundamental tool in quantum computing and several quantum information protocols, such as quantum teleportation, quantum cryptography and quantum key distribution. The basic unit of entanglement is the entangled bit ( ebit ), represented by a maximally entangled state of two qubits (quantum bits). Entanglement can also be implemented in a higher dimensional […]
Without any conflict with the second law of thermodynamics, heat can flow from a cooler but constantly heated body to another thermally connected and constantly hotter body. This anomalous heat transfer has been demonstrated in a two-phase liquid-vapor system composed of a Rayleigh–Bénard convection (RBC) cell filled one-half with normal liquid helium and one-half with […]
Pele is the Hawaiian goddess of volcanoes. Pele’s hairs are thin strands of molten basaltic glass drawn out from lava, thrown into the air from lava fountains, lava cascades or vigorous lava flows, and spun out by the wind. Each hair-like strand has a diameter less than 0.5 millimeters and is as long as 2 […]
Newton’s theory of gravitation assumes that the speed of gravity is infinite and the gravitational interaction is instantaneous. However, Einstein’s theory postulates that it is exactly equal to the speed of light. A team of Chinese physicists lead by Tang Ke Yun, at the Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China […]
Where is the half of the ordinary matter in the universe not observed yet? Computer simulations of cosmological galaxy formation predict the existence of large intercluster filaments of hot and low-density gas, the so-called cosmic web. For the first time, ESA’s Planck satellite has observed one of such filaments in the merging cluster pair A399-A401 […]