Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: space – Page 258

A novel state of thorium opens the possibility for a nuclear clock

Why are there atomic clocks but no nuclear clocks? After all, an atom’s nucleus is typically surrounded by many electrons, so in principle it should be less susceptible to outside noise (in the form of light). A nucleus, for high-atomic number atoms, contains more particles than does the element’s electrons. It holds nearly the entire mass of the atom while taking up only about 1/100,000th of the atom’s space. While the first atomic clock was invented in 1949, no nuclear clock has yet been feasible.

How Earth’s Magnetic Field Influences Flows in the Planet’s Core

A “Little Earth Experiment” inside a giant magnet sheds light on so-far-unexplained flow patterns in Earth’s interior.

Earth’s inner core is a hot, solid ball—about 20% of Earth’s radius—made of an iron alloy. The planet’s outer core, beneath the rocky mantle, is a colder, liquid metal. Geophysics models explain that, since the movement of a liquid metal induces electrical currents, and currents induce a magnetic field, convection and rotation produce our planet’s magnetic fields. But these models typically neglect an important contribution: how Earth’s magnetic field influences the very flows that generate it. Alban Pothérat of Coventry University, UK, and collaborators have now developed a theory that accounts for such feedback and vetted it using a lab-based “Little Earth Experiment” [1]. Their results inform a model pinpointing processes that might explain the discrepancies between theoretical predictions and satellite observations of Earth, opening new perspectives on the study of geophysical flows.

Understanding flows in planetary interiors is a long-standing challenge. “If you don’t account for the fact that the magnetic field itself changes the flow, then you won’t get the right flow,” says Pothérat. Indeed, both satellite data from the European Space Agency’s Swarm mission and state-of-the-art numerical simulations indicate certain circulating core flows where liquid produced at the boundary of the inner core is fed into the outer core, moves upward toward the poles, and from there finally flows back inward (Fig. 1).

Silent Signals: The Breakthrough Technology Powering Faster Space Data

In space exploration, long-distance optical links now enable the transmission of images, videos, and data from space probes to Earth using light.

However, for these signals to travel the entire distance undisturbed, hypersensitive receivers and noise-free amplifiers are essential. Researchers at Chalmers University of Technology in Sweden have now developed a system featuring a silent amplifier and an ultra-sensitive receiver, opening up possibilities for faster and more reliable space communication.

Space communication systems are increasingly relying on optical laser beams instead of traditional radio waves, as light experiences less signal loss over vast distances. However, even light-based signals weaken as they travel, meaning that optical systems need highly sensitive receivers to detect these faint signals by the time they reach Earth. Researchers at Chalmers have developed an innovative approach to optical space communication that could unlock new opportunities—and discoveries—in space.