Lifeboat Foundation

The basic physics of earthquakes is such that strong ground motion cannot be expected from an earthquake unless the earthquake itself is very close or has grown to be very large. We use simple seismological relationships to calculate the minimum time that must elapse before such ground motion can be expected at a distance from the earthquake, assuming that the earthquake magnitude is not predictable. Earthquake early warning (EEW) systems are in operation or development for many regions around the world, with the goal of providing enough warning of incoming ground shaking to allow people and automated systems to take protective actions to mitigate losses. However, the question of how much warning time is physically possible for specified levels of ground motion has not been addressed. We consider a zero-latency EEW system to determine possible warning times a user could receive in an ideal case. In this case, the only limitation on warning time is the time required for the earthquake to evolve and the time for strong ground motion to arrive at a user’s location. We find that users who wish to be alerted at lower ground motion thresholds will receive more robust warnings with longer average warning times than users who receive warnings for higher ground motion thresholds. EEW systems have the greatest potential benefit for users willing to take action at relatively low ground motion thresholds, whereas users who set relatively high thresholds for taking action are less likely to receive timely and actionable information.

Earthquake early warning (EEW) systems rapidly detect and characterize ongoing earthquakes in real time to provide advance warnings of impending ground motion. They use the information contained in the early parts of the typically low-amplitude ground motion waveforms to estimate the ensuing and potentially large-amplitude ground motion. Because EEW alert information can be transmitted faster than seismic wave propagation speed, such ground motion warnings may arrive at a target site before the strong shaking itself, thereby providing invaluable time for both people and automated systems to take actions to mitigate earthquake-related injury and losses. These actions might range from simple procedures like warning people to get themselves to a safe location to complex automated procedures like halting airport takeoffs and landings.

Gravitational waves have opened up new ways to test the properties of black holes — and Einstein’s theory of gravity along with them.

Theoretically, it should be possible to turn light into matter. In practice, well — “easier said than done” is an understatement.

Now, 84 years after the process was first theorised, some researchers reckon they’re going to be able to do it — and they’re about to start the experiment.

It’s called the Breit-Wheeler process, and it all has to do with E=mc.

Continue reading “Physicists Are About to Attempt The ‘Impossible’ — Turning Light Into Matter” »

You may have thought, “Hey, if we’re threatened by an incoming asteroid, we should just nuke it!” You’re not alone: a team of Russian scientists are working on a plot to do so, by detonating miniature asteroids in a lab.

In fact, several groups of researchers are now toying with the idea of asteroid nuking for the sake of planetary defense. The Russian team has even calculated about how much firepower they’d need to perform such a feat.

According to the translated paper published in the Journal of Experimental and Theoretical Physics: “Given the scale factor and the results of laboratory experiments, the undeniable destruction of a chondritic asteroid 200 m in diameter by a nuclear explosion with an energy above 3 Mt was shown to be possible.”

Continue reading “Russian Scientists Are Devising a Plan to Nuke Asteroids” »

Piezoelectric materials, which generate an electric current when compressed or stretched, are familiar and widely used: think of lighters that spark when you press a switch, but also microphones, sensors, motors and all kinds of other devices. Now a group of physicists has found a material with a similar property, but for magnetism. This “piezomagnetic” material changes its magnetic properties when put under mechanical strain.

“Piezomagnetic materials are rarely found in nature, as far as I’m aware,” said Nicholas Curro, professor of physics at UC Davis and senior author of a paper on the discovery published March 13 in the journal Nature Communications.

Curro and colleagues were studying a barium-iron-arsenic compound, BaFe2As2, that can act as a superconductor at temperatures of about 25 Kelvin when doped with small amounts of other elements. This type of iron-based superconductor is interesting because although it has to be kept pretty cold to work, it could be stretched into wires or cables.

Continue reading “Piezomagnetic material changes magnetic properties when stretched” »

Researchers have produced a “human scale” demonstration of a new phase of matter called quadrupole topological insulators that was recently predicted using theoretical physics. These are the first experimental findings to validate this theory.

The researchers report their findings in the journal Nature.

The team’s work with QTIs was born out of the decade-old understanding of the properties of a class of materials called topological insulators. “TIs are electrical insulators on the inside and conductors along their boundaries, and may hold great potential for helping build low-power, robust computers and devices, all defined at the atomic scale,” said mechanical science and engineering professor and senior investigator Gaurav Bahl.

Fusion technology promises an inexhaustible supply of clean, safe power. If it all sounds too good to be true, that’s because it is. For decades scientists struggled to recreate a working sun in their laboratories – little surprise perhaps as they were attempting to fuse atomic nuclei in a superheated soup. Commercial fusion remains a dream. Yet in recent years the impossible became merely improbable and then, it felt almost overnight, technically feasible. For the last decade there has been a flurry of interest –and not a little incredulity –about claims, often made by companies backed by billionaires and run by bold physicists, that market-ready fusion reactors were just around the corner.

Until recently the attractions and drawbacks of nuclear fusion reactors were largely theoretical. Within a decade this will not be the case.

Mon 12 Mar 2018 14.24 EDT Last modified on Mon 12 Mar 2018 19.15 EDT.

Continue reading “View on Nuclear Fusion: a Moment of Truth” »

Materials that conduct electricity without resistance might mimic black hole physics.

Back in 2015, researchers in Spain created a tiny magnetic wormhole for the first time ever. They used it to connect two regions of space so that a magnetic field could travel ‘invisibly’ between them.

Before you get too excited, it wasn’t the kind of gravitational wormhole that would theoretically allow humans to travel rapidly across space in science fiction TV shows and films such as Stargate, Star Trek, and Interstellar, and it wouldn’t have been able to transport matter.

But the physicists managed to create a tunnel that allowed a magnetic field to disappear at one point, and then reappear at another, which is still a pretty huge deal.

Continue reading “A Magnetic ‘Wormhole’ That Connects Two Regions of Space Was Created in The Lab” »