Lifeboat Foundation

Lately, there has been a flood of interest in gravitational waves. After the first official detection at LIGO / Virgo in 2015, data has been coming in showing how common these once theoretical phenomena actually are. Usually they are caused by unimaginably violent events, such as a merging pair of black holes. Such events also have a tendency to emit another type of phenomena—light. So far, it has been difficult to observe any optical associated with these gravitational-wave emitting events. But a team of researchers hope to change that with the full implementation of the Gravitation-wave Optical Transient Observer (GOTO) telescope.

The GOTO project is designed specifically to find and monitor the parts of the sky that other instruments, such as LIGO, detect gravitational waves from. Its original incarnation, known as the GOTO-4 Prototype, was brought online in 2017. Located in La Palma, in the Canary Islands, this prototype consisted of four “unit telescopes” (UTs) housed in an 18ft clamshell dome. In 2020, this prototype was upgraded to 8 UTs, allowing for a much wider view of the sky.

The wide field of view is necessary for its work detecting gravitational-wave based optical phenomena, as directionality of gravitational waves are notoriously difficult to pin down. The wider the field of view of a telescope, the more likely it will be able to detect an event that happens.

While analyzing artifacts from the SolarWinds Orion supply-chain attack, security researchers discovered another backdoor that is likely from a second threat actor.

Named SUPERNOVA, the malware is a webshell planted in the code of the Orion network and applications monitoring platform and enabled adversaries to run arbitrary code on machines running the trojanized version of the software.

The new atomic clock design, which uses entangled atoms, could help scientists detect dark matter and study gravity’s effect on time.

Atomic clocks are the most precise timekeepers in the world. These exquisite instruments use lasers to measure the vibrations of atoms, which oscillate at a constant frequency, like many microscopic pendulums swinging in sync. The best atomic clocks in the world keep time with such precision that, if they had been running since the beginning of the universe, they would only be off by about half a second today.

Still, they could be even more precise. If atomic clocks could more accurately measure atomic vibrations, they would be sensitive enough to detect phenomena such as dark matter and gravitational waves. With better atomic clocks, scientists could also start to answer some mind-bending questions, such as what effect gravity might have on the passage of time and whether time itself changes as the universe ages.

A monster lurks at the heart of many galaxies – even our own Milky Way. This monster possesses the mass of millions or billions of Suns. Immense gravity shrouds it within a dark cocoon of space and time – a supermassive black hole. But while hidden in darkness and difficult to observe, black holes can also shine brighter than an entire galaxy. When feeding, these sleeping monsters awaken transforming into a quasar – one of the Universe’s most luminous objects. The energy a quasar radiates into space is so powerful, it can interfere with star formation for thousands of light years across their host galaxies. But one galaxy appears to be winning a struggle against its awoken blazing monster and in a recent paper published in the Astrophysical Journal, astronomers are trying to determine how this galaxy survives.

A hypothetical particle known as the ultralight boson could be responsible for our universe’s dark matter.

Things are about to get… hairy.

Wait, are black holes fuzzballs, or are they hairless? The big quest to understand black holes continues in the form of new research about the fastest-spinning examples. Scientists have found that while most black holes follow a particular theorem about what falls inside, a black hole spinning fast enough can extend “hairs” all the way back into regular space.

The history of the Universe thus far has certainly been eventful, marked by the primordial forging of the light elements, the birth of the first stars and their violent deaths, and the improbable origin of life on Earth. But will the excitement continue, or are we headed toward the ultimate mundanity of equilibrium in a so-called heat death? In The Janus Point, Julian Barbour takes on this and other fundamental questions, offering the reader a new perspective—illustrated with lucid examples and poetically constructed prose—on how the Universe started (or more precisely, how it did not start) and where it may be headed. This book is an engaging read, which both taught me something new about meat-and-potatoes physics and reminded me why asking fundamental questions can be so fun.

Barbour argues that there is no beginning of time. The Big Bang, he maintains, was just a very special configuration of the Universe’s fundamental building blocks, a shape he calls the Janus point. As we move away from this point, the shape changes, marking the passage of time. The “future,” he argues, lies in both directions, hence the reference to Janus, the two-faced Roman god of beginnings and transitions.

Barbour illustrates his main points with a deceptively simple model known as the three-body problem, wherein three masses are subject to mutual gravitational attraction. In this context, the Janus point occurs when all three masses momentarily occupy the same point, in what is called a total collision. The special shape at the Janus point, explains Barbour, is an equilateral triangle, which is his model’s version of the Big Bang. I found this imagery helpful when trying to understand the more abstract, and necessarily less technical, application of this concept to general relativity.

Fast spinning black holes could have features different from those predicted by general relativity.

General relativity is a profoundly complex mathematical theory, but its description of black holes is amazingly simple. A stable black hole can be described by just three properties: its mass, its electric charge, and its rotation or spin. Since black holes aren’t likely to have much charge, it really takes just two properties. If you know a black hole’s mass and spin, you know all there is to know about the black hole.

This property is often summarized by the no-hair theorem. Specifically, the theorem asserts that once matter falls into a black hole, the only characteristic that remains is mass. You could make a black hole out of a Sun’s worth of hydrogen, chairs, or those old copies of National Geographic from Grandma’s attic, and there would be no difference. Mass is mass as far as general relativity is concerned. In every case the event horizon of a black hole is perfectly smooth, with no extra features. As Jacob Bekenstein said, black holes have no hair.

Continue reading “Black Holes Gain new Powers When They Spin Fast Enough” »

When a black hole is actively feeding, something strange can be observed: enormously powerful jets of plasma shoot from its poles, at velocities approaching light speed.

Given the intense gravitational interactions at play, exactly how those jets form is a mystery. But now, using computer simulations, a team of physicists has hit upon an answer — particles seeming to have “negative energy” extract energy from the black hole and redirect it to the jets.

And this theory has, for the first time, united two different and seemingly irreconcilable theories about how energy can be extracted from a black hole.