Black holes have been the subject of intense interest ever since scientists began speculating about their existence. Originally proposed in the early 20th century as a consequence of Einstein’s Theory of General Relativity, black holes became a mainstream subject a few decades later. By 1971, the first physical evidence of black holes was found and by 2016, the existence of gravitational waves was confirmed for the first time.
This discovery touched off a new era in astrophysics, letting people know collision between massive objects (black holes and/or neutron stars) creates ripples in spacetime that can be detected light-years away. To give people a sense of how profound these events are, Álvaro Díez created the Black Hole Collision Calculator (BHCC) – a tool that lets you see what the outcome of a collision between a black hole and any astronomical object would be!
Continue reading “Behold! The Black Hole Collision Calculator!”
If you’re a fan of science fiction, chances are you encountered a few franchises where humanity has spread throughout the known Universe. The ships that allow them to do this, maybe they use a warp drive, maybe they “fold space,” maybe have a faster-than-light (FTL) or “jump” drive. It’s a cool idea, the thought of “going interstellar!” Unfortunately, the immutable laws of physics tell us that this is simply not possible.
However, the physics that govern our Universe do allow for travel that is close to the speed of light, even though getting to that speed would require a tremendous amount of energy. Those same laws, however, also tell us that near-light-speed travel comes with all sorts of challenges. Luckily for all of us, NASA addresses these in a recently-released animed video that covers all the basics of interstellar travel!
Continue reading “NASA’s New Video Shows You What it’s Like Traveling Close to the Speed of Light”
Perhaps the most surprising prediction of general relativity is that of gravitational waves. Ripples in space and time that spread through the universe at the speed of light. Gravitational waves are so faint that for decades their detection was thought impossible. Even today, it takes an array of laser interferometers several kilometers long to see their effect. But what if we could detect them with a table-top experiment in a university lab?
In a recent paper published in the New Journal of Physics, a team of physicists proposes just such a device. Rather than using beams of light, they suggest using the quantum superposition of a single electron.
Continue reading “Could a tabletop experiment detect gravitational waves and determine the quantum nature of gravity?”
A cluster of galaxies is nothing trivial. The shocks, the turbulence, the energy, as all of that matter and energy merges and interacts. And we can watch all the chaos and mayhem as it happens.
A team of astronomers are looking at the galaxy cluster Abell 2255 with the European Low-Frequency Array (LOFAR) radio telescope, and their images are showing some never-before-seen details in this actively merging cluster.
Continue reading “Complete and Total Mayhem in a Distant Galaxy Collision”
A black hole as a source of energy?
We know black holes as powerful singularities, regions in space time where gravity is so overwhelming that nothing—not even light itself—can escape.
About 50 years ago, British physicist Roger Penrose proposed that black holes could be a source of energy. Now, researchers at the University of Glasgow in Scotland have demonstrated that it may be possible.
Continue reading “How an Advanced Civilization Could Exploit a Black Hole for Nearly Limitless Energy”
Most of the universe is made of one of two kinds of mysterious substances, called dark matter and dark energy. From all the evidence, these two cosmic components only interact with “normal” matter through the gravitational force. And a recent nuclear experiment reveals no presence of any dark contamination in the bonds between atomic nuclei to a level twenty times better than previously recorded.
Continue reading “There’s no evidence that dark matter interacts with any other force but gravity”
Dark matter is notoriously difficult to detect. So difficult that we haven’t detected it yet. Evidence for dark matter can be seen in everything from the warping of light near galaxies to the way galaxies cluster together. We are pretty sure dark matter is real, but we also know it can’t be made of any type of particle we currently know. But a new study has found some interesting data that could be evidence of dark matter, or not.
Continue reading “Japanese Dark Matter Detector is Seeing a “Surprising Excess of Events””
Using NASA’s MESSENGER spacecraft’s close encounters with Venus and Mercury, researchers were able to measure the lifetime of neutrons, an important prediction of the Standard Model of particle physics.
Continue reading “Spacecraft was able to measure how long neutrons last before they decay”
Believe it or not, time travel is possible.
In fact, you’re doing it right now. Every single second of every single day you are advancing into your own future. You are literally moving through time, the same way you would move through space. It may seem pedantic, but it’s a very important point. Movement through time is still movement, and you are reaching your own future (whether you like it or not).
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Time travel into the past is a tricky thing. We know of no single law of physics that absolutely forbids it, and yet we can’t find a way to do it, and if we could do it, the possibility opens up all sorts of uncomfortable paradoxes (like what would happen if you killed your own grandfather).
But there could be a way to do it. We just need to find a wormhole first.
Continue reading “Can wormholes act like time machines?”