When two black holes collide, the impact is so big that we can detect it all the way here on Earth. These objects are so immense that their collisions send ripples through spacetime itself. Scientists call these ripples gravitational waves.
Gravitational waves are distortions or ripples in the fabric of space and time. They were first detected in 2015 by the Advanced LIGO detectors and are produced by catastrophic events such as colliding black holes, supernovae, or merging neutron stars.
A fully automated process, including a brand-new artificial intelligence (AI) tool, has successfully detected, identified and classified its first supernova.
Developed by an international collaboration led by Northwestern University, the new system automates the entire search for new supernovae across the night sky—effectively removing humans from the process. Not only does this rapidly accelerate the process of analyzing and classifying new supernova candidates, it also bypasses human error.
The team alerted the astronomical community to the launch and success of the new tool, called the Bright Transient Survey Bot (BTSbot), this week. In the past six years, humans have spent an estimated total of 2,200 hours visually inspecting and classifying supernova candidates. With the new tool now officially online, researchers can redirect this precious time toward other responsibilities in order to accelerate the pace of discovery.
And that’s where the trouble really starts. Down there, nature is governed by quantum mechanics. This amazingly powerful theory has been shown to account for all the forces of nature, except gravity. When physicists try to apply quantum theory to gravity, they find that space and time become almost unrecognizable. They seem to start fluctuating wildly. It’s almost like space and time fall apart. Their smoothness breaks down completely, and that’s totally incompatible with the picture in Einstein’s theory.
(01:54) As physicists try to make sense of all of this, some of them are coming to the conclusion that space and time may not be as fundamental as we always imagined. They’re starting to seem more like byproducts of something even deeper, something unfamiliar and quantum mechanical. But what could that something be? Joining me now to discuss all this is Sean Carroll, a theoretical physicist who hosts his own podcast, Mindscape. Sean spent years as a research professor of physics at Caltech [California Institute of Technology], but he is now moving to Johns Hopkins as the Homewood Professor of Natural Philosophy. He’s also an external professor at the Santa Fe Institute. But no matter where he is, Sean studies deep questions about quantum mechanics, gravity, time and cosmology. He’s the author of several books, including his most recent, Something Deeply Hidden: Quantum Worlds and the Emergence of Spacetime. Sean, thank you so much for joining us today.
Dark energy, one of the most controversial physics ideas, is getting another challenge. After all, if this force is supposed to make up about 68% of the mass-energy of the universe, where exactly is it? A new paper by a pair of Russian astrophysicists says dark energy simply doesn’t exist. Instead, they point to the mysterious Casimir effect as the explanation for the accelerating expansion of the universe.
The study, from Professor Artyom Astashenok and undergraduate student Alexander Teplyakov of the Immanuel Kant Baltic Federal University, takes issue with the fact that as far as dark energy’s suggested role, “no one knows what is it and how it works,” as remarks Astashenok in a press release.
Scars of collisions with other universes could show up in radiation from the big bang. A new experiment aims to mimic these collisions and help us look for them.
From the vast expanse of galaxies that paint our night skies to the intricate neural networks within our brains, everything we know and see can trace its origins back to a singular moment: the Big Bang. It’s a concept that has not only reshaped our understanding of the universe but also offers profound insights into the interconnectedness of all existence.
Imagine, if you will, the entire universe compressed into an infinitesimally small point. This is not a realm of science fiction but the reality of our cosmic beginnings. Around 13.8 billion years ago, a singular explosion gave birth to time, space, matter, and energy. And in that magnificent burst of creation, the seeds for everything — galaxies, stars, planets, and even us — were sown.
But what if the Big Bang was not just a physical event? What if it also marked the birth of a universal consciousness? A consciousness that binds every particle, every star, and every living being in a cosmic tapestry of shared experience and memory.
If new particles are out there, the Large Hadron Collider (LHC) is the ideal place to search for them. The theory of supersymmetry suggests that a whole new family of partner particles exists for each of the known fundamental particles. While this might seem extravagant, these partner particles could address various shortcomings in current scientific knowledge, such as the source of the mysterious dark matter in the universe, the “unnaturally” small mass of the Higgs boson, the anomalous way that the muon spins and even the relationship between the various forces of nature. But if these supersymmetric particles exist, where might they be hiding?
This is what physicists at the LHC have been trying to find out, and in a recent study of proton–proton collision data from Run 2 of the LHC (2015–2018), the ATLAS collaboration provides the most comprehensive overview yet of its searches for some of the most elusive types of supersymmetric particles—those that would only rarely be produced through the “weak” nuclear force or the electromagnetic force. The lightest of these weakly interacting supersymmetric particles could be the source of dark matter.
The increased collision energy and the higher collision rate provided by Run 2, as well as new search algorithms and machine-learning techniques, have allowed for deeper exploration into this difficult-to-reach territory of supersymmetry.
Our solar system officially houses eight planets, but some scientists say there could be a ninth. And that’s not just Pluto aficionados – evidence suggests a huge undiscovered world lurks on the dark fringes out there. Now, a new study has found the outer solar system oddities could be explained by modified theories of gravity, an alternative idea to dark matter.
In the 19th century, astronomers measuring the orbit of Uranus noticed some inconsistencies between observations and predictions, and concluded that it was being influenced by the gravity of a large unseen body. Sure enough, the planet Neptune was soon discovered as a result.
In 2016 astronomers made a similar prediction: based on the bizarre orbital patterns of six icy objects in the Kuiper belt, an unknown planet with the mass of about 10 Earths could be tugging on them from the shadows. Further evidence from other objects and even the Sun’s tilt seemed to strengthen the case.
NASA’s Hubble Space Telescope has snapped a new photograph of a spiral galaxy located 78 million light-years away, originally discovered in 1877.
Simulations indicate an erratic and copious accretion of gas onto a black hole when the surrounding disk is tilted and the black hole spins rapidly.