In May of 2019, the gravitational wave observatories LIGO and Virgo detected the merger of two black holes. One had a mass of 85 Suns, while the other was 66 solar masses. The event was named GW190521 and was the largest merger yet observed. It produced a 142 solar mass black hole, making it the first gravitational wave observation of an intermediate mass black hole. But the event also raised several questions.Continue reading “An Exotic Explanation for the Most Extreme Gravitational Wave Detected so far”
The Low-Frequency Array (LOFAR) is a different kind of radio telescope. Although radio light has the longest wavelengths and lowest frequencies of the electromagnetic spectrum, much of radio astronomy has focused on the higher frequency end. Observatories such as ALMA study radio light at frequencies of hundreds of Gigahertz, and the VLA studies the fifty Gigahertz range, LOFAR captures radio signals below 250 Megahertz, which is in the range of the lowest radio frequencies that can be seen from Earth.Continue reading “A map of 25,000 Supermassive Black Holes Across the Universe”
What happens when galaxies collide? Well, if any humans are around in about a billion years, they might find out. That’s when our Milky Way galaxy is scheduled to collide with our neighbour the Andromeda galaxy. That event will be an epic, titanic, collision. The supermassive black holes at the center of both galaxies will feast on new material and flare brightly as the collision brings more gas and dust within reach of their overwhelming gravitational pull. Where massive giant stars collide with each other, lighting up the skies and spraying deadly radiation everywhere. Right?
Maybe not. In fact, there might be no feasting at all, and hardly anything titanic about it.Continue reading “When Galaxies Collide, Black Holes Don’t Always Get the Feast They Were Hoping for”
Fifty years ago, English mathematical physicist and Nobel-prize winner Roger Penrose proposed that energy could be extracted from the space around a rotating black hole. Known as the ergosphere, this region lies just outside an event horizon, the boundary within which nothing can escape a black hole’s gravitational pull (even light). It is also here where infalling matter is accelerated to incredible speeds and emits all kinds of energy.
This became known as the Penrose Process, which many theorists have since expanded on. The latest comes from a study conducted by researchers from Columbia University and the Universidad Adolfo Ibáñez in Chile. With support from organizations like NASA, they demonstrated how a better understanding of the physics at work around spinning black holes could allow us to harness their energy someday.Continue reading “A New Idea to Harness Energy From Black Holes”
What’s better than two gigantic galaxies swirling into one another until they collide? How about three galaxies swirling into one another until they collide – and they all have supermassive black holes at their core to boot! Recently, a team led by Dr. Adi Foord of Stanford combed through data from the WISE mission and the Sloan Digital Sky Survey to search for instances of three galaxies colliding with one another. In all that data, they managed to find 7 separate systems that met those criteria.Continue reading “What Happens to Their Supermassive Black Holes When Galaxies Collide?”
We use the term ‘supermassive black hole’ with a kind of casual familiarity. But stop and think about what they really are: Monstrous, beguiling singularities where the understood laws of physics and cosmology are brought to their knees. A region where gravity is so powerful that it warps everything around it, drawing material in—even light itself—and sometimes spitting out jets of energy at near-light-speed.Continue reading “Hubble Sees Dark Shadows That Could Be Cast by a Supermassive Black Hole”
The Theory of Relativity predicted the existence of black holes and neutron stars. Einstein gets the credit for the theory because of his paper published in 1915, even though other scientists’ work helped it along. But regardless of the minds behind it, the theory predicted black holes, neutron stars, and the gravitational waves from their mergers.
It took about one hundred years, but scientists finally observed these mergers and their gravitational waves in 2015. Since then, the LIGO/Virgo collaboration has detected many of them. The collaboration has released a new catalogue of discoveries, along with a new infographic. The new infographic displays the black holes, neutron stars, mergers, and the other uncertain compact objects behind some of them.Continue reading “Merging Black Holes and Neutron Stars. All the Gravitational Wave Events Seen So Far in One Picture”
Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that the reason for the Great Silence is that all the aliens have evolved beyond the need to explore!
In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?“
This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, several possible resolutions have been proposed, including the theory that advanced species eventually “transcend” the physical Universe, also known as the Transcension Hypothesis.Continue reading “Beyond “Fermi’s Paradox” XI: What is the Transcension Hypothesis”
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!”
In March 2018 astronomers watched a massive black hole surge in brightness. Then over the following year, its ring of light dimmed to near-invisibility before regaining its former strength. The potential culprit? The black hole swallowing an entire star.Continue reading “A ring of high-energy particles surrounding a black hole suddenly disappeared”