Black Holes Archives

September 14, 2021September 14, 2021 by Brian Koberlein

We Knew Black Holes Have a Temperature. It Turns out They Also Have a Pressure

Artist view of an active supermassive black hole. Credit: ESO/L. Calçada

In the classical theory of general relativity, black holes are relatively simple objects. They can be described by just three properties: mass, charge, and rotation. But we know that general relativity is an incomplete theory. Quantum mechanics is most apparent in the behavior of tiny objects, but it also plays a role in large objects such as black holes. To describe black holes at a quantum level, we need a theory of quantum gravity. We don’t have a complete theory yet, but what know so far is that quantum mechanics makes black holes more complex, giving them properties such as temperature and perhaps even pressure.

September 12, 2021September 10, 2021 by Paul M. Sutter

In Addition to Gravitational Waves, is There any way to Detect Merging Black Holes

In February 2016, LIGO detected gravity waves for the first time. As this artist's illustration depicts, the gravitational waves were created by merging black holes. The third detection just announced was also created when two black holes merged. Credit: LIGO/A. Simonnet. — Artist's impression of merging binary black holes. Credit: LIGO/A. Simonnet.

If two black holes merge in the middle of space, and nobody’s around to see it, does it really happen?

August 25, 2021August 25, 2021 by Andy Tomaswick

Advanced Civilizations Could be Using Dyson Spheres to Collect Energy From Black Holes. Here’s how we Could Detect Them

Black holes are more than just massive objects that swallow everything around them – they’re also one of the universe’s biggest and most stable energy sources. That would make them invaluable to the type of civilization that needs huge amounts of power, such as a Type II Kardashev civilization. But to harness all of that power, the civilization would have to encircle the entire black hole with something that could capture the power it is emitting.

August 25, 2021August 27, 2021 by Matt Williams

This is How a Supermassive Black Hole Feeds

Artist's impression of a quasar and a relativistic jet emanating from the center. Credit: NASA

At the heart of most massive galaxies in our Universe, there are supermassive black holes (SMBH) on the order of millions to billions of times the mass of the Sun. As these behemoths consume gas and dust that’s slowly fed into their maws, they release tremendous amounts of energy. This leads to what is known as an Active Galactic Nucleus (AGN) – aka. a quasar – which can sometimes send hypervelocity jets of material for light-years.

Since they were first discovered, astrophysicists have suspected that SMBHs play an important role in the formation and evolution of galaxies. However, as a result, there has also been considerable research dedicated to how these massive objects form and evolve themselves. Recently, a team of astrophysicists conducted a high-powered simulation that showed exactly how SMBHs feed and determined that a galaxy’s arms play a vital role.

August 18, 2021August 18, 2021 by Brian Koberlein

You can Tell how big a Black Hole is by how it Eats

An artist’s impression of an accretion disk rotating around an unseen supermassive black hole. Credit: Mark A. Garlick/Simons Foundation

Black holes don’t emit light, which makes them difficult to study. Fortunately, many black holes are loud eaters. As they consume nearby matter, surrounding material is superheated. As a result, the material can glow intensely, or be thrown away from the black hole as relativistic jets. By studying the light from this material we can study black holes. And as a recent study shows, we can even determine their size.

August 15, 2021August 15, 2021 by Brian Koberlein

If the First Black Holes Collapsed Directly, Could we Detect Radio Signals From Those Moments?

This artist’s impression shows a possible seed for the formation of a supermassive black hole. Credit: NASA/CXC/M. Weiss

The universe is littered with supermassive black holes. There’s one a mere 30,000 light-years away in the center of the Milky Way. Most galaxies have one, and some of them are more massive than a billion stars. We know that many supermassive black holes formed early in the universe. For example, the quasar TON 618 is powered by a 66 billion solar mass black hole. Since its light travels nearly 11 billion years to reach us, TON 618 was already huge when the universe was just a few billion years old. So how did these black holes grow so massive so quickly?

August 1, 2021August 1, 2021 by Matt Williams

A Black Hole Emitted a Flare Away From us, but its Intense Gravity Redirected the Blast Back in our Direction

Artist's impression of a black hole, as indicated by its bright accretion disk. Credit: NASA

In 1916, Albert Einstein put the finishing touches on his Theory of General Relativity, a journey that began in 1905 with his attempts to reconcile Newton’s own theories of gravitation with the laws of electromagnetism. Once complete, Einstein’s theory provided a unified description of gravity as a geometric property of the cosmos, where massive objects alter the curvature of spacetime, affecting everything around them.

What’s more, Einstein’s field equations predicted the existence of black holes, objects so massive that even light cannot escape their surfaces. GR also predicts that black holes will bend light in their vicinity, an effect that can be used by astronomers to observe more distant objects. Relying on this technique, an international team of scientists made an unprecedented feat by observing light caused by an X-ray flare that took place behind a black hole.

July 29, 2021July 29, 2021 by Matt Williams

The Event Horizon Telescope Zooms in on Another Supermassive Black Hole

Credit: M. Janssen, H. Falcke, M. Kadler, E. Ros, M. Wielgus et al.

On April 10th, 2019, the world was treated to the first image of a black hole, courtesy of the Event Horizon Telescope (EHT). Specifically, the image was of the Supermassive Black Hole (SMBH) at the center of the supergiant elliptical galaxy known as M87 (aka. Virgo A). These powerful forces of nature are found at the centers of most massive galaxies, which include the Milky Way (where the SMBH known as Sagittarius A* is located).

Using a technique known as Very-Long-Baseline Interferometry (VLBI), this image signaled the birth of a new era for astronomers, where they can finally conduct detailed studies of these powerful forces of nature. Thanks to research performed by the EHT Collaboration team during a six-hour observation period in 2017, astronomers are now being treated to images of the core region of Centaurus A and the radio jet emanating from it.

July 14, 2021July 12, 2021 by Paul M. Sutter

How did Supermassive Black Holes Form? Collapsing Dark Matter Halos can Explain Them

Artist's conception of a supermassive black hole in a galaxy's center. Credit: NASA/JPL-Caltech

We don’t quite understand how the first supermassive black holes formed so quickly in the young universe. So a team of physicists are proposing a radical idea. Instead of forming black holes through the usual death-of-a-massive-start route, instead giant dark matter halos directly collapsed, forming the seeds of the first great black holes.

July 5, 2021July 5, 2021 by Brian Koberlein

Hawking Made a Prediction About Black Holes, and Physicists Just Confirmed it

Computer simulation of plasma near a black hole. Credit: Hotaka Shiokawa / EHT

On its own, a black hole is remarkably easy to describe. The only observable properties a black hole has are its mass, its electric charge (usually zero), and its rotation, or spin. It doesn’t matter how a black hole forms. In the end, all black holes have the same general structure. Which is odd when you think about it. Throw enough iron and rock together and you get a planet. Throw together hydrogen and helium, and you can make a star. But you could throw together grass cuttings, bubble gum, and old Harry Potter books, and you would get the same kind of black hole that you’d get if you just used pure hydrogen.