Startling new evidence suggests black holes drive expansion of universe

Startling new evidence suggests black holes drive expansion of universe
An artist's impression of a black hole and its accretion disc
An artist's impression of a black hole and its accretion disc
View 1 Image
An artist's impression of a black hole and its accretion disc
An artist's impression of a black hole and its accretion disc

A groundbreaking new study could finally provide an answer to one of the most perplexing astrophysics mysteries – without needing to add anything new to our current models. Physicists suggest that black holes could contain a strange form of energy that’s accelerating the expansion of the universe.

Astronomers have known since the late 1920s that the universe is expanding, and for decades it was assumed that the rate of this expansion would be slowing down over time. After all, gravity pulls things closer together, and the gravitational pull of all the matter in the universe was thought to be dragging on everything.

But in the 1990s, astronomers using the Hubble Space Telescope made an unexpected discovery – the exact opposite was occurring. The farther an object was from our vantage point, the faster it seemed to be moving away from us, indicating the expansion of the universe was accelerating over time. With no explanation in models at the time, a force dubbed “dark energy” was formulated, which pushes everything away from everything else at an increasing rate.

Astronomers have been looking for signs of this dark energy ever since, based on the properties that it seems to have. And in a new study, an international team of scientists claims to have found evidence for where dark energy might be hiding – inside black holes.

Contrary to what we might think, a vacuum isn’t totally empty – random quantum fluctuations produce what’s known as vacuum energy, which exerts an outward pressure that could work against gravity and drive the expansion of the universe. In some models, vacuum energy could be found in black holes, and in the new study the team found the first observational evidence of this.

The astronomers started by studying the evolution of supermassive black holes at the centers of galaxies over the last nine billion years. These black holes gain mass mostly by swallowing up dust, gas, stars and other black holes, but in some galaxies, known as giant elliptical galaxies, this feedstock dries up. It should be expected then that the supermassive black holes in elliptical galaxies stop growing.

The researchers compared the masses of these black holes in distant elliptical galaxies (which are seen as they were billions of years ago) to those closer to us in space and time. And sure enough, the supermassive black holes in modern elliptical galaxies are between seven and 20 times more massive than they were nine billion years ago.

That indicates that supermassive black holes can gain mass through some other mechanism as well. And if they contain vacuum energy, they would both contribute to the expansion of the universe and gain mass from the process as well, in a phenomenon called cosmological coupling.

The team says this is the first observational evidence that black holes contain vacuum energy, and when they crunched the numbers they found that this could account for the amount of dark energy measured in the universe today.

While there’s been no shortage of other proposed sources of dark energy, the team says that this new model may be the neatest. That’s because it doesn’t require anything new to be added to our existing models – the gap can be plugged by black holes as predicted by Einstein’s general theory of relativity.

As an added bonus, the new model also explains another cosmological puzzle. In current models black holes are theorized to compress everything that falls into them into an infinitely dense singularity, a point where the laws of physics break down. They should be mathematically impossible, so physicists either find workarounds for them or take them to mean that our models are incomplete. But if black holes contain vacuum energy, singularities no longer need to exist, which could be a major breakthrough in our understanding and further evidence for the new model.

As intriguing as the study is, further research and observations will be needed to confirm the model.

The research was published in two papers in The Astrophysical Journal and the Astrophysical Journal Letters. The team describes the work in the video below.

Explainer: First evidence black holes are source of dark energy

Source: UK Research and Innovation

How can 'expansion' fit in with the theory of an infinite universe ?

harold angulo
The universe and the black holes expand to future in the time, so we can't see it or scan it. So it's appear to be infinite
Gene Preston
This makes sense from a fields standpoint. Consider that magnetic fields will push on wires to lower the magnetic field strength. Like charge electric fields also repel. So if black holes have a large amount of their energy (mass) outside the event horizon these fields will repel each other while at the same time the atomic matter will be attracted to the lowest gravity potentials. If the universe is expanding because of gravity field energy repelling its because the energy in gravity fields is huge, i.e. 95% of the energy in the universe. This is the so called dark matter.
Going from "nothing can escape a black hole" to "black holes recycle matter into force used to expand the universe" seems like a spectacular backflip.
Leslie Schwartz
Vacuum energy in the vicinity of black holes s not some additional source of energy and mass - this is really poor science, like whistling in the dark. It seems they will offer every bogus source they can think of to save their non-sense dark energy theory.
Vacuum energy (which should exist everywhere in the universe, not just in black holes) = energy = mass (equivalence predicted by General Relativity) = "gravitational force"/the warping of spacetime = which should result in the contraction of the universe, not the expansion.

If my logic has missed something, I'm sorry, but I think that this will need to be explained in a bit more depth if I am to be able to understand how this theory holds up.
To contribute details, while I don't know this area very well
Photons have energy and momentum but have zero rest/invariant mass, though I believe it's generally accepted that the EM field warps spacetime / causes curvature but I do not know the details of that.
I suppose dark energy's effect on curvature is necessarily the opposite of our conventional idea of gravity,
which would then seem to mean that spacetime curvature doesn't necessarily mean contraction, but either contraction or expansion.

It is called 'dark' for a reason but I'm definitely looking forward to hearing more.
If we are looking back in time when looking at the most distant objects, then how do we even know the universe is expanding?
Suppose we are looking at something from 10 billion years ago, and just receiving the light from it now.
If gravity started pulling it back towards us by, say, 20%, we would not even know that for another 2 billion years, right? By that time, the object might have moved even closer - assuming gravity operates at a constant influence.
It seems to me we cannot have confidence in a cosmic constant if we are not looking at the present time, or anything close to it.
Gene Preston
I was not talking about vacuum energy. I was talking about a gravity field containing energy. The gradient in the gravity potential itself just like an electric or magnetic field is a kind of warped space.
Alrighty then. Since dark energy and dark matter can escape the terrific gravity of the black holes, now please use that knowledge to develop anti-gravity theories and devices to let mankind get on out into the stars! CC: Elon Musk.
Load More