Here might be cracks in space-time, but humanity’s telescopes can’t see them.
The cracks, if they exist, are old, remnants of a time shortly after the Big Bang. But a new paper shows they might be too faint to detect.
New books by a physicist and science journalist mount aggressive but ultimately unpersuasive defenses of multiverses.
Supermassive black holes are true monsters of the Universe. From millions to even billions of times the mass of the Sun, there’s one in the very center of every big galaxy in the cosmos, and in fact each galaxy itself formed and grew along with its black hole; they affect each other profoundly. As matter falls onto the black hole it falls into an accretion disk, heats up, and emits huge amounts of energy and can also blow a fierce wind of material back into the galaxy (we call such galaxies with actively feeding supermassive black holes active galaxies). This wind can push away gas and dust that would otherwise fall onto the black hole, regulating its growth.
Under some conditions this wind can also compress the gas in the galaxy, which can increase the number of stars forming in the galaxy. But too much wind and the gas is blown right out of the galaxy. Even at some levels in between, it can heat the gas up enough that star formation is much harder. It’s like a pressure valve in the galaxy.
This is how it usually works, at least. Astronomers have found a compact group of galaxies clustered around an active galaxy, and that central galaxy’s black hole is so powerful it’s blowing a wind that’s causing star formation in the galaxies around it!
A typical but existentially terrifying feature of almost every galaxy is a monster lurking at its center: A supermassive black hole which can be hundreds or even billions of times the mass of our sun. The supermassive black hole sucks in dust and gas from the surrounding galaxy, leaving an empty spheroid shape right in the middle of the galaxy from which not even light can escape.
Very occasionally, astronomers spot not one but two of these hungry giants moving together, typically when they observe two galaxies merging. But now, researchers have spotted something utterly unprecedented: A galaxy with three supermassive black holes at its heart.
Dr. Peter Weilbacher, one of the researchers from the Leibniz Institute for Astrophysics Potsdam, underlined the significance of this finding: “Up until now, such a concentration of three supermassive black holes had never been discovered in the universe,” he said.
The shape of our Universe has long been recognized to be flat. But that isn’t the only possibility.
Born shortly after the Big Bang, these cosmic monsters have perplexed astronomers for years. A new study may shed light on their origins.
Astronomers believe that new measurements from NASA’s Hubble Space Telescope confirm that the Universe is expanding about 9% faster than expected based on its trajectory seen shortly after the big bang.
This means that the Hubble constant (H0) — the measure of the current expansion rate of the Universe, named after Edwin Hubble, the man who first observed said expansion — needs adjustment from its current figure of ~2 × 10-¹⁸ s-¹.
Adam Riess, Bloomberg Distinguished Professor of Physics and Astronomy at The Johns Hopkins University, Nobel Laureate, says of the disparity between old calculations and these new findings: “This mismatch has been growing and has now reached a point that is really impossible to dismiss as a fluke. This is not what we expected.”
In 2016, Attila Krasznahorkay made news around the world when his team published its discovery of evidence of a fifth force of nature. Now, the scientists are making news again with a second observation of the same force, which may be the beginning of a unified fifth force theory. The researchers have made their original LaTeX paper available prior to acceptance by a peer-reviewed journal. Study of the hypothesized fifth force, a subfield all by itself, is centered on trying to explain missing pieces in our understanding of physics, like dark matter, which could be expanded or validated by an important new discovery or piece of evidence.
Everything in our Universe is held together or pushed apart by four fundamental forces: gravity, electromagnetism, and two nuclear interactions. Physicists now think they’ve spotted the actions of a fifth physical force emerging from a helium atom.
It’s not the first time researchers claim to have caught a glimpse of it, either. A few years ago, they saw it in the decay of an isotope of beryllium. Now the same team has seen a second example of the mysterious force at play — and the particle they think is carrying it, which they’re calling X17.
If the discovery is confirmed, not only could learning more about X17 let us better understand the forces that govern our Universe, it could also help scientists solve the dark matter problem once and for all.
