Twisted in our universe lies one of science’s greatest unsolved mysteries. Where is all the dark matter? What is everything dark matter?
I mean, we know it’s there.
Galaxies, including the Milky Way, spin so fast that our physics predicts that everything inside should be flung out like horses on a runaway merry-go-round. But that clearly isn’t happening. You, me, the sun and the earth are anchored securely. Therefore, scientists theorize that something — probably in the form of a halo — must surround galaxies to keep them from falling apart.
Anything that includes those boundaries is called dark matter. We can’t see it, we can’t feel it, and we don’t even know if it is a thing. It’s the pinnacle of elusiveness. We only know that dark matter exists.
Despite our inability to see or touch the material itself, experts have interesting ways to identify its effects on our universe. After all, we inferred the presence of dark matter in the first place by noting how it holds galaxies together.
Scientists took advantage of that principle and released remarkable new findings about dark matter on Monday. Using a toolkit made up of warped space, cosmic remnants left over from the Big Bang, and powerful astronomy instruments, they discovered a deep space zone of previously unstudied dark matter halos — each located around an ancient galaxy, dutifully protecting the life of a merry-go-round nightmare.
These vortices, according to an investigation into the find published in Physical Review Lettersdate back 12 billion years, just under two billion years after the Big Bang. That could very well be the youngest rings of dark matter ever studied by mankind, the authors suggest, and possibly the prelude to the next chapter of cosmology.
“I was pleased that we opened a new window on that era,” said Hironao Miyatake of the University of Nagoya and author of the study. said in a statement. “Things were very different 12 billion years ago. You see more galaxies forming than now; the first clusters of galaxies are also starting to form.”
Wait, warped space? Cosmic residue?
Yes, you read that right. Let’s explain.
More than a century ago, when Albert Einstein invented his famous general theory of relativityOne prediction he made was that super-strong gravitational fields emanating from massive amounts of matter would literally distort the fabric of space and time, or spacetime. He turned out to be right. Today, physicists are taking advantage of the concept by using a technique called gravitational lensing to study very distant galaxies and other phenomena in the universe. It works something like this.
Imagine two galaxies. Galaxy A is in the background and B is in the foreground.
Basically, as light from galaxy A passes through galaxy B to get to your eyes, that luminescence is distorted by B’s matter, dark or not. This is good news for scientists, because such a distortion is common increases distant galaxies, a kind of lens.
Furthermore, there is a kind of reverse calculation you can do with this light warp to find out how much dark matter surrounds galaxy B. If galaxy B a lot of dark matter, would you have a lot more distortion than expected from visible matter — the things we can see — inside. But if there weren’t so much dark matter, the distortion would be much closer to your prediction. This system has worked quite well, but it has one caveat.
With standard gravitational lenses, researchers can only identify dark matter around galaxies that are up to 8 billion to 10 billion light-years away.
This is because as you look deeper and deeper into the universe, visible light becomes more and more difficult to interpret, eventually turning into infrared light that is totally invisible to human eyes. (That’s whyis such a big deal. It’s our best chance at catching the faintest, most invisible light coming from the distant cosmos.) But what this means is that visible light-distortion signals for dark matter research are far too blurred past a certain point to help us uncover the hidden light. to analyze things.
Miyatake came up with a solution.
We may not be able to notice standard light distortions to detect dark matter, but what if there is another type of distortion we can see? It turns out there is: microwave radiation released by the Big Bang. They are virtually big bang heat residues, formally known as cosmic microwave background or CMB radiation.
“Look at dark matter around distant galaxies?” Masami Ouchi, a cosmologist at the University of Tokyo and co-author of the study, said in a statement. “It was a crazy idea. Nobody realized we could do this. But after I gave a lecture on a big monster from distant galaxies, Hironao came up to me and said it would be possible to get to dark matter with the CMB to look around these galaxies.”
Essentially, Miyatake wanted to observe how dark matter lensed our universe’s first light through gravity.
Picking up pieces of the big bang
“Most researchers use source galaxies to measure the distribution of dark matter from now to 8 billion years ago,” Yuichi Harikane, an assistant professor at the University of Tokyo and co-author of the study, said in a statement. “However, we were able to look further back into the past because we used the more distant CMB to measure dark matter. For the first time, we measured dark matter from almost the earliest moments of the universe.”
To arrive at their results, the new research team first collected data from observations made by the Subaru Hyper Suprime-Cam Survey.
That led them to identify 1.5 million lens systems — a set of hypothetical Bs of galaxies — that can be traced back to 12 billion years ago. They then called on information from the European Space Agency’s Planck satellite about the microwave radiation from the Big Bang. Put it all together, and the team could find out if and how those lens systems distorted the microwaves.
“This result provides a very consistent picture of galaxies and their evolution, as well as the dark matter in and around galaxies, and how this picture evolves over time,” Neta Bahcall, a professor of astrophysical sciences at Princeton University and co-author of the study, said in a statement.
In particular, the researchers emphasized that their study found that dark matter from the early universe doesn’t appear as lumpy as our current physics models suggest. Ultimately, this piece could modify what we currently believe about cosmology, primarily theorems rooted in what’s called the Lambda-CDM model.
“Our finding is still uncertain,” Miyatake said. “But if true, it would indicate that the whole model is flawed the further back in time you go. This is exciting because if the result holds after the uncertainties are reduced, it could suggest an improvement in the model.” which can provide insight into the nature of dark matter itself.”
And then the research team plans to explore even earlier regions of space using information held by the Vera C. Rubin Observatory’s Legacy Survey of Space and Time.
“With LSST, we can observe half the sky,” Harikane said. “I see no reason why we couldn’t see the distribution of dark matter 13 billion years ago.”