Why Scientists’ Latest Dark Matter and Dark Energy Calculations Are a Big Deal

Why Scientists’ Latest Dark Matter and Dark Energy Calculations Are a Big Deal

In 1998, scientists Stumbled upon a surprising cosmic truth. Not only was the universe expanding, they realized, but it also appeared to be accelerated As the years go by, sped by a force we can’t see.

That mysterious effect would soon become known as dark energy, one of the great mysteries of physics.

This would equally complement the confusing aspect of our universe, called dark matter, a blanket concept scientists First proved in 1933 To describe anything that creates a hidden, halo-like barrier that prevents galaxies from disintegrating. (Yet another force that we cannot perceive with the human eye.)

But though we are unable to perceive the intangible nature Dark matter and dark energy With vision, we are able to measure it with mathematics. and Wednesday, in A series of papers in the Astrophysical JournalAstrophysicists managed to establish Still the most precise limit On the formation and evolution of our universe — including the dark universe.

Using a powerful analytical method called Pantheon+, the team found the composition of the cosmic matter to be about two-thirds dark energy and one-third matter, mostly in the form of dark matter. More specifically, they suspect that 66.2% of the universe manifests as dark energy, while the remaining 33.8% belongs to both dark and visible matter.

Even more exciting than the results of Pantheon+ is the mind-bending way it works. In short, the team used an array of powerful, cosmic flashlights to document the contents of the universe as it existed more than 10 billion years ago.

By “flashlight” I mean type 1a supernovae.

These starbursts are so bright that they outshine all galaxies and can therefore be seen billions of light-years away from Earth. They’re just like flashlights, but instead of illuminating a long hallway, they illuminate an infinite tunnel of space and time. In fact, they were crucial to the discovery of the dark universe, helping to uncover the existence of dark matter in 1933 and the existence of dark energy in 1998.

Pantheon+ takes things to the next level. The scientists behind the analysis focused on more than 1,500 supernovae that, when put together, collectively light up about three-quarters of the known universe. Oh, indeed.


A timeline of the universe.


“With this combined Pantheon+ dataset, we get a precise view of the universe from when it was dominated by dark matter to when the universe was influenced by dark energy,” said Dillon Braut, an astronomer at the Harvard-Smithsonian Center for Astrophysics. said in a statement.

“This dataset is a unique opportunity to see dark energy kicking in and driving cosmic evolution on the grandest scale in modern times,” Braut said.

This may settle some scientific controversies

Down the road, the Pantheon+ legacy is set to cross the dark universe.

As an added bonus, the analysis tool confirmed that the universe is indeed expanding at an accelerating rate, And This has yielded very promising evidence in support of the cornerstones of scientific thought: Standard model of particle physics.

This framework roughly outlines how every single known particle behaves independently, as well as with each other, and even serves as the basis for many leading theories about what the dark universe actually is.


A diagram of particles in the Standard Model.


“We’ve been able to put the most precise constraints on the dynamics and history of the universe to date,” Braut said. “We’ve combed through the data and can now say with more confidence than ever how the universe evolved over time, and the current best theories for dark energy and dark matter are robust.”

In other words, Pantheon+ might be telling us to wrap up some alternative theories of dark matter and dark energy unrelated to the standard model. These theories may, well, be wrong.

Furthermore, we also need to talk about my personal favorite consequence of the Pantheon + dataset. Ultimately, it may help put to rest the long-standing, rather heated, debate among physicists.

We may finally be on the road to decoding what is known as Hubble constant. type, variety.

Basically, we know the universe is expanding rapidly. We can literally watch it happen in real time. But scientists can’t agree on the exact rate of that expansion. The key to the solution is the Hubble constant, but different ways of calculating that constant seem to give different answers.


The arcs and lines of the galaxy cluster Abell 370 reveal “gravitational lensing,” the distortion of light from far-away, background galaxies by the cluster’s gravitational field. The lensing effect helps astronomers measure the distribution of dark matter in galaxy clusters.

NASA, ESA, and the Hubble SM4 ERO Team

However, after pooling the Pantheon+ sample with data from other scientific collaborations, a Harvard press release says we may now have the tightest local measure of the universe’s current expansion rate. (The keyword here is “local.” That will come later.)

In summary, the collaboration found Hubble’s constant to be 73.4 kilometers (45.6 miles) per second per megaparsec (km/s/mpc). 1.3% uncertainty.

“Stated another way, for every megaparsec, or 3.26 million light-years, the analysis estimates that in the nearby universe, space itself is expanding at more than 160,000 miles per hour,” the release explains. This image, for context, is from mid-2001 The landmark measurement is 72 km/s/mpc and later reports 74 km/s/MPC.

However, this is far from another leading measurement that suggests a constant of 69.8 km/s/Mpc.

Well, yes, there is still a discrepancy. And, again, based on Pantheon+’s constant “local” measurements.

As such, the Pantheon+ team emphasizes that “observations from a completely different era of the universe’s history predict a different story.” Thus, in a way, there is a new inverse Hubble constant force no Resolving the Hubble tension, rather than exacerbating an already fraught controversy? Like I said, it’s complicated.


A simulation of dark matter filaments throughout the universe.

Jarija Lukic/Lawrence Berkeley National Laboratory

“We thought it would be possible to find clues to a novel solution to these problems in our dataset, but instead we’re finding that our data rule out many of these options, and deep anomalies remain as stubborn as ever,” Braut said.

But at the end of the day, because Pantheon+’s results are so primitive, perhaps they can at least explain where the controversy lies in Hubble’s constant debate.

“Many recent theories are beginning to point to exotic new physics in the very early universe,” Braut said. “However, such unproven theories must withstand the scientific process, and Hubble’s pull continues to be a major challenge.”

Physics is brimming with complex puzzles and riddles and, indeed, straight roadblocks. But I like to think of these obstacles as motivation to continue in the field and turn the mind. This is why Pantheon+’s were invented in the first place.

And with this process, we’ve come a long way toward dissecting the truth about the dark side of our universe — at least. Or as Braut puts it, “Pantheon+ gives us our best chance to date to constrain dark energy, its origins, and its evolution.”

#Scientists #Latest #Dark #Matter #Dark #Energy #Calculations #Big #Deal

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