Astronomers have made the most detailed map ever of mysterious dark matter using the universe’s very first light, and the "groundbreaking" image has possibly proved Einstein right yet again.
The new image, made using 14 billion-year-old light from the turbulent aftermath of the Big Bang, shows the enormous matter tendrils that formed not long after the universe exploded into being. It turns out the shapes of these tendrils are remarkably similar to those predicted using Einstein's theory of general relativity.
The new result contradicts previous dark matter maps that suggested the cosmic web — the gigantic network of crisscrossing celestial superhighways paved with hydrogen gas and dark matter that spans the universe — is less clumpy than Einstein's theory predicted. The astronomers presented their findings April 11 at the Future Science with CMB x LSS conference at Japan's Yukawa Institute for Theoretical Physics.
"We've made a new mass map using distortions of light left over from the Big Bang," Mathew Madhavacheril, a cosmologist at the University of Pennsylvania, said in a statement. "Remarkably, it provides measurements that show that both the 'lumpiness' of the universe, and the rate at which it is growing after 14 billion years of evolution, are just what you'd expect from our standard model of cosmology based on Einstein's theory of gravity."
Scientists think that the universe that formed after the Big Bang teemed with matter as well as antimatter particles, which are identical to their matter counterparts but with opposite electrical charges.
Because matter and antimatter annihilate each other when they collide, if both were made in equal measure, all of the universe's matter should have been annihilated. However, the rapidly expanding fabric of space-time, along with some helpful quantum fluctuations, kept pockets of the universe's primordial plasma intact.
Then, according to the rules set out by Einstein's theory of relativity, gravity compressed and heated these plasma pockets so that sound waves — called baryon acoustic oscillations — rippled outward from the clumps at half the speed of light. These gigantic waves pushed out matter that hadn't already been sucked in on itself, creating the infant cosmic web: a series of thin films surrounding countless cosmic voids, like a nest of soap bubbles in a sink.
Once this matter cooled, it coalesced into the first stars, which pooled into matter-rich galaxies at the meeting points of the web's tangled strands.
But in the past, astronomers studying the cosmic web found what seemed to be a massive discrepancy — the matter was significantly more evenly distributed and less lumpy than expected. It was an ominous sign that existing cosmological models were missing important physics.
To dig into this apparent discrepancy, the researchers turned to the U.S. National Science Foundation's (NSF) Atacama Cosmology Telescope (ACT) in Chile, which scanned a quarter of the entire night sky from 2007 to 2022. Using its incredibly sensitive microwave detector, the telescope picked up light from the cosmic microwave background radiation (CMB) — the universe's very first light made just 380,000 years after the Big Bang — and used a process called gravitational lensing to map the concentrations of matter in the CMB.
Gravitational lensing is a phenomenon in which light moving through a region of space-time warped by powerful gravitational fields travels, in a curve — warping and twisting through a gigantic funhouse mirror until it emerges as a stretched-out arc called an Einstein ring. Gravitational lensing can detect dark matter, which makes up 85% of the universe's matter but cannot be directly observed.
The new map contradicted previous ones made with visible light from galaxies, and showed that Einstein's original theory was far more accurate than first thought.
What this means for our overall view of the cosmos' early evolution is still too early to say, but the researchers suggest that additional maps made using the ACT's data and fresh observations from the Simons Observatory — an under-construction Atacama Desert telescope that can scan the sky 10 times as fast as ACT — could finally resolve the perplexing cosmic mystery.
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Ben Turner is a U.K. based staff writer at Live Science. He covers physics and astronomy, among other topics like tech and climate change. He graduated from University College London with a degree in particle physics before training as a journalist. When he's not writing, Ben enjoys reading literature, playing the guitar and embarrassing himself with chess.
"Einstein's original theory was far more accurate than first thought."Reply
It is not accurate at all. It cannot even predict how light falls in a gravitational field. According to general relativity, the speed of light DECREASES as light falls:
"Contrary to intuition, the speed of light (properly defined) decreases as the black hole is approached...If the photon, the 'particle' of light, is thought of as behaving like a massive object, it would indeed be accelerated to higher speeds as it falls toward a black hole. However, the photon has no mass and so behaves in a manner that is not intuitively obvious." http://www.physlink.com/Education/AskExperts/ae13.cfm
"Einstein first discovered the gravitational time dilation in 1911, on the basis of his equivalence principle. From the time dilation, he immediately deduced the slow-down and deflection of light in a gravitational field. His 1911 result for the reduction of the speed of light was in error by a factor of 2, but he corrected this a few years later, in his theory of General Relativity." https://arxiv.org/ftp/arxiv/papers/1102/1102.2870.pdf
"Thus, as φ becomes increasingly negative (i.e., as the magnitude of the potential increases), the radial "speed of light" c_r defined in terms of the Schwarzschild parameters t and r is reduced to less than the nominal value of c." https://www.mathpages.com/rr/s6-01/6-01.htm......................................................................................................................................................................................
All Einsteinians know, and some explicitly admit, that the opposite is true - the speed of light INCREASES as light falls in a gravitational field:
James Hartle, Gravity: An Introduction to Einstein's General Relativity, p. 113: "If we accept the equivalence principle, we must also accept that light falls in a gravitational field with the same acceleration as material bodies." https://www.amazon.com/Gravity-Introduction-Einsteins-General-Relativity/dp/0805386629
Paul A. Tipler, Ralph A. Llewellyn, Modern Physics: "But according to the equivalence principle, there is no way to distinguish between an accelerating compartment and one with uniform velocity in a uniform gravitational field. We conclude, therefore, that A BEAM OF LIGHT WILL ACCELERATE IN A GRAVITATIONAL FIELD AS DO OBJECTS WITH REST MASS. For example, near the surface of Earth light will fall with acceleration 9.8 m/s^2." http://web.pdx.edu/~pmoeck/books/Tipler_Llewellyn.pdf
Wasn't this same story reported in 2004?Reply
The "map" isn't a map of dark matter then and could still be just as easily caused by something else.admin said:Light produced just 380,000 years after the Big Bang was warped by the universe's dark matter exactly the way Einstein predicted it would be.
Einstein was right about invisible dark matter, massive new map of the universe suggests : Read more
When will y'all give it up.