This Strange New Map Of ‘Dark Matter’ Proves Einstein Was Right, Say Scientists

Scientists using a telescope in Chile have produced groundbreaking new map of “dark matter” in 25% of the night sky that they say supports Albert Einstein’s theory of general relativity.

Although dark matter is invisible—emitting no light or energy, and so undetectable using telescopes—scientists using the Atacama Cosmology Telescope in Chile have been able to construct this map, above, which is hundreds of millions of light years across.

Its orange regions indicate where there is more mass and purple where there’s less mass. White is merely light reflecting off dust in the Milky Way galaxy, which is known as zodiacal light.

What is ‘dark matter?’

Dark matter is made from particles that are invisible, absorbing, reflecting or emitting no light or energy, according to NASA, so it’s undetectable directly. It’s therefore hypothetical, though it’s existence can be inferred by its effect on other things. Dark matter is thought to account for about 85% of matter in the universe and is thought only to interact with gravity.

How the new ‘dark matter’ map was made

Rather incredibly it uses the remnants of the first light in the universe—the cosmic microwave background (CMB)—as a backlight. The CMB is thought to be a shockwave of the Big Bang 13 billion years ago. Here it’s used to silhouette all the matter between us and the Big Bang.

‘It’s a bit like silhouetting, but instead of just having black in the silhouette, you have texture and lumps of dark matter, as if the light were streaming through a fabric curtain that had lots of knots and bumps in it,” said Suzanne Staggs, director of ACT and Princeton’s Henry DeWolf Smyth Professor of Physics. “The famous blue and yellow CMB image is a snapshot of what the universe was like in a single epoch, about 13 billion years ago, and now this is giving us the information about all the epochs since.”

What is Albert Einstein’s general theory of relativity?

There are four dimensions in space—height, length, width and time. Relativity describes what happens when mass is added to that mix. Einstein’s general theory of relativity, published in 1915, is most easily understood if you think about a bowling ball on a trampoline. Just as the trampoline sinks and curves around the ball, mass curves space-time. Light travels in a straight line, but space-time is curved by mass, so we observe it in curves. The radical theory was proven by photographs of the exact positions of stars taken during a solar eclipse on May 29, 1919.

“We’ve made a new mass map using distortions of light left over from the Big Bang,” said Mathew Madhavacheril, assistant professor in the Department of Physics and Astronomy at the University of Pennsylvania. “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.”

The ‘crisis’ in cosmology

Some scientists think the standard model of cosmology—which is built around Einstein’s general theory of relativity—may be broken. The key evidence is that background light from stars, rather than from the CMB, results in different measurements of dark matter. However, this new map of inferred dark matter itself is in perfect agreement with the standard model. “When I first saw them, our measurements were in such good agreement with the underlying theory that it took me a moment to process the results,” said Cambridge Ph.D. student Frank Qu, part of the research team.

“We have mapped the invisible dark matter across the sky to the largest distances, and clearly see features of this invisible world that are hundreds of millions of light-years across,’’ said Blake Sherwin, professor of cosmology at the University of Cambridge, where he leads a group of ACT researchers. “It looks just as our theories predict.”

The Atacama Cosmology Telescope

First proposed in 2003, this experiment has taken 15 years using the Atacama Cosmology Telescope, which was decommissioned in September 2022. However, a new telescope is planned for 2024 that will be able to map dark matter almost 10 times faster.

The research was presented on April 10 at the Future Science with CMB x LSS conference at the Yukawa Institute for Theoretical Physics in Kyoto University, Japan.

Wishing you clear skies and wide eyes.