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New research could help scientists use gravitational lensing — the warping of light from distant galaxies — to investigate the accelerating expansion of the universe.

Scientists are still coming up empty in the hunt for flaws in Einstein’s theory of general relativity that could explain the mysterious force driving the accelerating expansion of the universe. 

The researchers studied 100 million galaxies looking for signs that the strength of gravity has varied throughout the universe’s history or over vast cosmic distances. Any sign of such a change would indicate that Einstein’s theory of general relativity is incomplete or in need of revision. Variation could also shed light on what dark energy is, beyond that it’s the name scientists give to whatever is causing the expansion of the universe to accelerate.

Despite finding no such variations in gravity’s strength, the work will help two forthcoming space telescopes — the the European Space Agency’s Euclid mission and NASA’s Nancy Grace Roman Space Telescope — also hunt for changes in the strength of gravity through space and back through time.

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An artist’s interpretation of Einstein’s theory of general relativity. (Image credit: coffeekai via Getty Images)

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By firing a Fibonacci laser pulse at atoms inside a quantum computer, physicists have created a completely new, strange phase of matter that behaves as if it has two dimensions of time. 

The new phase of matter, created by using lasers to rhythmically jiggle a strand of 10 ytterbium ions, enables scientists to store information in a far more error-protected way, thereby opening the path to quantum computers that can hold on to data for a long time without becoming garbled. The researchers outlined their findings in a paper published July 20 in the journal Nature (opens in new tab). 

The inclusion of a theoretical “extra” time dimension “is a completely different way of thinking about phases of matter,” lead author Philipp Dumitrescu, a researcher at the Flatiron Institute’s Center for Computational Quantum Physics in New York City, said in a statement. “I’ve been working on these theory ideas for over five years, and seeing them come actually to be realized in experiments is exciting.“

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The new phase was made by firing lasers at 10 ytterbium ions inside a quantum computer. (Image credit: Jurik Peter via Shutterstock)

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An atom is best visualized as a tight, dense nucleus surrounded by buzzing, orbiting electrons. This picture immediately leads to a question: How do electrons keep whirling around the nucleus without ever slowing down? 

This was a burning question in the early 20th century, and a search for the answer ultimately led to the development of quantum mechanics (opens in new tab) itself.

In the early 20th century, after countless experiments, physicists were just beginning to put together a coherent picture of the atom. They realized that each atom had a dense, heavy, positively charged nucleus surrounded by a cloud of tiny, negatively charged electrons. With that general picture in mind, their next step was to create a more detailed model.

In the earliest attempts at this model, scientists took their inspiration from the solar system, which has a dense “nucleus” (the sun) surrounded by a “cloud” of smaller particles (the planets). But this model introduced two significant problems. 

For one, a charged particle that accelerates emits electromagnetic radiation. And because electrons are charged particles and they accelerate during their orbits, they should emit radiation. This emission would cause the electrons to lose energy and quickly spiral in and collide with the nucleus, according to the University of Tennessee at Knoxville (opens in new tab). In the early 1900’s physicists estimated that such an inward spiral would take less than one-trillionth of a second, or a picosecond. Since atoms obviously live longer than a picosecond, this wasn’t going to work.

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Our knowledge of atoms was changed forever when quantum mechanics peeked inside. (Image credit: Rost-9D via Getty Images)

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We live in a strange universe filled with unexplained phenomena that have perplexed humans since time immemorial. Scientists have pieced together a rough guide to the cosmos—known as the Lambda cold dark matter model (ΛCDM), or more simply, the standard model of cosmology—but many mysteries don’t seem to fit into this otherwise well-corroborated framework, especially as our view of space has gotten ever more precise in recent years.

Scientists are now especially preoccupied with intractable tensions that have emerged from different measurements of two cosmic properties: The rate at which our universe is expanding, known as the Hubble constant (Ho), and a value called sigma-8 (σ8), which describes variations in how matter clumps together across large cosmic scales.

Efforts to measure these properties in space have puzzlingly returned different values. When the Hubble constant is measured based on observations of brilliant stars that act as yardsticks in space, its speed is clocked as about 50,400 miles per hour per million light years. However, when it is measured using the cosmic microwave background (CMB), the oldest light in the universe, it is 46,200 miles per hour per million light years. Meanwhile, the value of sigma-8 is different when measured using the CMB, compared to other observational techniques.

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Cartwheel galaxy cat

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The Universe, truly, is full of wonders, and the James Webb Space Telescope has just given us our best views of one of them yet.

The object in question is a star around 5,600 light-years away, and Webb’s infrared eye has picked out an extraordinary detail: it’s surrounded by what appear to be concentric rings of light radiating outward.

While Webb’s characteristic diffraction spikes are not ‘real’, those concentric rings are – and there’s a wonderful and fascinating explanation for them.

The star is actually a binary pair of rare stars in the constellation of Cygnus, and their interactions produce precise periodic eruptions of dust that are expanding out in shells into the space around the pair over time.

These shells of dust are glowing in infrared, which has allowed an instrument as sensitive as Webb’s MIRI to resolve them in exquisite detail.

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James Webb Space Telescope’s new image of the spectacular nebula around WR 140. (JWST/MIRI/Judy Schmidt)

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