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Astronomers have picked up a gravitational-wave signal originating from a dramatic collision deep in the cosmos. The event, dubbed GW230529, was recorded by the LIGO Livingston detector in May 2023.

Gravitational waves are caused by the acceleration of massive objects, such as merging black holes or neutron stars. According to Albert Einstein’s theory of general relativity, massive objects like planets, stars, and black holes distort the fabric of spacetime around them.

When these massive objects accelerate or change speed, they create waves that propagate outward at the speed of light. The detection of gravitational waves opens up a new window for observing the universe, allowing scientists to study phenomena that were previously inaccessible, such as the mergers of black holes and neutron stars, as well as the nature of gravity itself.

Researchers have discovered what they’re calling a “cosmic glitch” in gravity, which could potentially help explain the universe’s strange behavior on a cosmic scale.

As detailed in a new paper published in the Journal of Cosmology and Astroparticle Physics, the team from the University of Waterloo and the University of British Columbia in Canada posit that Albert Einstein’s theory of general relativity may not be sufficient to explain the accelerating expansion of the universe.

Einstein’s “model of gravity has been essential for everything from theorizing the Big Bang to photographing black holes,” said lead author and Waterloo mathematical physics graduate Robin Wen in a statement about the research. “But when we try to understand gravity on a cosmic scale, at the scale of galaxy clusters and beyond, we encounter apparent inconsistencies with the predictions of general relativity.”

Researchers have stumbled upon a phenomenon that could rewrite our understanding of the universe’s gravitational forces. Known as the “cosmic glitch,” this discovery highlights anomalies in gravity’s behavior on an immense scale, challenging the established norms set by Albert Einstein’s theory of general relativity.

For over a century, general relativity has served as the backbone for our understanding of cosmic phenomena, ranging from the dynamics of the Big Bang to the intricacies of black holes. The theory posits that gravity influences not only the three spatial dimensions but also time itself.

Validated through numerous tests and observations, general relativity has been a robust model that physicists and astronomers worldwide rely on.

It strikes me as contradictory that the scientific community will say that we don’t know what dark matter is, but be happy to state things like “dark matter makes up about 85% of the cosmos” (source: phys.org)

Is there something wrong with the way I’m thinking about this? If MOND is correct for example, which seems to be a possibility still, wouldn’t this mean that the statement about dark matter making up a certain percentage of the universe be false?

Approximately 80% of the matter in the universe is predicted to be so-called “dark matter,” which does not emit, reflect, or absorb light and thus cannot be directly detected using conventional experimental techniques.

The big bang is the model that describes the birth and evolution of the universe. But where did the term come from? What does it actually mean?

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Continue reading “The Big Bang, as Simple as Possible” »

In a paper published in the Journal of Cosmology and Astroparticle Physics, scientists examined the theoretical and observational cases for a ‘cosmic glitch’ in Universe’s gravity.

Recently more careful examination of the structure of the universe has thrown up fresh reasons to doubt cold dark matter. Its concept may work well at the largest scales, but on the scale of individual galaxies, something seems incomplete.

According to the cold dark matter model, dark matter sub-halos of all sizes, right down to Earth-scale masses, should exist. This would be a lot of invisible cannonballs to be floating around the Milky Way and interacting with star streams, yet hardly any evidence has been found, besides in 2018, when Adrian Price-Whelan and Ana Bonaca found that one particular star stream, better known as GD-1, has gaps along its length, as if it has been hit multiple times.

Another more recent doubt about the cold matter concept is that simulations show halos should get denser towards the center of the galaxy: the closer you get to the center, the more dark matter per unit volume should be. However, when astronomers look at the way galaxies move, this isn’t what they see: the dark matter appears evenly distributed across the halo of our galaxy, especially in the core regions. Which could be a hint that something more complex is going on.

A new study will improve the detection of gravitational waves —ripples in space and time. Scientists at the University of Minnesota Twin Cities College of Science and Engineering co-led the research with an international team.

The research aims to send alerts to astronomers and astrophysicists within 30 seconds after the detection, helping to improve the understanding of neutron stars and black holes and how heavy elements, including gold and uranium, are produced.

The findings were recently published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS), a peer-reviewed, open access, scientific journal.