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Archive for the ‘cosmology’ category: Page 126

Oct 19, 2022

The most precise accounting yet of dark energy and dark matter

Posted by in categories: cosmology, evolution, physics

Astrophysicists have performed a powerful new analysis that places the most precise limits yet on the composition and evolution of the universe. With this analysis, dubbed Pantheon+, cosmologists find themselves at a crossroads.

Pantheon+ convincingly finds that the cosmos is composed of about two-thirds dark energy and one-third matter—mostly in the form of dark matter—and is expanding at an accelerating pace over the last several billion years. However, Pantheon+ also cements a major disagreement over the pace of that expansion that has yet to be solved.

By putting prevailing modern cosmological theories, known as the Standard Model of Cosmology, on even firmer evidentiary and statistical footing, Pantheon+ further closes the door on alternative frameworks accounting for dark energy and dark matter. Both are bedrocks of the Standard Model of Cosmology but have yet to be directly detected and rank among the model’s biggest mysteries. Following through on the results of Pantheon+, researchers can now pursue more precise observational tests and hone explanations for the ostensible cosmos.

Oct 19, 2022

Why modifying gravity doesn’t add up

Posted by in category: cosmology

The Universe gravitates so that normal matter and General Relativity alone can’t explain it. Here’s why dark matter beats modified gravity.

Oct 19, 2022

Record-Breaking Gamma Ray Burst May Indicate Birth of a Black Hole

Posted by in categories: cosmology, physics, robotics/AI

On Oct. 9, an unimaginably powerful influx of X-rays and gamma rays infiltrated our solar system. It was likely the result of a massive explosion that happened 2.4 billion light-years away from Earth, and it has left the science community stunned.

In the wake of the explosion, astrophysicists worldwide turned their telescopes toward the spectacular show, watching it unfold from a variety of cosmic vantage points — and as they vigilantly studied the event’s glimmering afterglow over the following week, they grew shocked by how utterly bright this gamma-ray burst seems to have been.

Eventually, the spectacle’s sheer intensity earned it a fitting (very millennial) name to accompany its robotic title of GRB221009A: B.O.A.T. — the “brightest of all time.”

Oct 19, 2022

Look! Fresh NASA image shows a chaotic blue blob supernova remnant

Posted by in category: cosmology

This chaotic scene is where life’s ingredients are cast off into space. Cassiopeia A exploded in the 17th century, making it a fairly recent one.

Oct 18, 2022

Shortly Before They Collided, two Black Holes Tangled Spacetime up Into Knots

Posted by in categories: cosmology, physics

In February 2016, scientists at the Laser Interferometer Gravitational-Wave Observatory (LIGO) announced the first-ever detection of gravitational waves (GWs). Originally predicted by Einstein’s Theory of General Relativity, these waves are ripples in spacetime that occur whenever massive objects (like black holes and neutron stars) merge. Since then, countless GW events have been detected by observatories across the globe – to the point where they have become an almost daily occurrence. This has allowed astronomers to gain insight into some of the most extreme objects in the Universe.

In a recent study, an international team of researchers led by Cardiff University observed a binary black hole system originally detected in 2020 by the Advanced LIGO, Virgo, and Kamioki Gravitational Wave Observatory (KAGRA). In the process, the team noticed a peculiar twisting motion (aka. a precession) in the orbits of the two colliding black holes that was 10 billion times faster than what was noted with other precessing objects. This is the first time a precession has been observed with binary black holes, which confirms yet another phenomenon predicted by General Relativity (GR).

Continue reading “Shortly Before They Collided, two Black Holes Tangled Spacetime up Into Knots” »

Oct 18, 2022

Astronomers decipher a few early warning signs for stars about to go supernova

Posted by in category: cosmology

Keep an eye on the sky.


New models show that stars about to blow up in a supernovae begin exhibiting strange behaviors a few months in advance.

Oct 18, 2022

A gamma ray burst — possibly the brightest of all time — sweeps over Earth

Posted by in categories: cosmology, space travel

In a breathless press release, NASA emphasized that their detectors all over the planet picked up on this, including NASA’s Fermi Gamma-ray Space Telescope, the Neil Gehrels Swift Observatory, and the Wind spacecraft.

Gamma-ray bursts are some of the most powerful releases of energy in the universe. Their causes may vary slightly, but typically relate to black holes. Some may be caused when merging neutron stars create a black hole, or when a neutron star and a black hole merge. Because they are so energetic, even a gamma-ray burst that originates on the other side of the universe will often be detectable by astronomers on Earth.

Oct 17, 2022

It’s the BOAT: Astronomers observe “brightest of all time” gamma-ray burst

Posted by in category: cosmology

On the morning of October 9, multiple space-based detectors picked up a powerful gamma-ray burst (GRB) passing through our solar system, sending astronomers around the world scrambling to train their telescopes on that part of the sky to collect vital data on the event and its afterglow. Dubbed GRB 221009A, astronomers say the gamma-ray burst is the most powerful yet recorded and likely could be the “birth cry” of a new black hole. The event was promptly published in the Astronomer’s Telegram, and observations are still ongoing.

“In our research group, we’ve been referring to this burst as the ‘BOAT,’ or Brightest Of All Time, because when you look at the thousands of bursts gamma-ray telescopes have been detecting since the 1990s, this one stands apart,” said Jillian Rastinejad, a graduate student at Northwestern University. Rastinejad led one of two independent teams using the Gemini South telescope in Chile to study the event’s afterglow.

“This burst is much closer than typical GRBs, which is exciting because it allows us to detect many details that otherwise would be too faint to see,” said Roberta Pillera, a graduate student at the Polytechnic University of Bari, Italy, and member of the Fermi Large Area Telescope (LAT) Collaboration. “But it’s also among the most energetic and luminous bursts ever seen regardless of distance, making it doubly exciting.”

Oct 16, 2022

Astronomers just spotted the most powerful flash of light ever seen

Posted by in categories: cosmology, military, satellites

Astronomers just detected what may be the most powerful flash of light ever seen.

The so-called gamma-ray burst, the most energetic type of electromagnetic explosion known to exist in the universe, was first spotted by telescopes Sunday (Oct. 9).

Gamma-ray bursts, which were discovered accidentally by U.S. military satellites in the 1960s, are likely produced when giant stars explode at the ends of their lives before collapsing into black holes, or when ultradense stellar remnants known as neutron stars collide. Within seconds, these explosions unleash as much energy as the sun will emit during its entire 10-billion-year lifetime.

Oct 16, 2022

This is why quantum physicists suspect the Multiverse very likely exists

Posted by in categories: cosmology, quantum physics

One of the most successful theories of 20th century science is cosmic inflation, which preceded and set up the hot Big Bang. W e also know how quantum fields generally work, and if inflation is a quantum field (which we strongly suspect it is), then there will always be more “still-inflating” space out there. Whenever and wherever inflation ends, you get a hot Big Bang. If inflation and quantum field theory are both correct, a Multiverse is a must.

When we look out at the Universe today, it simultaneously tells us two stories about itself. One of those stories is written on the face of what the Universe looks like today, and includes the stars and galaxies we have, how they’re clustered and how they move, and what ingredients they’re made of. This is a relatively straightforward story, and one that we’ve learned simply by observing the Universe we see.

But the other story is how the Universe came to be the way it is today, and that’s a story that requires a little more work to uncover. Sure, we can look at objects at great distances, and that tells us what the Universe was like in the distant past: when the light that’s arriving today was first emitted. But we need to combine that with our theories of the Universe — the laws of physics within the framework of the Big Bang — to interpret what occurred in the past. When we do that, we see extraordinary evidence that our hot Big Bang was preceded and set up by a prior phase: cosmic inflation. But in order for inflation to give us a Universe consistent with what we observe, there’s an unsettling appendage that comes along for the ride: a multiverse. Here’s why physicists overwhelmingly claim that a multiverse must exist.