Archive for the ‘cosmology’ category

Nov 21, 2023

1st Black Hole Ever Imaged by Humans Has Twisted Magnetic Fields And Scientists Are Thrilled

Posted by in category: cosmology

Observations from the Event Horizon Telescope show that the supermassive black hole at the heart of the galaxy M87 has twisted magnetic fields that help matter and light escape from the immense gravit.

Nov 20, 2023

Sean Carroll on Causality and the Arrow of Time

Posted by in categories: cosmology, physics

Sean Carroll speaking at the 6th International FQXi Conference, “Mind Matters: Intelligence and Agency in the Physical World.”

The Foundational Questions Institute (FQXi) catalyzes, supports, and disseminates research on questions at the foundations of physics and cosmology, particularly new frontiers and innovative ideas integral to a deep understanding of reality but unlikely to be supported by conventional funding sources.

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Nov 20, 2023

String Theory, Quantum Gravity and Black Holes (Or, Are We Holograms?)

Posted by in categories: cosmology, holograms, quantum physics

Join Brian Greene and Juan Maldacena as they explore a wealth of developments connecting black holes, string theory, quantum gravity, quantum entanglement, wormholes, and the holographic principle.

This program is part of the Big Ideas Series, made possible with support from the John Templeton Foundation.

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Nov 20, 2023

Supermassive black hole at the heart of the Milky Way is approaching the cosmic speed limit, dragging space-time along with it

Posted by in categories: cosmology, physics

The supermassive black hole at the heart of our galaxy isn’t just spinning — it’s doing so at almost maximum speed, dragging anything near it along for the ride.

Physicists calculated the rotational speed of the Milky Way’s supermassive black hole, called Sagittarius A* (Sgr A, by using NASA’s Chandra X-ray Observatory to view the X-rays and radio waves emanating from outflows of material.

Nov 20, 2023

New paper argues that the Universe began with two Big Bangs

Posted by in category: cosmology

This is a testable hypothesis, and with current technology, we should be able to confirm or disprove it within a few years.

Nov 20, 2023

What was it like at the beginning of the Big Bang?

Posted by in categories: cosmology, particle physics

Once inflation comes to an end, and all the energy that was inherent to space itself gets converted into particles, antiparticles, photons, etc., all the Universe can do is expand and cool. Everything smashes into one another, sometimes creating new particle/antiparticle pairs, sometimes annihilating pairs back into photons or other particles, but always dropping in energy as the Universe expands.

The Universe never reaches infinitely high temperatures or densities, but still attains energies that are perhaps a trillion times greater than anything the LHC can ever produce. The tiny seed overdensities and underdensities will eventually grow into the cosmic web of stars and galaxies that exist today. 13.8 billion years ago, the Universe as-we-know-it had its beginning. The rest is our cosmic history.

Nov 19, 2023

A New Study Finds a Surprising Answer on How Fast the Universe is Expanding

Posted by in category: cosmology

In this episode, we explore the Hubble constant problem, which is one of the most intriguing and perplexing mysteries in cosmology. We explain how a recent study used the Hubble Space Telescope to measure the expansion rate of the universe, and how it differs from the prediction of the cosmic microwave background and the standard cosmological model. We also discuss some of the possible implications and solutions for this discrepancy, such as the nature of dark energy, dark matter and dark radiation, and the need to revise our understanding of the universe.

00:00 Introduction.
01:13 Measuring the Hubble Constant.
03:36 Comparing the Results.
05:39 Implications and Solutions.
07:54 Outro.
08:39 Enjoy.

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Nov 19, 2023

The origins of the black hole information paradox

Posted by in categories: cosmology, information science, mathematics, quantum physics

While physics tells us that information can neither be created nor destroyed (if information could be created or destroyed, then the entire raison d’etre of physics, that is to predict future events or identify the causes of existing situations, would be impossible), it does not demand that the information be accessible. For decades physicists assumed that the information that fell into a black hole is still there, still existing, just locked away from view.

This was fine, until the 1970s when Stephen Hawking discovered the secret complexities of the event horizon. It turns out that these dark beasts were not as simple as we had been led to believe, and that the event horizons of are one of the few places in the entire cosmos where meets quantum mechanics in a manifest way.

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Nov 18, 2023

Tension for a Hubble-Tension Solution

Posted by in category: cosmology

An early-Universe spike in dark energy could resolve a disagreement between two cosmic-expansion-rate measurements, but such a spike may conflict with observations of quasar spectra.

Nov 17, 2023

Dark Matter Might Be Recycled To Form A Whole Invisible Periodic Table

Posted by in categories: chemistry, cosmology, particle physics, quantum physics, sustainability

Our current best understanding of the universe requires the existence of an invisible substance known as dark matter. The exact nature of dark matter (or its actual existence) is still unknown, and there are multiple competing theories to explain the effect of this matter on the Universe. An exciting new one is called Recycled Dark Matter.

The idea behind Recycled Dark Matter is that dark matter is produced in a specific mechanism that researchers have dubbed “recycling” in a paper awaiting peer-review, because dark matter forms twice in the universe, with weird quantum mechanics and a black hole phase in the middle. All of that just a few instants after the beginning of the cosmos.

So, let’s take a journey back about 13.8 billion years. You don’t have to move, because the Big Bang happened everywhere. At the very moment that time as we know it starts ticking, the fundamental forces and the building blocks of particles we know of (the Standard Model) are in equilibrium with the Dark Sector (we know it sounds like a bad fantasy novel location, but bear with).

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