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Archive for the ‘cosmology’ category: Page 120

Apr 5, 2023

A new measurement could change our understanding of the universe

Posted by in categories: cosmology, physics

The universe is expanding, but how fast exactly? The answer appears to depend on whether you estimate the cosmic expansion rate—referred to as the Hubble’s constant, or H0—based on the echo of the Big Bang (the cosmic microwave background, or CMB) or you measure H0 directly based on today’s stars and galaxies. This problem, known as the Hubble tension, has puzzled astrophysicists and cosmologists around the world.

A study carried out by the Stellar Standard Candles and Distances research group, led by Richard Anderson at EPFL’s Institute of Physics, adds a new piece to the puzzle. Their research, published in Astronomy & Astrophysics, has achieved the most accurate calibration of Cepheid stars—a type of variable star whose luminosity fluctuates over a defined period—for distance measurements to date based on data collected by the European Space Agency’s (ESA’s) Gaia mission. This new calibration further amplifies the Hubble tension.

The Hubble constant (H0) is named after the astrophysicist who—together with Georges Lemaître—discovered the phenomenon in the late 1920s. It’s measured in kilometers per second per megaparsec (km/s/Mpc), where 1 Mpc is around 3.26 million light years.

Apr 3, 2023

“Black Hole” Created Using Sound Waves Could Help Enable the Development of a Physical Warp Drive

Posted by in categories: cosmology, mathematics, physics, space travel

An artificial black hole produced using sound waves and a dielectric medium has been created in the lab, according to researchers with an international think tank featuring more than 30 Ph.D. research scientists from around the world.

The researchers say their discovery is significantly more cost-effective and efficient than current methods in use by researchers who want to simulate the effects of a black hole in a laboratory environment.

New York-based Applied Physics first achieved recognition with the 2021 publication of a peer-reviewed theoretical paper detailing the mathematics behind the construction of a physical warp drive. More recently, the organization published a method for using Cal Tech’s Laser Interferometer Gravitational-Wave Observatory (LIGO) to detect the use of warp drives in outer space, co-authored by Dr. Manfred Paulini, the Associate Dean of Physics at Carnegie Mellon University.

Apr 3, 2023

Astronomers discovered a black hole so big it’s almost unbelievable

Posted by in categories: cosmology, materials

2.7 billion light years away, in a galaxy cluster known as Abell 1,201, an ultramassive black hole lurks, measuring upwards of 32.7 billion times the mass of our Sun. This new measurement exceeds astronomers’ previous estimates by at least 7 billion solar masses. It’s one of the biggest black holes astronomers have ever detected and cuts close to how large we believe they can be.

Our universe is filled with black holes, including the supermassive black holes found in the center of galaxies throughout all the regions of space around us. Many of these are inactive, not excreting material that causes them to light up, making them easier to detect. Others are rogue black holes, roaming through space however they please. Others still are ultramassive black holes.

These black holes are much bigger than supermassive black holes like those found at the center of galaxies. And, because they’re so massive – and contain so much mass – they should theoretically be easier to find. However, as I noted above, it all depends on how active the black hole is and how much heat it emits. That’s because, by default, ultramassive black holes (and black holes overall) don’t emit light.

Apr 2, 2023

Black holes and the multiverse could account for all dark matter, astronomers claim

Posted by in category: cosmology

Year 2021 o.o!


A study suggests that tiny black holes from the early Universe could contain ‘baby universes’, and could explain dark matter.

Apr 1, 2023

Catching Dark Matter in a Basement in Neutrino Alley

Posted by in categories: cosmology, particle physics

Scientists at Oak Ridge National Laboratory attempted to observe dark matter in a brightly-lit hallway in the basement using the sensitivity of their neutrino detectors. Neutrino Alley, where the team works, is located beneath the Spallation Neutron Source, a powerful particle accelerator. Following up on years of theoretical calculation, the COHERENT team set out to observe dark matter, which is believed to make up to 85% of the mass of the Universe. The experiment allowed the team to extend the worldwide search for dark matter in a new way, and they are planning to receive a much larger and more sensitive detector to improve their chances of catching dark matter particles.

Few things carry the same aura of mystery as dark matter. The name itself radiates secrecy, suggesting something hidden in the shadows of the Universe.

A collaborative team of scientists called COHERENT, including Kate Scholberg, Arts & Sciences Distinguished Professor of Physics, Phillip Barbeau, associate professor of Physics, and postdoctoral scholar Daniel Pershey, attempted to bring dark matter out of the shadows of the Universe and into a slightly less glamorous destination: a brightly lit, narrow hallway in a basement.

Apr 1, 2023

How a Laser Physics Induced Kerr-Newman Black Hole Can Release Gravitational Waves without Igniting the Black Hole Bomb (Explosion of a Mini Black Hole in a Laboratory)

Posted by in categories: cosmology, physics

In 2018, a team of scientists at the University of California, Santa Barbara proposed a method for creating Kerr-Newman black holes using lasers. However, this method has not yet been tested experimentally.

The team of scientists, led by Philip Gibbs, proposed to create Kerr-Newman black holes by colliding two high-energy laser beams. The collision would create a plasma that would be compressed and heated to extreme temperatures, creating a black hole.


Abstract

Continue reading “How a Laser Physics Induced Kerr-Newman Black Hole Can Release Gravitational Waves without Igniting the Black Hole Bomb (Explosion of a Mini Black Hole in a Laboratory)” »

Apr 1, 2023

Is Our Universe a Hologram? Physicists Debate Famous Idea on Its 25th Anniversary

Posted by in categories: cosmology, holograms, particle physics, quantum physics

face_with_colon_three year 2022.


AdS/CFT Proves Its Usefulness

One of the first uses of AdS/CFT had to do with understanding black holes. Theoreticians had long been grappling with a paradox thrown up by these enigmatic cosmic objects. In the 1970s Stephen Hawking showed that black holes emit thermal radiation, in the form of particles, because of quantum mechanical effects near the event horizon. In the absence of infalling matter, this “Hawking” radiation would cause a black hole to eventually evaporate. This idea posed a problem. What happens to the information contained in the matter that formed the black hole? Is the information lost forever? Such a loss would go against the laws of quantum mechanics, which say that information cannot be destroyed.

Continue reading “Is Our Universe a Hologram? Physicists Debate Famous Idea on Its 25th Anniversary” »

Apr 1, 2023

Great Mysteries of Physics 4: does objective reality exist?

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

That means that these two people will say that the state of reality is different – they’d have different facts about where the particle is.

There are may other oddities about quantum mechanics, too. Particles can be entangled in a way that enables them to somehow share information instantaneously even if they’re light years apart, for example. This challenges another common intution: that objects need a physical mediator to interact.

Physicists have therefore long debated how to interpret quantum mechanics. Is it a true and objective description of reality? If so, what happens to all the possible outcomes that we don’t measure? The many worlds interpretation argues they do happen – but in parallel universes.

Mar 31, 2023

Multiverse or Cyclic Universe? Alan Guth vs Roger Penrose

Posted by in categories: cosmology, entertainment

Do we live in a multiverses or a cyclic universe? Most cosmologists today accept the universe underwent a very rapid period of expansion called inflation. But inflation seems to lead to an infinite multiverse. Not everyone is happy with this multiverse ; and some cosmologists have sought alternatives to inflation. These alternative schemes are often cyclic. The chief proponent of one such cyclic model is 2020 Nobel Prize Winner Sir Roger Penrose. In this video the father of inflation Alan Guth and Sir Roger discuss the pros and cons of the inflationary multiverse versus Sir Roger’s Conformal Cyclic Universe.
We highly recommend watching our film on eternal inflation with Alan Guth and colleagues.

and our film on CCC with Roger Penrose and colleagues.
https://www.youtube.com/watch?v=FVDJJVoTx7s.
and other films in our Before the Big Bang Series which features Stephen Hawking, Alex Vilenkin and others.

Mar 31, 2023

Seeing is more than believing: Exploring ‘de Sitter space’ to explain gravity in the expanding early universe

Posted by in categories: cosmology, quantum physics

Having more tools helps; having the right tools is better. Utilizing multiple dimensions may simplify difficult problems—not only in science fiction but also in physics—and tie together conflicting theories.

For example, Einstein’s theory of —which resides in the fabric of space-time warped by planetary or other massive objects—explains how gravity works in most cases. However, the theory breaks down under such as those existing in black holes and cosmic primordial soups.

An approach known as superstring theory could use another dimension to help bridge Einstein’s theory with , solving many of these problems. But the necessary evidence to support this proposal has been lacking.