Within the larger, “true” universe, ours could have branched off due to a random quantum fluctuation.
The ‘Hawking radiation’ emitted by black holes may be able to carry crucial information, a new study suggests. Scientists may have just found the solution to one of astrophysics most mind-boggling mysteries concerning black holes, also known as the ‘Hawking information paradox’. A study published in the journal Physics Letters B last month offers a resolution to a problem the late physicist Stephen Hawking was working on in his final years.
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.
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.
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.
Year 2021 o.o!
A study suggests that tiny black holes from the early Universe could contain ‘baby universes’, and could explain dark matter.
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.
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.
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.
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.
