Connect with us

Science

Scientists may have solved Stephen Hawking's black hole paradox – Phys.org

Published

 on


Credit: CC0 Public Domain

Researchers may have solved Professor Stephen Hawking’s famous black hole paradox—a mystery that has puzzled scientists for almost half a century.

According to two new studies, something called “quantum hair” is the answer to the problem.

In the first paper, published in the journal Physical Review Letters, researchers demonstrated that are more complex than originally thought and have gravitational fields that hold information about how they were formed.

The researchers showed that matter collapsing into a black hole leaves a mark in its —an imprint referred to as a “quantum hair.”

In a follow-up paper, published in a separate journal, Physics Letters B, Professor Xavier Calmet from the University of Sussex’s School of Mathematical and Physical Sciences and Professor Stephen Hsu from Michigan State University said quantum hairs resolve Hawking’s Black Hole Information Paradox.

In 1976, Hawking suggested that, as black holes evaporate, they destroy information about what had formed them.

That idea goes against a fundamental law of which states any process in physics can be mathematically reversed.

In the 1960s, physicist John Archibald Wheeler, discussing black holes’ lack of observable features beyond their total mass, spin, and charge, coined the phrase “black holes have no hair”—known as the no-hair theorem.

However, the newly discovered “quantum hair” provides a way for information to be preserved as a black hole collapses and, as such, resolves one of ‘s most famous quandaries, experts say.

Prof Calmet said: “Black holes have long been considered the perfect laboratory to study how to merge Einstein’s theory of general relativity with quantum mechanics.

“It was generally assumed within the that resolving this paradox would require a huge paradigm shift in physics, forcing the potential reformulation of either quantum mechanics or general relativity.

“What we found—and I think is particularly exciting—is that this isn’t necessary.”

Explaining the discovery of the “quantum hair,” Roberto Casadio, professor of Theoretical Physics at the University of Bologna, said: “A crucial aspect is that black holes are formed by the collapse of compact objects and then, according to the , there is no absolute separation between the interior and the exterior of the black hole.

“In the , the horizon acts as a perfect one-way membrane which does not let anything out and the exterior is therefore the same for all black holes of a given mass. This is the classical no-hair theorem,” Casadio added.

“However, in the quantum theory, the state of the matter that collapses and forms the black hole continues to affect the state of the exterior, albeit in a way that is compatible with present experimental bounds. This is what is known as ‘quantum hair.'”


Explore further

Wormholes help resolve black hole information paradox


More information:
Xavier Calmet et al, Quantum hair and black hole information, Physics Letters B (2022). DOI: 10.1016/j.physletb.2022.136995

Xavier Calmet et al, Quantum Hair from Gravity, Physical Review Letters (2022). DOI: 10.1103/PhysRevLett.128.111301

2022 dpa GmbH.
Distributed by Tribune Content Agency, LLC.

Citation:
Scientists may have solved Stephen Hawking’s black hole paradox (2022, March 18)
retrieved 18 March 2022
from https://phys.org/news/2022-03-scientists-stephen-hawking-black-hole.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Adblock test (Why?)



Source link

Continue Reading

Science

Boeing docks crew capsule to space station in test do-over – Phys.org

Published

 on


This image from NASA TV shows the Boeing Starliner preparing to dock at the International Space Station, Friday, May 20, 2022. Boeing’s astronaut capsule has arrived at the International Space Station in a critical repeat test flight. Only a test dummy was aboard the capsule for Friday’s docking, a huge achievement for Boeing after years of false starts. Credit: NASA via AP

With only a test dummy aboard, Boeing’s astronaut capsule pulled up and parked at the International Space Station for the first time Friday, a huge achievement for the company after years of false starts.

With Starliner’s arrival, NASA finally realizes its longtime effort to have crew capsules from competing U.S. companies flying to the space .

SpaceX already has a running start. Elon Musk’s company pulled off the same test three years ago and has since launched 18 astronauts to the space station, as well as tourists.

“Today marks a great milestone,” NASA astronaut Bob Hines radioed from the orbiting complex. “Starliner is looking beautiful on the front of the station,” he added.

The only other time Boeing’s Starliner flew in space, it never got anywhere near the station, ending up in the wrong orbit.

This time, the overhauled spacecraft made it to the right spot following Thursday’s launch and docked at the station 25 hours later. The automated rendezvous went off without a major hitch, despite the failure of a handful of thrusters.

If the rest of Starliner’s mission goes well, Boeing could be ready to launch its first crew by the end of this year. The astronauts likely to serve on the first Starliner crew joined Boeing and NASA flight controllers in Houston as the action unfolded nearly 270 miles (435 kilometers) up.

Boeing docks crew capsule to space station in test do-over
This image from NASA TV shows the Boeing Starliner docking at the International Space Station, Friday, May 20, 2022. Boeing’s astronaut capsule has arrived at the International Space Station in a critical repeat test flight. Only a test dummy was aboard the capsule for Friday’s docking, a huge achievement for Boeing after years of false starts. Credit: NASA via AP

NASA wants redundancy when it comes to the Florida-based astronaut taxi service. Administrator Bill Nelson said Boeing’s long road with Starliner underscores the importance of having two types of crew capsules. U.S. astronauts were stuck riding Russian rockets once the ended, until SpaceX’s first crew flight in 2020.

Boeing’s first Starliner test flight in 2019 was plagued by software errors that cut the mission short and could have doomed the spacecraft. Those were corrected, but when the new awaited liftoff last summer, corroded valves halted the countdown. More repairs followed, as Boeing chalked up nearly $600 million in do-over costs.

Before letting Starliner get close to the space station Friday, Boeing ground controllers practiced maneuvering the capsule and tested its robotic vision system. Everything checked out well, Boeing said, except for a cooling loop and four failed thrusters. The capsule held a steady temperature, however, and had plenty of other thrusters for steering.

Boeing docks crew capsule to space station in test do-over
This image from NASA TV shows the Boeing Starliner approaching the International Space Station, Friday, May 20, 2022. Boeing’s astronaut capsule has arrived at the International Space Station in a critical repeat test flight. Only a test dummy was aboard the capsule for Friday’s docking, a huge achievement for Boeing after years of false starts. Credit: NASA via AP

Once Starliner was within 10 miles (15 kilometers) of the space station, Boeing flight controllers in Houston could see the space station through the capsule’s cameras. “We’re waving. Can you see us?” joked Hines.

There was only silence from Starliner. The commander’s seat was occupied once again by the mannequin dubbed Rosie the Rocketeer, a space-age version of World War II’s Rosie the Riveter.

The gleaming white-with-blue-trim capsule hovered 33 feet (10 meters) from the station for close to two hours—considerably longer than planned—as flight controllers adjusted its docking ring and ensured everything else was in order. When the finally came, Starliner closed the gap in four minutes, eliciting cheers in Boeing’s control center. Applause erupted once the latches were tightly secured.

  • Boeing docks crew capsule to space station in test do-over
    A United Launch Alliance Atlas V rocket with Boeing’s CST-100 Starliner spacecraft launches from Space Launch Complex 41, Thursday, May 19, 2022, at Cape Canaveral Space Force Station in Florida. Credit: Joel Kowsky/NASA via AP
  • Boeing docks crew capsule to space station in test do-over
    A United Launch Alliance Atlas V rocket carrying the Boeing Starliner crew capsule lifts off on a second test flight to the International Space Station from Space Launch Complex 41 at Cape Canaveral Space Force station in Cape Canaveral, Fla., Thursday, May 19, 2022. Credit: AP Photo/John Raoux
  • Boeing docks crew capsule to space station in test do-over
    A United Launch Alliance Atlas V rocket that will launch Boeing’s CST-100 Starliner spacecraft to the International Space Station stands ready on launch complex 41 at the Cape Canaveral Space Force Station in Cape Canaveral, Fla., Wednesday, May 18, 2022. The launch is scheduled for Thursday evening. Credit: AP Photo/John Raoux
  • Boeing docks crew capsule to space station in test do-over
    A United Launch Alliance Atlas V rocket with Boeing’s CST-100 Starliner spacecraft is rolled out of the Vertical Integration Facility to the launch pad at Space Launch Complex 41 ahead of the Orbital Flight Test-2 (OFT-2) mission, Wednesday, May 18, 2022 at Cape Canaveral Space Force Station in Florida. The launch is scheduled for Thursday evening. Credit: Joel Kowsky/NASA via AP
  • Boeing docks crew capsule to space station in test do-over
    NASA astronauts Butch Wilmore, left, and Mike Fincke answer questions during a news conference at the Kennedy Space Center in Cape Canaveral, Fla., Wednesday, May 18, 2022. Credit: AP Photo/John Raoux

“These last 48 hours have just been a barnstorm, so it’s going to be very good to sleep tonight,” said Mark Nappi, and director of Boeing’s commercial crew program.

It was a double celebration for NASA’s commercial crew program director Steve Stich, who turned 57 Friday. “What an incredible birthday it was,” he told reporters.

The ‘s seven astronauts will unload groceries and gear from Starliner and pack it up with experiments. Unlike SpaceX’s Dragon capsule that splashes down off the Florida coast, Starliner will aim for a landing in New Mexico next Wednesday.


Explore further

NASA, Boeing say Starliner on track for May 19 launch


© 2022 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed without permission.

Citation:
Boeing docks crew capsule to space station in test do-over (2022, May 21)
retrieved 21 May 2022
from https://phys.org/news/2022-05-boeing-docks-crew-capsule-space.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

Adblock test (Why?)



Source link

Continue Reading

Science

Blood moon, big city: Skywatcher captures total lunar eclipse over New York – Galaxy Reporters

Published

 on


Image Credit: FtLaud/Shutterstock

The moon during eclipse burns red high above the yellow lights of New York City in beautiful photos caught by novice astronomer Alexander Krivenyshev.

Alexander Krivenyshev is the president of WorldTimeZone.com, who snapped images of the total lunar eclipse on Sunday night (May 15) from Guttenberg, New Jersey, outside the Hudson River from the Big Apple.

Krivenyshev told Space.com through the email that he maintained through cloudy conditions to get shots of the blood-red moon glowing like a beacon in a light-polluted sky.

The eclipse started at 9:32 p.m EDT on Sunday (0132 GMT on May 16) when the moon nosed into the dark part of Earth’s shadow, recognized as the penumbra, and stopped five hours later. The total eclipse phase, in which Earth’s huger umbral shadow blackened the moon, survived 85 minutes longer than any lunar eclipse in 33 years.

Earth’s closest neighbor temporarily turns coppery red during entire lunar eclipses. This “blood moon” impact is caused by Earth’s atmosphere, which bends some red light throughout the lunar surface while scattering away shorter-wavelength light.

Last weekend’s sky show was nicely observed from America and fractions of Western Europe and West Africa. It was the first total lunar eclipse of the year; however, it won’t be the last. One more eclipse will occur on Nov. 8. The Nov. 8 lunar eclipse will be observed from Australia, eastern Asia, and the western United States.

Adblock test (Why?)



Source link

Continue Reading

Science

Searching for the Milky Way's Black Hole – Skywatching – Castanet.net

Published

 on


When we look into the southern sky close to the horizon on summer evenings, we are looking towards the centre of our galaxy, the Milky Way.

It is lurking around 30,000 light years behind the stars making up the constellation of Sagittarius, “The Archer”. However, thanks to our location in the disc of our galaxy, our view is blocked by huge clouds of stars, gas and dust.

Our first images of the centre of the Milky Way were obtained by means of radio telescopes, which show us what the universe would look like if we could see radio waves rather than light. They revealed a strange, bright and unusually small radio source.

Measurements of the speeds stars orbit the centre of our galaxy indicate that at the same position as the bright radio source lies something very massive, very small and active. The best candidate to explain this is a black hole.

Radio waves have power to penetrate clouds and dust, which is why radar is so useful for navigation, detecting threats and avoiding hazards at night or in bad weather. However, radio waves have this greater penetration power because they are much longer than light waves. This means that to see detail when observing at radio wavelengths we need to use huge antennas.

To have the same ability to discern detail as the human eye, a radio telescope tuned to the wavelength of emissions from cosmic hydrogen (21cm) the antenna would need to be about a kilometre in diameter. Moreover, black holes are small by cosmic standards and at great distances, so to discern any details the radio telescope would need an antenna the size of the Earth.

This sounds impossible, but there is a solution, a technique called “Very Long Baseline Interferometry”.

In the 1960s, Canada was the first country to succeed in combining radio telescopes thousands of kilometres apart so that they would have the detail discerning ability of a radio telescope thousands of kilometres in diameter.

This procedure has made possible a powerful, new astronomical instrument, the Event Horizon Telescope (EHT).

Several radio telescopes, thousands of kilometres apart operate in collaboration to observe the centre of the Milky Way at the same time. One of them is the Atacama Large Millimetre Array, located in Chile, in which Canada is a partner. In addition, scientists at several Canadian universities are involved.

The collaboration is named after the boundary that forms around black holes, called the event horizon. This is a one-way boundary in space-time—stuff can fall in but nothing, not even light, gets out. This is why they are called black holes.

However, even if we cannot see the black holes directly, we can certainly see the disc of material swirling around the black holes as it gets sucked in. This stuff gets very hot, and has intense magnetic fields trapped in it, so the black hole announces itself with radio emissions and X-rays from that disc.

The first target for the Event Horizon Telescope was the galaxy M87, located some 55 million light years away. It had long been suspected that a very energetic black hole lies at its centre, a big one, around 5 billion times the mass of the Sun. The EHT gave us our first image of that black hole.

Then the EHT radio telescopes were turned on the centre of our galaxy, and got our first image of our black hole. Luckily for us, it is much less massive and active than the one at the centre of M87. At four million times the mass of the Sun, it is relatively tiny.

We believe most spiral galaxies have big black holes in their cores. It is not clear whether galaxies get them when they form or they appear later. However, learning about their roles in galaxies should tell us more about how galaxies form and evolve to the point where they develop stars and planets, and because we live in one, it would be nice to know.

•••

• Venus, Jupiter, Mars and Saturn are still lined up in the dawn glow, in order of decreasing brightness.

• The Moon will be new on May 30.

This article is written by or on behalf of an outsourced columnist and does not necessarily reflect the views of Castanet.

Adblock test (Why?)



Source link

Continue Reading

Trending