black holes tagged posts

Scientists find First Evidence that Black Holes are the Source of Dark Energy

NGC524.jpg
​NGC 524 is a galaxy in the constellation Pisces, and is one of the galaxies observed in this study. It is at a distance of about 90 million light years away from Earth. Credit: ESA/Hubble​

Observations of supermassive black holes at the centers of galaxies point to a likely source of dark energy—the ‘missing’ 70% of the universe.

The measurements from ancient and dormant galaxies show black holes growing more than expected, aligning with a phenomenon predicted in Einstein’s theory of gravity. The result potentially means nothing new has to be added to our picture of the universe to account for dark energy: black holes combined with Einstein’s gravity are the source.

The conclusion was reached by a team of 17 researchers in nine countries, led by the University of Hawai’i a...

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Are Black Holes Time Machines? Yes, but there’s a Catch

Are black holes time machines? Yes, but there's a catch
Credit: NASA / Goddard Space Flight Center / Jeremy Schnittman

Black holes form natural time machines that allow travel to both the past and the future. But don’t expect to be heading back to visit the dinosaurs any time soon.

At present, we don’t have spacecraft that could get us anywhere near a black hole. But, even leaving that small detail aside, attempting to travel into the past using a black hole might be the last thing you ever do.

What are black holes?

A black hole is an extremely massive object that is typically formed when a dying star collapses in on itself.

Like planets and stars, black holes have gravitational fields around them. A gravitational field is what keeps us stuck to Earth, and what keeps Earth revolving around the Sun.

As a rule of thumb, the mor...

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Resolving the Black Hole ‘Fuzzball or Wormhole’ debate

Study adds more certainty to theory involving information paradox. Black holes really are giant fuzzballs, a new study says.

The study attempts to put to rest the debate over Stephen Hawking’s famous information paradox, the problem created by Hawking’s conclusion that any data that enters a black hole can never leave. This conclusion accorded with the laws of thermodynamics, but opposed the fundamental laws of quantum mechanics.

“What we found from string theory is that all the mass of a black hole is not getting sucked in to the center,” said Samir Mathur, lead author of the study and professor of physics at The Ohio State University...

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Are Black Holes and Dark Matter the same?

“Black holes of different sizes are still a mystery,” Hasinger explained. “We don’t understand how supermassive black holes could have grown so huge in the relatively short time available since the universe existed.”

Proposing an alternative model for how the universe came to be, a team of astrophysicists suggests that all black holes — from those as tiny as a pin head to those covering billions of miles — were created instantly after the Big Bang and account for all dark matter.

That’s the implication of a study by astrophysicists at the University of Miami, Yale University, and the European Space Agency that suggests that black holes have existed since the beginning of the universe and that these primordial black holes could be as-of-yet unexplained dark matter...

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