Posted on 12/21/2018 12:36:00 PM PST by ETL
Black holes are among the most mysterious places in the universe; locations where the very fabric of space and time are warped so badly that not even light can escape from them. According to Einstein's theory of general relativity, at their center lies a singularity, a place where the mass of many stars is crushed into a volume with exactly zero size. However, two recent physics papers, published on Dec.10 in the journals Physical Review Letters and Physical Review D, respectively, may make scientists reconsider what we think we know about black holes. Black holes might not last forever, and it's possible that we've completely misunderstood their nature and what they look like at the center, according to the papers.
(Excerpt) Read more at livescience.com ...
Let’s wait and see.
Since the future hasn’t happened yet, I
BS.................
“and it’s possible that we’ve completely misunderstood their nature and what they look like at the center,”
Well, I agree with that part.
I’m having venison neck roast for supper.....
This is what happens when 8th grade science students smoke dope.
So this won't open up new career opportunities for history majors?
I can see the future headline: I was sucked into a black hole.
Hasn’t this been a hollywood science fiction plot line since, forever?
That’s impossible, so it doesn’t happen.
I’ve been to the future and I can assure you, nothing from this time made it there. Except a bag of Cheetos, something in my refrigerator, and a bill from Verizon that is more than 2,000 years overdue.
I was just reading about Arthur C. Clarke. He said his inspiration for that scene was looking at a slice of the human brain under a microscope.
Red Badger is following the fine example set by his ancestors through the centuries...
1. Galileo Galilei’s Experiment on Speed of Falling Objects - “BS”
2. James Prescott Joule‘s Energy Conservation Experiment - “BS”
3. Isaac Newton’s Discovery of Light Spectrum - “BS”
4. Henry Cavendish’s Earth Density Experiment - “BB”
5. Hippolyte Fizeau’s Experiment on Light Speed - “BS”
6. Robert Millikan’s Measurement of the Charge of Electron - “BS”
7. Enrico Fermi’s Nuclear Chain Reaction Experiment - “BS”
8. Rutherford’s Gold Foil Experiment and Atomic Structure - “BS”
9. Rosalind Franklin DNA Radiographs - “BS”
10. Foucault’s Pendulum Experiment - “BS”
I like chocolate.
Interesting.
December 10, 2018• Physics 11, 127
Loop quantum gravity—a theory that extends general relativity by quantizing spacetime—predicts that black holes evolve into white holes.
Black holes are remarkable entities. On the one hand, they have now become familiar astrophysical objects that have been observed in large numbers and in many ways: we have evidence of stellar-mass holes dancing around with a companion star, of gigantic holes at the center of galaxies pulling in spiraling disks of matter, and of black hole pairs merging in a spray of gravitational waves. All of this is beautifully accounted for by Einstein’s century-old theory of general relativity. Yet, on the other hand, black holes remain highly mysterious. We see matter falling into them, but we are in the dark about what happens to this matter when it reaches the center of the hole.
Abhay Ashtekar and Javier Olmedo at Pennsylvania State University in University Park and Parampreet Singh at Louisiana State University, Baton Rouge, have taken a step toward answering this question [1]. They have shown that loop quantum gravity—a candidate theory for providing a quantum-mechanical description of gravity—predicts that spacetime continues across the center of the hole into a new region that exists in the future and has the geometry of the interior of a white hole. A white hole is the time-reversed image of a black hole: in it, matter can only move outwards. The passage “across the center” into a future region is counterintuitive; it is possible thanks to the strong distortion of the spacetime geometry inside the hole that is allowed by general relativity.
This result supports a hypothesis under investigation by numerous research groups: the future of all black holes may be to convert into a real white hole, from which the matter that has fallen inside can bounce out. However, existing theories have not been able to fully show a way for this bounce to happen. That loop quantum gravity manages to do it is an indication that this theory has ripened enough to tackle real-world situations.
The reason why we are in the dark about aspects of black hole physics is that quantum phenomena dominate at the center and in the future of these objects. Classical general relativity predicts that a black hole lives forever and that its center is a “singularity” where space and time end. These predictions are not realistic because they disregard quantum effects. To tackle these effects we need a quantum theory of gravity. We don’t yet have consensus on such a theory, but we have candidates, some of which are now reaching the point of allowing actual calculations on the quantum behavior of black holes. Loop quantum gravity, which has a clean conceptual structure and a well-defined mathematical formulation based on representing the fabric of space as a spin network that evolves in time, is one such theory.
During the last few years, a number of research groups have applied loop theory to explore the evolution of black holes. These efforts are building a compelling picture based on a black-to-white-hole transition scenario (Fig. 1), which can be summarized as follows [2]. At the center of the black hole, space and time do not end in a singularity, but continue across a short transition region where the Einstein equations are violated by quantum effects. From this region, space and time emerge with the structure of a white hole interior, a possibility suggested in the 1930s by physicist John Lighton Synge [3].
As the hole’s center evolves, its external surface, or “horizon,” slowly shrinks because of the emission of radiation—a phenomenon first described by Stephen Hawking. This shrinkage continues until the horizon reaches the Planck size (the characteristic scale of quantum gravity) or earlier [4, 5], at which point a quantum transition (“quantum tunneling”) happens at the horizon, turning it into the horizon of a white hole (Fig. 2).
Thanks to the peculiar distorted relativistic geometry, the white hole interior born at the center joins the white horizon, completing the formation of the white hole.
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