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Mon Jun 10, 2019, 04:11 PM

White Holes: Black Holes' Neglected Twins


By Charlie Wood 3 hours ago



This visualization shows a jet blasting from a black hole near the speed of light. In theory, a white hole looks similar to a black hole, but instead of sucking matter in, a white hole pushes matter away. (Image: © NASA/JPL-Caltech)


White holes were long thought to be a figment of general relativity born from the same equations as their collapsed star brethren, black holes. More recently, however, some theorists have been asking whether these twin vortices of spacetime may be two sides of the same coin.

To a spaceship crew watching from afar, a white hole looks exactly like a black hole. It has mass. It might spin. A ring of dust and gas could gather around the event horizon — the bubble boundary separating the object from the rest of the universe. But if they kept watching, the crew might witness an event impossible for a black hole — a belch. "It's only in the moment when things come out that you can say, 'ah, this is a white hole,'" said Carlo Rovelli, a theoretical physicist at the Centre de Physique Théorique in France.

Physicists describe a white hole as a black hole's "time reversal," a video of a black hole played backwards, much as a bouncing ball is the time reversal of a falling ball. While a black hole's event horizon is a sphere of no return, a white hole's event horizon is a boundary of no admission — space-time's most exclusive club. No spacecraft will ever reach the region's edge.

Objects inside a white hole can leave and interact with the outside world, but since nothing can get in, the interior is cut off cut off from the universe's past: No outside event will ever affect the inside. "Somehow it's more disturbing to have a singularity in the past that can affect everything in the outside world," said James Bardeen, a black-hole pioneer and professor emeritus at the University of Washington.

More:
https://www.space.com/white-holes.html

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Response to Judi Lynn (Original post)

Mon Jun 10, 2019, 09:30 PM

1. Good stuff! Thanks for the link! nt

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Response to Wounded Bear (Reply #1)

Tue Jun 11, 2019, 04:25 AM

2. Thank you for reading it, Wounded Bear. n/t

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Response to Judi Lynn (Original post)

Tue Jun 11, 2019, 10:39 AM

3. Universe is amazing - but,

when the topic was "White Holes" I thought it was going to be about Trump supporters.

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Response to Judi Lynn (Original post)

Tue Jun 11, 2019, 11:24 AM

4. I hate to rain on this parade, but the existence of white holes is a purely hypothetical construct.

There is no know mechanism or physical process through which a white hole could be formed, nor has one ever been observed. The article seems to imply that there is evidence of white holes, but there is not. That is not to say one will never be found, but at this point it is a hypothesis and nothing more.

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Response to Nitram (Reply #4)

Tue Jun 11, 2019, 02:42 PM

5. Stating the obvious

rains on nobody's parade. Theorists tend to theorize, including Einstein, Hawking, and many more.

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Response to billh58 (Reply #5)

Tue Jun 11, 2019, 05:32 PM

6. It isn't even a theory, because there is no hypothesis yet for how such a phenomenon would occur.

In the case of black holes the theory was based on calculations on the known size and evolution of stars, and from that followed the theory that a star might collapse in on itself after a supernova.

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Response to Nitram (Reply #4)

Thu Jun 13, 2019, 09:45 PM

10. Excuse me

But TIME is also a construct.

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Response to Haggis for Breakfast (Reply #10)

Thu Jun 13, 2019, 10:38 PM

11. Cute. So is gravity. So is mathematics. So is physics. You are using a computer because they all are

relevant in the real world. White holes have no such theoretical support. They are just an idea.

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Response to Nitram (Reply #11)

Fri Jun 14, 2019, 12:23 AM

13. You seem to be taking this personally.

All I and others are saying is that it is possible, even though we still don't have actual scientific evidence of it. Hardly the first time in science for that order to appear before proof is detected.

Decades ago (early 80s), while in Grad School, I argued that there was a case to be made for water or ice to be found on Mars. At the time, NOBODY believed that was possible. I got slagged by everybody in the Geology Department. I had been able to acquire as much info/intel as NASA and others could sent me for my thesis. When I laid it all out and constructed my argument, step by step, process by process, chemical analysis by chemical analysis and all of the other obvious components and outliers, I made an excellent case. The Dean of the Geology Dept had heard of my paper and wanted to see it for himself. I wasn't finished with all my writing yet, so he asked me if I would allow him to be my editor for the paper (something that I never heard of anyone ever doing before). I didn't know what to think, but I didn't think it would be wise to say no. In the end all he did was write a preface to my paper. Part philosophical, part academic, he set up his section basically to open peoples' minds. It worked. I got the grade for the paper. Five years later, as I was leaving University, the science world was rocked by the news that small amounts of water had been verified on the surface of Mars. We held a Vindication Party for me. It was sweet. Maybe someday we'll be holding another vindication party for the students who puts it all together the first time that white holes are here. Won't that be great ?

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Response to Haggis for Breakfast (Reply #13)

Fri Jun 14, 2019, 07:10 PM

14. I don't take it personally, but I do take science seriously. I take the correct use of scientific

words seriously, The ignorance about science in this country has led to a large percentage of people not believing in evolution or climate change, and failing to understand the most basic of scientific concepts. The word "theory" being missed as the poster I replied to did is a perfect example of the scientific illiteracy that seems to run rampant in the US. My initial reaction to the article was that the way it is written is bound to mislead people with low scientific literacy into believing that the concept of a white hole is more than a hypothesis that has never been observed and which has no underlying scientific theory that can explain how white hole is formed. The "visualization" suggests observations have been made. I had to look the concept up to fond out that it is a bit of a unicorn.

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Response to Judi Lynn (Original post)

Tue Jun 11, 2019, 10:45 PM

7. Like a gamma ray burst?

I've never heard of white holes, but GRBs sound similar. Those devastate anything in their path.

Thanx for posting.

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Response to JohnnyRingo (Reply #7)

Thu Jun 13, 2019, 01:23 AM

9. Had never heard of the term before seeing this article.

Thanks for your post!

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Response to Judi Lynn (Original post)

Wed Jun 12, 2019, 06:31 PM

8. A white hole: An explosive event the magnitude of which ranges from a little belch to a Big Bang.

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Response to Marcuse (Reply #8)

Thu Jun 13, 2019, 10:40 PM

12. Oh, gosh! You mean like the Moby Dick, the Great White Whale?

Last edited Fri Jun 14, 2019, 07:11 PM - Edit history (1)

What evidence is there that white holes are explosive events which range from a little belch to a Big Bang?

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