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2019年4月11日星期四

拍到黑洞了 - 黑洞否定者現在做什麼好?

拍到黑洞了 - 黑洞否定者現在做什麼好?

Black Hole Photographed — What Do Black Hole Deniers Do Now?


“Black holes are the most mysterious objects in the universe. We have seen what we thought was unseeable. We have taken a picture of a black hole.”
Sheperd Doeleman, director Event Horizon telescope (EHT) — a network of eight radio telescopes spanning the globe that captured the image – revealed the photograph on April 10 at a press conference loaded with top scientists and astronomers waiting to view the definitive proof of what they have all believed on faith, indicators and scientific models – that black holes exist.
Or do they?
Wait, you say … didn’t you see the photograph? Sure, but there are tens of thousands of photographs of the Earth from outer space showing that it’s a globe. Do any of them convince the Flat Earthers?
“This work investigates the backreaction of Hawking radiation on the interior of a gravitationally collapsing star, in a Hartle–Hawking initial vacuum. It shows that due to the negative energy Hawking radiation in the interior, the collapse of the star stops at a finite radius, before the singularity and the event horizon of a black hole have a chance to form. That is, the star bounces instead of collapsing to a black hole.”

What do we do with all of these ‘artist depictions’ now?
Meet Laura Mersini-Houghton, author of “Backreaction of Hawking radiation on a gravitationally collapsing star I: Black holes?”, a paper she wrote in 2014 in which she used two seemingly conflicting theories to seemingly prove that black holes don’t exist because they can’t possibly come into being in the first place. Mersini-Houghton is a physics professor at the University of North Carolina at Chapel Hill. A press release by the college titled “Carolina’s Laura Mersini-Houghton shows that black holes do not exist” gives a simple explanation, referencing Stephen Hawking in an attempt to validate it.
“She and Hawking both agree that as a star collapses under its own gravity, it produces Hawking radiation. However, in her new work, Mersini-Houghton shows that by giving off this radiation, the star also sheds mass. So much so that as it shrinks it no longer has the density to become a black hole. Before a black hole can form, the dying star swells one last time and then explodes. A singularity never forms and neither does an event horizon. The take home message of her work is clear: there is no such thing as a black hole.”
There you have it. Needless to say, black hole believers reacted strongly against the paper. In 1974, Stephen Hawking proposed that a black hole temporarily entraps matter and energy that can eventually reemerge as outgoing radiation — Hawking Radiation. Most responses to Mersini-Houghton’s paper centered on the idea that a black hole doesn’t emit enough Hawking Radiation to shrink its mass down to Mersini-Houghton’s level which would prevent a black hole from forming.

Close but no cigar.
Mersini-Houghton was not the only black hole denier (No Black Holer?), just the latest and most famous. All had one last fall-back position – if black holes exist, why isn’t there a photograph of one. Well, now there is and there are sure to be more. As of this writing, there’s been no comment on the photo by Mersini-Houghton.
What do you think? Did the photo of Earth from the moon 50 years ago convince Flat Earthers?




https://mysteriousuniverse.org/2019/04/black-hole-photographed-what-do-black-hole-deniers-do-now/







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