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What Are Quantum Gravity's Alternatives To String Theory?
Fortune ^ | December 17, 2015 | Ethan Slegel

Posted on 12/19/2015 7:19:11 AM PST by C19fan

The Universe we know and love — with Einstein’s General Relativity as our theory of gravity and quantum field theories of the other three forces — has a problem that we don’t often talk about: it’s incomplete, and we know it. Einstein’s theory on its own is just fine, describing how matter-and-energy relate to the curvature of space-and-time. Quantum field theories on their own are fine as well, describing how particles interact and experience forces. Normally, the quantum field theory calculations are done in flat space, where spacetime isn’t curved. We can do them in the curved space described by Einstein’s theory of gravity as well (although they’re harder — but not impossible — to do), which is known as semi-classical gravity. This is how we calculate things like Hawking radiation and black hole decay.

(Excerpt) Read more at forbes.com ...


TOPICS: Science
KEYWORDS: gravity; physics; quantum; quantumgravity; string; stringtheory; theory
Are any of these alternative theories testable? String theory makes many uncomfortable because it is untestable.
1 posted on 12/19/2015 7:19:11 AM PST by C19fan
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To: C19fan

I’m sure that Sheldon on the Big Bang will clear this up next year.


2 posted on 12/19/2015 7:22:24 AM PST by Grampa Dave (Trump is making so much money for the media they’re learning to love capitalism!! (jimrob))
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To: C19fan

God does not play dice.


3 posted on 12/19/2015 7:48:03 AM PST by Hoodat (Article 4, Section 4)
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To: C19fan

Isn’t this all just theory anyway? Quantum mechanics experiments just seem to result in more questions. Maybe God doesn’t want us to know.


4 posted on 12/19/2015 7:53:17 AM PST by Wildbill22 (They have us surrounded again, the poor bastards- Gen Creighton Williams Abrams)
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To: C19fan

All that matters is whether any of these prove or are caused by anthropogenic global warming.


5 posted on 12/19/2015 7:55:27 AM PST by redangus
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To: C19fan

Woodwind Theory?


6 posted on 12/19/2015 7:56:24 AM PST by IronJack
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To: C19fan

Always get excited reading these articles.
Going to dust of my microscope and telescope and work on these problems today.


7 posted on 12/19/2015 8:00:22 AM PST by jcon40
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To: C19fan

You need shorter and more flexible pieces of string.


8 posted on 12/19/2015 8:05:25 AM PST by Paladin2 (my non-desktop devices are no longer allowed to try to fix speling and punctuation, nor my gran-mah.)
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To: C19fan

My version of string theory is testable. If she has big ones and the bikini string didn’t break then it is valid.

Note: From now on until the character problem is fixed on FR I am just going to read the title and make inane comments. This follows on my tradition of simply making inane comments for no reason.


9 posted on 12/19/2015 8:05:50 AM PST by mad_as_he$$ ("It gets late early around here..." Yogi)
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To: mad_as_he$$

The corollary of string theory is thong theory.


10 posted on 12/19/2015 8:09:18 AM PST by Noumenon (Resistance. Restoration. Retribution.)
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To: Hoodat
God does not play dice.

So said Einstein.

But on a quantum level God does nothing but dice with the universe.

The alternative is a universe where every action, no matter how great or small, is utterly fixed by the clockwork mechanics of the universe.

That pretty much eliminates free will.

11 posted on 12/19/2015 8:21:34 AM PST by null and void (I've been to Switzerland. I liked it, the flag's a big plus!)
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To: Noumenon
I'm pretty sure the flux capacitor was based on the thong theory.


12 posted on 12/19/2015 8:45:43 AM PST by DannyTN
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To: C19fan

Sheldon Cooper likes string theory, so I don’t.


13 posted on 12/19/2015 10:19:58 AM PST by I want the USA back (Patriarchal binary all original-equipment breeder and White-privileged crusader.)
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To: Hoodat

Yes, he does. And he throws them in places where you can’t see them. [That’s the historical response]


14 posted on 12/19/2015 10:31:16 AM PST by sparklite2 (Islam = all bathwater, no baby.)
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To: sparklite2; null and void

They probably said the same thing about the Bohr atom.


15 posted on 12/19/2015 10:36:09 AM PST by Hoodat (Article 4, Section 4)
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To: C19fan

There is no flat space if matter exists within it. Wherever matter exists, space is warped.


16 posted on 12/19/2015 10:55:17 AM PST by Ozark Tom
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To: Noumenon

But can they be connected. I personally think they should all be disconnected.


17 posted on 12/19/2015 11:34:48 AM PST by biff
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To: C19fan

The crisis, as Ellis and Silk tell it, is the wildly speculative nature of modern physics theories, which they say reflects a dangerous departure from the scientific method.

Many of today’s theorists - chief among them the proponents of string theory and the multiverse hypothesis - appear convinced of their ideas on the grounds that they are beautiful or logically compelling, despite the impossibility of testing them.

Ellis and Silk accused these theorists of ‘moving the goalposts’ of science and blurring the line between physics and pseudoscience. ‘The imprimatur of science should be awarded only to a theory that is testable,’ Ellis and Silk wrote, thereby disqualifying most of the leading theories of the past 40 years. ‘Only then can we defend science from attack.’

https://www.quantamagazine.org/20151216 ... f-science/


18 posted on 12/19/2015 12:45:46 PM PST by sparklite2 (Islam = all bathwater, no baby.)
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Wants me to disable ad blocking. No thanks


19 posted on 12/19/2015 11:58:05 PM PST by Old_And_Grumpy
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To: 6SJ7; AdmSmith; AFPhys; Arkinsaw; allmost; aristotleman; autumnraine; bajabaja; ...
Thanks C19fan.

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20 posted on 12/20/2015 1:52:29 PM PST by SunkenCiv (Here's to the day the forensics people scrape what's left of Putin off the ceiling of his limo.)
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