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What Are Quantum Gravity's Alternatives To String Theory?
Forbes/Science ^ | 17 Dec, 2015 | Ethan Siegel

Posted on 12/20/2015 8:13:09 AM PST by MtnClimber

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: particles; relativity

1 posted on 12/20/2015 8:13:09 AM PST by MtnClimber
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To: MtnClimber

There is still much we don’t know!


2 posted on 12/20/2015 8:14:40 AM PST by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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Einstein's theory on its own is just fine

If absolutes are a problem for you.

3 posted on 12/20/2015 8:18:45 AM PST by o_1_2_3__ ( –)
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To: MtnClimber

That is an understatement.


4 posted on 12/20/2015 8:24:58 AM PST by dhs12345
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To: MtnClimber

Simple answer...Get a big enough ball of string and it makes its own gravity.


5 posted on 12/20/2015 8:25:15 AM PST by soycd
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To: MtnClimber

David Bohms holographic universe. The observed evidence points this direction. Many have trouble dealing with its implications. Don’t ask me any more. There are probably less than two handfuls on the planet that can halfway grasp its implications. ( David Bohm was Einsteins protege at Princeton)


6 posted on 12/20/2015 8:33:05 AM PST by D Rider
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To: MtnClimber
This is how we calculate things like Hawking radiation and black hole decay.

Black hole decay.

obama. Unprotected sex. Just sayin'...

7 posted on 12/20/2015 8:33:16 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: MtnClimber

Back in the 80s, I remember talking to a physics professor along with a fellow student. As I recall, our Dr. Wersinger talked about the possibility of time being quantized and how it would mean that calculus wouldn’t be quite right since calculus assumed a continuum.


8 posted on 12/20/2015 8:48:15 AM PST by Maurice Tift (Never wear anything that panics the cat. -- P.J. O'Rourke)
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To: MtnClimber

Knock knock knock Penny. Knock knock knock Penny. Knock knock knock Penny.


9 posted on 12/20/2015 9:02:53 AM PST by goodwithagun (My gun has killed fewer people than Ted Kennedy's car.)
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To: MtnClimber

NERDS!


10 posted on 12/20/2015 9:03:22 AM PST by steve8714 (Evidently Breitbart.com has changed their name to "not responding".)
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To: Maurice Tift

Numerical approximation is a Good Thing.


11 posted on 12/20/2015 9:03:45 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: MtnClimber

What I’d like to know is...
with all the countless stars, all the planets, all the inhabited planets, all the intelligent life that should be in the universe, how come nobody has blown it up yet?


12 posted on 12/20/2015 10:04:11 AM PST by Buttons12
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To: Buttons12

Who is always standing by to say, “Hold on there buddy, you don’t want to touch that switch.”


13 posted on 12/20/2015 10:07:44 AM PST by Buttons12
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To: MtnClimber

I could go in to detail, bit I don’t want to hog the thread.


14 posted on 12/20/2015 10:36:56 AM PST by Wolfie
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To: Wolfie
I think the particle physicists should search search for 0bama's brain.
15 posted on 12/20/2015 10:43:20 AM PST by MtnClimber (For photos of Colorado scenery and wildlife, click on my screen name for my FR home page.)
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