What is the impact of the refutation of "quantum foam"?

  • Thread starter sshai45
  • Start date
  • Tags
    Impact
In summary, the article discusses a paper which claims that data shows that the "quantum foam" does not exist, and has no impact on current theories of quantum gravity.
  • #1
sshai45
86
1
Hi.

I just saw this:

http://phys.org/news/2015-03-einstein-scientists-spacetime-foam.html

They are saying that they have found data showing that the "quantum foam" does not exist. What is the impact of the disproof of "quantum foam", anyways, on the search for a theory of quantum gravity?
 
Physics news on Phys.org
  • #2
No impact on covariant LQG (spin foam models) because the theory does not predict energy-dependent speed of light.

I don't know of an approach to QG which is currently being worked on which does predict energy-dependent speed of light.

I can't say what the article means by "quantum foam" but the scientists quoted were testing for energy-dependent speed of light, so "quantum foam"must be some theory they have in mind which has that feature.
Or maybe it is just a way they and the journalist thought up to interest the public.
 
Last edited:
  • #3
  • #4
sbrothy said:
Sabine Hossenfelder discuss this paper at her blog I think. Or something similar at least.: http://backreaction.blogspot.dk/
...and a very nice and thorough, if perhaps unusually clement analysis of hers that is. Thanks for the link.
 
Last edited:
  • #5
marcus said:
No impact on covariant LQG (spin foam models) because the theory does not predict energy-dependent speed of light.

I don't know of an approach to QG which is currently being worked on which does predict energy-dependent speed of light.

I can't say what the article means by "quantum foam" but the scientists quoted were testing for energy-dependent speed of light, so "quantum foam"must be some theory they have in mind which has that feature.
Or maybe it is just a way they and the journalist thought up to interest the public.

The abstract for the paper is here:
http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3270.html

They claim it challenges something called "Wheeler's 'space-time foam' picture of quantum gravity (QG)" and that "Our results set a benchmark constraint to be reckoned with by any QG model that features spacetime quantization.".
 
Last edited by a moderator:
  • #6
Yes Sabine H. assigns the blame here more to the loose (to say the least) wording of these claims in the paper than to poor reporting by the journalists.

In short, none of the main proposed theories of QG is in the least impacted, the paper rules out a few somewhat exotic ones that were already considered unlikely.
 
Last edited:
  • #7
sshai45 said:
The abstract for the paper is here:
http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3270.html

They claim it challenges something called "Wheeler's 'space-time foam' picture of quantum gravity (QG)" and that "Our results set a benchmark constraint to be reckoned with by any QG model that features spacetime quantization.".
Their reference for that "picture" is to some pages in a 1964 book:

Wheeler, J. in Relativity, Groups and Topology (eds DeWitt, C. M. & DeWitt, B. S.) 467–500(Gordon and Breach, 1964).

As I said, I don't know any QG approach that is currently being worked on that fills the bill.

Brody and Wabbit have mentioned Bee Hossenfelder's blog commentary on this paper. You might find it informative. She is a recognized expert on QG testing and phenomenology---and has organized several international conferences on potential tests of QG theories/pictures/effects.

Wheeler (Feynman's PhD advisor) was a wonderfully creative man. Unfortunately he is not around these days to take up these authors' "challenge" to his 1964 foam notion.
 
Last edited by a moderator:

Related to What is the impact of the refutation of "quantum foam"?

1. What is "quantum foam" and why is it important?

"Quantum foam" refers to the concept of spacetime being made up of tiny, constantly fluctuating quantum particles. It is important because it is a fundamental aspect of quantum theory and has implications for our understanding of the universe and its origins.

2. What is the significance of the refutation of "quantum foam"?

The refutation of "quantum foam" would impact our current understanding of quantum theory and how it relates to the nature of spacetime. It would also have implications for theories about the early universe and the Big Bang.

3. How was the refutation of "quantum foam" discovered?

The refutation of "quantum foam" was proposed by theoretical physicists who were studying the effects of gravity on the quantum level. Through mathematical calculations and experiments, they found that the concept of "quantum foam" was not necessary to explain these effects.

4. What does the refutation of "quantum foam" mean for other theories in physics?

The refutation of "quantum foam" could potentially challenge other theories in physics that rely on the existence of this concept, such as string theory and loop quantum gravity. It may also lead to new theories and models being developed to better explain the nature of spacetime.

5. How will the refutation of "quantum foam" impact future research in the field of quantum physics?

The refutation of "quantum foam" will likely spark further research and discussions in the field of quantum physics as scientists work to understand the implications of this discovery. It may also lead to new experiments and investigations to better understand the fundamental nature of spacetime and the quantum world.

Similar threads

I Is the Continuum Limit of Spin Foam Dynamics Equivalent to Massless Gravitons?
    • Beyond the Standard Models
Replies
2
Views
2K
I Two recent tests of loop quantum gravity theory
    • Beyond the Standard Models
Replies
10
Views
1K
I At which point is gravity inconsistent with quantum mechanics?
    • Beyond the Standard Models
Replies
24
Views
4K
Landmark paper by Smolin pulls together recent QG research
    • Beyond the Standard Models
Replies
13
Views
4K
I Ads/CFT and Ashtekar variables or spinfoam
    • Beyond the Standard Models
Replies
7
Views
2K
Quantum foam -RIP, or needs new formulation?
    • Beyond the Standard Models
Replies
11
Views
3K
What is the Connection between Quantum Foam and Wormholes?
    • Beyond the Standard Models
Replies
2
Views
3K
I What Are the Empirical Challenges Facing Quantum Gravity Theories?
    • Beyond the Standard Models
4
Replies
105
Views
11K
A Symmetry/Conservation Violated in Quantum Anomaly
    • Beyond the Standard Models
Replies
2
Views
2K
I Can Core Theory Be Derived From Nine Lines?
    • Beyond the Standard Models
Replies
6
Views
2K

Hot Threads

Recent Insights

Back
Top