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Emergent Spacetime in Einstein's Schizophrenic World

September 7 2017 at 1:22 PM
Pentcho Valev 

 
Robbert Dijkgraaf: "In some sense, this exercise is exactly the opposite of what Einstein tried to achieve. His aim was to build all of the laws of nature out of the dynamics of space and time, reducing physics to pure geometry. For him, space-time was the natural "ground level" in the infinite hierarchy of scientific objects - the bottom of the Grand Canyon. The present point of view thinks of space-time not as a starting point, but as an end point, as a natural structure that emerges out of the complexity of quantum information, much like the thermodynamics that rules our glass of water." https://www.quantamagazine.org/to-solve-the-biggest-mystery-in-physics-join-two-kinds-of-law-20170907/

My comment in Quanta (removed immediately by Robbert Dijkgraaf):

Spacetime has already emerged, deductively, from Einstein's 1905 (false) constant-speed-of-light postulate - it cannot reemerge from other premises:

"Special relativity is based on the observation that the speed of light is always the same, independently of who measures it, or how fast the source of the light is moving with respect to the observer. Einstein demonstrated that as an immediate consequence, space and time can no longer be independent, but should rather be considered a new joint entity called "spacetime." http://community.bowdoin.edu/news/2015/04/professor-baumgarte-describes-100-years-of-gravity/

Pentcho Valev

 
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Re: Emergent Spacetime in Einstein's Schizophrenic World

September 7 2017, 1:39 PM 

Quanta Magazine moderates comments to facilitate an informed, substantive, civil conversation. Abusive, profane, self-promotional, misleading, incoherent or off-topic comments will be rejected. Moderators are staffed during regular business hours (New York time) and can only accept comments written in English.

 
 
Anonymous

Re: Emergent Spacetime in Einstein's Schizophrenic World

September 7 2017, 2:08 PM 

Quanta Magazine accepts all comments that say ------> its articles are brilliant - like this 1 - by Sonali Sengupta ------>>> {Insightful and Brilliant Article. A lot to ponder about."In many ways, thermodynamics is the gold standard of an emergent law, describing the collective behavior of a large number of particles, irrespective of many microscopic details. It captures an astonishingly wide class of phenomena in succinct mathematical formulas. The laws hold in great universality — indeed, they were discovered before the atomic basis of matter was even established. And there are no loopholes. For example, the second law of thermodynamics states that a system's entropy — a measure of the amount of hidden microscopic information — will always grow in time".}

 
 
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Re: Emergent Spacetime in Einstein's Schizophrenic World

September 7 2017, 3:20 PM 



The science news aggregator RealClearScience ranked Quanta Magazine No. 2 on its list of "The Top 10 Websites for Science in 2016
https://en.wikipedia.org/wiki/Quanta_Magazine

 
 
Pentcho Valev

Re: Emergent Spacetime in Einstein's Schizophrenic World

September 8 2017, 2:52 AM 

Robbert Dijkgraaf is not alone - there are many silly attempts to deduce spacetime from premises different from the principle of relativity and the constancy of the speed of light:

"With the help of a grant of over $60,000 from FQXi he [Sean Carroll] hopes to explain the very emergence of space and time using quantum physics. [...] The question of whether one can recover spacetime itself from the ideas of quantum mechanics, thereby understanding how all our classical notions arise from quantum theory, is a fascinating one." http://fqxi.org/community/articles/display/213

Sabine Hossenfelder: "...hints at a deeper truth: that space-time is made of small elements whose collective motion gives rise to the force we call gravity. In this case, gravity would not be a truly fundamental phenomenon, but an emergent one."
https://www.forbes.com/sites/startswithabang/2017/02/28/is-dark-matter-about-to-be-killed-by-emergent-gravity/

"The challenge is to somehow bring the notion of granularity to spacetime, bring the discrete to the continuous. This is the problem that has baffled theoretical physicists for at least half a century." http://radio.wpsu.org/post/reality-not-what-we-can-see

Bringing granularity to spacetime is equivalent to painting the principle of relativity in yellow. Spacetime is, essentially, the Lorentz transformation equations - nothing more, nothing less. One cannot deduce these equations from premises different from the principle of relativity and the constancy of the speed of light. If the present spacetime is wrong and should be replaced, then an underlying premise, e.g. Einstein's constant-speed-of-light postulate, is false.

Pentcho Valev

 
 
 
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