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03-12-2024, 09:33 PM
This post was last modified 03-12-2024, 09:45 PM by Maxmars.
Edit Reason: Edit to add Updated info
Long ago, before the woke internet, before COVID, before 9-11, someone began an inquiry in the field of cosmology.
The cosmos presented us with a weird observation... not enough mass to hold the galaxies together. The public was made aware of the popular concept of "dark matter" ... stuff we could not otherwise see... but that was only a theory, never proven, never directly measured (hence, "dark")...
but there was already another idea...
... Back in the 1980s, a physicist called Mordehai Milgrom suggested that on a galactic scale, Newton’s laws of motion might be subtly different to those observed on Earth. And that these Modified Newtonian Dynamics or MOND could provide the extra gravitational oomph to hold galaxies together instead of dark matter.
New work attempting to bridge the tangible disconnect between the quantum and the real
The new work is based on an idea that Oppenheim put forward several years ago to reconcile the incompatibility between two of the great foundations of modern physics: quantum mechanics and general relativity.
Quantum mechanics governs the behavior of the universe on the smallest scales, while relativity operates at the largest scales. But the character of these theories is utterly opposite, with quantum mechanics suggesting the universe is probabilistic in nature while relativity implying it is entirely classical.
This poses a dilemma when it comes to deriving a theory of quantum gravity, one that physicists have yet to solve.
The idea of quantum is of a 'non-deterministic' reality (with uncertainty at its core) while gravity (a la Einstein-relativity) is strictly deterministic (everything in a fixed place at a fixed time.) This work binds the two with a concept of a fluidity of Newtonian space time, giving rise to a "Brownian motion" of forces which could marry both gravity and quantum mechanics. And incidentally rendering dark matter unnecessary to resolve the mystery of the cosmos.
Oppenheim’s idea is that relativity is classical but fundamentally stochastic, by which he means that it has a random character, rather like Brownian motion, the random motion of particle suspended in a fluid. This allows quantum mechanics and relativity to be combined in a way that is mathematically compatible.
“We show that this stochastic behavior leads to a modification of general relativity at low accelerations,” they say. “In the low acceleration regime, the variance in the acceleration produced by the gravitational field…acts as an entropic force, causing a deviation from Einstein’s theory of general relativity.”
A worthy read... especially from my viewpoint, where convenient "imaginary invisible matter" should never suffice as a solution to any equation.
From Discover Magazine: Spacetime’s “Brownian Motion” Could Spell The Death of Dark Matter
Source paper from arXiv: Anomalous contribution to galactic rotation curves due to stochastic spacetime
I add here a video with a better-educated description than my own... and an interesting end point, that this theory might not work after all.... She may be right...
[Video: https://www.youtube.com/watch?v=PBA9ac3vg1w]
The cosmos presented us with a weird observation... not enough mass to hold the galaxies together. The public was made aware of the popular concept of "dark matter" ... stuff we could not otherwise see... but that was only a theory, never proven, never directly measured (hence, "dark")...
but there was already another idea...
... Back in the 1980s, a physicist called Mordehai Milgrom suggested that on a galactic scale, Newton’s laws of motion might be subtly different to those observed on Earth. And that these Modified Newtonian Dynamics or MOND could provide the extra gravitational oomph to hold galaxies together instead of dark matter.
New work attempting to bridge the tangible disconnect between the quantum and the real
The new work is based on an idea that Oppenheim put forward several years ago to reconcile the incompatibility between two of the great foundations of modern physics: quantum mechanics and general relativity.
Quantum mechanics governs the behavior of the universe on the smallest scales, while relativity operates at the largest scales. But the character of these theories is utterly opposite, with quantum mechanics suggesting the universe is probabilistic in nature while relativity implying it is entirely classical.
This poses a dilemma when it comes to deriving a theory of quantum gravity, one that physicists have yet to solve.
The idea of quantum is of a 'non-deterministic' reality (with uncertainty at its core) while gravity (a la Einstein-relativity) is strictly deterministic (everything in a fixed place at a fixed time.) This work binds the two with a concept of a fluidity of Newtonian space time, giving rise to a "Brownian motion" of forces which could marry both gravity and quantum mechanics. And incidentally rendering dark matter unnecessary to resolve the mystery of the cosmos.
Oppenheim’s idea is that relativity is classical but fundamentally stochastic, by which he means that it has a random character, rather like Brownian motion, the random motion of particle suspended in a fluid. This allows quantum mechanics and relativity to be combined in a way that is mathematically compatible.
“We show that this stochastic behavior leads to a modification of general relativity at low accelerations,” they say. “In the low acceleration regime, the variance in the acceleration produced by the gravitational field…acts as an entropic force, causing a deviation from Einstein’s theory of general relativity.”
A worthy read... especially from my viewpoint, where convenient "imaginary invisible matter" should never suffice as a solution to any equation.
From Discover Magazine: Spacetime’s “Brownian Motion” Could Spell The Death of Dark Matter
Source paper from arXiv: Anomalous contribution to galactic rotation curves due to stochastic spacetime
I add here a video with a better-educated description than my own... and an interesting end point, that this theory might not work after all.... She may be right...
[Video: https://www.youtube.com/watch?v=PBA9ac3vg1w]
