Three months after I wrote this, another group of astronomers analyzed the same data as the Korean group and came to the opposite conclusion. They find evidence AGAINST MOND in the same data where I have reported that the Korean group found evidence FOR MOND.
Please say more...I assume you are referring to the theory of "dark matter" and the competing theory that Newtonian gravity is modified when the field is very weak.
I'm just pointing out that MOND summarizes the galactic rotation data well with 1/R gravitational decay in the weak regime. If one wants to build a new theory, those sorts of relatively clean observations would seem to be a good starting point. How the theory connects to strong gravity and quantum mechanics remains to be seen.
As you wrote, the cherished superposition principle does not fit so easily into a one over R theory. But special relativity is also not very intuitive so perhaps everything needs to be reimagined. Nevertheless, I expect it will be more fruitful to focus on data than GUTs.
I'll add that the superposition principle with 1/R^2 decay is easily understood as non-interacting "field lines" that become geometrically less dense at greater source distances. Overlapping field lines from different sources amount to simple addition.
I'm no expert, but to get 1/R decay, one could imagine a sort of self-bunching of the field lines when gravity gets very weak. Instead of spreading out spherically forever, the lines pull together somehow, causing them to form a disk with density dropping like 1/R. Gauss's law could still hold.
Nevertheless, departure from 1/R^2 behavior opens the possibility that gravity is actually a non-conservative force... Travelling from the center to the far reaches of a disk galaxy might require less work via an out-of-plane trajectory than in-plane.
" Arthur Eddington's selective presentation of data from the 1919 Eclipse so that it supposedly supported "Einstein's" general relativity theory is surely one of the biggest scientific hoaxes of the 20th century. His lavish support of Einstein corrupted the course of history. Eddington was less interested in testing a theory than he was in crowning Einstein the king of science.
The physics community, unwittingly perhaps, has engaged in a kind of fraud and silent conspiracy; this is the byproduct of simply being bystanders as the hyperinflation of Einstein's record and reputation took place. " https://bibliotecapleyades.net/esp_einstein.htm
Interesting. Caveat -I have absolutely no expertise regarding Einstein, and haven't read the link, but in the ways of the internet, will spew something at least tangential to what you said that I'm interested in anyway. Thank you for reading. I often wonder about the "hyperinflation" and subsequent iconic status of individuals as a deeply corrupting influence that should be consciously adjusted for in every field. We all stand on the shoulders of our fallible predecessors, even if they were exceptional in their field in their time. The current-time glow of their cult of personality can be blinding. Once a story is created and hits newpapers (then) or internet (now), for most people the "real story" is over. And attenuating it even further.......once someone's quotes (sometimes incorrect, out of context by definition) are memed all over the internet and a billion stickers in a million gift shops display this person with their tongue sticking out for placement on laptop covers and school folders....well, let's just say the multi-faceted truth is distorted by the "gravity" of the romantic narrative. Ha. You know what I mean - the reduction of any current or historical public figure to a mousepad or Christmas tree ornament can create a feedback even into more rarified realms. One can hope that whatever the lay person (which is all of us, for some field) gets out of this tends toward the null or positive in net social effect. (I have no evidence for that.....) But for the denizens of the field in which the now-iconic person excelled, or at least became famous, a skeptical respect must be cultivated, and no one's work is ever beyond interrogation. (DUH, I guess, though seems worth saying these days) Of course, a scientist must earn any accolades received, even and especially posthumously, in the light of new investigations or the more thorough examination of the old ones. Otherwise, we've all lost the plot.
I like your comment . Some say that he also appropriated his first wife's work. "His 1907 views on plagiarism: "It appears to me, that even if the issue has already been solved by
other authors, then despite that fact, since the issues of concern are here addressed from a new point of view, I am entitled to leave out a thoroughly pedantic survey of the literature" and “The secret to creativity is knowing how to hide your sources.” " https://www.eps.mcgill.ca/~courses/c201_winter/Mileva-Maric-Einstein.pdf
Lest we be too hard on Einstein, keep in mind that standards for footnotes have changed greatly just in the last 30 years, since we have computer-generated bibliographies. It is common now for a paper to have hundreds of references, whereas in 1990 it was common to have a dozen references. And in the 19th century, the idea of citing sources was not a matter of intellectual honesty or crediting forerunners but rather offering your reader a place to read more. Darwin published the entire 1859 book Origin of Species without references. "I cannot here give references and authorities for my several statements; and I must trust to the reader reposing some confidence in my accuracy. " Here's an article on the history of plagiarism: https://www.turnitin.com/blog/5-historical-moments-that-shaped-plagiarism
Stephan J Gift published a paper detailing how GPS satellite clock corrections can be made without resorting to relativity. Essentially, he accounts for gravitational redshift by assuming a photon behaves as if it has mass and then equating the work done in raising the photon out of the gravitational field to the photon’s energy, where E = hf.
Also you might be interested to know that the gravitational constant G has recently been derived from Mach’s principle, adding weight (no pun intended) to an electromagnetic origin of gravity.
Yes, you can calculate the gravitational redshift using only special relativity. I'm not sure if you get exactly the same answer or only approximately the same answer, where "approximately" is already so good that it covers all measurements in practice.
The gravitational time dilation is something else. It is not covered by special relativity, and I don't think that you can calculate the correction used in GPS tracking without GR. I expect that the same computation from quantum field theory that gives the approximate (and adequate, in practice) GR answers for the three classic tests would also give an adequate approximation for the GPS satellites -- but I am not certain of this.
The mainstream view is that there is a time dilation onboard the satellite due to its relative velocity (special relativity) but a larger increase in clock rate due to the gravitational redshift effect on the atomic clock caesium atoms (they increase their frequency of oscillation in a weaker gravitational field). Thus there is a net increase in clock rate onboard the satellite. (This net amount is simply corrected for by adjusting the satellite clock rate before it is launched into space, from 10.23 MHz to 10.22999999543 MHz as per IS-GPS-705 Interface Specification 2019). The clock rate is slowed down so that when it reaches its predetermined altitude in space it increases to be exactly the same as the ground-based reference clock.
Gift (2021) shows that, mathematically at least, the increase in oscillation frequency at higher altitudes can be accounted for without recourse to GR. This was also the view of the inventor of the atomic clock, Louis Essen, who wrote a book challenging relativity theory.
Thank you, Brent. These are fascinating details. I have distinguished between gravitational redshift and gravitational time dilation. It's a deep question whether the two are necessarily related.
Yes I agree. The measured gravitational redshift in the Pound-Rebka experiment was taken as experimental validation of GR time dilation.
But if we measured the frequency of the emitted light using a pendulum-based clock, which slows down with increasing altitude, we would measure a gravitational blueshift... contradicting GR.
Whoa - not so fast. The fact that pendulums swing more slowly in a smaller gravitational field is not a time dilation effect, and is unrelated to effects that are peculiar to GR.
https://mitteldorf.substack.com/p/an-adjustment-to-newtons-gravity
Three months after I wrote this, another group of astronomers analyzed the same data as the Korean group and came to the opposite conclusion. They find evidence AGAINST MOND in the same data where I have reported that the Korean group found evidence FOR MOND.
https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stad3446/7438890
https://philsci-archive.pitt.edu/22325/1/Classic_tests_of_GR_JulyPreprint.pdf
This article describes how the experiments that support GR could equally well support other theories.
Parallell Universes are not perfectly aligned, but very close? Quantum Effect
Misalignment barely measurable,
and explains the jumping back and forth of tiny particles?
The divergence between even Newtonian gravity and galactic observations would seem to offer solid direction for improved theories.
Please say more...I assume you are referring to the theory of "dark matter" and the competing theory that Newtonian gravity is modified when the field is very weak.
https://mitteldorf.substack.com/p/an-adjustment-to-newtons-gravity
I'm just pointing out that MOND summarizes the galactic rotation data well with 1/R gravitational decay in the weak regime. If one wants to build a new theory, those sorts of relatively clean observations would seem to be a good starting point. How the theory connects to strong gravity and quantum mechanics remains to be seen.
As you wrote, the cherished superposition principle does not fit so easily into a one over R theory. But special relativity is also not very intuitive so perhaps everything needs to be reimagined. Nevertheless, I expect it will be more fruitful to focus on data than GUTs.
I'll add that the superposition principle with 1/R^2 decay is easily understood as non-interacting "field lines" that become geometrically less dense at greater source distances. Overlapping field lines from different sources amount to simple addition.
I'm no expert, but to get 1/R decay, one could imagine a sort of self-bunching of the field lines when gravity gets very weak. Instead of spreading out spherically forever, the lines pull together somehow, causing them to form a disk with density dropping like 1/R. Gauss's law could still hold.
Nevertheless, departure from 1/R^2 behavior opens the possibility that gravity is actually a non-conservative force... Travelling from the center to the far reaches of a disk galaxy might require less work via an out-of-plane trajectory than in-plane.
" Arthur Eddington's selective presentation of data from the 1919 Eclipse so that it supposedly supported "Einstein's" general relativity theory is surely one of the biggest scientific hoaxes of the 20th century. His lavish support of Einstein corrupted the course of history. Eddington was less interested in testing a theory than he was in crowning Einstein the king of science.
The physics community, unwittingly perhaps, has engaged in a kind of fraud and silent conspiracy; this is the byproduct of simply being bystanders as the hyperinflation of Einstein's record and reputation took place. " https://bibliotecapleyades.net/esp_einstein.htm
Interesting. Caveat -I have absolutely no expertise regarding Einstein, and haven't read the link, but in the ways of the internet, will spew something at least tangential to what you said that I'm interested in anyway. Thank you for reading. I often wonder about the "hyperinflation" and subsequent iconic status of individuals as a deeply corrupting influence that should be consciously adjusted for in every field. We all stand on the shoulders of our fallible predecessors, even if they were exceptional in their field in their time. The current-time glow of their cult of personality can be blinding. Once a story is created and hits newpapers (then) or internet (now), for most people the "real story" is over. And attenuating it even further.......once someone's quotes (sometimes incorrect, out of context by definition) are memed all over the internet and a billion stickers in a million gift shops display this person with their tongue sticking out for placement on laptop covers and school folders....well, let's just say the multi-faceted truth is distorted by the "gravity" of the romantic narrative. Ha. You know what I mean - the reduction of any current or historical public figure to a mousepad or Christmas tree ornament can create a feedback even into more rarified realms. One can hope that whatever the lay person (which is all of us, for some field) gets out of this tends toward the null or positive in net social effect. (I have no evidence for that.....) But for the denizens of the field in which the now-iconic person excelled, or at least became famous, a skeptical respect must be cultivated, and no one's work is ever beyond interrogation. (DUH, I guess, though seems worth saying these days) Of course, a scientist must earn any accolades received, even and especially posthumously, in the light of new investigations or the more thorough examination of the old ones. Otherwise, we've all lost the plot.
I like your comment . Some say that he also appropriated his first wife's work. "His 1907 views on plagiarism: "It appears to me, that even if the issue has already been solved by
other authors, then despite that fact, since the issues of concern are here addressed from a new point of view, I am entitled to leave out a thoroughly pedantic survey of the literature" and “The secret to creativity is knowing how to hide your sources.” " https://www.eps.mcgill.ca/~courses/c201_winter/Mileva-Maric-Einstein.pdf
Lest we be too hard on Einstein, keep in mind that standards for footnotes have changed greatly just in the last 30 years, since we have computer-generated bibliographies. It is common now for a paper to have hundreds of references, whereas in 1990 it was common to have a dozen references. And in the 19th century, the idea of citing sources was not a matter of intellectual honesty or crediting forerunners but rather offering your reader a place to read more. Darwin published the entire 1859 book Origin of Species without references. "I cannot here give references and authorities for my several statements; and I must trust to the reader reposing some confidence in my accuracy. " Here's an article on the history of plagiarism: https://www.turnitin.com/blog/5-historical-moments-that-shaped-plagiarism
Stephan J Gift published a paper detailing how GPS satellite clock corrections can be made without resorting to relativity. Essentially, he accounts for gravitational redshift by assuming a photon behaves as if it has mass and then equating the work done in raising the photon out of the gravitational field to the photon’s energy, where E = hf.
Also you might be interested to know that the gravitational constant G has recently been derived from Mach’s principle, adding weight (no pun intended) to an electromagnetic origin of gravity.
Bring on the revolution!
Yes, you can calculate the gravitational redshift using only special relativity. I'm not sure if you get exactly the same answer or only approximately the same answer, where "approximately" is already so good that it covers all measurements in practice.
The gravitational time dilation is something else. It is not covered by special relativity, and I don't think that you can calculate the correction used in GPS tracking without GR. I expect that the same computation from quantum field theory that gives the approximate (and adequate, in practice) GR answers for the three classic tests would also give an adequate approximation for the GPS satellites -- but I am not certain of this.
The mainstream view is that there is a time dilation onboard the satellite due to its relative velocity (special relativity) but a larger increase in clock rate due to the gravitational redshift effect on the atomic clock caesium atoms (they increase their frequency of oscillation in a weaker gravitational field). Thus there is a net increase in clock rate onboard the satellite. (This net amount is simply corrected for by adjusting the satellite clock rate before it is launched into space, from 10.23 MHz to 10.22999999543 MHz as per IS-GPS-705 Interface Specification 2019). The clock rate is slowed down so that when it reaches its predetermined altitude in space it increases to be exactly the same as the ground-based reference clock.
Gift (2021) shows that, mathematically at least, the increase in oscillation frequency at higher altitudes can be accounted for without recourse to GR. This was also the view of the inventor of the atomic clock, Louis Essen, who wrote a book challenging relativity theory.
Thank you, Brent. These are fascinating details. I have distinguished between gravitational redshift and gravitational time dilation. It's a deep question whether the two are necessarily related.
Yes I agree. The measured gravitational redshift in the Pound-Rebka experiment was taken as experimental validation of GR time dilation.
But if we measured the frequency of the emitted light using a pendulum-based clock, which slows down with increasing altitude, we would measure a gravitational blueshift... contradicting GR.
Whoa - not so fast. The fact that pendulums swing more slowly in a smaller gravitational field is not a time dilation effect, and is unrelated to effects that are peculiar to GR.
That raises the question, what feature of an atomic clock allows it to measure gravitational time dilation, whereas other clocks cannot?
To put it another way, how does gravity affect the atomic clock in a way that is different to say, a pendulum clock?
Thanks Josh, for an informative and enjoyable read.