DESI, and comparing Einstein's modified and reseated Newton's gravity
v. 5 n. 25
CORRECTION: Note the addition of "space" in the sentence, "The locality here is between the normal particle and space near and far; not between any two particles (regardless of proximity)."
As a confirmation of the conventional Lambda Cold Dark Matter cosmology, Dark Energy Spectrographic Instrument (DESI) has been employed as an alternate means of determining long distances in space, in excess of that from the Type II supernova approach of standard candles; this new approach uses a "standard ruler" by means of Baryonic Acoustic oscillations -- picture a stone dropping in a still pond and measuring the distance between water wave crests. This is analogous to the varying density of matter in space due to the initial "dropping of the stone," or the Big Bang (conventional Lambda CDM) theory based on general relativity modified by the observed acceleration of expanding space, Lambda or unknown dark energy. [1] Formal papers on DESI are available from links within Reference [2].
The opposing views of gravity in these Letters could not be more distinct, even though both views are based on apparently similar axioms. General relativity (GR) as originally conceived is based on the equivalence of gravity and acceleration in general (with the exception of that of the Universe itself!). The reseated Newtonian view of these Letters is based on the identity of gravity and the acceleration of the Universe. Conventionally, gravity is opposed to the acceleration of the Universe. In the proposed reseated Newtonian view, gravity is identical with the acceleration of the Universe. The acceleration of the Universe is accounted for in GR by the addition of the cosmological constant, dark energy, to the mathematics after the observation of acceleration, which is not considered to be associated with gravity.
Conventionally, gravity is opposed to the acceleration of the Universe. In the reseated Newtonian view, gravity is identical to the acceleration of the Universe.
With the conventional view of gravity, it was expected that the Universe would be slowing down due to an anticipated fundamental attractive gravity among all the visible matter. Instead, observations with Type II supernova, indicated a repulsive acceleration. General relativity was modified accordingly with the cosmological constant and unknown dark energy. Now the DESI observations indicate that the acceleration itself is not constant, subject to further study.
In contrast, reseated Newtonian gravity requires no such modification, and dark energy is explained as gravity being fundamentally repulsive and only apparently attractive at smaller scales, as discussed in several Letters. The locality here is between the normal particle and space near and far; not between any two particles (regardless of proximity). Gravity itself is explained as the acceleration of the Universe.
It is interesting to speculate on whether Einstein would have taken the acceleration of the Universe into account in formulating general relativity if the observation would have been known at the time, so that the cosmological constant might have been implicit. [3]
"Reseated unmodified Newtonian gravity" was discussed in the previous article and elsewhere. The equation retains its classical mathematical form, but is applied to accelerated expanding space, so that gravity is proposed as identical to this acceleration condition, or Lambda, instead of dark energy being classified as "unknown." [4]
In the first year of the DESI experiment a discrepancy from Lambda CDM convention was noticed, to possibly put this convention into question. To quote:
"However, when DESI’s first-year results are combined with data from other studies, there are some subtle differences with what Lambda CDM would predict. As DESI gathers more information during its five-year survey, these early results will become more precise, shedding light on whether the data are pointing to different explanations for the results we observe or the need to update our model." [1]
Possible variation in the cosmological constant was discussed. [5]
Also, in a previous article it was suggested that there could have been a greater mass-energy in the space per se (greater potential energy) of the early Universe than now. However, this should not imply that a change in acceleration of the Universe as pointed to in this on-going DESI experiment is necessarily associated with the proposed reseated Newtonian gravity. In any case, this suggestion of greater early mass-energy of space is without regard for electromagnetic mass-energy or condensed matter. [6]
[1] First Results from DESI Make the Most Precise Measurement of Our Expanding Universe – Berkeley Lab News Center ( lbl.gov )
[2] First results from DESI make the most precise measurement of our expanding universe | SLAC National Accelerator Laboratory ( stanford.edu )
Cover image caption: Newton and Einstein.