Pascual Jordan, Varying Gravity, and the Expanding Earth

Kragh, Helge

doi:10.1007/s00016-015-0157-9

Cited by 9 publications

(50 citation statements)

References 33 publications

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“…He was among the first to recognize that G is unusual because of its very weak value when compared to the other coupling constants found in nature, and its inherent canonical dimension. Soon afterwards, Jordan [23] [24] [25] [26] related a cosmologically time varying G to Hubble's constant. Since then, there have been many attempts to observe such a variation, with limited success.…”

Section: G = G(a) Modelsmentioning

confidence: 99%

Scaling Behavior for the Susceptibility of the Vacuum

Pilot¹

2021

IJAA

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Using the two-component superfluid model of Winterberg for space, two models for the susceptibility of the cosmic vacuum as a function of the cosmic scale parameter, a, are presented. We also consider the possibility that Newton's constant can scale, i.e., ΩΩ Ω Ω = . While this is an unconventional assignment, differing from the ΛCDM model, we believe this is correct, as localized dark matter (LDM) contributions can be much higher in this epoch than cosmic smeared values for susceptibility. All density parameter assignments in Friedmanns' equation are cosmic averages, valid for distance scales in excess of 100 Mpc in the current epoch. We also evaluate the transition from ordinary matter dominance, to dark matter dominance, for the cosmos as a whole. We obtain for the transition points, 1.66 z = , for susceptibility model I, and, 2.53 z = , for susceptibility model II.

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Section: G = G(a) Modelsmentioning

confidence: 99%

Scaling Behavior for the Susceptibility of the Vacuum

Pilot¹

2021

IJAA

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“…Equation (1)(2)(3)(4)(5)(6)(7)(8)(9), by a correction factor, * 106.75 g = . See references [16] [17].…”

Section: B =mentioning

confidence: 99%

“…This still does not take into account dark matter, nor dark energy, but it does factor in what is definitely known. If we multiply Equation (2)(3)(4)(5)(6)(7)(8)(9), by this correction factor, * 106.75 g = , we will have effectively taken into account, as well, the radiation that coalesced as material particles between then and now.…”

Section: B =mentioning

confidence: 99%

“…Recently [1] [2], it was argued that this may not be the case. Actually, a variable G has a long history going back to the early works of Dirac in his large number hypothesis (LNH) [3] [4] [5], and Jordan [6] [7] [8] [9]. They both claimed that G must vary as a function of cosmological time, and moreover, in the case of Jordan, that G must be related to Hubble's parameter via the relation, G G H = −  .…”

Section: Introduction Cosmic Inflation With a Varying Gmentioning

confidence: 99%

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Inflation and Rapid Expansion in a Variable G Model

Pilot¹

2020

IJAA

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Cosmic inflation is considered assuming a cosmologically varying Newtonian gravitational constant, G. Utilizing two specific models for, ( ), where, a , is the cosmic scale parameter, we find that the Hubble parameter, H, at inception of G −1 , may be as high as 7.56 E53 km/(s Mpc) for model A, or, 8.55 E53 km/(s Mpc) for model B, making these good candidates for inflation. The Hubble parameter is inextricably linked to G by Friedmanns' equation, and if G did not exist prior to an inception temperature, then neither did expansion.The CBR temperatures at inception of 1 G − are estimated to equal, 6.20 E21 Kelvin for model A, and 7.01 E21 for model B, somewhat lower than CBR temperatures usually associated with inflation. These temperatures would fix the size of Lemaitre universe in the vicinity of 3% of the Earths' radius at the beginning of expansion, thus avoiding a singularity, as is the case in the ΛCDM model. In the later universe, a variable G model cannot be dismissed based on SNIa events. In fact, there is now some compelling astronomical evidence, using rise times and luminosity, which we discuss, where it could be argued that SNIa events can only be used as good standard candles if a variation in G is taken into account. Dark energy may have more to do with a weakening G with increasing cosmological time, versus an unanticipated acceleration of the universe, in the late stage of cosmic evolution.

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“…For other reviews of Jordan's and Dicke's thinking about an evolving G and its possible effects in geophysics and cosmology see Kragh (2015aKragh ( , 2015b.…”

Section: The Scalar-tensor Gravity Theorymentioning

confidence: 99%

Robert Dicke and the naissance of experimental gravity physics, 1957–1967

Peebles

2016

EPJ H

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The experimental study of gravity became much more active in the late 1950s, a change pronounced enough be termed the birth, or naissance, of experimental gravity physics. I present a review of developments in this subject since 1915, through the broad range of new approaches that commenced in the late 1950s, and up to the transition of experimental gravity physics to what might be termed a normal and accepted part of physical science in the late 1960s. This review shows the importance of advances in technology, here as in all branches of natural science. The role of contingency is illustrated by Robert Dicke's decision in the mid-1950s to change directions in mid-career, to lead a research group dedicated to the experimental study of gravity. The review also shows the power of nonempirical evidence. Some in the 1950s felt that general relativity theory is so logically sound as to be scarcely worth the testing. But Dicke and others argued that a poorly tested theory is only that, and that other nonempirical arguments, based on Mach's Principle and Dirac's Large Numbers hypothesis, suggested it would be worth looking for a better theory of gravity. I conclude by offering lessons from this history, some peculiar to the study of gravity physics during the naissance, some of more general relevance. The central lesson, which is familiar but not always well advertised, is that physical theories can be empirically established, sometimes with surprising results.

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Pascual Jordan, Varying Gravity, and the Expanding Earth

Cited by 9 publications

References 33 publications

Scaling Behavior for the Susceptibility of the Vacuum

Scaling Behavior for the Susceptibility of the Vacuum

Inflation and Rapid Expansion in a Variable G Model

Robert Dicke and the naissance of experimental gravity physics, 1957–1967

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