On Sunday, February 2, 2025 at 3:24:53 PM UTC-7 Brent Meeker wrote: On 2/2/2025 12:42 AM, Alan Grayson wrote:
Einstein claimed that when his GR field equations predicted an explanding universe when he believed in the Steady State theory, he added the CC to GR to make it consistent with his belief. That's not quite accurate. He saw that solutions to the GR equations for a universe contained an undetermined constant, the Cosmological Constant. So he sought to determine it from the observed data. He consulted the best astronomers of his time and they assured him that the universe consisted of Milky Way and a some scattered nebula and it was unchanging. So he set the CC value to make the universe in equilibrium. Google says the following: The cosmological constant, often associated with dark energy, represents a positive force that drives the accelerated expansion of the universe, acting as a repulsive force against gravity. If the GR field equations imply an expanding universe without a CC, how can an accelerated expansion using the CC result in a steady state universe, the one E believed to be the case? Wasn't the insertion of the CC supposed to force the field equations to imply a steady state universe? How can it do that if the expansion rate is accelerated? AG As soon as he published this, it was pointed out to him that this would be an unstable equilibrium and was not consistent with the observed existence of the universe. About the same time Hubble published his discovery that the universe was expanding and Einstein called the CC, "My greatest blunder." If not for the astronomers he might have predicted the expansion of the universe before Hubble observed it. What a coup that would have been. But I recall a remark by Vic Stenger that the constant could have arisen naturally as the constant in an indefinite integral. Is there any substance to Stenger's claim? Sure. But the value of the constant can't be derived from the equation. Like any constant of integration it has to be determined by something else, usually boundary conditions. Brent That is, in the opaque process of creating the GR field equations, do INDEFINITE integrals play a role? AG. -- -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to everything-list+unsubscr...@googlegroups.com. To view this discussion visit https://groups.google.com/d/msgid/everything-list/193b48d6-976a-4089-83ea-a1a904b19105n%40googlegroups.com.
