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Halve the Hubble constant! (still appears to be 72km/s/Mpc)

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Halve the Hubble constant! (still appears to be 72km/s/Mpc)

Postby John » Sun Jul 09, 2017 8:17 am

Hello Physicists,

If anyone is interested in a radical solution to the dark energy problem, here is quite a simple one.

It's by a change to the usual scalefactor-redshift relation, which can remove the main arguments for an accelerating universe...radical, but true?

4 page paper + appendix attached
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Re: Halve the Hubble constant! (still appears to be 72km/s/

Postby JohnDuffield » Sat Jul 15, 2017 2:44 pm

Hi John. That looks interesting. You have an s missing in:

"The conclusion that dark energy exist is from different types of evidence".

And I'm confident that the Robertson-Walker metric is wrong. Your radial ray of light is speeding up.

Funnily enough, I've just written a piece on dark energy. Here's the start of it:

John Duffield wrote:In the Wikipedia dark energy article you can read how the term "dark energy" was coined by Michael Turner in 1998. This was in a paper referring to the type 1a supernovae observations made by the Supernova Cosmology Project and the High-Z Supernova Search Team. Their observations indicated that the expansion of the universe is accelerating, which was contrary to expectations and led to Nobel prizes in 2011:

Expanding universe image courtesy of NASA Goddard Space Flight Centre

However dark energy goes back further than that. As to how far it’s hard to say. There’s an interesting historical paper by Helge Kragh dating from 2011. It’s Preludes to dark energy: Zero-point energy and vacuum speculations. He starts by saying “according to modern physics and cosmology, the universe expands at an increasing rate as the result of a “dark energy” that characterizes empty space”. Kragh also talks about Walther Nernst’s zero-point energy hypothesis dating from 1916. He says “to many physicists and cosmologists, the cosmological constant and the zero-point energy density of vacuum are just two names for the same thing”. That’s interesting.

Vesto Slipher measures galactic redshift

Another interesting historical paper was written by Cormac O'Raifeartaigh in 2012. It’s on the contribution of VM Slipher to the discovery of the expanding universe. Way back in 1913 Vesto Slipher had measured a blue-shift for the Andromeda nebula equivalent to 300 km/s. By 1917 he had results for 25 spiral nebulae, of which 21 were red-shifted, by up to 1100 km/s. O'Raifeartaigh says “such large recession velocities were a great anomaly and suggested to some that the spirals could not be gravitationally bound by the Milky Way. Thus, Slipher’s redshift observations became well-known as one argument for the ‘island-universe’ hypothesis”. But not known to Einstein, it would seem.

Einstein’s cosmological constant §1

Dark energy is usually considered to have originated with Einstein’s cosmological constant. See O'Raifeartaigh’s 2017 Physics Today article Albert Einstein and the origins of modern cosmology. It’s about Einstein’s general relativity wherein Gμν = -κTμν. The Gμν term is a tensor that describes the geometry of a region of spacetime, Tμν is a tensor that describes the stress-energy-momentum within that region, and κ is the Einstein constant. The article is also about Einstein’s 1917 paper which added a λgμν term and “laid the foundations of modern theories of the universe”. Einstein’s paper was called cosmological considerations in the general theory of relativity. In the introduction Einstein talked about Poisson’s equation ∇²φ = 4πκρ and how he might describe “boundary conditions” for gravitational potential in an infinite universe. In section §1 Einstein talked about the “Newtonian system of the universe”. He was referring to a universe consisting of an island of stars in an infinite ocean of space...
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