The Tully-Fisher relation or The Tully-Fisher law is expression of observations showing that for disk galaxies the fourth power of the circular velocity of stars around the core of the galaxy is proportional to the luminosity .
The Tully-Fisher relation and halo dark matter
Since luminosity is proportional to the mass of the galaxy, it follows that the fourth power of the circular velocity is proportional to . Newtonian mechanics, however, states that the square of the circular velocity is proportional to . In order to rectify this discrepancy, astronomers assume the existence of halo dark matter. M.Carmeli was able to derive this well-known Tully-Fisher relation after 5-dimensional modification and extension of Einstein's general theory albeit in fact he showed that the relationship was with the mass of the galaxy which is assumed to relate to its luminosity. The Tully-Fisher relation is considered to be so reliable in astronomy that it is routinely used to measure the distance to galaxy, because it gives a measure of the brightness of the source. According to J.Hartnett it would be a strange coincidence if all galaxies had just right amount of 'dark' matter to allow for this relation and emphasizes that Carmeli's new theory questioned its existence. Both Carmeli and Hartnett declared that Hartnett was able to extend Carmeli's theory to account for alleged missing mass without the need for 'dark' matter on galactic scale.
- Hartnett, John (2007). Starlight, Time and the New Physics. Creation Ministries International, 47–54. ISBN 978-0-949-906687. “...Technically, what astronomers are doing is measuring the rotation speeds of the outermost tracer gases on the edge of the disks of stars. In these regions the rotation curves are usually constant as a function of radial distance, so one can imagine this to be a rotation speed for the whole galaxy.”
- Silvia Behar, Moshe Carmeli (19 Jul 1999). Derivation of the Tully-Fisher Law from General Relativity Theory: Doubts about the Existence of Halo Dark Matter 1397–1404.
- Carmeli, Moshe (2006). Cosmological relativity: the special and general theories of the structure. Danvers, MA, USA: World Scientific Publishng Co.. ISBN 981-270-075-7. Retrieved on 2012-10-05. “It was shown by Dr. John G. Hartnett that there is no need to assume the existence of dark matter in the universe.”