In this paper, we recall the mutation of the Minkowski spacetime for empty space into the covering isospacetime caused by physical media; we recall its experimental verifications via the isoredshift of laser light in a metal pipe containing air at pressure, as well as additional experimental verifications in other fields; and we present, apparently for the first time, experimental confirmations of Santilli's 1991 prediction of the isoredshift as the primary origin of the redness of direct Sunlight at Sunset and Sunrise without any appreciable relative motion between Earth and Sun, said isoredshift being proportional to the distance traveled by Sunlight in air. Absorption is dismissed as a source of said redness of the Sun because air predominantly absorbs red, as experimentally established, without dismissing minor contributions, e.g., for the shape (but not the shift) of wavelengths. The widely accepted conjecture that scattering is the origin of said redness of the Sun, without dismissing minor contributions, is shown to be inapplicable for direct Sunlight, to have no representational capability for the needed very large shifts (measured up to 200 nm), and to have been dismissed experimentally at the cosmological level with recent measurements via Hubble's telescope, as well as on Earth by recent scattering measurements by some of us. Since intergalactic spaces are far from being empty, and physical laws must be the same throughout the universe, the preceding experimental results are shown to be evidence for the absence of the expansion of the universe, the absence of the acceleration of the expansion, the absence of the big bang, and the elimination of the far reaching conjecture that space itself is expanding as needed, from Hubble's law, to prevent a return to the Middle Ages with Earth at the center of the universe. It is finally shown that the same experimental confirmations of Santilli isoredshift imply the absence of dark matter and dark energy since the universe is nowhere empty, with consequential universal validity of Santilli isospacetime and its Lorentz-Poincaré-Santilli isosymmetry.

In this paper, we outline the mathematical and physical foundation of the 1991 hypothesis by R. M. Santilli of IsoRedShift (IRS), namely, a frequency shift of light toward the red characterized by the loss of energy by light to a cold medium without any relative motion between the source, the medium and the observer; we outline the corresponding foundations of Santilli's IsoBlueShift (IBS), namely, a frequency shift of light toward the blue characterized by the acquisition of energy by light from a hot medium without relative motion; we show the compatibility of Santilli's IRS and IBS with the axioms of special relativity under their proper mathematical formulations; we review the original experimental confirmations of IRS by Santilli in 2010 for a blue laser light in a tube containing air at pressure; we review the experimental confirmations of both IRS and IBS by G. West and G. Amato in 2011; we review the confirmatory measurements by Santilli, West and Amato done in 2012 on the West coast of Florida on the IRS origin of the redness of the Sun in the transition from the Zenith to the horizon; we present, for the first time, additional confirmatory measurements of IRS of Sunlight from the Zenith to Sunset done by the authors at the island of Kos, Greece, on September 20, 2012; we present, also for the first time, additional confirmatory measurements of IRS of Sunlight from Sunrise to the Zenith done in Cocoa Beach, East Coast of Florida, on October 20, 2012; we review the compatibility of Santilli's 1991 IRS hypothesis with Zwicky's 1929 hypothesis of Tired Light and identify their difference in the process originating the redshift; we recall the fit of cosmological redshift done by P. LaViolette in 1986 with Zwicky's Tired Light hypothesis; we confirm Santilli's 2010 argument according to which the IRS origin of the redness of the Sun at the horizon without relative motion is visual evidence on the expected absence of the expansion of the universe and of related conjectures; and we present the dismissal of various objections against Santilli's IRS and its interpretation of the cosmological redshift. In essence, we agree with Santilli that cosmologists should follow Galileo's teaching by establishing cosmological models via experiments on Earth prior to their application to the universe.

While stressing the need for additional independent verifications, in this paper we provide: 1) Confirmatory measurements of Santilli's 1991 hypothesis of the anomalous IsoRedShift (IRS) for the propagation of a blue laser light in a 60 ft ≈ 18 m long steel pipe containing air at a maximum of 70 • F ≈ 21 • C and at 2,000 psi ≈ 137 bars without any relative motion between the source, the medium and the analyzer; 2) Confirmatory measurements of Santilli's 1991 hypothesis of the anomalous IsoBlueShift (IBS) for a blue laser light in the same conditions as above except for air being at a minimum of 130 • F ≈ 54 • C; 3) Experimental evidence on the transition from IRS to IBS with the increase of the temperature, thus confirming Santilli's NoIsoShift (NIS); 4) Measurements showing no frequency shift for a blue laser light reflected on a polished metal mirror at temperatures ranging from 70 • F ≈ 21 • C to 280 • F ≈ 137 • C, with consequential apparent absence of frequency shift for the scattering of light in a gas, since the Boltzman distribution apparently implies no frequency shift for light scattering in a gas due to relative motions averaged down to zero; and 5) Consequential confirmation of Santilli's 1991 hypothesis that the large difference in cosmological redshift between certain quasars and associated galaxies when physically connected via clear gamma spectroscopic evidence, originates from largely different IRS in the dramatically different quasars chromospheres and innergalactic media. Cosmological and other implications of Santilli IRS, IBS and NIS are discussed by other contributions in these proceedings.