Introduction

Images (enlarge by clicking on it):
include Solar and Red Shift spectra, Gravitational Lensing,
Hickson Compact Group, several galaxies en brochette,
and a Hubble Deep Field image.
By:
- National Aeronautics and Space Administration (NASA);
- European Southern Observatory (ESO);
- Students for the Exploration and Development of Space (SEDS);
- David Malin, Jack Newton, Bill Keel.
- M31, Sagittarius and the Moon by author.

Also a 112kb image of the spectra By NASA and ESO.

. . . . . .
Gravitational lensing (2x) -- Hickson Compact Group -- Hubble Deep Field image (NASA)

Face-on galaxies by NASA, David Malin, Jack Newton and the SED collection.
...
Galaxies in ensemble by NASA, Jack Newton; David Malin; Bill Keel, and SED.
Montage assembly, M31: "Sagittarius and Moon" by the author (M.L.) The galaxies thumbnail is sideways.

An ultraviolet spectrum of the Sun is shown scaled to wavelength with two redshifted spectra from distant objects. It was necessary to extend the Sun spectrum out to 800 millimicrons because of the increase in wavelength of the redshifted spectra. Spectrographic data from redshift gives no positive indication of its cause and is distinct only because it has only one direction of shift--toward longer wavelengths.
National Aeronautics and Space Administration: nasa.gov
European Southern Observatory: eso.org

Gravitational Lensing

Gravitational lensing is similar to refraction through a medium which contains gradients of refractive index. In space, the medium is described by the stress-action tensor which is composed of the explicit gravitational component and the explicit electrodynamic component; both are part of the same tensor. Light waves are a part of the same stress-action field tensor which comprises the curved space-time around massive object and it is therefore not possible to say that they are exclusively electrodynamic; they are in a way also indistinguishable from gravitational waves. It might be appropriate to say that the gravitational energy density is greater near a massive object is greater, than far away. The waves are refracted in the space-time medium which contains varying proportions of gravitational and electric field energy. The red shift, per se, is not demonstrated by gravitational lensing but it is observed at the large distances which permits significant red shift to accumulate.

Hickson Compact Group

The Hickson Compact Group of Galaxies is believed to be cohesive through gravitational fields. It illustrates that Doppler Shift can be used to estimate relative velocities of the components, but the "absolute" group velocity (relative to Earth) cannot be directly determined by spectral shift alone because the distance is not yet included in the calculations and the photon wavelength and frequency change with distance. Only with a prior estimate of distance (as from luminosity) can a velocity relative to Earth be determined from Hubble Red Shift. The Red Shift can be used to estimate distance, but the object velocity will constitute an error in that estimate. The distance estimate will depend of course on correlation with parallax measurements and Cepheid variable luminosity. Photon decay does not impair the utility of the Hubble Red Shift as a gauge of distance, but the Hubble Red shift alone cannot determine either velocities or distance of very distant objects simultaneously. This is a familiar condition in the quantum mechanics, which appears explicitly in wave mechanics. One or the other must be estimated by other means.