THE FARTHER ONE telescopically peers into the depths of space, the faster the stellar objects appear to recede from us. A linear relationship for this velocity vs. distance was worked out circa 1929 by Edwin Hubble and is known as the Hubble constant. It more commonly is referred to as the redshift.
Prior to 1929, certain stars were found that pulsated rather linearly, with their brightness determining their period of pulsation. These stars are known as cepheid variables.
Knowing the distance to a few of the closest cepheids made it simple for astronomers to estimate the distances to other local galaxies in the neighborhood of the Milky Way by checking the pulsation period of these distant cepheids. Because light intensity decreases as the square of the distance increases, astronomers determined that M-31, the Andromeda Galaxy, is 2 million light-years away.
A small redshift of perhaps 15 km/sec is calculated in this measurement. For even more distant galaxies where no individual stars can be discerned, this redshift meterstick is applied to ascertain both a galaxy's distance and its velocity of recession from us. In the case of quasars, this can be a sizable fraction of the speed of light.
There has been no Heisenberg Uncertainty Principle guiding this measurement. The Hubble constant, which has demonstrated some reliability over the relatively short distance of a few million light-years, has been extended--stretched might be a better term--to hundreds of millions, if not billions, or light-years. I've always had a bit of trouble with this.
The measurement of both distance and velocity in a single determination must disturb Heisenberg's ghost. When light travels huge distances in intergalactic space, it passes through an extremely tenuous but pervasive gaseous medium that is laced with gravitic and magnetic fields.
This medium depletes the energy of passing photons. This depletion is imperceptible at first but ultimately shifts the photon toward longer and longer wavelengths with increasing distances, until finally its light disappears from the visible spectrum and shifts deep into the infrared.
In a like manner, microwave electromagnetic radiation would become ordinary radio waves, visible green light would shift beyond infrared, and x rays would become visible blue light. This redshift would span the entire electromagnetic spectrum.
The Hubble constant, as a tool for measuring the velocity of recession, thus loses its usefulness beyond a handful of megaparsecs. Its misapplication also introduces anomalies that throw a wrench into the works.
Since the original quasar discovery in 1963 by Maarten Schmidt, the extraordinary redshift of these nebulous blue objects has been measured using the Hubble constant and deemed the most distant ever observed. Halton Arp, who initially shared this view, later changed his mind and argued himself out of an astronomical job.
One amazing quasar was radio-telescopically shown to be splitting, with each half receding from the other at 10 times the speed of light. In addition, some quasars pulsate with periods ranging from days to weeks. But none of these conditions should be apparent for objects at the edge of the universe at our present level of technology. Not being a believer in cosmic thaumaturgy, I must agree with Halton Arp and John W. Campbell that quasars are really galactic neighbors.
The late John Campbell wrote in his last editorial published posthumously in Analog in December 1971: "It has been shown that a whole galaxy, if it approaches the density of some of the known dense star clusters, can become a black galaxy, having light trapped by its deep gravity well.
"Then--what about a galaxy that's halfway to being a fully 'black' galaxy?" Campbell asks. "One in which the density has risen to such a degree that light would lose half its energy climbing out of thousands of light-years to get into intergalactic space? Clearly, the light would be heavily redshifted.
"Now if you assume that all galactic redshifts are always due to velocity of retreat and distance, such a galaxy would seem to be immensely distant, even if it were, in fact, only a few million light-years distant," Campbell concludes.
Campbell was an astute observer whose editorial eye in this instance had a telescopic lens, bringing far-flung quasars into our own galactic backyard.
Blue stellar objects, such as quasars, are intensely radiating bodies, even if they are redshifted. Blue stars burn themselves out in relatively short cosmic lifetimes. But if a quasar is on its inexorable way to becoming a black hole--or "collapsar" as Campbell put it--all the interstellar matter and star stuff surrounding this gravitational collapse would be screaming in cosmic agony throughout the electromagnetic spectrum while being sucked into this ineffable vortex.
X rays would be redshifted into ultrablue light. Even otherwise powerful radio-quasars would be quiet, as these longer wavelengths would be redshifted into silence, for some suspected quasars are indeed radio-quiet.
Nearby pulsating nebulosities thus become much more tenable objects for the observer, along with quasars separating at merely a tenth the velocity of light. And we don't have to invent any theories to account for anomalous behavior in an expanding universe.
Actually, I think the universe has been unobservably collapsing for some time now.
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|Title Annotation:||red shift|
|Author:||Jueneman, Frederic B.|
|Publication:||R & D|
|Date:||May 1, 1990|
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