The Cosmic Background Radiation


We are not through with our bashing of the astronomical community.  The saga of the Cosmic Background Radiation is another in the “If we can convince the National Science Foundation that this is a real problem, we will have jobs for years” lists.  This story ranks right up there with the search for missing mass as one of the biggest boondoggles in modern scientific history.

Discovering the Cosmic Background Radiation

The story of the discovery and subsequent investigations into the Cosmic Background Radiation (CBR) by astronomers is one of the most telling sagas of the inflexibility in thinking of our astronomical community.  If it were not for the fact that billions of dollars have been spent researching this subject it would be a pathetic chapter in scientific endeavors.  As it is, it illustrates why there are constant frustrations for those who take exception to the flow of modern astronomical research.


We begin our story in 1964 at a lonely outpost in Holmdel-Keyport, New Jersey.  Arno Penzias and Robert Wilson are testing the Bell Telephone Laboratories 24-foot radio reflector.  This reflector was designed with low background noise, but they consistently detected a hissing from the microwave region.  After eliminating all known sources of noise (including pigeon nests in the antenna) they came to the realization that the radiation was coming from outside the atmosphere.  In fact, wherever they pointed the telescope they detected the same faint signal, as if it were coming from outer space.  Based on their early experiments they estimated that the noise they were observing had blackbody characteristics with a temperature of about 2.7 degrees Kelvin (just slightly above absolute zero).  They called it the Cosmic Background Radiation (CBR).


Several years before the discovery of the microwave background radiation, George Gamow, a famous astrophysicist and one of the originators of the Big Bang theory, published a paper in which he predicted that the Big Bang should have created an afterglow—a very small residual heat throughout the universe.  He predicted that the temperature of this residual heat would be somewhere between 5 and 50 degrees Kelvin, depending on the age of the universe.


Proponents of the Big Bang theory eventually connected the background radiation discovered by Penzias and Wilson to Gamow’s prediction, and broadly proclaimed this discovery as proof that the Big Bang really happened.


Another characteristic of the residual heat predicted by Gamow was that it should be non-isotropic—that is, it should show some variations from place to place in the sky.  These variations would be expected, since when one looks to the distant universe it is clumpy.   Galaxies tend to be found in clusters, and clusters of galaxies tend to be found as even bigger clusters.  This non-even distribution of matter throughout the universe should be reflected by a non-even distribution of residual heat from the Big Bang.  Put another way, if the clustering of the universe was caused by anisotropy in the initial Big Bang explosion, then the residual heat should be anisotropic as well (anisotropic means non-even or clumpy).  That is, it should vary slightly from place to place. It should also have a blackbody radiation pattern.


The background microwave radiation discovered by Penzias and Wilson seemed to fit what astronomers were looking for. It appeared to be a black body radiation. However, it appeared to be very consistent in all directions, which did not fit with Gamow’s predictions. In spite of this apparent discrepancy, astronomers almost immediately jumped on the findings as “the discovery of the century”, to quote astrophysicist Steven Hawkings.


There were a few burrs under the saddle, however.  In the first place, the temperature was far lower than had been predicted by Gamow (2.78 degrees measured versus 5-30 degrees predicted), but what the heck—nobody’s perfect.  What are a few degrees among astronomers?


The other nagging problem is that the radiation appeared to be too uniform to suit the model described by Big Bang theorists.  Remember, the background radiation should be clumpy, to match the clumpiness of the galaxies and galactic clusters in the universe, but ground-based measurements found the temperature to be extremely consistent everywhere the radio telescopes were pointed.  Still, astronomers were confident it would be eventually found to be clumpy when better measuring techniques were used.

Searching For Clumpiness

So the COBE satellite (COsmic Background Explorer) was launched in 1989 to measure the background radiation from space, where not only could better measurements be taken, but measurements could be made in parts of the spectrum which could not be observed from earth because of the shielding effects of our atmosphere.  After several years of data collection, the announcement so long awaited by astronomers about the clumpiness of the background radiation leaked out!


No luck!  The radiation was isotropic (that is, virtually no variation in any direction). There was no clumpiness, except for small variations expected due to the motion of the earth and solar system through the universe!  It looked like the Big Bang theory was about to be trashed.  Without clumpiness, the background radiation could not have come from a primordial explosion.  The Big Bang theory was dead!


Or so it seemed.  But charging to the rescue came George Smoot and others of the COBE project.  Using a highly ‘sophisticated’ data analysis program and high-speed computers, the data was re-analyzed, a process that took several years.  (Sort of reminds you of the Kevin Costner movie No Way Out, during which a fuzzy polaroid photo is analyzed and re-analyzed for days by the CIA until, finally, an incriminating image appears.)


And you guessed it, the result of the COBE analysis came out just as expected—the radiation was clumpy!  The Big Bang was not only saved, it was proven, and life could go on as usual for all those astronomers who have spent their lives living off the Big Bang theory.  A mighty cheer for George!


Of course, the clumpiness, required for the Big Bang theory, was really not as large as astronomers would have liked, as evidenced by the title of Mr. Smoots book, Wrinkles in Time[1].  But it was enough to save the Big Bang for another day.  The unevenness actually amounted to a deviation of only 1 part in 100,000 from perfect symmetry.  This is roughly equivalent to a 200-foot rock protruding from the ocean if the earth were completely inundated with water!  Watch out for that wrinkle!  And even this minuscule variation has been put in question by a Russian satellite. More recently, the IMAP satellite has confirmed the smoothness of the background radiation.

The Search That Needn’t Have Been

Actually one must question why there ever was any doubt of a background temperature, or why it has cosmological importance.  Many years ago in a compendium of science articles, astrophysicist Jesse Greenstein made the statement “at the radiation temperature of space (3° K)”.  This book was published in 1951, long before the cosmic background radiation was first measured and before Gamow’s predictions as well.  This temperature, first calculated by the famous physicist Sir Arthur Eddington in 1926, is essentially the heat of starlight, and is just what scientists have expected from space for many years.  But suddenly when a background radiation was actually found, it became something different that the expected space temperature—it became the afterglow of the Big Bang.


This, it seems to me, is scientific opportunism at its finest!  Scientists quickly ignored the past history of an expected space temperature and embraced the findings as “proof” that their shaky Big Bang theory was true.  And even after the spatial distribution of the background radiation was found to be smooth as a billiard ball, in complete violation of every Big Bang requirement, it still suits their purpose to lean on it as their needed proof.  Go figure!


It is my position that the redshift of distant galaxies is a result of the gravitational reduction in velocity of light passing through space—the Shapiro effect. This effect does not require that distant galaxies be receding, and does not require an expanding universe. If the universe is not expanding there is no justification to believe that the universe started with a Big Bang. So just what is the cosmic background radiation?  Frankly, I don’t care. It could be a lot of things.  After all, we receive heat from the sun every day, so why not heat from the stars. Why can’t the background radiation just be the heat from all the distant stars in the universe? The Shapiro effect provides the mechanism for redshifting of distant starlight, so we should expect to observe redshifted starlight, and that is exactly what we see.


The 2.7 degree cosmic background radiation simply means that the solar system resides in a space that is 2.7 degrees warm (that’s pretty darned cold—just above absolute zero, so don’t slip off the sweater yet).  This warmth could have come from the remains of some supernova explosion within our galaxy some millions or billions of years ago, or as Eddington has calculated, it could simply be the warmth of the ‘star-shine’—the accumulated heat from the light received from all the stars in the universe.


Whatever it is, it definitely is not proof for a Big Bang!



Return to the Main Page



[1] Wrinkles in Time by George Smoot, published by William Morrow and Company, 1993