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Mr. Hubble and the Urantia Papers
by Dick Bain
Blame it all on Henrietta Leavitt. If it hadn't been for her, Edwin Hubble might never have discovered that the universe is flying apart due to an event that would later be known as the "Big Bang." Ms. Leavitt, while studying Cepheid variable stars in the Small Magellanic Cloud in 1912, discovered that the luminosity or brightness of these variable stars is directly related to the time required for the star to go from maximum to minimum brightness or luminosity. It's unfortunate that this brilliant woman astronomer hasn't received more credit for her work.
Cepheid Variable Stars
Cepheid variable stars are one of the so called "standard candles" that astronomers use to determine the distance to other galaxies. The property that allows determining distance using these variables is the constant relationship between their actual or absolute brightness and their period of variability. The problem is that we don't know their absolute brightness, only their relative brightness. The relative brightness is how bright a light source appears from whatever distance we happen to view it. The absolute brightness is how bright stars appear if all are viewed from the same distance. For instance, our sun appears much brighter than Sirius (the Dog Star) because it is much closer to us, but if Sirius were viewed at the same distance as our sun, Sirius would appear much brighter because its absolute brightness is greater. So, we have a conundrum we need to solve. We want to use Cepheid variables to determine distance, but first we need to know the distance to a few of them so we can calibrate the absolute brightness versus distance knowing the period of variability. This problem can be solved using another of the standard candles known as parallax.
If you hold one finger up at arm's length and view it first with your left eye closed and the right one open, then with your right eye closed and your left one open, you will note that the finger appears to move from side to side. This is due to the fact that your eyes are spaced apart (to give us stereo vision and depth perception,) and the finger is viewed at different angles by your two eyes. Astronomers can use this apparent motion of stars as viewed from widely spaced observatories to determine the distance to nearby stars. Fortunately, there are several Cepheid variable stars close enough to measure the distance to them using parallax. After calibrating our Cepheid variable standard candles, we can use them to measure the distance to other galaxies that contain this type of variable stars.
It is worth noting that the authors of The Urantia Book endorse the use of variable stars to measure distances in the universe. On page 459B, the authors inform us, "In one group of variable stars the period of light fluctuation is directly dependent on luminosity, and knowledge of this fact enables astronomers to utilize such suns as universe lighthouses or accurate measuring points for the further exploration of distant star clusters."
Using Ms. Leavitt's relationship between brightness and the period of variability of Cepheid variables, Hubble was able to determine the distance to M31, known as the Andromeda galaxy. Hubble found that the distance to M31, our closest neighbor galaxy, is about 1 million light years. And in fact this is the figure that The Urantia Book indicates on p 170. Unfortunately, this figure is in error. Today, it is known that the distance is actually about 2.2 million light years from Urantia, our planet, to M31. In 1952, Walter Baade discovered that there are two types of Cepheid variables with different period-luminosity relationships.1 Hubble had used the wrong population, and thus came up with the wrong distance to M31. Because of Walter Baade's discovery, the size of the astronomers' universe doubled overnight! The popular press had a field day poking fun at the astronomers for this sudden inflation of the universe.
Mr. Hubble's Variable Constant
As Edwin Hubble observed galaxies at greater and greater distance, he noted that the farther a galaxy is from us, the faster it seems to be receding from us. He could tell this from the so-called "red shift" of the light reaching us from the distant galaxy. When a star or galaxy moves away from us, its various colors of visible light are shifted toward the red end of the spectrum. This red shift is mentioned on p 134 of The Urantia Book.
The conclusion Hubble reached from his observations was that the universe is expanding. Initially, Hubble had trouble accepting this conclusion. At first, he supported the so-called "tired light" theory, which supposes that something happens to the light as it passes through space to lower it's frequency and hence move its color toward the red end of the spectrum; this could account for the red shift. But later he decided that the red shift was indeed a sign of an expanding universe. This idea was another of the major cosmological shocks to which science had introduced the world in the past few centuries. An earlier one was the concept that the earth is not the center of the universe. Everyone had considered the universe as stable and unchanging; to go from a stolid, steady, and dependable universe to an expanding one was too much of a change for some people. Even the brilliant Albert Einstein rejected the expanding universe notion. It wasn't until he visited Mt. Palomar and saw for himself the evidence on the photographic plates that he accepted the idea of an expanding universe.
Hubble used the information he had gathered to determine a relationship between the
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