Is the Sun shrinking?

• Does the size of the sun change over the years? Recently, "John A. Eddy (Harvard -Smithsonian Center for Astrophysics and High Altitude Observatory in Boulder) and Aram A. Boornazian (a mathematician with S. Ross and Co. in Boston) have found evidence that the sun has been contracting about 0.1% per century…corresponding to a shrinkage rate of about 5 feet per hour. The diameter of the sun is close to one million miles, so that this shrinkage of the sun goes unnoticed over hundreds or even thousands of years. There is no cause for alarm for us or for any of our descendants for centuries to come because the sun shrinks so slowly. Yet the sun does actually appear to shrink. The data Eddy and Boornazian examined spanned a 400-year period of solar observation, so that this shrinkage of the sun, though small, is apparently continual.
• What does the shrinkage of the sun have to do with creation and evolution? The sun was larger in the past than it is now by 0.1% per century. A creationist, who may believe that the world was created approximately 6 thousand years ago, has very little to worry about. The sun would have been only 6% larger at creation than it is now. However, if the rate of change of the solar radius remained constant, 100 thousand years ago the sun would be twice the size it is now. One could hardly imagine that any life could exist under such altered conditions. Yet 100 thousand years is a minute amount of time when dealing with evolutionary time scales.
• How far back in the past must one go to have a sun so large that its surface touches the surface of the earth? The solar radius changes at 2.5 feet per hour, half the 5 feet per hour change of the solar diameter. The distance from the sun to the earth is 93 million miles, and there are 5,280 feet in one mile. One must remember that the 20 million year B.C. date is the extreme limit on the time scale for the earth's existence. The time at which the earth first emerged from the shrinking sun is 20 million B.C. A more reasonable limit is the 100 thousand year B.C. limit set by the time at which the size of the sun should have been double its present size.
• A further word of explanation is needed about the assumption that the rate of shrinkage of the sun is constant over 100 thousand years or over 20 million years. The shrinkage rate centuries ago would be determined by the balance of solar forces. Since the potential energy of a homogeneous spherical sun varies inversely with the solar radius, the rate of shrinkage would have been greater in the past than it is now. The time at which the sun was twice its present size is less than 100 thousand B.C. The time at which the surface of the sun would touch the earth is much less than 20 million B.C. Therefore, the assumption of a constant shrinkage rate is a conservative assumption.
• The shrinkage of the sun greatly alters what we believe to be the energy source within the sun. The sun shrinks because of its own self-gravitational attraction. As it compresses itself, it heats itself. This heat is then liberated in the form of solar radiation.