Reforming Science

John Byl has written an excellent book on approaching cosmology under the assumption that the Biblical account of creation is accurate, time scales and all. Taking this view immediately brings one into conflict with much of modern astronomy; a helpful list of the difficulties can be found in some of the books by Hugh Ross. The most glaring difficulty is the light from distant stars. Not only do we see light from stars that we think are thousands or millions of light-years away (a light-year is simply the distance light can travel in one year), but we see things happening at those distances (there are variations in the light from distant stars or galaxies on observable time scales). The common creationist explanation that the transmitted light was created at the same time as the stars doesn’t apply to light that is changing at large distances.

As Byl points out, there are four possible explanations for this: 1) the distances are not what we think they are, 2) Earth time is different from astronomical time, 3) the speed of light is not a constant, or 4) the light that appears to be coming from the distant stars is actually being created at closer distances. While any one of these are possible, I would favor the explanation that light travels faster than we think it does. The primary difficulty I have with the final explanation is that it too easily avoids the conflict inherent in the antithesis - modern astronomy can proceed unhindered by this explanation. The other three explanations (which are not entirely unrelated, since we use light to measure distances and times) have more direct scientific implications.

A varying speed of light per se does not violate modern scientific theories. There are researchers (secular, and therefore unmotivated by biblical assumptions) who investigate such an idea from time to time, and it has even been demonstrated that the equations of general relativity can be derived by assuming a spatially-varying speed of light. The theory of special relativity includes the idea that light is a constant independent of the observer. It is a local theory, however, and says nothing about the relative speed of light at two distant points. One of the primary reasons for assuming that the locally-measured speed of light is a universal constant is the Copernican Principle - why should the speed of light be any different here than it is everywhere else?

Since we investigate light by its interaction with matter (it’s emitted from, say, the atmosphere of a distant star and absorbed by a telescope), there is no way to tell if its speed is changing during the transit from there to here. If light traveled faster in regions devoid of matter, there would be no way to measure it from Earth. Let’s assume for the moment that light has some dependence on density such that it is faster when density is lower, and vice versa; such a dependence is not necessary (it could just have a spatial variation independent of density), but what are its implications? The average density of the matter in voids (the lowest density regions in the universe) is on the order of one particle per cubic meter. The average density in our solar system is closer to a million particles in the same volume. Notice the ratio of these two densities is about the same as the ratio between the age of the universe based upon modern cosmology and the age based upon biblical chronology (13 billion/6000 = 2 million). If light traveled a million times faster in the voids (where the density is a million times smaller than regions where we’ve measured the speed of light), we could see things at the edge of the observable universe on the time scale of thousands of years.

There’s a catch in the above reasoning, however. We can measure the speed of light to an accuracy of one part in a billion, so a gradual change with density (which was implied in the above estimate) would be detectable and a sharper transition is therefore required (and could be made to accommodate any change in the speed of light). Sharp transitions at particular densities or temperatures occur in other contexts (with entirely new results), such as Bose-Einstein condensation, so it is not a priori unreasonable.

There are a couple of space craft currently in the outer reaches of the solar system called the Voyager probes, and they have enough power to last until at least 2020. They should be able to reach the heliopause by that time (a transition between the material in our solar system and the lower density material in between stars that’s a factor of about 100), and any change in the speed of light would affect the signals being sent back to us. The light travel time at that distance is about 13 hours, so our current accuracy on measuring the speed of light translates into a measurable discrepancy on the order of microseconds.

One way to test this would be with a low-density vacuum. You can create a vacuum (a low-pressure region) by lowering the density or the temperature of a fixed volume of gas; the latter is what is done to generate the lowest pressure vacuums in the laboratory since it’s easier to slow particles down than to get rid of them. Even the best artificially-created vacuums have a million more particles per unit volume than the material in our solar system. A typical gas has about 10^29 (that’s shorthand for 1 with 29 zeros after it) particles per cubic meter, so these vacuums do reduce the number of particles by a significant amount (10^17). There may be technical difficulties associated with doing this in space, but if a vacuum was created starting with solar system material, one could in principle get down to the density of voids and see if this had any effect on the speed of light.

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