And his feet shall stand in that day upon the mount of Olives, which is before Jerusalem on the east, and the mount of Olives shall cleave in the midst thereof toward the east and toward the west, and there shall be a very great valley; and half of the mountain shall remove toward the north, and half of it toward the south. [5] And ye shall flee to the valley of the mountains; for the valley of the mountains shall reach unto Azal: yea, ye shall flee, like as ye fled from before the earthquake in the days of Uzziah king of Judah: and the Lord my God shall come, and all the saints with thee. [6] And it shall come to pass in that day, that the light shall not be clear, nor dark: [7] But it shall be one day which shall be known to the Lord, not day, nor night: but it shall come to pass, that at evening time it shall be light. Zechariah 14:4-7

A most unusual phenomenon:  light at night from the sun!  When will it occur?  The answer is found in verses 4 and 5, which describe the cleavage of the Mount of Olives, a definite occurrence of the latter portion of the Tribulation Period.  In the latter part of the Tribulation Period the great cloud shroud of figure 14 will have established itself around the entire earth above the tropopause.  It is this great cloud shroud that will fulfill the prophecies of verses 6 and 7.  Verse 6 states that the light will not be clear nor dark.  To a Hebrew clear light was unobstructed light, a light that came from its source to fall on an object with no obstructions between.  A Hebrew viewed darkness as the absence of light.  So we are advised that there will be some light (it will not be pitch dark), but the light will not be clear light (it will be partially obstructed).  This is a perfect description of what we call a cloudy day.  On days when the skies are overcast we do have light, but it is not clear light, for the clouds obstruct our view of the sun.  The light on a cloudy day reaches us by a process that involves reflection, refraction, and scattering of the light from the sun.  During the latter portion of the Tribulation Period man will not see the sun.  But limited light, of varying degrees, will penetrate the great cloud shield in the stratosphere.  It will be a dull, gray, depressing light in which the inhabitants of the earth are struggling for survival.  But how can it come to pass “that at evening time it shall be light?”  How is it possible that, at every location on the face of the earth, there will be some light during the evening hours when normally it is pitch dark?

About 20 years ago, after presenting a lecture series in California for Dr. Reed, I departed the Los Angeles area by jet to Dallas, flying at an altitude just below 40 thousand feet.  It was a beautiful day from the surface to the top of the atmosphere along the entire flight path, with clear skies above and below the aircraft.  As we crossed Arizona and New Mexico the light from the sun beamed upon the ground below us, and through the air above us.  When we crossed into Texas there were no clouds below or above us, and the sun was beaming on the aircraft with its full brilliance, but as I looked toward the earth’s surface I begin to notice tiny pinpoints of light on the ground.  People had turned on the lights below us because it was dark at ground level.  The curvature of the earth had already blocked off the surface rays of the sun at ground level across Texas, but at our flight level and above it was broad daylight.  If there had been a way for me to take the light at high levels and direct it downward, it would have produced   dim light on the surface below, where darkness had enshrouded Texas.  It is not by accident that the God of light, who is Light, has very conveniently established a law in nature where this is predictably possible – The law of refraction.

Laws are not theories.  They are like God because they are made by God.  They are consistent and can always be counted to act in a predictable, unchanging manner.  It is not my purpose to teach physics, so I will refrain from a technical discussion of the law itself, and will rather refer those interested in such a dissertation to any general physics textbook.  Refraction occurs because light waves travel at different speeds through different substances.  Refraction involves the bending of light waves as they move from one medium to another.  In figure 15 you can see the bending effect on light as it passes from a less dense medium (air) into a more dense medium (water).  If you want to see this bending of light in action, drop a pencil and a coin into a glass about three-fourths full of water.  The pencil will appear to be broken at the water surface, and the coin will appear to be on the side of the glass.  This is a phenomenon produced by refraction.

Why is it that we still have light long after the sun has disappeared over the horizon?  And why do we have light in the morning before the sun comes into view?  You guessed it!  It is the law of refraction at work.  As the sun’s rays travel through space, they move very rapidly, as if in a vacuum, but when contact is made with the more dense atmospheric medium of the earth, the light decelerates, and is bend around the curvature of the earth by the law of refraction.  This law causes the light to reach the surface before the sun appears in the morning, and to trail behind on the surface long after the early evening sun disappears.

The great cloud of volcanic smoke will be firmly established as shown in figure 14 by the time the battle of Armageddon occurs.  This great encompassing shroud will vertically be thousands of feet thick and, as such, a very dense medium through which the sun’s rays must filter on their way to the earth’s surface.  As the rays filter through by refraction and scattering, they will be severely bent around the curvature of the earth’s surface.  As you may observe in figure 16, the small island, on the opposite side of the earth from the sun, would normally be experiencing an evening of complete darkness.  However, because of the refraction and scattering of sunshine through the great volcanic cloud, light would be bent around the earth to strike the island, and “it shall come to pass, that at evening time it shall be light.”  Such would be the case at every location on the surface of the earth.  The intensity of the light at any given point would be affected by the distance it had to be refracted, and by the thickness of cloud through which it had to pass.  No spot on the earth would receive clear light (unobstructed), and no spot on the earth would ever be dark (lightless).

And it shall come to pass in that day, that the light shall not be clear, nor dark: [7] But it shall be one day which shall be known to the Lord, not day, nor night: but it shall come to pass, that at evening time it shall be light. Zechariah 14:6,7