Question: "What is the canopy theory?"
Answer: The canopy theory seeks to explain the reference in Genesis 1:6 to “the waters above the firmament,” assuming that “firmament,” or “expanse,” as the Hebrew word is alternatively translated, refers to our atmosphere. According to the canopy theory, there was a canopy of water above the atmosphere until the cataclysm of Noah’s day, at which point it disappeared either by collapsing upon the earth or dissipating into space. It is presumed to have consisted of water vapor because a canopy of ice could not have survived the constant bombardment of celestial objects like meteoroids which perpetually barrage the earth’s atmosphere.
While Genesis 1:20 (KJV) does say that birds fly in the firmament, suggesting the earth’s atmosphere, it also says that the sun, moon and stars reside there (Genesis 1:14-17), suggesting the entire sky from the earth’s surface outward, where birds fly and celestial objects reside. The Hebrew word alternatively translated “firmament” in some translations and “expanse” in others is raqiya. It appears nine times throughout the first chapter of Genesis (in verses 6-8, 14-18 and 20) and eight more times throughout the rest of the Old Testament (in Psalms, Ezekiel and Daniel).
According to Genesis, before there was air or land or any form of life, the earth was a formless mass of primordial water. On the second day of creation, God created the raqiya, placing it in the midst of the water, thereby separating it into two parts: “the waters above the firmament [raqiya]” and the waters below it. The waters below the raqiya He named “sea” (yam in Hebrew) and the raqiya itself He named “heaven,” “air” or “sky,” depending on your translation of the Hebrew word shamayim. But Genesis does not provide a name for the waters above the raqiya, nor is there any water above our atmosphere today, assuming that raqiya does mean “atmosphere.”
Advocates of the canopy theory once speculated that the collapse of such a vapor canopy might have provided the water for the heavy rains which inundated the earth during Noah’s flood. One problem with the canopy theory, however, is, the latent heat of water and the sheer quantities of water involved. If such a vapor canopy were to collapse into rain, it would literally cook the entire planet. This is because when water converts from vapor to liquid, energy or latent heat is released in the process, causing the surrounding area to heat up; this is known as an exothermic result. Conversely, when water converts from solid form—ice—to liquid or from liquid to vapor, energy is absorbed and the surrounding area is cooled—an endothermic result.
The Genesis account calls for five-and-a-half weeks of constant rain. If a canopy consisting of enough water vapor to provide that amount of rain were to collapse, it would cook the entire planet. This is not to say that there was no vapor canopy or that it did not collapse, only that, if it did, it could not have provided the amount of rain in question (the less water, the less heat).
It is interesting to note that, if a frozen canopy were able to exist in the atmosphere despite cosmic bombardment, its collapse into liquid rain would have an extreme cooling effect and might be an explanation for the commencement of the Ice Age. Despite the fact that we know that it happened, the complex factors involved in getting an Ice Age started makes it seem impossible and baffles modern science to this day. Advocates of the canopy theory also cite the existence of a canopy as a possible cause for a variety of pre-flood anomalies, including human longevity and the apparent lack of rain or rainbows. They claim that such a canopy would filter out much of the cosmic radiation that is harmful to humans and cause the lack of rain or rainbows. However, opponents dispute such a canopy’s ability to produce these results.
In defense of the view that raqiya means “atmosphere,” the reference in Genesis 1:14-17 to the sun, moon and stars residing there may have simply been a phenomenological statement, just as our modern terms “sunset” and “sunrise” are phenomenological descriptions. That is, we know full well that the sun is stationary and doesn’t really “rise” or “set,” despite our usage of terms implying its movement from our earth-bound vantage point.
Whatever the case may be, there is no canopy up there today and any suggestion that there was one in the past is speculation because there simply isn’t enough evidence one way or the other, except for the one enigmatic reference to waters above the firmament in Genesis 1:6, and no one claims to know for sure what that means.