A
Amorphous
Guest
One pet theory held among young earth creationists is that the original earth possessed a canopy consisting of vapor (most common interpretation) or ice that engulfed the earth through the tropopause (~ 11 km). The canopy is posited as the source of all the water required to explain a global flood of Genesis. Isaac Vail (1840 –1912) first proposed the canopy theory in 1874.1 He believed a canopy formed millions of years ago as the earth evolved from a molten state. It has remained a source of embarrassment for creationists since this time.
Doing a back of the envelope calculation, one can take a look at the fallacy first hand.
For the sake of argument, suppose that the Antediluvian flood covered the surface of the earth up to a height of 1000 meters. [Scriptures allege that the actual waters covered the earth to height that covered the mountains of the earth to a depth of 15 cubits (about 8m). If so, Mt. Everest towers to over 8 km. However, a common retort is that the earth was much flatter before the flood and the flood waters themselves carved out the geologic features we observe today. A more modest value of 1000 meters is then used]
If the atmosphere were to hold 1000 meters of water in vapor or ice form, there would need to be a corresponding increase in surface pressure:
∆P=ρ*g*∆z
If
∆z= 100 m
g=9.8 m/s^2
ρ=1000 kg/m^3 (assuming moderate temperatures)
then
∆P≈9.8E06 Pascals or ~980 atmospheres (ignoring the 1 atmosphere of pressure that we already experience). For comparison's sake, the surface pressure on Venus has been measured at ~80 atmospheres. Needles to say, only organisms that thrive in the deep oceans can survive pressures such as these on the Earth's surface. Certainly, Noah and his clan would be instantly crushed by the weight of Earth's atmosphere prior to the flood.
The difficulties do not end here. Assuming a water vapor only canopy, the water equivalent mass of the vapor canopy in question would amount to ~2.8E27 gm. Knowing each gram of water vapor (steam) that condenses to a liquid releases about 539 calories of heat, (Lc) and that the specific heat at constant pressure for air and water are .242 cal/gm C (Cpa) and 1.0 cal/gm C (Cpa), respectively, then atmospheric temperatures be on the order of:
T=Lc*2.8E27 gm/(5.1E21 gm*Cpa+2.8E27 gm*Cpw) ≈ 536 C ≈ 997 F.
where the weight of the dry atmosphere is ~5.1E21 gm.
Needless to say, this is hot enough to melt lead. Noah and company would not only be flattened by the extreme surface barometric pressures but crispy fried by heat.
Thankfully, most but not all creationists have abandoned the water canopy theory for these and several other reasons. I suppose that they look foolish enough already without further manipulating some basic hydrostatic principles and simple thermodynamics.
Doing a back of the envelope calculation, one can take a look at the fallacy first hand.
For the sake of argument, suppose that the Antediluvian flood covered the surface of the earth up to a height of 1000 meters. [Scriptures allege that the actual waters covered the earth to height that covered the mountains of the earth to a depth of 15 cubits (about 8m). If so, Mt. Everest towers to over 8 km. However, a common retort is that the earth was much flatter before the flood and the flood waters themselves carved out the geologic features we observe today. A more modest value of 1000 meters is then used]
If the atmosphere were to hold 1000 meters of water in vapor or ice form, there would need to be a corresponding increase in surface pressure:
∆P=ρ*g*∆z
If
∆z= 100 m
g=9.8 m/s^2
ρ=1000 kg/m^3 (assuming moderate temperatures)
then
∆P≈9.8E06 Pascals or ~980 atmospheres (ignoring the 1 atmosphere of pressure that we already experience). For comparison's sake, the surface pressure on Venus has been measured at ~80 atmospheres. Needles to say, only organisms that thrive in the deep oceans can survive pressures such as these on the Earth's surface. Certainly, Noah and his clan would be instantly crushed by the weight of Earth's atmosphere prior to the flood.
The difficulties do not end here. Assuming a water vapor only canopy, the water equivalent mass of the vapor canopy in question would amount to ~2.8E27 gm. Knowing each gram of water vapor (steam) that condenses to a liquid releases about 539 calories of heat, (Lc) and that the specific heat at constant pressure for air and water are .242 cal/gm C (Cpa) and 1.0 cal/gm C (Cpa), respectively, then atmospheric temperatures be on the order of:
T=Lc*2.8E27 gm/(5.1E21 gm*Cpa+2.8E27 gm*Cpw) ≈ 536 C ≈ 997 F.
where the weight of the dry atmosphere is ~5.1E21 gm.
Needless to say, this is hot enough to melt lead. Noah and company would not only be flattened by the extreme surface barometric pressures but crispy fried by heat.
Thankfully, most but not all creationists have abandoned the water canopy theory for these and several other reasons. I suppose that they look foolish enough already without further manipulating some basic hydrostatic principles and simple thermodynamics.
just a few comments.
