The pair of nuclear plant cooling towers above appears to be disappearing into the water. Read on and we will explore the reason for this visual curiosity. The small inset photo shows a nuclear cooling tower from a much closer perspective.
MYSTERY OF SINKING NUKE TOWERS--
A year or so ago I stood on the beach at Crane Creek State Park on the south shore of Lake Erie between Port Clinton and Toledo and pondered the tops of nuclear plant cooling towers I could partially see in the general direction of Monroe, Michigan.
Driving to that park from the Sandusky Bay bridge on state route 2 you pass the Davis-Bessie
nuclear plant and get a really close look at its single cooling tower. It is huge. Later research revealed these towers are often as tall as 600 plus feet with a diameter sometimes more than 300 feet.
You can see that tower from a long way off.
Why then, was I seeing only the top 1/3 or so of those towers across the western corner of the lake on that year-or-so-ago day? That was at a distance later determined to be about 24 miles.
Have you guessed the answer? Yup, those towers just north of Monroe were disappearing from view because of the curvature of the Earth.
Your line of sight travels in a straight line, in this case, tangent to the horizon. Because the earth is round, things beyond the visible horizon drop about 8” per mile. That’s 6 feet in 9 miles. You scientific purists out there should be thinking of the theorem of Pythagoras about now.
Actually, the apparent drop can be much greater than that because of terrestrial refraction—the bending of light waves in proportion to air density, which tends to be greatest near the surface. The thermal effects of variations between on and off shore also aggravate the precise measure of this visual phenomenon.
In the large photo above about 2/3 of the towers has disappeared from view. If the lake were another 12 miles or so wider in this view those towers would have dropped out of our sight—assuming, naturally, our viewing elevation does not change.
If you have the patience you can watch a big ship likewise disappear from view as it travels away from shore.
Me? If I am reclining on a beach it is quite likely my attention will be somewhere other than on Mr. Pythagoras and his geometrical musings.
MYSTERY OF SINKING NUKE TOWERS--
A year or so ago I stood on the beach at Crane Creek State Park on the south shore of Lake Erie between Port Clinton and Toledo and pondered the tops of nuclear plant cooling towers I could partially see in the general direction of Monroe, Michigan.
Driving to that park from the Sandusky Bay bridge on state route 2 you pass the Davis-Bessie
nuclear plant and get a really close look at its single cooling tower. It is huge. Later research revealed these towers are often as tall as 600 plus feet with a diameter sometimes more than 300 feet.You can see that tower from a long way off.
Why then, was I seeing only the top 1/3 or so of those towers across the western corner of the lake on that year-or-so-ago day? That was at a distance later determined to be about 24 miles.
Have you guessed the answer? Yup, those towers just north of Monroe were disappearing from view because of the curvature of the Earth.
Your line of sight travels in a straight line, in this case, tangent to the horizon. Because the earth is round, things beyond the visible horizon drop about 8” per mile. That’s 6 feet in 9 miles. You scientific purists out there should be thinking of the theorem of Pythagoras about now.
Actually, the apparent drop can be much greater than that because of terrestrial refraction—the bending of light waves in proportion to air density, which tends to be greatest near the surface. The thermal effects of variations between on and off shore also aggravate the precise measure of this visual phenomenon.
In the large photo above about 2/3 of the towers has disappeared from view. If the lake were another 12 miles or so wider in this view those towers would have dropped out of our sight—assuming, naturally, our viewing elevation does not change.
If you have the patience you can watch a big ship likewise disappear from view as it travels away from shore.
Me? If I am reclining on a beach it is quite likely my attention will be somewhere other than on Mr. Pythagoras and his geometrical musings.
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