In this article I'd like to check out the claim that Samuel Rowbotham was right after all about his flat earth theory and experiment, based on this video of a similar experiment in Willard Bay, Utah. The story goes like this:
"According to the globe earth model, when looking at a height of 32 inches above the water level towards the other side of the bay, 6.23 miles away, there should be a 11.86 ft drop in curvature. But when we ran an experiment we were able to spot a 4 ft mirror on the other side of the lake, at least the top part of it. This proves that the expected curvature does not exist. Therefore, the earth is flat."
Sounds promising, doesn't it? Let's see.
Before we get to the numbers we need to have a long hard think about what happens when a wave approaches and hits a beach. Scientists call the phenomenon I'm referring to as "wave run up"1. Remember when as a cute little child you went to the beach. You would run close to the edge of the water, only to be chased back by an incoming wave. So, you would run back up to the beach until the wave stopped chasing you. The wave then retreated and the whole process would start all over again.
You think this phenomenon is minimal? Think for a minute about how a Tsunami forms. A wave that is hardly noticeable at open sea starts "climbing" as it approaches the beach, and the shallower the beach is the more the wave climbs. Such a wave can travel quite a distance inland, as well as uphill. Occasionally, wave run up's of a 100 ft have been observed, that's 100 ft upwards, measured vertically!
Obviously in the video mentioned above we're not dealing with a tsunami, but the author does assure us that there is a stiff breeze which is causing up to 2 ft waves on the water. What happens do you think when such waves hit the beach? Indeed, they run up the slope a certain distance and height. We don't know yet how much they run up, but they certainly don't pull the water line downwards!
Now consider that the water line has to be equal or above the height of the waves. Why? Because the waves hit the beach, they don't disappear before they hit the beach. Maybe you say they start shrinking as they approach the beach? Sure, they do, but only because at the same time they travel up the slope, just like a tsunami travels up the slope when it approaches a beach.
Back to the experiment.
We are shown that the mirror which is held up at the water line on the other side of the bay becomes about half (or more?) obscured by the waves. Even though the camera is several feet above the waves! In other words, both the camera and the mirror are located above the water line, as well as above the top of the waves. If the earth was flat we would be able to see the whole mirror. But we don't. Oops!
Now to the numbers.
The author assures us that the camera is about 32 inches tall, but quite a few people have commented it looks more like a full 3 ft. Additionally, looking at the video, the camera is at least 12 ft from the water line, possibly more. And since the beach is not flat but sloping, that amounts for let's say 3 ft extra elevation. If you think that's too much, try it out for yourself next time you go to the beach. Any builder/fencer/landscaper would be able to tell you that estimating elevations, especially from a photo or video, can yield some nasty surprises.
But as we indicated before, there is also a certain amount of wave rune up. How much? I could not find an easy formula or online calculator, but if I had to guestimate, I would say that the run up would be at least one foot above the top of the waves. The same happens at the other side, where the mirror is held at the water line.
It is important to note that the mean surface level of the water does not change on account of the waves. For every gallon of water that rises above the mean level (the crest of the wave), there has to be an equal amount of water being taken from underneath the water level (the trough of the wave). All the time, the mean level of the water remains the same. So, the "visual level" rises by half the amount of the swell, in this case 1 ft.
Now lets put these figures into our calculator. The elevation of the camera above the mean water level is : 1ft from the mean water level to the crest of the waves, plus 1 ft wave run up measuring from the top of the waves, plus 3 ft because of the sloping beach, plus about 3ft for the height of a tripod and camera. This gives us a total of 8 ft. While on the other side of the bay the mirror is placed at the waterline, being 2 ft elevation above the mean water level (wave height plus run up).
Entering these figures into our Earth Curve Calculator2 we expect about 5.1 ft to be hidden by the curve of the earth. But we know that the bottom of the mirror is already at 2ft elevation (the waterline), and since the mirror is 4ft tall the top of the mirror is 6ft above the mean water level. Which leaves us 0.9 ft that we expect to be visible still. It is hard to see from the video how much of the mirror is still visible, but it is rather clear that some of the mirror is hidden.
Conclusion, even though the camera is located 8ft above mean water level, and the mirror between 2 and 6 ft above mean water level, we clearly see that at least part of the mirror is obscured by the water, while the waves only reach 1ft above mean water level. As expected, the water level and the earth's surface are curved and our calculations are as close as can be expected from an experiment where no accurate measurements and conditions are given.
True, we haven't accounted for the 1 ft wave height in the middle of the bay, but there are other factors that come into play as well on such a big water mass, including the much feared mirage phenomenon. But given that we're given very few of the essential measurements, I think this pretty much should suffice to prove the point.
Sorry, no flat earth in Utah folks!
Stay tuned for more flat earth excitement!