Captain Nemo wrote on Jun 26
th, 2019 at 2:15pm:
Not sure if anyone has mentioned the shortest distance in long distance sailing (or flying) = using a "great circle arc"?
I was thinking about that yesterday.
More proof that the earth
isn't flat.
Great circle sailing takes advantage of the shorter distance along the great circle between two points, rather than the longer rhumb line. The arc of the great circle between the points is called the great circle track. If it could be followed exactly, the destination would be dead ahead throughout the voyage (assuming course and heading were the same). The rhumb line appears the more direct route on a Mercator chart because of chart distortion. The great circle crosses meridians at higher latitudes, where the distance between them is less. This is why the great circle route is shorter than the rhumb line.
https://i.imgur.com/F5bad0L.jpg Raven once saw a flat earth presentation. Although the guy admitted he didn't have any kind of science background he did have on a white lab coat. Just to give him authority.
He presented a picture of the Chicago skyline from 60 miles out in Lake Michigan. The problem was, if the Earth was curved, you shouldn't have been able to see any buildings.
Now the guy had said moments earlier that all photo's from NASA are photoshopped but we can believe his one.
One bloke who was what you would call a flat earth sceptic asked if he had heard of the "Superior Mirage Effect," which is a familiar physical phenomenon whereby—depending on the temperature of the surface of the water relative to the temperature of the air on any given day—what you saw in the photo was NOT actually the city of Chicago, but its super position as a mirage in the sky. It was an optical illusion. (We've all seen a similar illusion of the "Inferior Mirage Effect" when, on a hot day, there seems to be water on the pavement.) Light doesn't always travel in straight lines.
Of course the presenter laughed and said it was made up.
So the bloke asked him "Why didn't you just go 100 miles out?"
"What?"
"A hundred miles. If you'd gone out that far not only the city would've disappeared but also the mirage too. If it didn't, you'd have your proof."
He shook his head, "We couldn't get the captain of the boat to go out that far."
"What? You've devoted your entire life to this work and you didn't go? You had the definitive experiment within reach and you couldn't go out an extra 40 miles?"
The bloke turned and started talking to other people.