Seen the two NASA photos of Earth with differing land mass sizes?
SDHoS was asked a question about the apparent differences in land mass size between two photos of the Earth, one from 1978 and the other from 2012.
The apparent differences were used by the flat earth crowd and various other conspiracy theorists to support the claim that the photos were faked. Could this be true???
The observed difference is exactly what we would predict to see in images of a sphere taken at different distances.
This can be verified experimentally at home. All you need is a fairly large beach ball, a Sharpie marker, and a camera.
(Please refer to my crudely-drawn picture.)
Draw a circle on the front of the beach ball so that the proportions are similar to Figure A. (Blue circle is the beach ball, black circle is your Sharpie-circle) Put the beach ball on a chair against one wall.
With the black circle facing you, move all the way across the room (10-12 feet should be sufficient) and take a picture of the beach ball, as in Figure B.
Next, move as close as you possibly can while still keeping the entire beach ball visible in the camera frame, as in Figure B and take another picture.
Download and open both photos on your computer and expand the first picture so that the beach ball is the same size in both.
You’ll notice that in the second photo, the black circle appears to be larger than in the first.
What the hell? It;s the same circle!
In my crude drawing, take a look at the yellow lines. These lines represent the diameter of the circle you would actually see from both distances. Note that the yellow line in Figure C is shorter than the one in Figure B. That means that you are seeing less of the surface of the ball in Figure C. In both cases, you are still able to see 100% of the black circle.
As distance decreases, you’ll see a smaller and smaller percentage of the surface of the ball. As distance increases, you are able to see a greater percentage of the ball. You’ll never be able to see exactly 50% of it, as that would require you to be an infinite distance away.
Hope this has been helpful.
As always, thanks for reading!