The Flat Earth “theory”. It’s taken up a mighty resurgence in the past few years, and it needs to be addressed, because it is filled with awful science and terrible refutations. It also relies heavily on inane conspiracy theories, and simply doesn’t work due to our understanding of physics. From the question of how gravity works (some say the disk of the Earth is accelerating upward at 9.8m/s², others claim that it comes from the disk itself, and still others say that there is some great attractor under the Earth) to failing to identify how ships disappear bottom-up going over the horizon, to the topic at hand: crepuscular rays.
Crepuscular rays, or “God’s rays”, are those nifty sunshafts you see near sunset when intermittent clouds block some of the light but let some through, being reflected off dust and moisture in the air to become visible. They’re a great sight, and make for some amazing photos. The problem is, they seem, at first, to verify the flat earth world view. After all, we’re told that the sun’s light is effectively parallel by the time it hits the Earth, so how could it possibly have this ascending cone of light leading from the ground back up to it? Their answer is simple: The sun is actually only 3,000 miles away from the Earth. Also, keep this explanation in mind for part 2, as it’s going to be crucial for showing why their ideas are inconsistent. This makes sense in this limited example, as the rays seem to emanate from a point light source, all meeting up somewhere in the middle where the sun is. This kinda works on an intuitive level, but intuition, unfortunately, is often wrong. This is also an issue for their own theory as well, but again, we’ll come back to that at a later time.
So how does the roughly-spherical Earth with parallel light explain this phenomenon? Simply-put: perspective. Before I get too far into the perspective, take a look at this conspiracy-created photograph of crepuscular rays from “space”. NASA wants you to think that’s what they actually look like, but flat Earth theorists know better. As you can see, the rays are clearly parallel here. Straight lines directly from the clouds, fading out as they get further away due to the shape of the clouds themselves and light being above them as well. You can also see why, on “ball Earth”, they’re called “crepuscular rays”. The “God’s rays” we commonly think of only really happen during twilight, hence the word crepuscular. If the flat Earth theory were correct, we would see these rays at noon on a partly-cloudy day. Now, that’s not to say they’re never visible during mid-day. After all, if you’re wandering through a forest with lots of particulates in the air, you’ll see something similar because the trees are taking the place of the clouds. The key here is the distance between yourself and the treetops, compared to yourself and the clouds, creating relatively long, thin shadows.
Think of train tracks. They’re probably the most often-seen example of perspective on parallel lines. If you’re standing in the middle of the track, they seem to move off and vanish to a point. The reality is, they’re probably disappearing only a few miles away, because they’re so thin and not spread that far apart. The shadows of clouds, however, are massive comparatively. They seem to come together and vanish much further away, but they’re doing the exact same thing as the train tracks, just on a much more massive scale. The same is true for our forest shadows. They’re much shallower and smaller than those of the clouds, so rather than blanketing an entire area in shade, they are stretched thin and appear to meet much closer to the viewer’s perspective. This is actually even more of a refutation of the sun being 3,000 miles away. The rays seem to meet up just beyond the tree-tops, not millions or tens of millions of miles away. Thousands of feet, maybe. It’s the same light, the same distance away, how can it seem to have the same angle in both examples if it’s simply because the sun is shooting out light in multiple directions at once? Simply: It cannot. You’re simply closer to the source of the shadows under trees than under clouds, meaning they meet up at a closer point, but they’re still the photon-created train tracks of your brain.
That’s it for this debunk. Next up: The Sun, the Moon and perspective.