FE Meme
Crepuscular Rays Prove Parallel Lines Diverge?
#56: Crepuscular rays fan outward so dramatically that parallel sunlight cannot explain them, perspective fails and the Sun must be nearby.
The Meme
Aerial landscape photo with bright sun behind cloud deck; wide god-rays spreading downward across the plain (no on-image macro text).
Why It Spreads
Crepuscular rays fan outward so dramatically that they look like they burst from a nearby spotlight, and arguing that parallel lines cannot diverge on the Y-axis sounds technical to viewers who have never traced parallel columns viewed toward their source. The aerial photo does the heavy lifting: wide god-rays feel like a knockout against parallel sunlight without mentioning anticrepuscular rays or cloud depth.
What It Gets Wrong
The aerial god-rays fan outward dramatically, but sunlight arrives as nearly parallel columns across the roughly 150 million km Earth-Sun distance. Crepuscular rays are those parallel shafts scattered by haze and cloud gaps at different altitudes; looking toward the Sun makes parallel tracks appear to converge, the same perspective that makes railroad tracks seem to meet on the horizon. Anticrepuscular rays on the opposite sky re-converge on the antisolar point worldwide, which a nearby flat lamp could not reproduce. TestTheGlobe's Sun Rays Prove A Local Sun and TestTheGlobe's Crepuscular Ray Perspective walk through the observations and predictions this image skips.
The Debunk
Parallel sunlight from a source roughly 150 million km away predicts the fan-shaped crepuscular rays in the aerial photo; perspective toward the cloud deck fits that optics model. Treating diverging god-rays as proof of a nearby flat Sun is inconsistent with anticrepuscular symmetry and latitude-dependent solar noon angles. Use TestTheGlobe's Crepuscular Ray Perspective to compare the meme's claim with a measurable prediction.
- TestTheGlobe's Sun Rays Prove A Local Sun: parallel sunlight through layered clouds at different altitudes produces the fan shape in the meme's aerial landscape photo, a perspective effect not proof of a nearby disc.
- TestTheGlobe's Sun Rays Prove A Local Sun page walks through anticrepuscular symmetry and why parallel rays appear to spread when viewed toward their source.
- TestTheGlobe's Sun Rays Prove A Local Sun: anticrepuscular rays on the far horizon show the symmetry expected from distant parallel sunlight, inconsistent with a nearby flat spotlight.
- TestTheGlobe's A Local Sun Explains Day and Night: solar noon elevation changes predictably with latitude on a round Earth, matching measurements that a local disc Sun cannot reproduce globally.