Oscillating Line Illusion
Watch as a simple wave appears to crawl across the screen.
🧐 What do you see?▼
A sine wave moving across the screen. Does it look like it's sliding to the left (or right)? In reality, each point on the line is only moving up and down.
🧠 Why this works▼
Our visual system prioritizes horizontal motion when tracking wave-like patterns. Adding the phase shift to the sine function (sin(kx - wt)) creates a traveling wave. Even though individual pixels simply oscillate vertically, the collective group motion is perceived as horizontal translation.
🧪 Try variations▼
- Focus on one point: Isolate a single peak with your finger. You'll see it only moves vertically.
- Increase Speed: The horizontal motion becomes stronger as frequency increases.
❓ FAQ▼
Is anything actually moving left/right?
Ideally, no. In a transverse wave, the medium (or particles) oscillates perpendicular to the direction of wave propagation.