No, all rainbows are not the same. While the underlying physics of light refraction and reflection in water droplets remains consistent, resulting in a similar spectral sequence (red on the outside, violet on the inside for primary rainbows), several factors create visual differences.
Factors Affecting Rainbow Appearance
- Perspective: Each person views a rainbow from a unique location, with a unique antisolar point and horizon. Therefore, no two individuals see precisely the same rainbow. (National Geographic, [Source 19-Oct-2023]) Someone observing near the apparent "end" of one person's rainbow will see a different rainbow extending from their horizon.
- Atmospheric Conditions: The number of rainbows (single, double, or even multiple), their brightness, and the vibrancy of their colors are significantly influenced by atmospheric conditions like the density and size of water droplets, light intensity, and presence of other atmospheric particles. (ScienceABC)
- Water Droplet Size: The size of water droplets affects the dispersion of light, influencing the brightness and sharpness of the rainbow's colors. (Earth Science Stack Exchange)
- Not all "Rainbows" are Created Equal: While rainbows are formed by sunlight and raindrops, similar phenomena, such as fogbows or those formed by mist, dew, or ice, might appear different due to variations in the size and type of particles interacting with light. These phenomena are not technically "rainbows" in the strictest sense. (Smithsonian Magazine)
Size and Shape
Although the angular size of a rainbow is constant due to the consistent properties of water, the visible portion of the rainbow varies depending on the observer's perspective and the extent of the rain shower. We only ever see a portion of the full circular rainbow. A rainbow from a high vantage point might appear larger due to a more extensive view of the circle. (Reddit - AskScience, Quora, Big Think)
In Conclusion
While the underlying principle of rainbow formation remains consistent, the resulting visual manifestation varies due to observer location, atmospheric conditions, and the nature of the water particles involved. Therefore, though all rainbows share a fundamental similarity in their light-based formation, they are not identical.
