1. ATMOSPHERIC REFRACTION

2. SUN SETS
The sun has actually already set when we observe it. The light refracts due to the earths atmosphere.

3. STARS Stars twinkle because their light passes
through several miles of
Earth's atmosphere. A
combination of
refraction and moving
air masses cause a
twinkle effect.

4. HUBBLE TELESCOPE
The Hubble telescope is placed above the earths atmosphere to reduce refraction and atmospheric effects when photographing stars, planets and other celestial bodies.

5. Sky
The color of the sky is from light scattering off suspended particles in the atmosphere. When the sun is higher (day) it refracts towards blue colors. Lower the sky produces red and orange.

6. RAINBOWS
Water droplets refract different colored light at different angles. The light is reflected from the opposite side of the droplet and refracted again separating the colors more.

7. RAINBOWS
The person observing the rainbow must be at 42 degrees with the arc and have the sun behind them.
A double rainbow is a reflection of the first. The color bands of the second are reversed.

8. Rainbows
All rainbows are actually circular and we see them as being approximately degrees due to us being on the ground.
* There is no pot of gold at the end of the rainbow.

9. MIRAGE
This looks like a beach on a large body of water. Its actually an airport.
Warm air is less dense than cool air and refracts light away from the surface

10. MIRAGE
Because light travels in a straight line, we think the effect indicates something reflective on the road like water or oil.

11. MIRAGE