Why the Sun looks red at sunset

When the Sun is $h$ degrees high, its light crosses about $\dfrac{1}{\sin h}$ times as much air as from overhead. In this simple model, the share of blue light left is $e^{-0.21 \times \text{air}}$ and of red light $e^{-0.05 \times \text{air}}$. You will make the program find the air, the blue and the red left for eight heights of the Sun, and the first height (going down) where red light is more than twice the blue. Then it draws both shares.

Your tasks.

1. Inside the loop, work out air, how many times as much air the light crosses.
2. Work out blue and red, the shares of each colour that are left.
3. Find first, the first height in the list where red is more than twice blue.