White rainbows are real—but very rare

National Geographic

boundless (adj)

without limits; seeming to have no end

astonishment (n)

a feeling of very great surprise

glory (n)

something that is beautiful, impressive, or deserves praise

hue (n)

a particular shade of a colour

fairly (adv)

to some extent but not very

whitish (adj)

fairly white in colour

droplet (n)

a small drop of a liquid

observatory (n)

a special building with a telescope or other equipment that scientists use to watch the stars, the weather, etc.

bend (v)

to make something change from straight into a curved shape

indigo (adj)

very dark blue in colour

reflect (v)

to throw back light, heat, sound, etc. from a surface

refract (v)

to make waves, such as those of light, sound or energy, change direction when they go through at an angle

diffract (v)

to break up a stream of light into a series of dark and light bands or into the different colours of the spectrum

year-round (adv)

throughout the year

condensation (n)

the process of a gas changing to a liquid

spherical (adj)

like a sphere in shape

optics (n)

​the scientific study of sight and light (quang học)

illuminate (v)

shine light on something

elevation (n)

the height of a place, especially its height above sea level

atop (prep)

on top of; at the top of