10 Science Myths You Probably Still Believe

6. Water Is Blue Because It Reflects The Sky

Most of us learn this as a kid, when our beleaguered parents have spent all day answering our persistent questions about the world. By the time the "Why is the sea blue?" question rolls around, they're too tired to even google it and will probably have told us that it's because it reflects the sky (unfortunately, this usually leads to the "Why is the sky blue?" conversation).

In fact, water is blue because it's blue.

In small quantities, it appears to be clear, water's blue hue becomes more and more apparent as the volume increases. Large quantities of water are actually blue, regardless of the colour of the sky, because it absorbs longer light wavelengths (the "red" end of the spectrum) and scatters the shorter blue wavelengths. Basically, the ocean is blue for the same reason the sky is blue.