Thursday, October 20, 2011

Quick Fact: Why Water Is Blue

Today, we're going to tackle one of the most commonly misconceived questions of life. Why are the oceans blue? Many believe that the ocean is blue due to the reflection of the sky on the surface of the water. But owhy is it that water in a small glass, when placed outside, turn blue from the reflection of the water? Clearly, witchcraft is related to this scenario.

The true reason why water is blue, is because in reality, water is technically, blue. But how is it that in small quantities, water is depicted as crisp, clean, colorless substance, but in large bodies of water, is observed as blue? What's different between the two? They're both water, right? Yep, they are. Way to go, genius.

"They're both water" - You

The reason that smaller bodies of water appear clear and large bodies of water appear blue, is because water has an intrinsic property, which is caused by absorption and scattering of the the color red. In small amounts, light passes through water relatively easily without changing the 'white light' noticeable to the naked eye. In large amounts, the water absorbs and scatters parts of the white light to create a blue hue of the water. This can be demonstrated by looking at white light through a one meter pipe filled with purified water, closed on both ends with a completely transparent window.

The primary reason that I said "purified water", wasn't to make myself sound fancy or rich, but so you can do the experiment correctly. Any particles or impurities in the water can slightly alternate the color of the water to slightly different hues of blue, or even a completely different color. This is shown in places in which water is combined with high concentrations of 'some substance' which can change the hue. For example, green algae in rivers and streams can often lead to a greenish-blue color.

An oceanic alien invasion. A red tide off the Californian coast.

Purifying the water, also proves that the water itself is making the light change, not some strange ultra-small particle in the water. While we're at it, another fun fact is that water color can actually tell you a lot of things about the physical, chemical, and bacterial concentrations of the water. Since the true color of water is blue, what's making that water in the drinking fountain, greenish?

Here's some examples of water colors and possible water conditions:
Greenish Water: Copper from copper plumbing, algae growth
Creepily Blue Water: Copper, industrial cleaners
Redish Water: Rust from iron pipes, airborne bacteria from lakes/water sources
Blackish Water: Sulfur (Used to control bacteria growth in hot water tanks set lower than 120 degrees)

You get where I'm going with this? The thing is, naturally occurring water isn't always 100% sterile and filtered down to 0.001 microns. Imperfections in the water from chemicals, organic compounds, and impurities in the water can lead to slight discoloration.

These oranges wedges are contaminating my water!

Now that you know why water's blue, it's time to confuse your friends and colleagues in vain attempts to explain this insanity. Good luck.