5 Really Weird Things About Water

Water, good ol' H₂O, seems like a pretty simple substance to you and me. But in reality, water - the foundation of life and most common of liquid - is really weird and scientists actually don't completely understand how water works.

1. Hot Water Freezes Faster Than Cold Water

Take two pails of water; fill one with hot water and the other one with cold water, and put them in the freezer. The hot one would be frozen before the cold one. But wait, you say, that's counterintuitive: wouldn't the hot water have to cool down to the temperature of the cold water before proceeding to freezing temperature, whereas the cold one has "less to go" before freezing?

  How do scientists explain this strange phenomenon? It turns out that no one really knows but there are several possible explanations, including differences in supercooling (see below), evaporation, frost formation, convection, and effects of dissolved gasses between the hot and cold water.

*In reality - of course - it's much more complex than that: hot water freezes first (it forms ice at a higher temperature than cold water), whereas cold water freezes faster (it takes less time to reach the supercooled state from which it forms ice).

2. Supercooling and "Instant" Ice

Everybody knows that when you cool water to 0 °C (32 °F) it forms ice ... except that in some cases it doesn't! You can actually chill very pure water past its freezing point (at standard pressure, no cheating!) without it ever becoming solid.

Scientist know a lot about supercooling: it turns out that ice crystals need nucleation points to start forming. These nucleation points could be anything from gas bubbles to impurities to the rough surface of the container. Without these things, water would continue to be a "supercooled" liquid well below its freezing point.

  3. Glassy Water

                                                          Quick: how many phases of water are there? If you answer three (liquid, gas, and solid) you'd be wrong. There are at least 5 different phases of liquid water and 14 different phases (that scientists have found so far) of ice.

  it turns out that no matter what you do, at -38 °C even the purest supercooled water spontaneously turns into ice (with a little audible "bang" no less). But what happens if you continue to lower the temperature? Well, at -120 °C something strange starts to happen: the water becomes ultra viscous, or thick like molasses. And below -135 °C, it becomes "glassy water," a solid with no crystal structure. 

 4. Quantum Properties of Water

At a molecular level, water is even weirder. In 1995, a neutron scattering experiment got a weird result: physicists found that when neutrons were aimed at water molecules, they "saw" 25% fewer hydrogen protons than expected.

Long story short, at the level of attoseconds (10^-18 seconds) there is a weird quantum effect going on and the chemical formula for water isn't H₂O. It's actually H_1.5O! 

5. Does Water Have Memory?

In the alternative medicine of homoeopathy, a dilute solution of a compound is purported to have healing effects, even if the dilution factor is so large that statistically there isn't a single molecule of anything in it except for water. Homeopathy proponents explain this paradox with a concept called "water memory" where water molecules "remember" what particles were once dissolved in it.

This made no sense to Madeleine Ennis, a pharmacologist and professor at Queen's University in Belfast, Northern Ireland. Ennis, who also happened to be a vocal critic of homeopathy, devised an experiment to disprove "water memory" once and for all - but discovered that her result was the exact opposite!

Ankita Das

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