A New Generation of Robotic Weapons - 3D Interactive Graphic…
Why lakes freeze from the top down
When it’s cold enough, you can walk on water–the solid phase of water, that is. Like most liquids, water becomes heavier as it gets colder. However, below 39.2 degrees, water actually becomes lighter as it approaches its freezing point of 32 degrees. Water’s solid phase, ice, is lighter still. A cubic foot of ice weights only 57.2 pounds compared to a cubic foot of water which weights about 62.4 pounds.
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