Dr. Universe: Why does water in ponds not get soaked up by the dirt at the bottom? – Rocky, 11, California
rcwebber
That’s a great observation. If we investigated the bottom of a pond, we might find a few different things. Read More ...
Dear Alysin,
At first, I thought the answer to your question might take us deep into the ocean. But it turns out the source of our salty seas is actually on land.
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