October 22, 1998 transcript # 256-4
Subject(s): folklore, egypt
Title: ANCIENT WEATHER THEORYScientists tell us that way back in history, weather used to be different. Our back yards were flooded by prehistoric oceans, frozen under glaciers, and buried in sand dunes. Strange weather. Hi, I'm Dave Thurlow and this is The Weather Notebook.
The strangest weather of all, or at least the strangest weather phenomena, seems to have happened in ancient Egypt. So says Herodotus, the Greek historian who visited Egypt in the 5th century BC. Herodotus wondered why the Nile floods every summer. "Where does all that water come from?" he thought. Normally, floodwater is fed by snowmelt coming off of the mountains in the spring. But the Nile starts in the south, and in Egypt, the farther you go south, the hotter it is. So melting snow can’t be the answer; it’s too hot.
So how does Herodotus explain the flooding of the Nile? Simple. It doesn't flood. What appears to be a flood in the summer is just the regular flow of the river. He believed that, during the winter, strong winds somewhere to the south—now get this—winds blew so hard that they made the sun come to a complete halt. And since it’s just sitting there, there’s more heat to evaporate waters of the Nile, so that the river becomes lower in the winter. Now when the wind dies down in summer, the sun moves on, things go back to normal, and here comes the so-called flood.
Hmmm. It’s an interesting theory. I wonder if that sun-being-stopped-by-the-wind thing has anything to do with global warming? Or maybe El Nino.
Today’s contributing writer was Larry Massett. The Weather Notebook is a production of the Mount Washington Observatory, with underwriting is provided by Subaru, the beauty of all wheel drive, and by the National Science Foundation.