Tides, a Dummies Explanation

Position of the Moon and Tides

In case you haven't noticed, a lot of people are concerned about the rising level of scientific illiteracy of the American public – one of the reasons you keep hearing about STEM programs in the schools. We have staffers who've been involved in STEM programs for more than 20 years, but when they see some of the dumbassery published by freelancers on the internet, they despair. Take, for instance, the "explanation" of "What Causes High and Low Tides?"¹ that journalism and creative writing graduate Ross Garner penned for eHow.com...

Garner apparently had no problem finding a reference that explains the reason for tides: after all, that sort of information can be found in a typical middle-school science book... probably in an elementary school book. Ross also managed to cobble together some sort of explanation of Newton's law of universal gravitation without even mentioning apples (or Newton). In his introduction, Garner informs us that

"Both the Earth and moon are constantly pulling at each other, but because they are both rather solid pieces of rock the effect is hardly noticeable."

The staff geologist vomited a little bit in his mouth at that "rather solid pieces of rock" crap... Garner followed that dumbassery up with the observation that

"As water is a liquid, it moves far easier than solid rock, resulting in two high tides a day and two low tides."

We're pretty sure that equal masses of rock and water move just as "easily." What Garner really wanted to say was that a volume of liquid changes shape more easily than a volume of solid.  That would, however, require that Ross remember something about the states of matter from science class... oops. While Garner did a fairly good job of explaining how a bulge of water follows the position of the moon – and to a lesser extent the position of the sun – across the face of the earth, causing high tides, it's quite clear he is either ignorant of the science involved or of how to express it. In his explanation of the second high tide of the day, Ross explains that

"...the gravitational pull of the moon is far weaker on the far side of the Earth than on the side closest to the moon. So weak, in fact, that the water level actually rises as the moon's pull is not enough to squeeze it closer to the sea bed."

Say what, dumbass? The moon's gravity is responsible for squeezing the water "closer to the sea bed"? What a moron! And a grammatical buffoon as well²!

No, Ross, that's not how it works. Even on the opposite side of the planet, the added influence of the moon's gravity causes ocean water to migrate toward the point diametrically opposite the moon -- that's what causes the second, lower, high tide of the day. It's not some sort of "antigravity" effect. Rubbish like this is precisely why the Antisocial Network started handing out the Dumbass of the Day award, of which Garner is the latest recipient.

¹ The original has been deleted by Leaf Group, but can still be accessed using the Wayback machine at archive.org. Its URL was    ehow.com/info_8211746_causes-high-low-tides.html
² He means the side closer to the moon, not "closest."

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