Determining Density for Dummies

Water density vs. temperature

Sigh... the more we listen to our "congresscritters" argue, the more we regret the epidemic of scientific illiteracy that's swept our nations. If we hear one more TEA Party Republican solemnly intone. "I am not a scientist," we're gonna barf. Well, right-wing politicians aren't the only technoboobs on the planet; there are also self-appointed freelancers of unknown politics  who write for websites like eHow.com. Take, for instance, elementary educator Stacy Zogheib, who couldn't even manage to reword the simple facts from wikipedia to answer (and we use the term loosely), "What Happens to the Density of Water as the Temperature Decreases?"¹

As is typically the case with eHow answers, the question could have been answered in far fewer words than the 420-plus Stacy needed: "Water density is inversely proportional to temperature, increasing as temperature decreases. Pure water reaches maximum density at approximately 4° C." There: twenty words, four of them arguably superfluous. But Zogheib? she found it necessary to first "explain" density:

"...Many people think of density as a measure of how heavy something is, but although density and weight are related, they are not the same thing. For example, one pound of foam weighs as much as one pound of stone, but a pound of stone is much more dense than a pound of foam..." Ugh: that's not a definition, that's a daffynition! Someone more knowledgeable of the topic would most likely say that a pound of stone occupies a smaller volume than a pound of foam (whatever "foam" is) because stone is denser; but what do we know? Rhetorical: we know more than Stacy or anyone unlucky enough to read this tripe.

As for the rest of Zogheib's post, it's sometimes accurate and sometimes not -- though why she finds it necessary to discuss melting and boiling points to answer that question is somewhat curious. Be that as it may, Stacy does her readers a disservice mainly because she has no idea what she's talking about. In other words, she commits dumbassery such as

• "Beginning at 0 degrees Celsius, pure water, or in this case ice, has a density of .9150 grams per cubic centimeter (g/cm3)." -- more or less true, though you can measure the density of water at 0° C -- it's 0.9999 g/cm³ (that links, oddly, to one of  the sources Zogheib misapplies)
• "Water has a maximum density of 1 g/cm3 at 4 degrees Celsius or about 34 degrees Fahrenheit." -- Stacy, Stacy, Stacy... 4° C is 39° F, not 34! Dumbass!

So she can't even get the temperature conversion right... heaven knows how many fifth-graders out there think 4°C is 34° F because of this dimwit. So, for mangling the definition of foam and for failure to apply the formula F = 9*(C/5)+32, we think Stacy is a perfect example of the sort of freelancer we award the Antisocial Network's Dumbass of the Day.

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_7788526_happens-density-water-temperature-decreases.html

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