Category Archives: Body

Purity of Essence

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Do you realize that fluoridation is the most monstrously conceived and dangerous Communist plot we have ever had to face?
General Jack D. Ripper
Dr. Strangelove, Or: How I Learned To Stop Worrying And Love The Bomb

Fluoride in Water Prevents Adult Tooth Loss, Study Suggests

For children whose adult teeth haven’t shown yet, fluoride still improves tooth enamel, the highly mineralized tissue on teeth’s surface. Fluoride also helps teeth damaged from the decay process and breaks down bacteria on teeth.

Clavula, Next Stop! Next Stop, Clavula!

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Interesting “body as a map” artwork by Samantha Loman

Bony Landmarks – The cranium drawn as a map

Underskin – the body’s various systems drawn as a subway graphic, and there’s no Taconic parkway leading to the clavula (did Ty just make that up?)

Unfortunately only part of the Underskin drawing is shown in high resolution; I found another site with the work that lets you click for more detail

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Other artsy stuff inspired by subway graphics

Sigh

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iPhone city San Francisco is first in U.S. to demand radioactivity warnings on mobiles

The home city of the iPhone has passed a law requiring warning radioactivity warning labels on new mobiles.

San Francisco retailers will soon have to provide information on the specific absorption rate (SAR) of all handsets stocked.

Repeat with me: “Radiation” and “radioactive” are not the same thing.
The specific absorption rate in question is of radiofrequency radiation, which is non-ionizing, and in no way implies that the source is radioactive (i.e. comes from a spontaneous nuclear reaction), because it doesn’t.

On the other hand, it’s the Daily Mail. They apparently handle science no better than Robert Green handles weak shots-on-goal by Americans. (Bang!)

As far as the legislation goes, I think it’s antiscience being sold as informing consumers. But what information is being provided? I think specific absorption rate is being abused here, because it’s not being explained. If I have a mass of 100 kg, does a phone with an SAR of 1.6W/kg mean it is emitting 160 Watts? And for a user who has a mass of 70 kg, the power magically drops to 112 Watts? No. SAR is measured using a calibration standard of one gram of tissue (in the US; in Europe it’s 10 grams) meaning the gram of tissue absorbs 1.6 milliwatts of radiation from the source, under some geometry. The actual power emitted by a cellphone is of order a Watt. But even that information is almost useless without context; the human body radiates somewhere around 800-900 Watts in a more-or-less blackbody spectrum. Is that a cause for concern?

Solving the Resolving

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Bad Astronomy: Resolving the iPhone resolution

In other words, at 12 inches from the eye, Jobs claims, the pixels on the new iPhone are so small that they exceed your eye’s ability to detect them. Pictures at that resolution are smooth and continuous, and not pixellated.

However, a display expert has disputed this. Raymond Soneira of DisplayMate Industries, was quoted both in that Wired article and on PC Mag (and other sites as well) saying that the claims by Jobs are something of an exaggeration: “It is reasonably close to being a perfect display, but Steve pushed it a little too far”.

This prompted the Wired article editors to give it the headline “iPhone 4’s ‘Retina’ Display Claims Are False Marketing”. As it happens, I know a thing or two about resolution as well, having spent a few years calibrating a camera on board Hubble. Having looked this over, I disagree with the Wired headline strongly, and disagree (mildly in one case and strongly in another) with Soneira. Here’s why.

Jobs’s claim is 300 dpi at 12 inches. I remember this as 600 dpi at the nearpoint of ~6 inches (15 cm), which is the same angular resolution. Closer than this and most adults can’t focus; your nearpoint is generally larger if you are older. Which is the same claim, and an explanation as to why 300-600 dpi is generally considered photo quality for images that are printed, and 1200 dpi is the highest resolution you’d ever need.

What Superman Sees

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X-Ray of speech

This is me (female subject) saying “både” (“both”). The sequence is an excerpt from a 20 second X-Ray film registred at the Danderyd Hospital in Stockholm in March 1997.

In this sequence I noticed that the lips form an interesting image as the mouth opens; I assume it’s from lipstick of uneven thickness and application, which can be seen when the mouth is fully open. I wonder what kind of heavy elements are in there that help screen higher-energy photons. The effect is absent for the male subject (and apparently “pion” in Swedish means “peony” rather than “meson made of up and down quarks.” Silly Swedes.)

Pick Your Poison

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Harmful Drinks in America

(Update: link dead. Try this one instead, seems to be the same list)

The 20 worst drinks, along with a food equivalent.

5. Worst Frozen Fruit Drink
Krispy Kreme Lemon Sherbet Chiller (20 fl oz)

980 calories
40 g fat (36 g saturated)
115 g sugars

Sugar Equivalent: 16 medium-size chocolate eclairs

Imagine taking a regular can of soda, pouring in 18 extra teaspoons of sugar, and then swirling in half a cup of heavy cream. Nutritionally speaking, that’s exactly what this is, which is how it manages to marry nearly 2 days’ worth of saturated fat with enough sugar to leave you with a serious sucrose hangover. Do your heart a favor and avoid any of Krispy Kreme’s “Kremey” beverages. The basic Chillers aren’t the safest of sippables either, but they’ll save you up to 880 calories.

Bad Name for a Medical Partnership

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Scott and Scurvy

How the cure for scurvy was found and lost again.

They had a theory of the disease that made sense, fit the evidence, but was utterly wrong. They had arrived at the idea of an undetectable substance in their food, present in trace quantities, with a direct causative relationship to scurvy, but they thought of it in terms of a poison to avoid. In one sense, the additional leap required for a correct understanding was very small. In another sense, it would have required a kind of Copernican revolution in their thinking.

I find this fascinating: the application — almost — of the scientific method, only to fail at the crucial falsification stage. And how the wrong answer propagates because of this failure.