I'm Radioactive Man!: The boots hide my ankle bracelet!
Courtesy whaltHey Buzzketeers! Welcome to the new week! Is it everything you imagined it would be?

So, if I said “Radioactive Man,” would y’all get the Simpsons reference? Bart’s favorite comic book hero is Radioactive Man, a guy who survived an atomic blast, and a lightning bolt shaped piece of metal stuck in his head.

Hey, guess what! There’s a real life Radioactive Man running around now!

Oh… but the radioactivity is potentially dangerous. And he’s some kind of sex offender, who has run away from the authorities.

So that’s a bummer, but the situation provides some opportunity for science education (which is, like, my favorite thing).

How does a sex offender get to be radioactive? Good question.

Not all sex offenders are radioactive. For the most part, you still don’t want to come in close contact with them, but not because of radioactivity.

This particular sex offender, Thomas Marius Leopold, is radioactive because he has an overactive thyroid gland.

The thyroid gland hides out in your neck, and it produces hormones that help regulate your metabolism. Too much thyroid hormone, and your metabolism goes nuts—you get weak and hungry, you can lose weight, and your heart rate becomes jittery. That sort of thing. Some thyroid conditions also cause your eyes to become protuberant, and your thyroid gland to swell, forming a goiter.

One of the treatments for hyperthyroidism involves the use of radioiodine. Radioiodine is an isotope of the element iodine. Iodine is number 53 on the periodic table, so it has 53 protons in each atom. Naturally occurring iodine has 74 neutrons in each atom, but iodine can have different numbers of neutrons (different isotopes). The radioiodine isotope has 78 neutrons, but the atom isn’t stable with that many neutrons, so they decay until there are just 74 left. These decaying neutrons give off beta emissions (electrons and positrons), and gamma rays (highly energetic electromagnetic radiation).

Normally we want to avoid this sort of radioactive stuff, but materials like radioiodine can be very useful when they’re targeted at certain cells or organs (sort of like how we blast tumors with radiation to treat cancer). It just so happens that the thyroid naturally traps iodine in our bodies (it needs iodine to make hormones), so when a patient is given radioactive iodine, the thyroid sucks it right up. When the emissions from decaying neutrons blast into thyroid tissue, the thyroid kind of gets worn out, and slows down—that’s why radioiodine can be good for a thyroid that was overactive in the first place.

Radioiodine is radioactive enough, however, that hospitals often recommend keeping extra space between someone who is on the treatment, like this sex offender on the lam, and folks who might be particularly susceptible to radiation, like small children, or arresting police officers.

The radioactivity isn’t super bad, at least, and it doesn’t last forever—radioiodine has a half-life of about 8 days. That means that after 8 days, half of the radioactive material is gone (turned into something more stable). And after 8 more days, half of what was left is gone (so there’s just ¼ of the original amount left). Eventually the amount of radioiodine left in the body is so negligible that you’re safe hugging pregnant women and handcuffing fugitives.

Wasn’t that interesting? We know about radioiodine now! So if you’re in Great Britain (where this story came from), and there’s a creepy-looking dude who seems to be ruining your film just by being around you, call the police!

Tags : radioactivity, radioactive decay, iodine, nuclear medicine, health

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Gravitational compression

Will Earth ever freeze?: Internal radioactive decay is expected to keep Earth heated for billions of years.
Courtesy NASA In its beginning, the Earth was so hot that it was entirely melted. That heat was generated because of gravitational compression. As gravity pulls materials in outer space towards each other they are compressed. When atoms and molecules are squeezed together they generate heat. Matter at the earth's center is very compressed; in fact, Earth is the densest planet in the Solar system.

Gravitational sorting

Penn State professor of geosciences, Chris Marone, feels that the original heat from that molten earth is only about 5 to 10 percent of the total heat within our planet. Another source of heat is from gravitational sorting.

In a gravitational sorting process called differentiation, the denser, heavier parts were drawn to the center, and the less dense areas were displaced outwards. The friction created by this process generated considerable heat, which, like the original heat, still has not fully dissipated.

Latent heat

Another source of heat is latent heat. When material in the center of the Earth changes from a liquid to a solid, heat is released. The solidified material also expands, which increases the pressure, thereby increasing the temperature. "The inner core is becoming larger by about a centimeter every thousand years," Marone says.

Almost all Earth's heat comes from radioactive decay

Marone says, the vast majority of the heat in Earth's interior—up to 90 percent—is fueled by the decaying of radioactive isotopes like Potassium 40, Uranium 238, 235, and Thorium 232 contained within the mantle. The amount of heat caused by this radiation is almost the same as the total heat measured leaving the Earth.

Source: Penn State University Live

Tags : earth, earth science, Chris Marone, Penn State, geosciences, radioactive decay

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