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  • What do your phone, the sun, the stove, far-off black-holes and the palm of your hands all

  • have in common? Radiation, baby. It's everywhere.

  • Up and atom friends, Trace here emitting and absorbing radiation at your eyeballs for DNews!

  • When I say radiation, most people do this, but to be honest, radiation on it's own isn't

  • necessarily harmful! The term radiation is super broad, gamma rays shooting out of stars

  • is radiation, heat coming off the pavement on a hot day is radiation, and the radio waves

  • picked up and emitted by cell phones, radio stations and WiFi networks are radiation too

  • -- even the light you're seeing on this screen is radiation. The thing is, even though radio,

  • microwave, visible and infrared, are technically radiation -- when we SAY radiation, most people

  • think of dangerous high-energy particles called IONIZING radiation. That includes Ultraviolet,

  • X-Rays, or Gamma Rays. Which makes sense, but what can that stuff DO to you when it

  • hits your body?

  • In 1927, in the journal Science, Hermann Muller published a paper showing the ionizing radiation

  • of x-rays damaged the genes of fruit flies. He later won a Nobel prize! Ionizing radiation

  • is high-energy radiationit's got a lot of energy. When this high-energy particle

  • or wave hits an atom, the atom absorbs the energy; causing the weakest electron to pop

  • off! This creates a charged atom called an ion!

  • Do that enough and all that high-energy can cause chemical changes in our tissue. If ionizing

  • radiation affects too many cells at once, or we absorb a bunch over time -- that's when

  • we risk sickness, radiation poisoning, or eventually cancer. That happens when the radiation

  • changes how things fit together. It might knock off bits of our DNA, mess with its structure,

  • or (at worst) break one or both strands of the DNA double helix! That alone isn't damaging,

  • but sometimes, the body makes mistakes when repairing that damage -- causing wide-spread

  • issues.

  • But chances are, you'll never have to worry too much about how much radiation you're being

  • exposed to. Radiation dosage is measured in sieverts. One sievert in a short time can

  • cause radiation sickness and 10 can kill. But because we'd never really encounter a

  • full sievert, scientists usually talk in millisieverts. Every year, just living on Earth exposes us

  • to 2.4 mSv in natural background radiation, and its fine. A chest x-ray, for example,

  • is 6.8 mSv, so while ONE X-Ray won't hurt you, a bunch throughout your life (or all

  • at once) can damage your tissues enough to cause health problems.

  • If that weren't complicated enough, there are different types of ionizing radiation!

  • Alpha, Beta, Gamma and X-Rays; listed in increasing energy levels. Alpha radiation is the slow

  • big fella, it can't really penetrate your body, but it's essentially a handful of protons

  • and neutrons. Beta is basically a tiny fast-moving electron; it can penetrate your body, but

  • not some denser materials, like aluminum. Then there's gamma radiation, which is just

  • fast-moving pure energy! It's so small it can pass between your cells, but if it hits

  • your DNA it'll mess you up -- though it won't make you green and invulnerable. In fact gamma

  • so high energy, it can pass though you, aluminum and even concrete walls -- though not lead

  • it's too dense. X-Rays are like gamma rays, but lower energy.

  • In the end, you probably don't have to worry a LOT about ionizing radiation. UV rays can

  • damage DNA over time, so wear sunscreen. X-Rays are highly regulated, and hopefully you haven't

  • spent too much time near unbridled nuclear reactions, or exposed yourself to cosmic rays.

  • Most radiation is just regular non-ionizing stuff. Heck, even humans emit infrared radiation

  • in the form of heat and some ionizing radiation that we absorb from food, like bananas. It's

  • everywhere! And though some of it can damage you, it's not all bad.

What do your phone, the sun, the stove, far-off black-holes and the palm of your hands all

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輻射如何改變你的DNA (How Radiation Changes Your DNA)

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    Jack 發佈於 2021 年 01 月 14 日
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