Name: 32. Chemical and Biological Effects of Radiation, Smelling Nuclear Bullshit
Uploaded: 2020-03-29T16:10:19.000Z
Duration: 59 min 36 s
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to get into the most politically and emotionally fraught

topic of this course for stuff on chemical

Now that you know the units of dose, background dose,

we're going to talk about what ionizing radiation does

and we're going to get into a lot of the feelings associated

And by the end of this lecture, or Thursday,

I'm going to teach you guys how to smell bullshit.

Because we're going to go through one of millions

of internet articles about things that cause cancer,

In this case, it's going to be radiation from cell phones.

So I'm going to try to reserve at least 10 minutes

at the end of this class for us to go through a bunch of quote,

And I was going to pick my favorite of the 44 studies,

and looking through them all, my favorite are all of them.

MICHAEL SHORT: So we'll see how many we can get through.

so you can understand a bit about what goes on

is an extremely multi-time-scale process.

Everything from the physical stage, or the ballistic stage,

of radiation damage to biological tissues

is just the physical knocking about atoms and creation

of free radicals, these ionized species, which in metals you

wouldn't care about, in biological organisms you

and creation of other strange radiolytic species

and the diffusion and reaction of those things,

microsecond, before most of these things are neutralized.

And then, later on, the buildup of those oxidative byproducts

of these chemical reactions undergo the biological stages

All of the free radicals with biological molecules

So radiation goes in, a millisecond later the damage

Then you start to affect, let's say, cell division.

It takes, on average, minutes for a rapidly dividing cell

So, the division of one cancerous cell into two

won't change the way your body functions,

but the doubling in size of a tumor that blocks other tissue

And so, it all starts in this sub-femtosecond regime,

when most of you-- well, for this entire year,

we've been approximating humans as water.

We're going to continue to do so for the purposes

So, let's say you, a giant sack of water,

And that gamma ray undergoes Compton scattering.

Which, now you know how to tell what the energy of the Compton

We never talked about what happens with the molecule where

And since you're not especially electrically conductive,

And you can be left over with either a free radical

And then what happens next is the whole basis

of radiation damage to biological organisms.

These free radicals can then encounter other ones,

and let's say an H2O+, can very quickly find a neighboring

water molecule, which they're almost touching and form OH

This is better known as H+, and that OH is a kind of unstable

And these excited electrons here can also become these

H2O+'s, leading to this cascade of what we call radiolysis

things like an OH plus an aqueous electron,

which could come from anywhere, like Compton scattering,

like any other biological process that frees an electron,

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32. Chemical and Biological Effects of Radiation, Smelling Nuclear Bullshit

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