I wish the media would use their fact checkers. Sure the situation in Japan is breathtakingly horrific, but saying ridiculous things about radiation makes it seem orders of magnitude worse.

 

For example, it was reported that the Navy was moving their ships due to radiation concerns. That's much more terrifying than it sounds at face value if you know anything about radiation. Even without shielding, radiation drops incredibly quickly with distance.

 

[math]D_2=D_1\frac{x_1}{x_2}[/math]

 

Where D₂ is the dose(amount of radiation you'd receive) you're trying to find at location x₂ and D₁ is the dose you know at location x₁. To see how dramatically the radiation decreases, let's use some easy numbers.

 

Let's assume that we know the dose D₁ at 1 foot away from the radiation source. We need to find the dose at 2 feet away from the radiation source.

 

[math]D_2=D_1\frac{x_1}{x_2}=D_1\frac{1}{2}[/math]

 

The radiation level already decreased by half!

 

If they were moving the ships due to radiation concerns, there would be a burn radius around the plants where everything was melted or on fire.

 

What's infinitely more likely is that they're moving the ships due to contamination concerns. If there is a meltdown and contamination is breached, it could send a lot of radioactive material airborne. Alpha particles and beta particles don't really do a whole lot of damage when they're on the outside of your body; they are both stopped by the layer of dead skin. However, if you inhale radioactive alpha and beta sources, then it's a bad day indeed.

Any chance you can calculate the radiation level California would be getting? I just want to see how overreacted people are.

 

 

The underlying point to ydoaPs post was that it's contamination that is making the trek. You have to know how much there is and how it's being dispersed before you could come up with a dose rate. i.e. the source of the dose is moving around.