Why am I listening to my History teacher? Because he's been teaching at my school longer than any other teacher, and because we discuss this stuff every day. And that's what I was saying, you can inhale radiation. Whether or not it's already mixed with something else, it's still being inhaled. I never said it was a form of gas or liquid, don't try to correct me when I have nothing to be corrected.Also, I'd love to see where you saw me say that radiation travels through empty space?