The original question was: From what I understand, an accelerating charged object will emit radiation (such as an accelerating electron). However, considering that our bodies consist almost entirely of charged particles, why is it not that we are constantly emitting electromagnetic radiation. Every time I move, say while typing this email, every electron in my arm is being accelerated. So, why am I not emitting a constant stream of radiation while doing so?
Physicist: There are a couple reasons; firstly, your charges are in balance, and secondly, a human can only move so fast.
Very nearly every electron in your body is right next to a positively charged nucleus. Every movement of a negative charge that would create a wave in one direction is coupled to an opposite wave created by a nearby positive charge.
Moving a charge makes a wave. Moving an opposite charge makes exactly the same wave, just oppositely. If the charges are right next to each other, these two waves cancel each other almost completely.
Since the charges are merely very close to each other, and not in exactly the same place, there are some very slight “near field” effects. But that’s not radiation (radiation is sometimes called the “far field“). Also, even if you built up a huge static charge (so that not every charge was balanced) the acceleration it would take to radiate a noticeable amount of energy would not be survivable. The electrons in a radio tower regularly experience accelerations in excess of tens of million G’s.
8 Responses to Q: If accelerating charges radiate, and everything is full of charges, then why don’t I radiate every time I move?