Gravity and radiation from charge

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
5 replies · 1K views
sweet springs
Messages
1,223
Reaction score
75
Reading a thread in relativity I would like to know more precisely about radiation from charge.

1
I put a charge on the table of my house. Gravity and table reaction force work on the charge.
They cancel so net force does not work on the charge, thus no-force no-velocity cause no radiation. Am I right ?
2
A charge is put on the Earth that rotates around the Sun. Does synchrotron radiation by rotation motion take place ? Does it takes place but in non measurable tiny amount ?
3
Say a charge is free falling attracted by gravity of an electrically neutral planet, radiation takes place from a charge due to acceleration motion. But in co-moving local frame of reference with the charge, nothing particular including radiation would take place. How do we conciliate these views?
 
Physics news on Phys.org
sweet springs said:
How do we conciliate these views?
You simply recognize that radiation is frame dependent. What is invariant is not whether or not there is radiation, but whether or not a given detector detects a fluctuating voltage/current.
 
  • Like
Likes   Reactions: sweet springs
I have thought something running with speed c, radiated electromagnetic wave, is commonly recognized to all the frames. I will do practice with your teaching. Thanks.
 
sweet springs said:
I have thought something running with speed c, radiated electromagnetic wave, is commonly recognized to all the frames.
All inertial frames, yes. Not non inertial frames.
 
Thanks for your teaching. I will read PDF to get it.