Hi this is my first thread since joining the website, so let me know if I am violating any rules here. I read a bunch of rules to follow in the website but don't think I can remember everything.
I am reading chapter 18 on Feynman's Lectures on Physics volume 2 (electromagnetism). It talks about how electric and magnetic fields can propagate in a free space.
Here is the situation: There's an infinite sheet of charge at the origin in y-z plane. Axis z points out of the page, x axis points towards right, and y axis points up. The attached figure will help understanding the situation.
Attachment 70213
Then the sheet of charge accelerates to a certain velocity towards positive y direction (upward) and maintains the velocity. There is also sheet of opposite charge at the origin to cancel any electrostatic effect.
Once the acceleration starts, B field is generated as such in the figure due to modified Ampere's Law (One of Maxwell's equations). While B is changing, there will be electric field generated due to Faraday's Law.
However, once the sheet of charge reaches a certain velocity, its velocity will stay constant, meaning although the B field generated due to Ampere's Law will be maintained, the E field generated due to Faraday's Law, (curl E = rate of change of B) will be eliminated due to the constant value of B.
The book, however, assumes that E field stays, taking a part in the electromagnetic wave propagating through space. I wonder if Feynman's assumption is wrong, or what prevents the E field being eliminated.
I am reading chapter 18 on Feynman's Lectures on Physics volume 2 (electromagnetism). It talks about how electric and magnetic fields can propagate in a free space.
Here is the situation: There's an infinite sheet of charge at the origin in y-z plane. Axis z points out of the page, x axis points towards right, and y axis points up. The attached figure will help understanding the situation.
Attachment 70213
Then the sheet of charge accelerates to a certain velocity towards positive y direction (upward) and maintains the velocity. There is also sheet of opposite charge at the origin to cancel any electrostatic effect.
Once the acceleration starts, B field is generated as such in the figure due to modified Ampere's Law (One of Maxwell's equations). While B is changing, there will be electric field generated due to Faraday's Law.
However, once the sheet of charge reaches a certain velocity, its velocity will stay constant, meaning although the B field generated due to Ampere's Law will be maintained, the E field generated due to Faraday's Law, (curl E = rate of change of B) will be eliminated due to the constant value of B.
The book, however, assumes that E field stays, taking a part in the electromagnetic wave propagating through space. I wonder if Feynman's assumption is wrong, or what prevents the E field being eliminated.