How Does Maxwell's Current Term Suggest Light is an Electromagnetic Wave?

AI Thread Summary
Maxwell's addition of the current term to Ampère's law indicates that a changing magnetic field generates an electric field, which is fundamental to understanding light as an electromagnetic wave. This relationship shows that varying electric and magnetic fields can propagate through space, leading to the conclusion that light operates within the electromagnetic spectrum. Specifically, light is identified as an electromagnetic wave at a higher frequency. The discussion emphasizes that the interplay between conduction and displacement currents results in varying fields, reinforcing the concept of light as part of electromagnetic waves. Overall, this connection highlights the nature of light in the context of electromagnetic theory.
commelion
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yo

ok progress on the electromagnetic wave front is progressing nicely...finally, but

i have stumbled on a area that i need some help with. see below

when maxwell took amperes law, he added what's known locally ! as the current term, this was done because he realized that a changing magnetic field gives rise to an electric field.

Q how does this current term suggest that light must be an electromagnetic wave ?

if anyone has any consise explanations i would appreciate it, i don't need the maths as i have them in front of me. just think of it as a table quiz kind of answer !

thanks in advance
 
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commelion said:
yo

ok progress on the electromagnetic wave front is progressing nicely...finally, but

i have stumbled on a area that i need some help with. see below

when maxwell took amperes law, he added what's known locally ! as the current term, this was done because he realized that a changing magnetic field gives rise to an electric field.

Q how does this current term suggest that light must be an electromagnetic wave ?

if anyone has any consise explanations i would appreciate it, i don't need the maths as i have them in front of me. just think of it as a table quiz kind of answer !

thanks in advance

Light is just EM wave in much higher frequency spectrum. It is a frequency thing. I am not good enough to explain in plain English, from my understanding:

\nabla \times \vec H= \vec J +\epsilon_0 \frac{\partial \vec E}{\partial t}\;\Rightarrow \int_c \vec H\cdot d\vec l = I_ C+I_D\;\;\hbox { where it is conduction current and displacement current respectively.}

This just said a varying conduction and/or displacement current will produce a varying magnetic field. Which in turn the varying magnetic field will be accompanied with a varying electric field by:

\nabla \times \vec E =-\frac {\partial \vec B}{\partial t}

But nothing is said about the frequency. As said, light is just the upper range of the EM wave frequency.
 
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