# B Maxwell Equations without Faraday's Law

1. Nov 7, 2018 at 6:14 PM

### kiki_danc

Maxwell equations are composed of:

Gauss's Law
Gauss's Law for Magnetism
Faraday's Law
Ampere's law with Maxwell addition

If you take out Faraday's Law.. can other laws re constitute it? Or are they independent?

I want to know how the world would behave if there were no Faraday's Law. Note Faraday's Law is mostly related to generators, transformers, motors. So if this law didn't exist. Light would still behave the same and others?

2. Nov 7, 2018 at 6:45 PM

### Staff: Mentor

They are independent. If you remove Faraday’s law you cannot reconstitute it.

No, light would not work either. There would not be a wave solution of Maxwell’s equations

3. Nov 7, 2018 at 7:01 PM

### kiki_danc

Can one say motors and light differ due to the frequency of the magnetic and electric field?

So perhaps if only high frequency magnetic and electric field could be made to exist (for sake of discussion).. then only light can exist and all motors, generators would cease to function?

4. Nov 7, 2018 at 7:45 PM

### Staff: Mentor

I would say that the more important difference is that light is a vacuum solution and motors are not vacuum. You can have “light” at arbitrarily low frequencies.

Last edited: Nov 7, 2018 at 7:55 PM
5. Nov 7, 2018 at 8:09 PM

### kiki_danc

What kind of light is produced at arbitrarily low frequencies? examples?

6. Nov 7, 2018 at 8:20 PM

### Staff: Mentor

7. Nov 7, 2018 at 9:28 PM

### kiki_danc

In unified theories or quantum electrodynamics.. is it possible to decouple high frequency em (light) from low frequency em (motors) by breaking or unbreaking symmetries? Meaning you let only high frequency em work and suppress all low frequency em from the laws of nature such that in another multiverse, motors can't exist but light can.. Or they are still binded together in even in any final theory?

8. Nov 7, 2018 at 9:31 PM

### Staff: Mentor

They become more closely bound in more advanced theories, not less. In most of them you cannot even write Faraday’s law separately.

9. Nov 7, 2018 at 9:33 PM

### kiki_danc

Why, in our current incomplete theories.. can you write Faraday's law separately? How?

10. Nov 7, 2018 at 9:33 PM

### Staff: Mentor

I don’t understand that question

11. Nov 7, 2018 at 9:52 PM

### kiki_danc

You stated that "In most of them you cannot even write Faraday’s law separately.". So there is possibility that in our current theory we can write Faraday's law separately? how?

12. Nov 7, 2018 at 9:59 PM

### Staff: Mentor

Not just a possibility, a certainty:
$\nabla \times E = -\frac{\partial}{\partial t} B$

13. Nov 7, 2018 at 10:01 PM

### kiki_danc

Any illustration or youtube video what they mean and how to write Faraday's law separately? How come in advanced theories... they become more closely bound?

14. Nov 7, 2018 at 10:11 PM

### Staff: Mentor

I just showed you how in post 12.

Why did you randomly insert “...” in your question? It is very distracting and makes no sense. It looks like you are trying to add a pause, but it makes no sense to pause there.

They are more closely bound in the advanced theories because the advanced theories tend to use mathematical constructs where Faraday’s law is either a mathematical identity or it is combined with Gauss’ law for magnetism into a single equation.

Last edited: Nov 7, 2018 at 10:26 PM
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