Not much about the underlying math, but how can an electromagnetic field exist when the electric and magnetic field is zero?

  • $\begingroup$ The potential can exist. It's like asking how gravitational potential energy can exist on a flat surface. It exists, it just doesn't do anything because there is no derivatives, meaning no force. The special thing here is that apparently this is not always the case. $\endgroup$ Dec 25 '19 at 19:17
  • 1
    $\begingroup$ The answers in the linked duplicates are highly debatable. $\endgroup$
    – my2cts
    Dec 25 '19 at 22:55
  • $\begingroup$ Possible duplicate: physics.stackexchange.com/q/56926/2451 & physics.stackexchange.com/q/99505/2451 $\endgroup$
    – Qmechanic
    Dec 26 '19 at 7:42
  • $\begingroup$ If the previous answers are wrong, then e.g. use a bounty for better answers rather than asking the same question again in a new thread. $\endgroup$
    – Qmechanic
    Dec 26 '19 at 10:43
  • $\begingroup$ Ya I have voted to reopen the question. $\endgroup$
    – Karthik
    Dec 26 '19 at 11:32