On Wednesday, October 30, 2024 at 5:18:26 AM UTC-6 John Clark wrote:
On Wed, Oct 30, 2024 at 1:17 AM Alan Grayson <[email protected]> wrote: * > What are you measuring that you call permeabiliy and permativity? AG * *Permeability is a measure of how easily a material (or a vacuum) allows a magnetic field to be established within it, and permittivity is a measure of how easily a material allows an electric field to be established within it. For the numerical values of the vacuum, neither value can be found by theory alone, but both values were found by experimental means in the 19th century. And if you know the permeability (μ₀) and permittivity (ε₀) of the vacuum then you can calculate the speed of light because **Maxwell gave us a simple formula for doing so:* * c = 1/√(μ₀ε₀)* *What I'd like to know is how EM wave motions can exist absent a medium which was thought to be necessary for it to be manifested. IOW, when repeated MM experiments had null results, what model was developed, if any, to explain the existence of EM wave motions? AG * mwk -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/2113a2a5-0b41-498c-91fd-34ee14c83049n%40googlegroups.com.
