Physics MOD 7 Confusion - any help asap is appreciated (1 Viewer)

[amdspotter]

hello, so my question is related to the measurement of the speed of light.

1. Maxwell predicted existence of em waves in 1864. He then went on to calculate the theoretical speed of an em wave. he then said that light is also an em wave.

2. then in 1900's hertz proved that em waves existed by finding radio waves.

3. since light is also an em wave and it was known that all em waves travel at same speed they started finding the speed of light through measuring speed of radio waves.

but my question is that maxwell had already calculated the speed of em wave and since light is also an em wave then why did scientists continue to measure the speed of light. isnt it known that light would also travel at the speed of em wave which maxwell calculated.

the only answer i can think about is that maxwells calculations were all theoretical and not experimentally proven.

Any help ASAP would be greatly appreciated

 

[tito981]

hello, so my question is related to the measurement of the speed of light.

1. Maxwell predicted existence of em waves in 1864. He then went on to calculate the theoretical speed of an em wave. he then said that light is also an em wave.

2. then in 1900's hertz proved that em waves existed by finding radio waves.

3. since light is also an em wave and it was known that all em waves travel at same speed they started finding the speed of light through measuring speed of radio waves.

but my question is that maxwell had already calculated the speed of em wave and since light is also an em wave then why did scientists continue to measure the speed of light. isnt it known that light would also travel at the speed of em wave which maxwell calculated.

the only answer i can think about is that maxwells calculations were all theoretical and not experimentally proven.

Any help ASAP would be greatly appreciated

yeah, like you said, a key thing was that it was in theory that maxwell calculated v=1/sqrt(epsilon x mu), so obviously practical test had to confirm this. and iirc, maxwell did not yet know that there was a continuous spectrum of wavelengths of light, so scientists had to measure all possibilities incase they were of different speed.

 

[amdspotter]

yeah, like you said, a key thing was that it was in theory that maxwell calculated v=1/sqrt(epsilon x mu), so obviously practical test had to confirm this. and iirc, maxwell did not yet know that there was a continuous spectrum of wavelengths of light, so scientists had to measure all possibilities incase they were of different speed.

oh ok yep, maxwell said there may be other em waves which form a spectrum but he didn't have any experimental data. thanks a lot mate - you cleared up my confusion.