• Congratulations to the Class of 2024 on your results!
    Let us know how you went here
    Got a question about your uni preferences? Ask us here

Physics Speed of Light Help Needed ASAP (2 Viewers)

Modern4DaBois

Member
Joined
Oct 25, 2021
Messages
42
Gender
Male
HSC
2022
Sup everyone,
I have a depth study on methods to measure the speed of light and I needed some help with the Evenson's experiment (about the method he followed). If any of ya'll have any info bout that, or any other experiment to measure the speed of light (after 1900), could you please please please let me know?

Thanks
 

OreoMcFlurry

Member
Joined
Jul 13, 2021
Messages
40
Gender
Male
HSC
2021
I'm going to be honest here, I've never heard of Evenson's experiment - so unfortunately I can't really help with that.

This is a somewhat short summary of other methods of measuring the speed of light, but with that said, it's highly recommended that you do your own research on this:

Galileo
1635642856721.png
By using direct measurement, it was a failed attempt in determining whether the speed of light is finite.N/A
1676 – Ole Romer
1635642792359.png
Eclipse of Jupiter’s moon Io – Romer observed that the recorded time taken for Io to re-emerge from the eclipse was different for different positions of the earth relative to Jupiter. As earth approached the far side of the orbit, the time taken increased – hence implying that light’s velocity was finite. As no eclipse measurements were possible at positions ‘H’ and ‘E’ on Romer’s diagram, Romer calculated that the maximum possible time difference would be 22 minutes. Christian Huygens used this, to calculate the speed of light to be (2.2x108)m/s
1728 – James Bradley
1635642802615.png
Stellar Aberration – Bradley noticed that as earth orbited the sun, there was a shift in a star’s position in the sky.Bradley calculated the value to be: (3.01x108)m/s
1849 – Hippolyte Fizeau
1635642811011.png
Rotating Cogwheel – Fizeau had a toothed cog with 720 teeth, and had adjusted the speed of the spinning cog in order for the light to pass through a pair of teeth, get reflected by a mirror (8km) and pass through the adjacent gap. This was the first experimental measurement of light.

Fizeau’s calculations resulted in the value to be: (3.13x108)m/s
1862 – Leon Foucault
1635642823474.png
Rotating Mirror – Foucault replaced the rotating cog in Fizeau’s experiment with a rotating mirror, and light gets reflected by a mirror (20m) and then gets reflected by the rotating mirror. The small angle between the newly reflected light and the original light source is then recorded. The angles of reflection would differ with the frequencies of the rotating mirror.He used the fact that angles of reflection differed according to the rate of rotation to calculate the speed of light as: (3.09x108)m/s
Modern day – 1958 – Keith Davy Froome
1635642830574.png
Radio interferometry – Froome used Michelson and Morley’s setup in attempting to confirm the existence of the ether. Yet, Froome used a coherent and monochromatic radio source and using the interference patterns detected on the detector, found the speed of light.Due to the interference of radio wave he calculated the speed of light to be: (2.99792x108)m/s
 

Users Who Are Viewing This Thread (Users: 0, Guests: 2)

Top