How Did Physicists Determine the Speed of Light?

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SUMMARY

Physicists determined the speed of light through various experiments and calculations, notably using methods such as rotating mirrors and astronomical observations. Early experiments by Ole Rømer in 1676 utilized the timing of Jupiter's moons to estimate light's speed, while Albert Michelson's precise measurements in the late 19th century employed rotating mirrors and advanced optics. The relationship between mass and energy, encapsulated in Einstein's equation E = mc², also provides a theoretical framework for understanding light's properties.

PREREQUISITES
  • Understanding of basic physics concepts, particularly light and waves.
  • Familiarity with historical experiments in physics, such as those by Ole Rømer and Albert Michelson.
  • Knowledge of Einstein's theory of relativity, specifically E = mc².
  • Basic principles of optics, including the behavior of light in mirrors and telescopes.
NEXT STEPS
  • Research the Michelson-Morley experiment and its implications for the speed of light.
  • Explore the historical context of Ole Rømer's measurements and their significance.
  • Study the principles of optics related to rotating mirrors and their application in measuring light speed.
  • Investigate modern techniques for measuring the speed of light, including laser interferometry.
USEFUL FOR

Students of physics, educators, and anyone interested in the historical and experimental methods used to measure the speed of light.

T.O.E Dream
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This isn't on why the speed of light is the cosmic speed limit. I want to know how did physicist determine it? What experiment did they perform? What calculations did they make? They obviously didn't go into outer space and shined a light then see how long it took. Did they use a telescope? Help!
 
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I did some google:
http://www.colorado.edu/physics/2000/waves_particles/lightspeed_evidence.html

One can also measure the speed of light by measuring masses of particles (E = mc^2) etc.
 
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