Einstein's Epiphany of Constant Light Speed

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Discussion Overview

The discussion centers around how Einstein first conceptualized the idea of the constant speed of light in all frames of reference. Participants explore the historical context, thought processes, and influences that may have led to this groundbreaking idea, touching on aspects of electromagnetism and earlier scientific developments.

Discussion Character

  • Exploratory
  • Historical
  • Conceptual clarification

Main Points Raised

  • One participant questions how Einstein might have arrived at the idea of constant light speed, suggesting it seems bizarre given the prevailing assumptions about additive velocities.
  • Another participant notes that the concept of constant light speed predates Einstein, referencing developments in classical electrodynamics from the mid-1800s.
  • A different participant asserts that Einstein's realization was based on observations showing the invariance of light speed, indicating that relativity served as an explanation for this phenomenon.
  • Some participants propose that Einstein's insights were influenced by his studies of electromagnetism, particularly the symmetry in interactions between moving wires and magnets.
  • One participant references Einstein's work "On the Electrodynamics of Moving Bodies" to support their claims about the symmetry in electrodynamics.

Areas of Agreement / Disagreement

Participants express differing views on the origins of Einstein's ideas, with some attributing them to earlier scientific developments and others focusing on his unique insights. The discussion remains unresolved regarding the specific thought processes and influences that led to the concept of constant light speed.

Contextual Notes

There are limitations in the discussion regarding the clarity of historical timelines and the specific contributions of earlier scientists to the concept of light speed. Participants do not fully resolve the connections between Einstein's work and prior theories.

thetexan
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How did Einstein first contemplate the idea that the speed of light was constant in all frames or reference?
Did he say "I wonder what would happen if we considered light speed to be constant" in some kind of thought experiment. Did the concept fall serendipitously from the results of calculations?

I'm just wondering how it would occur to someone to think of that when additive velocities were just generally assumed. The very idea of a constant light speed was so bizarre in that realm of thought that I'm curious, especially when time being a linear constant was so accepted. I'm sure the story is out there but I can't find it.

tex
 
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The idea that the speed of light was constant actually predates Einstein I believe. If I remember correctly, it dates back to the mid-1800's when classical electrodynamics was developed fully and certain problems were noticed. See here: https://en.wikipedia.org/wiki/History_of_special_relativity
 
thetexan said:
How did Einstein first contemplate the idea that the speed of light was constant in all frames or reference?
Did he say "I wonder what would happen if we considered light speed to be constant" in some kind of thought experiment. Did the concept fall serendipitously from the results of calculations?

I'm just wondering how it would occur to someone to think of that when additive velocities were just generally assumed. The very idea of a constant light speed was so bizarre in that realm of thought that I'm curious, especially when time being a linear constant was so accepted. I'm sure the story is out there but I can't find it.

tex
It was an observation. Experiments showed the speed of light is invariant.

Relativity was an explanation

Sent from my SM-G550T2 using Physics Forums mobile app
 
thetexan said:
How did Einstein first contemplate the idea that the speed of light was constant in all frames or reference?

I think he claimed it came from his study of electromagnetism. If a loop of wire is moved relative to a stationary magnet a current arises in the wire. And if a magnet is moved relative to a stationary loop of wire a current arises in the wire. Einstein was able to show that these two interactions are the same, a symmetry that was lacking in the laws of electrodynamics.
 
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Mister T said:
I think he claimed it came from his study of electromagnetism. If a loop of wire is moved relative to a stationary magnet a current arises in the wire. And if a magnet is moved relative to a stationary loop of wire a current arises in the wire. Einstein was able to show that these two interactions are the same, a symmetry that was lacking in the laws of electrodynamics.
This is what I gathered from reading On the Electrodynamics of Moving Bodies.

Edit- might as well post it to save someone a google search.

https://www.fourmilab.ch/etexts/einstein/specrel/www/
 
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