Understanding special relativity

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Understanding special relativity

Fig. 1a. Albert Einstein (1879-1955), German/Swiss/American physicist. One of the great physicists of the twentieth century, started much of the current "modern physics", including relativity and quantum mechanics.

Fig. 1b. Albert Einstein's usage of "time" and "space" makes his theory of relativity confusing to the average person.

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Einstein's theory of special relativity has been an unquestionable success in accounting for the behavior of very rapidly moving objects. From its beginnings to explain the behavior of light, it has been expanded to cover anything to that is moving extremely rapidly. It is particularly central to the understanding of high energy subatomic particles such as those occurring in nuclear (radioactive) events.

This posting introduces the history of this theory and goes on to explain it using an approach suggested by John Bell. This approach uses an absolute reference frame to introduce relativistic effects as an alternative to the warping of space and time which the average person finds difficult to understand. While Einstein seemed to greatly dislike the use of an absolute metric, his theory does not rule it out and its use greatly aids the introduction to relativity. This approach also leaves open the possibility of an absolute metric in the minds of students, who may someday go on to invent new physics based it. Some thoughts about the meaning of an absolute metric are also explored.

This paper presents relativity at a non-mathematical level, stressing the history, phenomena, and philosophy of relativity. Some readers might also be interested in a set of postings of a subsequent article that delve into the mathematical side of the subject.

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Contents of "Understanding special relativity"

1. Preview
2. Contents
3. A brief history of relativity
   • Maxwell and the speed of light
   • Speed, relative to what? Animation.
   • Waves as disturbances and ether. Animation.
   • Exactly what is an electric or magnetic field?
   • The Michelson-Morley experiment
   • A constant speed of light
   • Lorentz transformations
   • Length contraction and time dilation. Animation.
   • What is the internal mechanism that causes length contraction and time dilation?
   • Einstein starts with a constant speed of light
4. Thought experiments

   Fig. 1c. The decay sequence for radioactive neptunium. Einstein's theory of special relativity provided the basic background knowledge that led to the understanding of the complexities of nuclear physics.

   • Experiment 1 (animation)
   • Experiment 2 (animation)
   • The results
   • What's happening here?
   • Einstein's view
5. The confusing aspects of Einstein's approach
6. Lorentz transforms as a pragmatic calculational tool
7. Several applications of special relativity
8. Summary
9. General relativity
10. What is space?
11. Is ether dead?
12. Progression of clocks at the National Institutes of Science and Technology
13. Advantages of including Lorentz's approach in the teaching of relativity
    • No ether limits a line of scientific inquiry
    • The question: why is the speed of light constant?
    • Maxwell's equations hide the velocity of light
    • Occam's razor
    • A bunch of transforms
    • Warping time and space violates their common usage
    • Relativity makes good press
    • Relativity to the extreme
    • A parallel ether theory may be better for engineers
14. Links and references
15. The mathematics of special relativity

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next - history of relativity