Comments about "Luminiferous aether" in Wikipedia

This document contains comments about the article Luminiferous aether in Wikipedia
In the last paragraph I explain my own opinion.




The article starts with the following sentence.
It was invoked to explain the ability of the apparently wave-based light to propagate through empty space, something that waves should not be able to do.
See Reflection 1 - general
The assumption of a spatial plenum of luminiferous aether, rather than a spatial vacuum, provided the theoretical medium that was required by wave theories of light.
This requires the definition of vacuum. Same link as above.
This led to considerable theoretical work to explain the propagation of light without an aether.
IMO the explanation that light are photons does the trick. In fact the whole universe is filled with photons.
etc. the development of modern physics, which includes the quantum theory, explains the wave-like nature of light.
IMO that is all what is needed to explain light.
As such aether and photons are equivalent.

1. The history of light and aether

1.1 Particles vs. waves

To Robert Boyle in the 17th century, shortly before Isaac Newton, the aether was a probable hypothesis and consisted of subtle particles, one sort of which explained the absence of vacuum and the mechanical interactions between bodies, and the other sort of which explained phenomena such as magnetism (and possibly gravity) that were inexplicable on the basis of the purely mechanical interactions of macroscopic bodies, etc
This picture is not totally wrong.

1.2 Bradley suggests particles

1.3 Waves theory triumphs

1.4 Electromagnetism

1.5 Problems

2 Relative motion between the Earth and aether

2.1 Aether drag

2.2 Negative aether-drift experiments

2.2.1 First order experiments

2.2.2 Second order experiments

3 Lorentz aether theory

4 End of aether?

4.1 Special relativity

With the development of the special relativity, the need to account for a single universal frame of reference had disappeared and acceptance of the 19th century theory of a luminiferous aether disappeared with it.
This are two different problems. How can you describe the movement of different galaxies without a single frame?
For Einstein, the Lorentz transformation implied a conceptual change: that the concept of position in space or time was not absolute, but could differ depending on the observer's location and velocity.
IMO Newton will agree. If you try to compare the observations of an observer on earth and an observer on the moon, both from there own postion in the solar system, you run into troubles.
Particles obviously do not need a medium to travel, and thus, neither did light. This was the first step that would lead to the full development of quantum mechanics, in which the wave-like nature and the particle-like nature of light are both considered as valid descriptions of light.
The most important issue that you need to explain is the propagation speed of light. It is in some sense equivalent with the propagation speed of water waves. The underlying water particles almost do not move. The water waves, as an ensemble, move.

4.2 Other models

4.3 Einstein's views on the aether

5. Aether concepts

6. See also

Following is a list with "Comments in Wikipedia" about related subjects

Reflection 1 - general

The discussion about aether theory in some sense also involves concepts like: What is space, what is a vacuum, is outer space empty.
The problem is outer space is not empty. Empty means there is nothing. That is not true. The universe is filled with electromagnetic radiation i.e. photons.
You can compare this with a fish in a waterbasin. From the point of view of the fish he or she floats in empty space. Viewed into a more global context, we know that that is not true.

Reflection 2

Reflection 3


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Created: 12 December 2017

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