Wednesday, June 30, 2021

The Aether was not a Fringe Theory

An anonymous Wikipedia comment:
I'm perplexed that the other commenters identify ether theory as a fringe theory. I suppose, by their definition, Newtonian mechanics is also a "fringe theory" simply because it is outdated, and yet nobody is out to debunk Newtonian mechanics (in fact we teach it in schools). "Debunking" ether theory and obscuring its pedagogical utility is clearly an emotional pursuit for these people. It's hard to understand where this religious mentality about ether theory comes from, except in the context of a century of propaganda, as you pointed out. The attitude is clearly political and inappropriate (yet all too common) on Wikipedia.
I agree. If you think that aether theory was somehow wrong or unscientific, then read J.C. Maxwell's 1878 article in the Encyclopedia Britannica. He did not know that the aether had to be invariant under Lorentz transformations, but his essay holds up pretty well.

Here is what Lorentz's famous 1895 relativity paper said. After dismissing some aether theories:

It is not my intention to enter into such speculations more closely, or to express assumptions about the nature of the aether. I only wish to keep myself as free as possible from preconceived opinions about that substance, and I won't, for example, attribute to it the properties of ordinary liquids and gases. If it is the case, that a representation of the phenomena would succeed best under the condition of absolute permeability, then one should admit of such an assumption for the time being, and leave it to the subsequent research, to give us a deeper understanding. ​That we cannot speak about an absolute rest of the aether, is self-evident; this expression would not even make sense. When I say for the sake of brevity, that the aether would be at rest, then this only means that one part of this medium does not move against the other one and that all perceptible motions are relative motions of the celestial bodies in relation to the aether.
Einstein said essentially the same thing in 1905:
The introduction of a “luminiferous ether” will prove to be superfluous inasmuch as the view here to be developed will not require an “absolutely stationary space” provided with special properties, nor assign a velocity-vector to a point of the empty space in which electromagnetic processes take place.
Poincare wrote in a popular 1902 book that the aether is a convenient hypothesis what will someday be thrown aside as useless.

The lesson from relativity was not that the aether was wrong, or unscientific, or nonexistent, or exemplary of 19th century thinking.

The lesson was that theories based on motion against the aether were disproved.

The aether is sometimes defined as whatever transmits electromagnetism. If it is Lorentz invariant, then it poses no problem for relativity.

The existence of a preferred frame poses no problem either. The cosmic microwave radiation can be used to define what a rest frame is, so there is nothing wrong with that concept.

There was a time, maybe a century ago, when one could make fun of ancient scientists for lacking the imagination to understand that a vacuum might be empty space. But a vacuum is not really empty in today's theories either.

4 comments:

  1. Here’s a good book celebrating aspects of the Ether penned by a Nobel Laureate: https://www.amazon.com/Lightness-Being-Ether-Unification-Forces/dp/0465018955/ref=nodl_

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    1. Product Description
      A Nobel-prize winning physicist takes on the essential question: what are we made of?

      Our understanding of nature's deepest reality has changed radically, but almost without our noticing, over the past twenty-five years. Transcending the clash of older ideas about matter and space, acclaimed physicist Frank Wilczek explains a remarkable new discovery: matter is built from almost weightless units, and pure energy is the ultimate source of mass. He calls it "The Lightness of Being." Space is no mere container, empty and passive. It is a dynamic Grid-a modern ether- and its spontaneous activity creates and destroys particles. This new understanding of mass explains the puzzling feebleness of gravity, and a gorgeous unification of all the forces comes sharply into focus. The Lightness of Being is the first book to explore the implications of these revolutionary ideas about mass, energy, and the nature of "empty space." In it, Wilczek masterfully presents new perspectives on our incredible universe and envisions a new golden age of fundamental physics.

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  2. Nikola Tesla thought the Ether was a pretty good idea too, for many mechanical reasons, and that it also contributed greatly to his calculations, theories, inventions, and developing AC, he notably said as much.

    Before everyone goes all preachy Michelson Morley on me, just be aware that almighty mainstream physics STILL doesn't exactly know what charge is... besides a '+','-', diagrammatically (courtesy of Ben Franklin), a mere manifestation of spin direction, or a non physical numerical value they merely keep track of with no physical presence.

    If I demonstrated a car without a battery or fuel tank that could drive around endlessly, you would think someone remotely scientifically minded (or the least bit curious) would eventually ask:
    What makes it go?

    So, here we have atoms literally everywhere, they keep going endlessly, spinning, connecting, separating,

    and yet
    they don't seem to wind down, indicating loss of energy
    they have no inner power source we know of,
    they measurably aren't consuming their own mass for energy to power their movement which actually requires a fair amount of energy...

    and they obviously have a very NON-Rutherford (outdated monkey bread nucleus and satellites model)structure that allows them to channel whatever causes them to move through some mechanical means.

    Soooooo... what makes them go?
    It would have to be a pervasive background field of something that is continuous enough to be everywhere matter is found, and capable of interacting with atomic structures and keep them spinning....almost like ***gasp!*** a dynamo requiring charge...

    P.S.
    The Michelson Morley experiment proved very little because of the gross assumptions it was based upon, mainly, is 'luminous Aether' a uniform un-moving static background regardless of matter and its movement through it, or does it move along in swirling currents affected by matter? If you have ever studied a literal stream of almost anything (air, water, magma), that there are eddies and currents, places of high movement/concentration and low movement/concentration. Testing the movement of of water in an eddy will produce a very different kind of movement than the middle of the very stream it is a small part of. Since matter is observedly not evenly or uniformly distributed, why would you expect or assume a potential Aether to be?

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  3. Wilczek's book is great. He avoids the term "aether", but that is what he is talking about.

    Yes, Michelson-Morley did not prove much directly. It was crucial for relativity, because it was combined with other experiments and assumptions.

    A physicist might say that an electron never stops spinning because it is already in the ground state. Not a great explanation.

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