Friday, October 1, 2010

A New Aether

In honour of Graham D's quantum vacuum aether, and his diligence in rereading Newton, let us recall the long history and mutation of the meaning of the aether, which even Einstein revived in a new form for General Relativity. In Newton's time, modern materialism was as yet unknown and various forms of Aether media were discussed. His original Aether proposal was intended to support a Particle theory for light, and he strongly objected to the wave proposal, which was more absolutist in its separation of light and background. Newton says:
And so if any one should suppose that Aether (like our Air) may contain Particles which endeavour to recede from one another (for I do not know what this Aether is) and that its Particles are exceedingly smaller than those of Air, or even than those of Light: The exceeding smallness of its Particles may contribute to the greatness of the force by which those Particles may recede from one another ... and exceedingly more able to press upon gross Bodies, by endeavoring to expand itself.
We see that Newton was not necessarily committed to a Particle nature for the Aether itself, but to the necessity of complexity in the mechanism of separation between Particle bodies. It was not Newton's Aether that was rejected in 1905, but rather a $19$th century descendant, after the success of Maxwell's theory for light. Ironically, the reintroduction of a Particle theory for light occurred so near to the abandonment of the Aether of the time that the distinct ideas of Newton were largely forgotten.

The great anti-materialist Mach criticised Newton for his absolutist views, but in the sea of $19$th century classical thought it must have been difficult to appreciate the true intention of Newton's words. From a more quantum perspective, the absolutism still appears to muddy Newton's world, but now it swells up from his views on the divine, while the local mechanics of the Aether retains its wonder.

12 comments:

  1. Sepp's blog post "Grusenick repetition of Michelson-Morley interference experiment" on Natural Philosophy Alliance discuss this 'aether'.

    http://worldnpa.ning.com/profiles/blogs/grusenick-repetition-of...

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  2. No Ulla, you are really missing the point, just like almost everybody else. The Michelson-Morley experiment stands. The new 'aether' is an even larger step away from the 19th century one. The so called quantum vacuum does not reside in the Absolute. Read some Mach and some Hegel and some Newton and some contempories of Newton.

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  3. Grusenicks's finding (which might be artefact if the own weight of the interferometer deforms the system enough) does not allow explanation in terms of light velocity depending on direction. The arguments of those believing in variation of light velocity contain elementary blunders and Mickelson Morley therefore survives. The direction dependence of light-velicity could come from the deviation of nearby gravitational of Earth from the standard form.

    Ether in the old fashioned sense can be safely forgotten. To my opinion the attempts to give aether a new quantal meaning is play with words which does not bring in anything useful. The notion of aether is like the notion of substance: it has no universal mathematical (or physical) meaning as the notion of geometry has, and there is no reason for its comeback after the fantastic successes of the physics as geometry program.

    The next natural step (already taken by the way;-) is to generalize physics as geometry program to the level of quantum field theory by bringing in the notion of world of classical worlds as a geometric object. Quantum field theories and string theories indeed unavoidably lead to path integrals in infinite-dimensional manifolds. The first thing that should come in mind of anyone having understood the basics of general relativity is to try to identify the underlying geometry. The deep irony and one essential aspect of landscape misery is that nothing has been done in this direction by the establishment despite the marvelous success of Einstein's program in finite-dimensional situation. Just wondering...

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  4. Matti, naturally I agree that it is a bad idea to bring back the word ether, but if a few astronomers want to do so, then it is not for anyone to stop them, so long as they understand what they are doing. And I don't think you appreciate that they do know what they are doing. They would not be busy calculating hundreds of astrophysical observables (more or less) correctly if they did not appreciate this 'world of worlds'. Personally, I don't like the term 'world of worlds' any better than the term 'ether'.

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  5. It is pretty inessential what term one wants to use. The crucial point is that Einstein's geometrization program has been extremely powerful already in finite-dimensional case. In infinite-dimensional context its unifying power increases exponentially. There I feel sad when I see that time is wasted with all these ad hoc ideas whose proper place would be in trash bin. Dead ideas never die.

    Cosmologists have used huge amounts of computer time for approaches like inflation based on ad hoc constructions like Higgs potentials with extremely artificial shape. The calculation of hundreds of observables is waste of time if the theory used involves this kind of constructions.

    We are living time of mediocrisy in sciences. Computerization has given us excellent technical tools but chimpanzee with computer is still a chimpanzee. Mediocrits dominate in science as they dominate in media and popular blog science (and not only that) has become the counterpart of the simplest popular music. Almost as a rule the topics discussed in blogs are the worst ideas of the month. This allows the participants to feel themselves more intelligent than those responsible for this stuff. Very few are interested in genuinely interesting ideas for the simple reason that it would require hard work to understand what has been said. It is much easier to produce highly emotional bursts.

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  6. This is incredibly!!!
    I read the tread of Graham D.
    http://www.galaxyzooforum.org/index.php?topic=277933.msg498509#msg498509

    and http://www.galaxyzooforum.org/index.php?topic=277933.0

    Everyone, read it, I don't believe my eyes. Kea, you are too modest :)

    Quote: The neutrino interference between the first two or electron neutrinos is an attractive force, then that parity flip by changing the direction of linear momentum upon absorptio of the LH solar antineutrinos would be identical to the gravitational force!! But the new force is gravity! It's a residual quantum gravity effect, a consequence of the extraordinary non local interference of neutrino oscillations. Quote end.

    But I also think, like studying an elephant with a microscope, you can end up with different theories depending on what kind of 'language' you speak. It is hard to recognize it belongs to the same subject when it looks so different. Both Matti and you are right :) Both writes the New Physics! No harsh words :)

    Wilczeks 'grid' is a better term? It hints at these 'nets'.

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  7. Well, you are right that words don't really matter, but I think we are at the point now where it is important to communicate more clearly with people (outside theoretical physics). Quantum gravity must be turned into something extremely elementary, as Graham D has understood. Physics is not just thousands of pages of mathematics hoisted upon the world with a triumphant air.

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  8. Matti, a bad day? Emotional burst? Look in the mirror! This time I think it is you who waste time.

    If you looked at this you would see it has no Higgs potential in general meaning. It is a muonic duality, and it certainly feels familiar to you. You already have started with the twistors. Look at the Higgs candidate - a dimuon.

    But it sounds a bit too good. I hear alarms.
    And Kea is right, thousand pages of pure math is like egyptian hieroglyphes to me :)

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  9. Ulla, it is quite true that the current state of the theoretical physics profession is something one can only view with horror.

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  10. Lawrence B. CrowellOctober 5, 2010 at 1:55 AM

    I do not see the current period in physics as some period of mediocrity. There are many elements of particle physics which carry over to other fields in understood physics. The Higgs field is really just the Landau-Ginsburg potential physics applied to quantum field theory. This physics carries over to the physics of Curie points, ferromagnetism, superfluidity, superconductivity and so forth. The AdS~CFT correspondence is showing up in quantum criticality physics of Landau electron fluids in condensed matter physics. Some of this physics is making its way into heavy ion scattering as well:

    http://www.bnl.gov/rhic/stringTheory.asp

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  11. Lawrence, most of this work is now utterly redundant.

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  12. In one sense that is the beauty of it. Nature exhibits the same structure in a wide range of processes and different scales. I find that to be highly remarkable.

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