On The Ether Concept In Physics

[cyberdyno]

Notes by ScienceWeek:

In the late 19th century, what we now call "classical" physics incorporated the assumed existence of the "ether", a hypothetical medium believed to be necessary to support the propagation of electromagnetic radiation. The famous *Michelson-Morley experiment of 1887 was interpreted as demonstrating the nonexistence of the ether, and this experiment became a significant prelude to the subsequent formulation of Einstein's *special theory of relativity. Although it is often stated outside the physics community that the ether concept was abandoned after the Michelson-Morley experiment, this is not quite true, since the classical ether concept has been essentially reformulated into several modern *field concepts.

The following points are made by Frank Wilczek (Physics Today January 1999):

1) Isaac Newton (1642-1727) believed in a continuous medium filling all space, but his equations did not require any such medium, and by the early 19th century the generally accepted ideal for fundamental physical theory was to discover mathematical equations for forces between indestructible atoms moving through empty space.

2) It was Michael Faraday (1791-1867) who revived the idea that space was filled with a medium having physical effects in itself... To summarize Faraday's results, James Clerk Maxwell (1831-1879) adapted and developed the mathematics used to describe fluids and elastic solids, and Maxwell postulated an elaborate mechanical model of electrical and magnetic fields.

3) The achievement of Einstein (1879-1955) in his paper on special relativity was to highlight and interpret the hidden symmetry of Maxwell's equations, not to change them. The Faraday-Maxwell concept of electric and magnetic fields, as media or ethers filling all space, was retained by Einstein. Later, Einstein was dissatisfied with the particle-field dualism inherent in the early atomic theory, and Einstein sought, without success, a unified field theory in which all fundamental particles would emerge as special solutions to the field equations.

4) Following Einstein, Paul Dirac (1902-1984) then showed that photons emerged as a logical consequence of applying the Rules of Quantum Mechanics to Maxwell's electromagnetic ether. This connection was soon generalized so that particles of any sort could be represented as the small-amplitude excitations of quantum fields. Electrons, for example, can be regarded as excitations of an electron field, an ether that pervades all space and time uniformly. Our current and extremely successful theories of the *strong, electromagnetic, and weak forces are formulated as *relativistic quantum field theories with *local interactions.

5) The author states: "Einstein first purified, and then enthroned, the ether concept. As the 20th century has progressed, its role in fundamental physics has only expanded. At present, renamed and thinly disguised, it dominates the accepted laws of physics."

http://scienceweek.com/2005/sw050708-6.htm

Physics Today http://www.physicstoday.org

 

[malawi_glenn]

Why do you publish this crap here?

 

[cyberdyno]

THEORETICAL PHYSICS: ON THE AETHER AND BROKEN SYMMETRY

The following points are made by Frank Wilczek (Nature 2005 435:152):

1) The concept that what we ordinarily perceive as empty space is in fact a complicated medium is a profound and pervasive theme in modern physics. This invisible inescapable medium alters the behavior of the matter that we do see. Just as Earth's gravitational field allows us to select a unique direction as up, and thereby locally reduces the symmetry of the underlying equations of physics, so cosmic fields in "empty" space lower the symmetry of these fundamental equations everywhere. Or so theory has it. For although this concept of a symmetry-breaking aether has been extremely fruitful (and has been demonstrated indirectly in many ways), the ultimate demonstration of its validity --cleaning out the medium and restoring the pristine symmetry of the equations -- has never been achieved: that is, perhaps, until now.

<copyright violation: text edited by cristo>

References (abridged):

1. Cramer, J., Miller, G., Wu, J. & Yoon, J. -H. preprint at http://www.arxiv.org/nucl-th/0411031[/URL] (2004)

2. Kolb, P. F. & Heinz, U. in Quark Gluon Plasma Vol. 3 (eds Hwa, R. C. & Wang, X.-N.) (World Scientific, Singapore, 2004); preprint at [PLAIN]http://www.arxiv.org/nucl-th/0305084[/URL] (2003)

3. Adcox, K. et al. (The PHENIX collaboration) Nucl. Phys. A (submitted); preprint at [PLAIN]http://arxiv.org/nucl-ex/0410003[/URL] (2005)

4. Adams, J. et al. (The STAR collaboration) Nucl. Phys. A (submitted); preprint at [PLAIN]http://arxiv.org/nucl-ex/05010095[/URL] (2005)

5. Back, B. B. et al. (The PHOBOS collaboration) Nucl. Phys. A (in the press); doi:10.1016/j.nuclphysa.2005.03.084 (2005)

Nature [url]http://www.nature.com/nature[/url]

 

[malawi_glenn]

What do you want to discuss?

There are plenty of 'ether'-threads in this forum.

 

[Hurkyl]

Although it is often stated outside the physics community that the ether concept was abandoned after the Michelson-Morley experiment, this is not quite true, since the classical ether concept has been essentially reformulated into several modern *field concepts.

Saying that is like saying the modern atomic theory of matter is a reformulation of Democritus's notion of atoms. There's a (very) superficial resemblance, but that's it.

 

[cyberdyno]

aether: AKA Higgs field, free space, physical space, perfectly flat quantum vacuum, topological space, inertial space, momentum space... etc., etc., etc...