Sunday, May 22, 2011

Is Ether Back?

A May 19, 2011 story in Science Daily (here) carries this headline: Dark Energy is Driving Universe Apart: NASA’s Galaxy Evolution Explorer Finds Dark Energy Repulsive. Most of the text is quoted directly from NASA’s own site here, a press release also dated 5/19/2011.

Fascinating story. We’re approaching a major redefinition of reality. Herewith some background I’ve extracted from Wikipedia. The notion of dark matter surfaced in 1934 and is attributed to the Swiss astronomer Fritz Zwicky. His calculations suggested that the Coma galaxy cluster had to have considerably more mass than its luminosity indicated. He referred to the invisible mass, necessary for the rotational behavior of the cluster, to be due to “dark matter.” Dark energy got its name in 1998 from the American cosmologist Michael S. Turner. He took his phrasing from Zwicky to give a name to something. That “something” was an even more invisible mass necessary in the cosmos, but present outside of galaxies. This “something” was what caused the observed expansion of the universe; it was some kind of force. Ironically, the theoretical root of this concept dates to 1917 when Einstein introduced a fudge factor into his gravitational field equations; he called it the cosmological constant. Einstein’s equations suggested that gravity would ultimately cause the universe to collapse. A steady-state universe was then the orthodox view; the cosmos was neither growing nor expanding; for this reason Einstein chose a constant that would counteract the gravitational pull suggested by his equations just to the right extent to keep the cosmos in a steady state. When Edwin Hubble’s later observations suggested an expanding universe, Einstein is said to have labeled his constant his biggest blunder; and removed it. Prematurely, it seems. The constant is now back, as dark energy.

Indeed there is, based on calculations of the expansion (now said to be accelerating) and the anomalies observed in galactic rotation (that cannot be explained by gravity working on the visible bodies), far more of it than anything else. Contemplate the picture (from Wikipedia here but downloaded from NASA) of the constitution of the cosmos. Virtually all of the cosmos is dark energy and dark matter, leaving a mere 4 percent for matter; of that 4 percent only 0.4 percent are stars, and the matter of planets is too small to note.

To this I might add that both dark energy and dark matter are based on inferences, not on direct observations, one of cosmic expansion the other of anomalous galactic rotation. I will not be surprised if, in the fullness of time, the two will be found to be the same. It’s all dark energy. And that, folks is the cosmos.

* * *

Now Brigitte (my unfailing muse) pointed me to that story in Science Daily yesterday because of an earlier discussions about David Bohm (see this post). It turns out that Bohm’s own formulation of Quantum Theory in 1993—but already articulated in various forms in 1980 and before—offers a grand theory of the cosmos entirely in consonance with what we are seeing today. Bohm suggests that reality consists of two orders. One he calls the Implicate (enfolded) and the other the Explicate (unfolded) Order. He pictures the first as an “immense ocean of cosmic energy.” A sudden wave pulse within that ocean could create our universe, the Explicate Order, in extent tiny relative to that ocean. “This pulse,” Bohm continues, “would explode outward and break up into smaller ripples that spread yet further outward to constitute our ‘expanding universe’.” These words are from Bohm’s Wholeness and the Implicate Order (1980), p. 192. The scientific presentation of these ideas is in his 1993 The Undivided Universe.

In Wholeness Bohm introduces this subject saying:

What is implied by this proposal is that what we call empty space contains an immense background of energy, and that matter as we know it is a small, ‘quantized’ wavelike excitation on top of this background, rather like a tiny ripple on a vast sea.… In this connection it may be said that space, which has so much energy, is full rather than empty. The two opposing notions of space as empty and space as full have indeed continually alternated with each other in the development of philosophical and physical ideas. Thus, in Ancient Greece, the School of Parmenides and Zeno held that space is a plenum [fullness]. This view was opposed by Democritus, who was perhaps the first seriously to propose a world view that conceived of space as emptiness (i.e., the void), in which material particles (e.g., atoms) are free to move. Modern science has generally favored this latter atomistic view, and yet, during the nineteenth century, the former view was also seriously entertained, through the hypothesis of an ether that fills all space. Matter, thought of as consisting of special recurrent stable and separable forms in the ether (such as ripples or vortices), would be transmitted through this plenum as if the latter were empty. [p. 191]
Well, it seems to me that ether is back once more, but differently named. New names are necessary because reputation is so vital in science, and while it is now fashionable to be darkly energetic, it will not do to be ethereal.

Words, words, words. To see our great universe as a minor bubble deep in an ocean of eternity, a bubble broken up and carried by the ocean’s immense energy towards re-absorption in the whole (read expanding universe), is humbling but has a promising flavor. Indeed, NASA seems to agree. It suggests that as Dark Energy has its way with the universe, time will come when we will no longer see the stars out there. Eventually even our own galaxy will begin to spread apart.

1 comment:

  1. It does remind one of the Ether very much, does it not? When one adds waves, such as gravitational waves, to particles and energy, the cosmos does seem a plenum rather than empty.

    ReplyDelete