Quote from your post: "I was watching this week's "Scientific American Frontiers" with Alan Alda on PBS. They were doing an episode on dark matter, dark energy and the expansion of the universe. I(t) brushed on the notion of some kind of conversion to explain the change in the Hubble constant over the history of the universe. Dark matter is the overriding force pulling the universe toward collapse. Dark energy is the counterforce driving the universe toward expansion."
It could be the two are somewhat interchangeable or convertable from one to the other. Such a conversion would explain the change in the Hubble constant.
"Dark matter is the over-ridig force pulling the universe toward collapse". The relationship between a force and its direction gets tricky in higher D than the (traditional) four. It is true that from our frame, the universe is accelerating outward toward its antimatter (dark matter) side. However, from our frame, the proper time collapse of the system is into the matter side, the submicroscopic, not the astronomical. This proper time collapse is crossread by us in GR time dilation as taking cosmological time, and creates our stable reality. We are emerging from a white hole or "big bang".
And yet, the distant universe is accelerating outwards as observed from our frame. This is a result of foundational higher dimensionality.
The universe as observed by life migrates toward both poles at the same time because of its Schwarschild two sphere geometry...white hole, big bang= black hole planck realm and the reverse.
"Dark Energy is the counterforce driving the universe toward expansion". There is one accepted "given" about the Planck Realm, cosmic abyss or dark energy, whatever we wish to call it. It is balanced and exists everywhere, making up 73% of the mass of the universe. Depending on whether we observe the universe from its antimatter or matter side, we see the universe as moving into the dark energy (black hole) or away from it (white hole), but the dark energy itself is stable and unseen- but very detectable.
Like the "speed" of light, I suspect the Hubble Constant is constant only from our frame- and may not be constant even from our frame near the edge of the observed universe; that there are applicable functions for both of these relating to the frame from which they are observed. Close to a black hole, strange things happen to light. The Hubble Constant has to likewise relate to frame of observation
Sorry I missed that program!
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