“It turns out that roughly 70% of the Universe is dark energy. Dark matter makes up about 25%. The rest – everything on Earth, everything ever observed with all of our instruments, all normal matter – adds up to less than 5% of the Universe. Come to think of it, maybe it shouldn’t be called “normal” matter at all, since it is such a small fraction of the Universe.” [italics added]
It’s all related to the slowing down and speeding up of the expansion of the universe:
And then they offer numerous speculative theories to account for this: from properties of space (ho-hum) to “temporary (“virtual”) particles that continually form and then disappear” (cool), to something called “quintessence,” a “dynamical energy fluid or field” that “fills all of space” but affects the expansion of the Universe in an opposite manner to that of matter and normal energy (??), and finally to a new theory of gravity that would disprove Einstein (gasp).
Does no one speculate that something on the outside of this universe might have put pressure on it to slow it down and then speed it up? Say, another universe, environmental forces, social forces at an inter-universal scale, whatever. (What’s out there, anyway?) Maybe even just a random blip, a massive wind current, the flap of a universe-sized insect’s wings, where the giant insect’s perception of time is on a scale far larger than the time it takes for our universe to burp into existence, expand, and maybe burn itself out altogether.
Granted, we couldn’t study that, given the limits of our tools — and given that we hardly seem to know what the #%$* is going on in here (they’ve just admitted we only see a tiny fraction of it). But is that a reason to limit our speculations to internalist accounts only? Is there evidence to suggest that the universe is a self-contained and clearly bounded object, utterly isolated from its environmental relations? That beyond this universe there is… nothing?
I’m afraid this question will stump me for a long time.
See Dark Energy, Dark Matter – NASA Science for more.