Well, that is good news

There’s a bit of sarcasm in that title, on multiple levels perhaps, but let’s take it from the beginning.

Almost four years ago, I had a paragraph within a post (down after the page break, here) that commented on the present state of cosmological physics and my ‘gut reaction’ to it. In short: the universe is not only expanding, it’s accelerating, and to do this it needs something to make it accelerate, which has been dubbed, “Dark energy.” We actually have no idea what dark energy is or how it would manifest, but the evidence of the acceleration is there from multiple measurements and methods, so it remains as a placeholder.

The upshot of this is, it would mean that the universe is destined to expand forever, eventually matter becoming so dissipated that energy exchange cannot take place and is simply lost to the depths of space; even the electron orbits of individual atoms dies out and the universe undergoes a ‘heat death.’ This happens so far off in the future that it’s academic, long after our own planetary system is destroyed by the death of the sun, and long after all of the other stars in the universe have lived out their own lives and dwindled into nothing. The time frame that is expressed here is millions of times the current age of the universe, though a great deal of that time would be spent dark and cold anyway as stars got more distant and petered out.

I mentioned there that the whole concept bothered me, the idea that the universe had this massive one-way trip, incredible energy exchanges and galaxy formations and all that jazz, to just drift off and die out, all change coming to an end. It didn’t seem right to me, to the point that this is a theory that I figure has got to be wrong. The Big Bang was/is extremely cool (probably not the best adjective there,) and it ends like that? No, I reckoned that there was something that made it cyclical, some process or undiscovered law of physics that slowed and eventually reversed the expansion, likely back down to the singularity that existed immediately before the Big Bang, whereupon a new universe could start from there. Yet, I recognize that this was only emotional, the distaste over the cessation of change, that went against what I felt was logical, and if I was fully accepting of the evidence, that was the way the universe would end, like it or not.

And then, there’s this paper, which says, “Maybe not. In fact, the acceleration may already be dying down, the expansion may stop soon, and the universe may start to contract again” [I am paraphrasing a bit here, but not inaccurately.]

Immediately, a part deep inside of me exults, “Nailed it!” even though I had no theory of my own (not quite true, but it was decidedly half-ass) and can’t be said to have forwarded any stance on the matter. It just validated my ‘gut instincts,’ which even I will admit weren’t instincts of any kind but just an emotional desire to see things differently. And soon afterward, my skepticism started kicking in.

With any scientific paper that promotes a significant change to our current understanding, the very first bit is to ask, “Has this been vetted and/or replicated yet?” A lot of new papers extend ideas that, with a bit of research or the attempt to duplicate the results, turn out to be overblown or just outright incorrect. Some of them aren’t even ‘papers,’ per se, in that they haven’t been published in serious peer reviewed journals – too many internet articles promote these without any recognition of this. Yet this paper has been published in the Proceedings of the National Academy of Sciences of the United States of America [PNAS], which ranks pretty decently. As for replication, well, there can’t be any, since the physics and math involved don’t, and cannot, show any avenue of testing. Given that however, the numbers fit with the observations, at least according to reviewers. There isn’t anything in here, to my knowledge, that distinctly overturns the present nonstop expansion view, it just proposes a different set of rules.

Which means it’s too soon to feel good about it, even if you’re so inclined. And we need to recognize that cosmological time frames are something else. The paper indicates that the acceleration may end within 65 million years, and the expansion itself within 100 million. In comparison to the 13.78 billion year age of the universe, this is like, “next week,” but for perspective, “we” (meaning our human ancestors) had recently achieved walking upright not quite four million years ago, while 65 million years ago was the beginning of the end for the dinosaurs – it’s not like we’re going to see something happen. Quite frankly, I think we’ll be lucky to see the next half-million years.

From my personal standpoint, I’m not going to even see the universe fifty years from now, so what happens after that is academic; why should I concern myself with dark energy or any ultimate fate? No matter what, it’s too far in the future to even conceive of. Liking or disliking any theory of what happens is pointless, from any perspective you care to name, but we’re weird like that; understanding our universe seems important, likely from badly misplaced evolutionary goads, and liking one concept over another is… what? I honestly don’t know, which is why this article has been on my mind the past couple of days, because I’m not even sure what it says about us. Or at least me.

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Another page break. Just for the sake of it, I’ll bring up that there’s another theory on the fate of the universe, one that I’d been unaware of until reading this paper (or the parts that I could understand, anyway, which wasn’t much.) In that, the vacuum of our universe has a positive energy state, and may be separated from a neutral or negative energy state vacuum elsewhere (they’re using “bubble” as a descriptor, though whether we’re inside or outside of it is unclear.) Eventually, the bubble wall will pass over/through us, ending expansion – but also us, since the “ultrarelativistic” properties will alter pretty much everything. With no warning that this would be coming. Sleep tight.

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