…Scientists have believed dark energy was a “cosmological constant,” but it is actually changing over time in unexpected ways…current data shows that, at the beginning of the universe, dark energy was very strong. But it has weakened with time and will continue to do so…The new research builds on data released from DESI in April 2024 that found signs that dark energy was changing. DESI has been surveying the universe for four years and an analysis of five years’ worth of data is next for its research
I wonder what we will see once physics has really understood all this dark matter and dark energy stuff.
I guess they will then talk about those like when we talk about pre germ theory medicine, when people believed that “bad air” causes sickness, and vermin was “created” by dirt.
The only difference I see is that “dark” is understood as unknown and not necessarily a single thing.
A lot of older stuff we talk about seems to be assertive in their existence and what they are. Not all of course, but in the absence of a term that indicates “we really don’t know”, it seems random ideas were pretty common.
That’s not to say we don’t still do that, but I think it’ll be ideas that came out of or overly supported “dark” nomenclature. Like, say we find out we got Hubble’s constant wrong. I don’t think history will remember us as “believing in dark energy”. Just that we got Hubble’s constant wrong.
But probably not before I have to go to work on Monday, huh?
There’s always vacuum decay. Simply put, the entire universe could be in an unstable “false vacuum” state and all it would take is something suitably cataclysmic, yet of a form beyond that we can detect, and what we know of as spacetime would unravel from that point outwards at light speed, undetectable until it hits us. If you’ve ever seen those slow motion videos of a water balloon popping, it’d be a bit like that, with us on the bit of balloon that hasn’t quite “realised” that half the balloon is gone already.
But then, predictions range from “complete annihilation of all things” to “imperceptible shift in cosmological constants that doesn’t affect much at all”. Heck, it might have already happened once or twice if that’s the case.
But if it hasn’t… POP!
Found signs
Is this a “best fit” sort of result or an actual significant measurement on the equation of state?
String theorists have conjectured that the exclusion of a (positive) cosmological constant explanation for dark energy is a prediction of string theory. If this result holds up, that line of research seems quite interesting.
I wonder if its a result of the topography of spacetime? Like, if we were to assume the universe is toroidial, and then superimpose a coordinate system over the torus where each point on the grid is one Plank-legnth from its neighbors, I wonder if the distance between grid squares would look bigger at the outside edge of the torus than in the central funnel? If Earth were near the center, then when we look outward/backward we’d observe objects apparent acceleration outward even though from the perspective of those objects themselves they are jumping from grid square to grid square at a constant rate.
The way the expansion of the universe works is that every point in space is expanding, think of it like a balloon, every point stretches. Our current understanding is that there is no center of the universe, which means from every objects point of view, space is expanding away from them. This does open up some interesting questions about dark energy, but I’m not sure we can consider space static like you’re saying here with just varying lengths between points.
I still think we’ll end up thinking of the Big Bang as not a singular thing not even a cyclical thing that keeps happening.
More like fireworks in an empty sky, where if we zoom out enough there’s “big bangs” happening all over the fucking place, constantly.
Ours will fade out someday, but there were ones before, during, and after ours.
What we’ve been doing is like if we saw an apple after it started falling and declared it was never in the tree, and will never hit the ground.
We’re just not looking at it on a long/big enough scale.
Well the problem is we may never be able to observe anything beyond our universe, thus can’t observe anything on that scale or timescale.
But yes. If it can happen once, there’s no reason it won’t happen again, or be recreated artificially. Nothing else in the universe is once only. There’s no precedent to think the big bang would be.
Who knows?
Our edge might be trillions of years from the closest edge and entropy will make us “nothing” before we collide.
Tomorrow the overlap could happen, an entire different reality with maybe complete different physics and life could just suddenly overlap with our boundaey. If it was “new” it would fly thru ours, almost instantly. If it was “old” it could take billions of years to notice. It might start off a chain reaction where we annihilate each other, we might merge, or even just pass thru each other with zero effect on either.
Like, this is just one of a literal dumbfounding amount of things that we just have zero idea about.
We want to never know the answers, but some day we might just find out with zero warning.
This is essentially the kind of universe described by Eternal Inflation, one of the more popular theories of modern cosmology.
