We have been aware that our Universe has been expanding for going on nearly a century now. Of course we are also aware, from a quite considerable earlier time that what goes up must come down. In other words, gravity grabs. The Universe has lots and lots of gravity, so presumably, what goes up (I.e. – the expansion rate) must come down (I.e. – the expansion rate must at least slow down, maybe even stop and reverse). Cosmologists were very interested in finding out exactly what the rate of deceleration was. How fast was the Universe’s expansion rate decreasing? It’s like you car might be going uphill, but at an ever slower and slower rate.
Okay, so, several teams of astronomers did the relevant observations and crunched the numbers and guess what – the Universe’s expansion rate was accelerating, gravity be damned. That’s sort of like driving your car uphill and having it go faster and faster without you putting the pedal to the metal. Well, that surely was an unexpected result. So, they needed an explanation. The astronomers (team leaders anyway) got the Nobel Prize, but that was for the discovery, not for the explanation. You see, there wasn’t any explanation. So, what do we want – an epicycle. When do we want it – now! What was the ad-hoc epicycle to be? It was called “Dark Energy”, a sort of antigravity that was pushing the Universe apart faster and faster and faster. Trouble is, nobody then, or now, has the foggiest idea what Dark Energy is, yet in order to account for what this epicycle does, it must represent some roughly 70% of what makes the Universe up. That’s a lot of epicycle that lacks any plausible explanation. Did someone mention rabbits and hats?
When considering all things cosmological, it’s become apparent that astronomers only observe about 4% of the matter plus energy that should be present. That is, about 96% of the matter plus energy that should be present and detectable to account for the observed behaviour of our observable universe is missing! Now 1% might be understandable given measurement uncertainty (error bars), but hardly 96%! So, cosmologists have postulated concepts sterke sticker termed ‘Dark Matter’ and ‘Dark Energy’ to make up the deficit. However, nobody has the foggiest idea what exactly ‘Dark Matter’* and ‘Dark Energy’ actually are. Neither has actually been detected, either out there, or in the laboratory down here – obviously. The anomaly here is that ‘Dark Matter’ and ‘Dark Energy’ are both ad hoc theoretical concepts to make sense of various astronomical observations, but without benefit of any actual observation of ‘Dark Matter’ and/or ‘Dark Energy ‘to back things up. That’s a rather slight-of-hand trick, and until cosmologists put actual observational money on the board where their theoretical mouth is, it’s all an anomalous pie-in-the-cosmic-sky.
Further, there is a quintet of really big problems with Dark Energy.
Problem One: Conservation laws – the bedrock of physics that are rammed down your throat in high school science – are violated. Apparently the density of Dark Energy remains constant while the volume of the Universe expands. Expanding space creates additional Dark Energy which further expands space which creates additional Dark Energy; round and round in an endless cycle. That’s something from nothing. That’s a free lunch. Of course the phrase “Dark Energy” was just tacked on to ‘explain’ the accelerating universe, though it explains nothing. We, to repeat my earlier observation, still haven’t a clue what Dark Energy actually is, even though the concept has now entered its mid-teenage years, enough time you’d think for cosmologists to pin this anomaly down.