A completely off-the-wall blog post struck me as a good way to introduce 2014 – almost literally.
It was not widely reported, but the beginning of 2013 saw confirmation of a truly startling astronomical discovery – and the end of 2013 saw confirmation of one twice as startling.
It has long been known that the Earth forms part of the Solar System which forms part of the Milky Way Galaxy which forms part of the Local Group of Galaxies which forms part of the Virgo Supercluster of Galaxy Groups.
To put this back on earth, it is almost like living in a neighbourhood in a district of a city which forms part of a county which forms part of a province/state, for example. The neighbourhood is the Solar System, the province/state is the Supercluster.
There is an argument, however, that with increasing populations cities are increasingly merging – the ultimate example of this, arguably, is the East Coast of the United States, which may now be seen to constitute effectively a single interdependent urban coastal zone running all the way from Boston to Washington DC.
In the same way it is increasingly being recognised that galaxies and clusters of galaxies can form “filaments” – vast interconnected (gravitationally bound) strings of galaxies. Similarly huge groups of quasars have been established too.
Here is the problem: it is increasingly the case that groups of quasars (most obviously in January 2013 the Huge-LQG) and filaments (most obviously in November 2013 the Hercules-Corona Borealis Great Wall) are being found, which are simply too big to have formed since the Big Bang.
The Hercules-Corona Borealis Great Wall is a staggering 9.8 billion light years across (more than double the Huge-LQG, previously the biggest structure on record). Or, to be precise, it was 9.8 billion light years across when the light left it that we see on Earth – almost exactly 10 billion years ago… but that means we are seeing it as it was less than 3.8 billion years after the Big Bang, at which stage it could not possibly have grown to that size…
I am merely the most amateur of amateur astronomers, having long since lost the telescope I was given for my ninth birthday! However, it does strike me that we are finding so many gravity-bound structures of this scale, that the Big Bang theory as we currently understand it needs a fundamental re-write.
A few amateur thoughts about what we have wrong:
1. Could we have the age of the Universe/time of the Big Bang wrong? I suggest we could, but by nothing like enough to make a structure of the size of the Hercules-Corona Borealis Great Wall to have grown (the current estimate is around 13.8 billion years; this Great Wall would need it to be more like 30 billion!)
2. Could large gravitationally bound structures somehow overcome expanding space and/or the Cosmological Constant? One essential feature of the Universe is that not only can/do objects move away from us at up to the speed of light, but space itself if expanding (theoretically even at faster than the speed of light, though current estimates suggest it is at a relatively constant, though historically varying, rate) – this means we can actually “see” objects/structures more than 13.8 billion light years away. This expanding space is not relevant to the local cluster of galaxies, because they are gravitationally bound. Is it possible that somehow gravity can (or, more likely, once upon a time could) overcome this constant expansion of space, thus merging structures into the vast sizes we see? I doubt it.
3. Could structures such as the Hercules-Corona Borealis Great Wall actually be in, er, another Universe? Perhaps, to put this another way, is it possible there was more than one “Big Bang”? Hmm… I have not seen any experts posit this option. Should they?!
4. Could there have been more than one Big Bang time-wise? In other words, is it possible that there was one around 13.8 billion years ago, but that it was merely one of many – perhaps happening every 20 billion years or so? I doubt this, as evidence would already have been obvious.
5. Is there something wrong with our model of exactly what happened when the Big Bang occurred – perhaps specifically with something like the rates of expansion we have applied to it historically, or perhaps just generally? This seems the most likely, yet the rates of expansion suggested are already unbelievable.
It’s all very odd. Perhaps Richard Haass and Meghan O’Sullivan could help us sort it out?!