To the best of our ability to tell, the Universe is being shaped by things we can't directly detect: dark matter and dark energy. That makes it somewhat challenging to determine if our understanding of these influences is roughly correct. It's simply hard to be confident that we haven't missed some other dark entity that's lurking beyond our abilities of detection.
One of the ways we can have some confidence that we're not missing anything major is to run models of the Universe. If we've got the basic physics right, then you should be able to set these models loose at an early point in the Universe's history and end up with something that looks like the Universe we're living in.
In general, these models have been remarkably successful, producing a cosmic web of dark matter with clusters of galaxies at the points where the web's filaments intersect. But enough of the details have been wrong in these models that they raise a difficult question: is there something wrong with our understanding, or have we simply run up against the computational limits on what we can simulate?
A new simulation of the Universe argues strongly that we can blame the computers (or, more precisely, our lack of computational power.) By increasing the size and resolution of the modeled Universe, a team has been able to reproduce many more details of the actual Universe's history.To read more, click here.