• Question: Why is the rate of universe acceleration increasing?

    Asked by Harry Oo to Connor, Jillian, Lidunka, Sarah, Steven on 21 Jun 2015.
    • Photo: Steven Thomson

      Steven Thomson answered on 21 Jun 2015:

      Dark energy!

      To be more specific, we don’t really know why the expansion of the universe is happening at an increasing rate. That’s what our observations seem to indicate, though, and to make the observations fit with the maths we need to add this so-called ‘dark energy’ into the equation.

      In doing that, we find that the only way to reconcile the maths with the observations is if 68% of the universe is made up of this mysterious stuff. Scientists are still on the hunt to figure out what dark energy is…or even if it exists at all. It could be that either the current theory is just wrong and there’s a better theory out there that doesn’t require dark energy.

    • Photo: Jillian Scudder

      Jillian Scudder answered on 22 Jun 2015:

      Dark energy is the short answer! Why is dark energy doing it, that’s a much harder question to answer, and an active field of study. What we can say is that the universe’s expansion is definitely accelerating, and we have 68% of the universe that must be in the form of some kind of energy that we don’t understand. But we certainly don’t have a good handle on the mechanisms pushing the universe to expand ever more rapidly, or why it waited so long to kick in!