Contrary to the way almost everything else in the world works, scientists would be overjoyed to be shown that our simple picture for how dark energy worked — that it was just a cosmological constant inherent to space that never changed over time — was wrong, and failed to match the reality of what we were observing. What we call the Standard Model of cosmology, or the ΛCDM model, is almost certainly only an approximation to our true physical reality, albeit an approximation that’s served us very well so far. If we can find an observational test where that approximation is no longer a good one, that’s almost certainly a clue that will lead us to a richer understanding of our Universe as it actually is.

Perhaps dark energy isn’t truly a constant, after all. Perhaps it is something that changes and evolves with time.