Dark Matter and Dark Energy: A Slow Reaction ✎ express
The Universe is expanding, and the rate of this expansion is a matter of debate. Edwin Hubble discovered the expansion nearly a hundred years ago, but modern measurements yield different values. The key to the puzzle may lie in the interaction between dark matter and dark energy — they make up 95% of the cosmos. A new model depicts them as substances that can transform into each other, like a reversible chemical reaction.
Scientists applied the Ludwig Boltzmann equation (which usually describes the collision frequency of atoms) to the dark sector. It showed that transitions between matter and energy are a natural consequence of particle physics, not an artificial fudge. Testing against telescope data confirmed agreement with observations and gave an expansion rate of 67.7 (the Hubble constant).
It turned out that the transformation frequency is negligible: over 13.8 billion years, the entire visible Universe could have seen no more than a couple of thousand events. This rarity explains why we don't notice them, and sets strict limits for future theories.
If such a process ran at the maximum allowed rate, there would still have been only a few thousand transformations in the entire visible Universe since the Big Bang.