We have to find out what happened to that dark energy.

The dark energy had something to do with it, I'm almost sure.

The dark energy is renewed every first day of the week.

Or have the physical properties of dark energy, whatever it is, changed?

There had been darker energy here not so long ago.

Even though this research won the Nobel, no one knows what dark energy actually is.

The dark energy that had fired him for four years was now missing.

We might not know what dark energy is just yet, but scientists have a few leading theories.

The data suggest that, in fact, dark energy has changed little, if at all, over the course of cosmic history.

The data will yield more information about the nature and distribution of dark energy.