In the dark

No, it's not a preview of cover art for my next mix...it's just your work-a-day Mysterious Force...hard @ work for the last nine billion years:

Mysterious force's long presence:

"Dark energy - the mysterious force that is speeding up the expansion of the Universe - has been a part of space for at least nine billion years. That is the conclusion of astronomers who presented results from a three-year study using the Hubble Space Telescope.

The finding may rule out some competing theories that predict the strength of dark energy changes over time. Dark energy makes up about 70% of the Universe; the rest is dark matter (25%) and normal matter (5%)..."

For more on this mystery, click any of the links, above.