APOD: 2007 August 27 - Huge Void Implicated in Distant Universe"Explanation: What has created this huge empty volume in the universe? No one is yet sure, and even the extent of the estimated billion-light year void is being researched. The void is not a hole in space like a black hole, but rather a vast region of the universe that appears to be mostly devoid of normal matter and even dark matter. The void is still thought to contain dark energy, though, and is clearly
traversable by light. The
void's existence is being postulated following scientific curiosity about how unusually cold spots came to appear on
WMAP's map of cosmic microwave background (
CMB) radiation. One possibility was that this
CMB region was not actually very cold but light from the spot somehow became more cosmologically
redshifted than normal along the way.'
From
NASA's Astronomy Picture of the Day. That void is like my appetite is most of the time!! I still don't grasp the concept of
Dark Energy or
Dark Matter. Okay, maybe dark matter, but dark energy! These slow down the expansion of the universe. Also, see the
Pioneer Anomaly.Two Pioneer spacecraft, launched 30 years ago on a mission to the outer solar system, are now leaving the immediate vicinity of the solar system. While they are not yet in interstellar space, their speeds and trajectories do not match Newtonian and Einsteinian predictions. Either there is something new in gravity or problems in measurements or math. See the link for some new thoughts on the matter.