The Hubble volume

“The Hubble volume is the sphere of space visible to the Hubble telescope—i.e. everything that’s not receding from us at a rate greater than the speed of light due to the expansion of the universe. The Hubble volume is an unfathomably large 10³¹ cubic light years.”

— That’s 846,800,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 cubic kilometers.

http://waitbutwhy.com/2015/01/artificial-intelligence-revolution-2.html