Well, from our perspective anyway. It seems that someone has done calculations recently to show that not only is the universe expanding, but it’s accelerating its expansion such that portions will gradually become beyond our visual and radio reach by moving at or beyond the speed of light as seen from Earth, leaving us cosmically isolated with only our immediate neighbors within a few billion years.
Unfortunately, it seems this study has not yet reached the printing presses of publication, so I wasn’t able to look at the math (it’s a subscription-only journal until the article is a few months old anyway), and don’t have the time to work through it myself at the moment. Consider that a challenge to work out some provisional numbers to see how/what/when things could be expanding beyond the speed of light as seen from earth. Is it just things on the opposite side of the universe, our side, or all of it? Which things will we lose first? Are any of the more notable stars/clusters/constellations/objects on the list for the (cosmically) near future?
The article also talks about a “frozen” ghost image left as things blip out, but I couldn’t tell if this means we just see an unchanging image for a brief time before nothingness, or if the ghost images remain somehow, but are just never updated. I don’t have quite enough grasp of the things involved to work that portion out - anybody have some insight?
Regardless, it’s all some pretty weird stuff - the idea that portions of the universe that we can see now and have used to prove very fundamental portions of the physics governing things will no longer be within reach later is a bit disconcerting. Some portions are already beyond the event horizon, and who knows what information we may have missed by not having those data points? So, SETI@Home contributors, you may want to fire up a few more dual-cores, because your time is (sort of) limited. :P
Read the full story on Space.com, and a related article with some extra details.