As a minor tribute to Carl Sagan and his Cosmos book and 13 part TV series, I decided to change the name of this category before anyone starts linking to it.
With all of the info we have available, scientists believe the universe is about 15 billion years old. The universe seems to be ever expanding, with objects accellerating (not just speeding away but actually going faster and faster) away from one another. Can we actually see to the edge?
Thinking about the other post on the speed of light, I wonder about other “constants”. Is it possible that gravity was weaker or stronger in the past? Might it just appear to be a constant now because at this moment that we look at it, over some thousands of years of human history, it doesn’t seem to have changed?