“Now the question that has occurred to all of us at some point is: what would happen if you traveled out to the edge of the universe and, as it were, put your head through the curtains? Where would your head be if it were no longer in the universe? What would you find beyond?

The answer, disappointingly, is that you can never get to the edge of the universe. That’’s not because it would take too long to get there— — though of course it would — but because even if you traveled outward and outward in a straight line, indefinitely and pugnaciously, you would never arrive at an outer boundary. Instead, you would come back to where you began (at which point, presumably, you would rather lose heart in the exercise and give up). The reason for this is that the universe bends, in a way we can’’t adequately imagine, in conformance with Einstein’’s theory of relativity… [W]e are not adrift in some large, ever-expanding bubble. Rather, space curves, in a way that allows it to be boundless but finite. Space cannot even properly be said to be expanding because, as the physicist and Nobel laureate Steven Weinberg notes, “’solar systems and galaxies are not expanding, and space itself is not expanding.”’ Rather, the galaxies are rushing apart. It is all something of a challenge to intuition. Or as the biologist J. B. S. Haldane once famously observed: “’The universe is not only queerer than we suppose; it is queerer than we can suppose.'”

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From Bill Bryson’s A Short History of Nearly Everything.

The image below is a three-dimensional map of the perceptible universe. It stretches 380 million light years, includes 43,000 galaxies, and covers 95 percent of our sky. It took a team of world-class scientists over a decade to compile, and it represents only a tiny fraction of the entire universe. The colors signify the respective red-light-shifts of each galaxy (the “third dimension” of an otherwise 2D image).

If you can understand it, well, you’re cleverer than me.

Read on:

• Einstein, Newton, Carl Sagan, and Neil DeGrasse Tyson relate how science requires childlike wonder
• Baruch Spinoza theorizes how the universe might have began ex nihilo
• Gottfried Leibniz takes a different crack at the question