ADVERTISEMENT

Does Time Run Backward in Other Universes?

One of the most basic facts of life is that the future looks different from the past. But on a grand cosmological scale, they may look the same
THIS IS A PREVIEW.
or subscribe to access the full article.

More In This Article

The universe does not look right. That may seem like a strange thing to say, given that cosmologists have very little standard for comparison. How do we know what the universe is supposed to look like? Nevertheless, over the years we have developed a strong intuition for what counts as “natural”—and the universe we see does not qualify.

Make no mistake: cosmologists have put together an incredibly successful picture of what the universe is made of and how it has evolved. Some 14 billion years ago the cosmos was hotter and denser than the interior of a star, and since then it has been cooling off and thinning out as the fabric of space expands. This picture accounts for just about every observation we have made, but a number of unusual features, especially in the early universe, suggest that there is more to the story than we understand.

THIS IS A PREVIEW.
or subscribe to access the full article.
Buy Digital Issue $7.99
Digital Issue + All Access Subscription $99.99 Subscribe
Rights & Permissions
Share this Article:

Comments

You must sign in or register as a ScientificAmerican.com member to submit a comment.
Scientific American Holiday Sale

Scientific American Mind Digital

Get 6 bi-monthly digital issues
+ 1yr of archive access for just $9.99

Hurry this offer ends soon! >

X

Email this Article

X