Bigger than you think

The universe, that is. New estimates for its size, based on measured microwave radiation, are up to 78 billion light years. And that’s a minimum. The bad news? Given this size, it is less likely that light can “wrap around” an odd-shaped universe, allowing us to see what the earth looked like four billion years ago. And here’s more evidence that the universe is dominated by “dark energy,” causing it to expand, possibly forever.