New research by the Atacama Cosmology Telescope (ACT) collaboration has produced the clearest images yet of the universe's infancy—the earliest cosmic time yet accessible to humans. Measuring light ...

We live in a world defined by inches, feet and miles (or centimeters, meters and kilometers, if you prefer), and it’s not difficult for most of us to comprehend sizes and distances given in these ...

The boundary of everything humans can observe stretches roughly 92 billion light-years across, a figure shaped by 13.8 billion years of cosmic expansion since the Big Bang. That number, derived from ...

Before defining what a light-year is, we should define what a light-year is not: It is not a measure of time, but rather a measure of distance. The confusion arises from the “year” that comes at the ...