The surface of Earth is finite. We can measure it. If it was expanding, then its size would grow with time. And once again, good ol' Earth helps us understand what the universe might be doing beyond ...

Calculating the total mass of the universe is not simple, because most of the mass is invisible. In a pie chart of the contents of the universe, only 5 percent is normal matter, atoms that make up all ...

For years, cosmologists have argued over a simple question with an awkward answer: How fast is the universe expanding right now? The expansion rate, called the Hubble constant, ought to come out the ...

The most precise measurement of the expansion rate ever made suggests an unknown force may be affecting the universe.

Schematic of the expansion of the universe from the big bang (starting on the left side) to the present day. We have known for several decades that the universe is expanding. Scientists use multiple ...

We have known for several decades that the universe is expanding. Scientists use multiple techniques to measure the present-day expansion rate of the universe, known as the Hubble constant. These ...