In simplest terms, the rate at which the universe expands on paper doesn’t match actual astronomical observations. That speed ...

If dark energy is weakening, as suggested by recent results, then the cosmos is far stranger than most physicists had ...

Physicist Richard Lieu first explored the idea that gravity could exist without mass—now he’s got a new cosmological model that eschews the need for dark energy.

Then, by comparing that distance to how fast the galaxy is moving away, they get the expansion rate for that part of the universe. This gives a value of around 73 kilometers per second per megaparsec.

Cepheid variables are an important rung on the cosmic distance ladder, a system astronomers use that builds one observation on another to draw ... in the universe's rate of expansion.

Here’s what we know, and what we don’t. [ Related: The universe isn’t just expanding—it may be spinning. ] Let’s get the disappointment out of the way early: “There is physically ...

The expansion of the Universe is not constant. Recent measurements have shown that the rate of the Universe's expansion is increasing. The evidence for this area of physics comes from observations ...

Nobel laureate Dr. James Peebles will discuss the still-unanswered questions regarding the expansion of the universe, dark matter and more. We have good evidence that the universe we see around us is ...