We’ve grown up with the idea that the universe will expand forever, meaning the "cosmological constant" is positive. What if ...

If there is an absolute law in the universe, it’s that nothing can travel faster than the speed of light. Space is big, and ...

"Fast radio bursts shine through the fog of the intergalactic medium, and by precisely measuring how the light slows down, we can weigh that fog, even when it's too faint to see." Half of the universe ...