Why did they form at that time? Astronomers know from observing distant exploding stars that the size of the universe has ...

Note: This video is designed to help the teacher better understand the lesson and is NOT intended to be shown to students. It includes observations and conclusions that students are meant to make on ...

In a quiet lab at Northwestern University, a team of scientists peered into a high-powered microscope, holding their breath. What they saw was something no human had ever witnessed: the moment ...

Researchers discovered the hydrogen atoms in a common metal hydride material are much more tightly spaced than had been predicted for decades -- a feature that could possibly facilitate ...