Ultrafast electron imaging reveals never-before-seen nuclear motions in hydrocarbon molecules triggered by light. The ...

Hypersonic vehicles' complex interactions with gases in the air are revealed for the first time in a new 3D simulation.

But factors other than altitude also effect the density of air. For one thing, water molecules have less mass than other gas molecules in air; so as water vapor increases, the density of air ...

That's why there's no sound in space. For sound to travel it needs air molecules to vibrate. In deep space there's no air. We call this a vacuum. You can muffle or reduce sound by using thick ...

But during warmer weather, the air is less dense, and the baseball collides with few molecules. With less resistance, the ball can maintain its speed and travel further.