Center of Gravity, the point at which all of the weight of an object appears to be concentrated. If an object rotates when thrown, the center of gravity is also the center of rotation. When an object is suspended so that it can move freely, its center of gravity is always directly below the point of suspension. An object can be balanced on a sharp point placed directly beneath its center of gravity. It is important for automobiles and trucks to have their centers of gravity located close to the road, because a low center of gravity gives them stability.
Don't know your elbow from your accelerator? Don't be put off. Our Large Hadron Collider quiz isn't for experts only. Learn a little about the particle accelerator and what it does with our LHC quiz.
If you want to see a hologram, you don't have to look much farther than your wallet. But the most impressive holograms are large scale and illuminated with lasers or displayed in a darkened room with carefully directed lighting. Learn how a hologram, light and your brain work together make clear, 3-D images.