Читать книгу String Theory For Dummies - Andrew Zimmerman Jones - Страница 88

Kinetic energy is most obvious in large objects, but it’s present in objects of all sizes, down to molecules and atoms. Heat (or thermal energy) is really just a bunch of atoms moving rapidly, representing a form of kinetic energy. When water is heated, the particles accelerate until they break free of the bonds with other water molecules and become a gas. The motion of particles can cause energy to be emitted in different forms, such as when a burning piece of coal glows white hot.

Sound is another form of kinetic energy. If two billiard balls collide, the particles in the air will be forced to move, resulting in a noise carried by a wave. Normally this is a tiny amount of energy, but it can actually reach destructive levels when we consider the blast of an explosion or the waves in a fluid other than air — for instance, a tsunami in the ocean. It turns out that light and radiation are also described by waves, and they also carry energy, but they do so in a different way than sound waves and ocean waves do. We will come back to this in Chapter 7.