Answer:

Light does not go away by leaking out through doors and windows. Light goes away by being quickly absorbed by materials and converted to heat and other forms of energy. In contrast to wind or smoke, light has no mass and is not composed of atoms. Because of this, light travels quickly in straight lines until it hits an object. It does not float around, billow with the wind, or leak out like gas.

When light hits an object, part of the light gets absorbed, part of it is transmitted through the object, and part of it is reflected/scattered. Exactly how much gets absorbed, transmitted, or reflected depends on the material, shape, and thickness of the object. Thick metal objects like cooking pots reflect most of the light that hits them, absorb a little of the light, and transmit almost none of the light. In contrast, clear glass transmits most of the light, reflects a little of the light, and absorbs almost none. Coal absorbs most of the light that hits it and reflects and transmits almost none. Understanding and predicting exactly how much light of a certain color that a certain object absorbs, transmits, and scatters involves a complex field of study that involves many different effects not worth examining here. However, we can summarize the basic principles behind absorption.