What is a characteristic of all light?

Light is a form of energy that is essential for our ability to see, and one of its fundamental characteristics is that it has a source. This means that light originates from something, such as the sun, light bulbs, or stars. Without a source, there would be no light to illuminate our surroundings. This inherent property of light distinguishes it from other forms of energy or phenomena that do not require a source for manifestation.

Other choices do not accurately describe all light. For example, while light can travel in a straight line under certain conditions, it can also bend or spread out when it encounters different materials, and it does not solely travel straight. Light is not restricted to night-time visibility; it is present during the day and produced by various artificial and natural sources at all times. Furthermore, not all light is white; light can be made up of various colors, as seen in rainbows or through prism effects, meaning it can be red, blue, green, and more. Thus, the characteristic of all light having a source is a clear and essential trait that fits all types of light stimuli we encounter in our environment.