fluorescent.
That refers to a change in frequency in light, sound, or some other wave, from the point of view of an observer, caused by a relative movement between the source and the observer. In other words, the source of a wave moves towards us, or away from us. For more details, I suggest you consult the Wikipedia article on "Doppler effect", or some other similar source.
a type of light emission that is the same as fluorescence except for a delay between excitation and de-excitation, which provides an afterglow. The delay is caused by atoms being excited to energy levels that do not decay rapidly. The afterglow may last from fractions of a second to hours, or even days, depending on the type of material, temperature, and other factors.
Another name for light beam is ray of light. Other similar names are beam of light, shaft of light, and irradiation.
If two people are standing next to each other, and illuminated by a light source, think of this as a triangle. Imagine a line from the light source to person A, and then continuing on. This person will block some of the light and that is the shadow that is cast (along this straight line). Imagine a line from the light source to Person B, and continue that on. This person's shadow will be cast along the line from the light source to him, and continuing on. Since the two lines intersect at the light source, then they are not parallel lines. The farther away the light source is from the two people (relative to their distance from each other) the angle between the lines will decrease, so that they may seem to be almost parallel at some point. The Sun is essentially far enough away that you'd have a difficult time seeing the difference.
For one, as the sound spreads over a larger area, the intensity decreases. This is similar to a light becoming dimmer, the farther away you get away from the light source - the light, too, spreads over a larger area, so in both cases, less energy is available per unit area. On the other hand, part of any sound (or light, or other wave) will be absorbed - converted to other types of energy.
The primary light source is the sun for the planet Earth.
Sun, Moon for light, Light bulb etc
the 3 other ones are bioluminescence, phosphorescence and electroluminescence
That refers to a change in frequency in light, sound, or some other wave, from the point of view of an observer, caused by a relative movement between the source and the observer. In other words, the source of a wave moves towards us, or away from us. For more details, I suggest you consult the Wikipedia article on "Doppler effect", or some other similar source.
The other stars in the sky.
Yes. Stars.
Light doesn't reflect light, nor does any other electromagnetic radiation.
when objects get lighted from other source of light it is known as illumination
a type of light emission that is the same as fluorescence except for a delay between excitation and de-excitation, which provides an afterglow. The delay is caused by atoms being excited to energy levels that do not decay rapidly. The afterglow may last from fractions of a second to hours, or even days, depending on the type of material, temperature, and other factors.
the sun or other light source
Similar to each other; of the same source.
Yes. It is the main source of visible light in the solar system. Some would say the only source. The only other source is the other stars in the sky. The amount of light they provide is extremely small. Keep in mind that light reflected of a moon's surface is still sunlight.