surajc0504 said:imagine a photon (travelling with the speed of light) is moving straight towards a huge mass say 10^10 Msun. what will happen to its speed/energy as it comes closer to it?
Photons are fundamental particles of electromagnetic radiation, which carry energy and have no mass. They are considered to be the basic units of light and other forms of electromagnetic radiation, such as radio waves, microwaves, and X-rays.
No, photons do not have a resting or relaxed state. They are always in motion, traveling at the speed of light. This is because they have no mass, and according to Einstein's theory of relativity, objects with no mass must always travel at the speed of light.
Photons cannot be created or destroyed, but they can be converted into other forms of energy. For example, when a photon is absorbed by an atom, it can cause the atom's electrons to jump to a higher energy level. This energy can then be released as another photon when the electron returns to its original energy level.
Photons can interact with matter in a variety of ways, depending on their energy and the properties of the matter. They can be absorbed, reflected, or scattered by matter, which can result in the emission of new photons or the conversion of their energy into other forms.
Since photons travel at the speed of light, time does not pass for them. This means that from the perspective of a photon, it is created and absorbed at the same instant. This is why photons are often described as timeless or eternal.