Light rays may change direction when they travel from one material into another material (eg air and glass or plastic or water). When the light rays travel into a denser or thicker material they ...
The first recorded measurements were performed by Danish astronomer Ole Rømer, who demonstrated in 1676 using light measurements from Jupiter’s moon Io to show that light travels at a finite ...
Light travels slower in a medium than it does in a vacuum, and the speed is proportional to the density of the medium. This speed variation causes light to bend at the interface of two media -- a phenomenon called refraction. The angle at which it bends depends on the densities of the two media and the wavelength of the incident light.
In contrast, light waves can travel through a vacuum, and do not require a medium. In empty space, the wave does not dissipate (grow smaller) no matter how far it travels, because the wave is not interacting with anything else. This is why light from distant stars can travel through space for billions of light-years and still reach us on earth.
However, the wavelength of visible light is so small that you can make beams which travel in straight lines without spreding out very much. Light changes direction when it bumps into some sort of change in material, as we describe below. (1) Reflection. Reflection is what happens when light bounces off of something.
Light travels both in straight lines and through reflection, which is a process in which light enters a prism and bends. Discover how light bends when going from one material to another with ...
How Does Light Travel? Light travels in waves of frequency and as particles of matter. There are many types of light, of which the visible spectrum is a small part. Visible light is the light that can be seen with the naked eye. It is one type of electromagnetic radiation, which results from the vibrations of electric and magnetic fields.
Phys1 wrote, "Firstly, light does not have a frame of reference with special relativity." I was not referring to the photon's frame of reference, but the frame through which it travels.
Firstly, you have to have a single photon. Light doesn't as a rule work that way: it is usually a superposition of many states with different numbers of photons. Secondly, a photon, like other “particles”, is a bundle of properties (energy, moment...
I will start this answer by the great Albert Einstein’s quote All the fifty years of conscious brooding have brought me no closer to the answer to the question, ‘What are light quanta?’ Of course today every rascal thinks he knows the answer, but ...