Einstein called these energy packets photons, and these are now recognised as a fundamental particle. Visible light is carried by photons, and so are all the other kinds of electromagnetic radiation like X-rays, microwaves and radio waves. In other words, light is a particle.
So, what are the different form of light?
The Electromagnetic Spectrum outside the visible is subdivided into several parts that also have special names: radio waves, microwaves, infrared, ultraviolet, x-rays and gamma rays. Despite the variety of names, they are all forms of light.
Most scientists think that dark matter is composed of non-baryonic matter. The lead candidate, WIMPS (weakly interacting massive particles), have ten to a hundred times the mass of a proton, but their weak interactions with "normal" matter make them difficult to detect.
If by "matter" you mean massive (in the sense of having nonzero rest mass), then photons are not matter. Photon is a fundamental particle, a force carrier for electromagnetic interaction. It has zero charge, zero rest mass, and is a spin 1 particle (a boson).
A photon is produced whenever an electron in a higher-than-normal orbit falls back to its normal orbit. During the fall from high energy to normal energy, the electron emits a photon -- a packet of energy -- with very specific characteristics.
Light is a form of energy, not matter. Matter is made up of atoms. Light is actually electromagnetic radiation. Moving electric charge or moving electrons (electric current) cause a magnetic field, and a changing magnetic field creates an electric current or electric field.
An incident ray is a ray of light that strikes a surface. The reflected ray corresponding to a given incident ray, is the ray that represents the light reflected by the surface. The angle between the surface normal and the reflected ray is known as the angle of reflection.
The photon is a type of elementary particle, the quantum of the electromagnetic field including electromagnetic radiation such as light, and the force carrier for the electromagnetic force (even when static via virtual particles). The photon has zero rest mass and always moves at the speed of light within a vacuum.
There is no limit to how fast the universe can expand, says physicist Charles Bennett of Johns Hopkins University. Einstein's theory that nothing can travel faster than the speed of light in a vacuum still holds true, because space itself is stretching, and space is nothing.
Actually, lots of things aren't made of atoms. Light and other electromagnetic waves are an obvious example. Individual protons, neutrons, and electrons don't constitute atoms until they're combined.
Incandescent light bulbs consist of an air-tight glass enclosure (the envelope, or bulb) with a filament of tungsten wire inside the bulb, through which an electric current is passed.
Energy is not made of anything, energy is a term used to describe a trait of matter and non-matter fields. When matter has velocity, for example, it is said to have kinetic energy. There are also various forms of potential energy.
Waves and fields. EM radiation is created when an atomic particle, such as an electron, is accelerated by an electric field, causing it to move. The movement produces oscillating electric and magnetic fields, which travel at right angles to each other in a bundle of light energy called a photon.
The colour of visible light depends on its wavelength. These wavelengths range from 700 nm at the red end of the spectrum to 400 nm at the violet end. White light is actually made of all of the colours of the rainbow because it contains all wavelengths, and it is described as polychromatic light.
Light is made up of little packets of energy called photons. Most of these photons are produced when the atoms in an object heat up. Heat “excites” the electrons inside the atoms and they gain extra energy. This extra energy is then released as a photon.
The idea is called wave-particle duality, and is a fundamental tenet of the theory of quantum mechanics. Depending on which type of experiment is used, light, or any other type of particle, will behave like a particle or like a wave. So far, both aspects of light's nature haven't been observed at the same time.
Like those ripples, each light wave has a series of high points known as crests, where the electric field is highest, and a series of low points known as troughs, where the electric field is lowest. The wavelength is the distance between two wave crests, which is the same as the distance between two troughs.
A light beam or beam of light is a directional projection of light energy radiating from a light source. Sunlight forms a light beam (a sunbeam) when filtered through media such as clouds, foliage, or windows. Light from certain types of laser has the smallest possible beam divergence.
Sunlight travels at the speed of light. Photons emitted from the surface of the Sun need to travel across the vacuum of space to reach our eyes. The short answer is that it takes sunlight an average of 8 minutes and 20 seconds to travel from the Sun to the Earth.
Sound is made when something moves or vibrates. The movement sets up a sound wave in the surrounding air. Continuous sounds, such as drumming, are made when an object vibrates back and forth. A sudden clap or bang sends out a single sharp pulse of sound called a shock wave.
So, for a surface gravity wave of length 10m, the packet would travel at approximately 1.97 m/s, or 4.4 mph. Assuming a Pacific Ocean 5000 miles in width, it would take 1136.36 hours, or 47.34 days for a deep water wave to traverse the Pacific basin.
In physics, the term light sometimes refers to electromagnetic radiation of any wavelength, whether visible or not. In this sense, gamma rays, X-rays, microwaves and radio waves are also light. The study of light, known as optics, is an important research area in modern physics.