Light. Molecules and color

Do you want to learn more about light, its properties and physical characteristics?

The online light simulations on this page will help you to discover what light is from a physics point of view and what are its most important characteristics and properties.

Light is a form of electromagnetic radiation that behaves either as a particle (photon) or as a wave. This dual property of light is described by quantum theory and electromagnetic theory. According to quantum theory, light is composed of photons, massless particles that travel at the speed of light and have energy and momentum. According to electromagnetic theory, light propagates as an electromagnetic wave, with characteristics such as wavelength, frequency, amplitude and speed.

The wavelength of light determines its color. Visible light ranges from approximately 400 nanometers (violet) to 700 nanometers (red). Different wavelengths are perceived by our eyes as different colors. The speed of light in a vacuum is a fundamental constant in physics and has the value of 299,792,458 m/s.

Light interacts with matter in various ways. It can be reflected, absorbed or transmitted by different objects. Reflection occurs when light bounces off a surface, such as a mirror. Absorption occurs when light is captured by an object and converted into thermal energy. Transmission occurs when light passes through a medium without being absorbed or reflected.

Light has numerous applications in technology and everyday life. It is used in lighting, optical communication (such as fiber optics), photography, medicine (such as laser therapy), precision optics, display technology (such as LED and OLED displays) and many other fields.

Below are several simulations and other educational resources, which can also serve as very illustrative examples. In addition, a selection of books and courses is included to help you broaden your knowledge of this subject.

Beam
Molecules
Color

Beam of light

Beams of light coming from a light source can be divergent, convergent or parallel. Find examples of parallel rays in addition to the sun's rays.

Molecules and light

Turn on the light source to explore. Watch what happens in the observation window as you set up different combinations of light source and molecule. This simulation has a zoom function, so you can enlarge sections of the simulation for a closer look, if necessary.

File

Click here to start the simulation

Color vision

Create a rainbow by combining red, green and blue light. Change the wavelength of a monochromatic beam or white light filter. See light as a solid beam, or as individual photons.