Physics – Concepts – Nature of Light

Physics – Concepts – Nature of Light
We have covered quite a chunk of information in this Physics portions of the website. All that is left is to officially introduce light.As we already know, Sir Isaac Newton discovered light consists of fundamental colors. Continued work by Sir William Herschel, Johann Ritter and Michael Faraday demonstrated the visible light is only a small portion of a much larger electro-magnetic spectrumAlbert Einsteinshowed us the true nature of light:

  • Light is a wave
  • Light consists of small particles (quanta)

Thus light is both particle and wave.

Its easy to associate light with just the fundamental colors of the rainbow,

but this is only a tiny part – 400 nanometers (blue) to about 700 nanometers (red). Or 4000 angstroms to about 7000 angstroms.

The image on the left demonstrates the wave nature of light. This effect is called diffraction, and results when only parts of the wave can enter the slit. The net effect is the dark lines visible on the bar to the left – representing the illumination through the lens. The wave in the center is brighter than the others – this is because of the wave (particles would spread out naturally).

On the flip side, this image shows a diagram of what Astronomer’s call “lensing.” The galaxy in the center of the image has a strong gravity influence causing the light to bend. This demonstrates the particle nature of light.

Because of this, light has both a frequency and wavelength:

Additionally, light is the fastest object in the Universe – traveling close to 300,000 km/s.

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