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Light
Term | Definition |
---|---|
Pythagoras | Greek philosopher who thought light was made of beams of particles |
Zaccharias and Hans Janssen | Dutch scientists who created the first compound (more than one lens) light microscope |
Galileo | Made his own lenses, which he used to build a telescope, and tried to measure the speed of light with lanterns |
Young and Augustin | English scientists that proved light behaves like a wave |
Energy | The capacity to apply a force over a distance |
Force | A push or pull on an object |
Crest | The highest point in a wave |
Trough | The lowest point in a wave |
Wavelength | The distance from crest to crest or trough to trough of a wave. |
Amplitude | The height of a wave crest or depth of a wave trough |
Frequency | The number of cycles per second of a wave |
Hertz | The unit used to measure frequency |
Transverse wave | When a wave moves up and down |
Compression wave | The wave moves back and forth in the same direction (scrunches up and stretches out) |
Wave model of light | Light is a type of wave that travels through empty space and transfers energy from one place to another. |
Visible light | Waves of light that you can see |
Refraction | The bending or changing direction of a wave of light |
Spectrum | The range of colours or frequencies of visible light |
Reflection | When a light wave strikes an object and bounces off |
Radiant energy | Energy, like light, that travels by radiation |
Electromagnetic radiation | The transmission of energy in the form of waves that extend from the longest radio waves to the shortest gamma rays. |
Radio waves | A type of electromagnetic radiation that has the lowest energy and the longest wavelength. Can be used for radio and TV broadcasting. |
Microwaves | Waves that have the shortest wavelength and highest frequency of all the radio waves. Can be used to cook food as well as send information to space and back. |
Infrared waves | A type of electromagnetic radiation that, relative to light, has a longer wavelength and lower energy and frequency. Can be used in remote controls and thermal images. |
Ultraviolet waves | A type of electromagnetic radiation that, relative to light, has a shorter wavelength, and higher energy & frequency. Can give sunburns, and can be used in solving crimes. |
X-Rays | Have much shorter wavelength and higher energy and frequency than UV waves. Can be used to photograph teeth and bones. |
Gamma rays | Have the highest energy and frequency, and the shortest wavelength portion of the electromagnetic spectrum. Can be used to kill cancer cells. |