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Unformatted text preview: Chapter 5 Light travels through empty space at a speed of 300,000 km/s Galileo t ried but found light moves too quickly to be measured by human resources. 1676 Olaus Romer first to suggest light does NOT travel instantaneously: watching Jupiters moons realized that eclipses occurred sooner or later based on how close to Earth it was 1850 Armand-Hippolyte Fizeau & Jean Foucault measured speed of light. Reflected light off a rotating mirror and a stationary mirror. Got close to 300,000 km/s C= speed of light in a vacuum which is 299,792.458 km/s or 3.00x10 5 According to Einsteins theory of relativity, nothing can travel faster than speed of light. Light is electromagnetic radiation and is characterized by its wavelength Spectrum the result of dispersing a beam of electromagnetic radiation so that components with different wavelengths are separated in space people thought a prism breaks white light into multiple colors, but Newton disproved that with a second prism. Thought light composed of particles too small to detect individually Christiaan Huygens suggested light moves in waves. Thomas Young proved it by passing a beam of light through two parallel slits in an opaque screen. On a white surface in the distance, the light formed bright and dark bands. What is waving light? Idea came from electricity & magnetism. electromagnetism electric and magnetic phenomena, including electromagnetic radiation James Maxwell showed that electric and magnetic fields should travel through space in the form of waves at the exact same speed as light does. electromagnetic radiation radiation consisting of oscillating electric and magnetic fields. Examples include gamma rays, x rays, visible light, ultraviolet and infrared radiation, radio waves, and microwaves. wavelength distance between two successive wave crests visible light light to which the human eye is sensitive Visible light has really short wavelengths that are hard to detect....
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