Tiny particles of light. Energy released by atoms through photons. Einstein won nobel prize for discoverin in 1921
In the fifth century
Empedocles said aphrodite made eye with fir in it.
Christian huygens agreed with davinci that light is wave. Pointed out when two beams cross they pass tgru eachother
Huygens book was called
Treatise on light
Scottish james maxwell discovered that waves travel at constant speed. He thought it was radiation. Supported huygens
German heinrich hertz discovered frequencies of light such as violet cause metals to lose electrons. Used red lught no effect. Showed. Violet light were stronger. Photoelectric effect. Agreed with newton
Movement of electrons when light shines on it
Early twentieth century
Einstein used previous works to explain photons. Photons energy level depended on light frequency
Wave theory of light was accepted until...
Einstein studied photoelectric effect. Indicated particle nature. Also as wave.
Theory of wave particle duality
Einstein created. States light is a wave and particle. Received nobel prize in 1922 for it
Scientists think lught is a wave and particle. Particles in wave pattern
Theoretical physics. Replaces classical mechanics at atomic and subatomic levels. From latin quantum means how many. Based on probability.
Range of electromagnetic waves in order. Transverse waves that transfer electric and magnetic energy. Travel at same speed. Different wavelengths and frequencies. Travel in vacuum. Electric and magnetic.
Radiation in wavelengths u can see is
Visible.light. mostly invisible
Longest wavelength. Lowest frequency. Radio tv radar
Wireless and microwAves
Energy as heat. Qll objects give off. Cant see,only feel. Shorter wavelengths and higher frequencies than microwaves
Type of infrared. Thermographic cameras detect radiation and make images of it
Electromagnetic waves that are visible To human eye
Composed of seven colors roy g biv . Form white. Newton discovered it. Coined term spectrum from Latin spectaculum or appearance
Frequencies hugher than visible light. More energy. Can damage or kill cells. Uv lamps used to kill hospital bacteria
Higher grequencies than uv rays. Used in medicine
Shortest wavelength and hughest frequency. Greatest energy. Given off in nucleur stuff
Four properties of light are:
Speed wavelength frequency and amplitude.
Speed of light
In a vacuum measured at 300000 km/s or 186000 m/s
Distance fro crest to trough of one wave to crest to tro of another
Number of light wavs that pass by each second
Height of wave
Give off own light
Can be seen bc they reflect light. Ex moon
Block light. Ex ur hand
Allow light o pass thru unchanged. Ex clear glass water air
Qllow some scattered light to pass thru. No details. Ex frosted glass and wax paper
Bouncing back of wave when hits surface thru which it cant pass. Objects r seen bc light reflects off them
Bending of light waves as enter other medium. When light enters new medium chabge in speed causes bending
Curved piece of glass used to refract light. Different shapes . New image based on shape