Electromagnetic Spectrum

Electromagnetic Spectrum Created by Dr. A. Davila

In the above diagram the white line represents the position of the medium when no wave is present. http://id.mind.net/~zona/mstm/physics/waves/partsOfAWave/waveParts.htm#frequency

http://id.mind.net/~zona/mstm/physics/waves/partsOfAWave/waveParts.htm#frequencyhttp://id.mind.net/~zona/mstm/physics/waves/partsOfAWave/waveParts.htm#frequency

Radio Waves Are produced by feeding an electric signal to the mast or antenna of a transmitter.

Radio Waves • Radio waves have the longest wavelengths in the electromagnetic spectrum. • These waves can be longer than a football field or as short as a football.

Radio Waves The signal makes the electrons in the metal atoms of the mast or antenna change energy levels and emit light rays.

RAY’S TV reception uses radio_ waves The SATELITE_ at Ray’s TV – receives movies via radio waves from a satellite TAXI_ - Car radio receives radio wave signals TAXI_ - Driver receives instructions on a CB radio which uses radio waves. RADIO TOWER - broadcast’s radio signals LARGE SATELITE _ dish in field – receives radio waves from distant stars

3 8 5 0

3 8 5 100,000 m 0 1 m

3 1000 m 8 100000000 m 5 100,000 m 0 1 m

Microwaves • Microwaves have wavelengths that can be measured in centimeters • The longer microwaves, those closer to a foot in length, are the waves which heat our food in a microwave oven Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

Microwaves • Microwaves are good for transmitting information from one place to another because microwave energy can penetrate haze, light rain and snow, clouds, and smoke. Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

Microwaves • Shorter microwaves are used for radar like the doppler radar used in weather forecasts. Microwaves, used for radar, are just a few inches long. Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

MICROWAVES in Wavesgrill – uses microwave to cook food. Antennas on tower they send microwave communications

9 8 -2

9 1000000000 m 8 100000000 m -2 0.01 m

Infrared Waves • The longer, far infrared wavelengths are about the size of a pin head and the shorter, near infrared ones are the size of cells, or are microscopic. Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

Infrared Waves • The heat that we feel from sunlight, a fire, a radiator or a warm sidewalk is infrared. • Shorter wavelengths are the ones used by your TV's remote control. Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

Infrared Waves • Satellites like GOES 6 and Landsat 7 look at the Earth. Special sensors, like those aboard the Landsat 7 satellite, record data about the amount of infrared light reflected or emitted from the Earth's surface. Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

Infrared lights above food in Wavesgrill – use infrared waves to keep food hot Infrared remotes - Remote controls use infrared waves to communicate with the TV Trees, brashes, crops, and short vegetation reflects short infrared waves Astronomers study thermal infrared (long infrared waves) from stars

11 12 -3

11 100000000000 m 12 1000000000000 m -3 0.001 m

Visible Spectrum • Cones in our eyes are receivers for these tiny visible light waves. • The Sun is a natural source for visible light waves and our eyes see the reflection of this sunlight off the objects around us. Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

Visible Spectrum • The color of an object that we see is the color of light reflected. All other colors are absorbed. • Light bulbs are another source of visible light waves. Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

VISIBLE LIGHT Water droplets cause white light to break apart into seven colors (Visible Light). Portrait photographers use film sensitive to visible light Astronomers look at visible light from planets and stars

14 15 -6

14 100000000000000 m 15 1000000000000000 m -6 0.000001 m

Ultraviolet Waves • Astronomers have to put ultraviolet telescopes on satellites to measure the ultraviolet light from stars and galaxies - and even closer things like the Sun Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

A tanning booth uses ultraviolet waves to tan our skin ultraviolet waves - sunglasses protect our eyes from the ultraviolet waves Sunblocks - protects our skin from ultraviolet waves ultraviolet waves astronomers see some ultraviolet radiation from planets and stars

15 17 -8

15 1000000000000000 m 17 100000000000000000 m -8 0.00000001 m

X-Rays • X-ray light tends to act more like a particle than a wave. X-ray detectors collect actual photons of X-ray light. • The Earth's atmosphere is thick enough that virtually no X-rays are able to penetrate from outer space all the way to the Earth's surface. Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

X-Rays • X-ray telescopes and detectors are placed on satellites. We cannot do X-ray astronomy from the ground can not be done from Earth • comets emit X-rays • The Sun also emits X-rays • Many things in deep space give off X-rays Images from: http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

17 19 -10

17 10000000000000000 m 19 10000000000000000000 m -10 0.0000000001 m

At EMS, Dr. Bob uses X-ray detectors collect actual photons of X-ray light in his Clinic. Nuclear Medicine is used to treat cancer. Gamma radiation kills sick cells.

Gamma Rays • Gamma-rays are generated by radioactive atoms and in nuclear explosions • They can kill living cells, a fact which medicine uses to its advantage, using gamma-rays to kill cancerous cells. http://science.hq.nasa.gov/kids/imagers/ems/gamma.html

Gamma Rays • .Gamma-rays travel to us across vast distances of the universe, • Instruments aboard high-altitude balloons and satellites like the Compton Observatory provide our only view of the gamma-ray sky

19 23 -12

19 1000000000000000000 m 23 100000000000000000000000 m -12 0.000000000001 m

Electromagnetic Spectrum