The Colors of Light

Not your ordinary Rainbow

Did you know, there are parts of the rainbow you can’t see!!

There are colors that Insects can see that you can’t!

TheThe CCololors ors of of LigLightht These colors are presented from:

Lowest Frequency to Highest Frequency

Lowest Energy to Highest Energy

Longest Wavelength to Shortest Wavelength

Frequency and Wavelength

• Wavelength Distance between peaks or troughs

• Frequency Number of waves per second – in Hz

(kHz, MHz, GHz)

Troughs

Peaks

Frequency and Wavelength

• The Longer the wavelength – the Lower the frequency

AM radio – 650 kHz = 300 meters

• The Shorter the wavelength – the Higher the frequency FM radio – 89.7 MHz = 3 meters

R-M-FIR-NIR-ROYGBIV-UV-X-Gamma

• RADIO– ELF – VLF – LF – HF – VHF – UHF – SHF - EHF– Km 100M 10M 1M 10cm 1cm

•

^AM broadcast

^FM Broadcast

^Cell Phones

^Microwave ovens

^Messages tosubmarinesunderwater

Amateur Radio

This part of “radio” overlaps into the microwave region

M82 – Merlin&VLA5GHz – Jodrell Bank

R-M-FIR-NIR-ROYGBIV-UV-X-Gamma

• Microwave– 20 cm to 1 cm to 1 mm

• Microwave ovens use just one of the frequencies of microwave radiation. The one that causes water molecules to spin. As they spin, they bump into other molecules – and warm them up!

• Microwaves are used in radio transmissions, and radio astronomy.

(Source: Jensen, 2000)

• Far Infrared Thermal Infrared

• FIR

R-M-FIR-NIR-ROYGBIV-UV-X-Gamma

MilkyWay in FIR

• Near Infrared – NIR

• William Herschel discovered

• Plants reflect nearly all NIR – so they look White (in imagery)

• www.echeng.com/photot/infrared/tutorial/• www.ipac.caltech.edu/Outreach/Edu/Regions/irregions.html

R-M-FIR-NIR-ROYGBIV-UV-X-Gamma

Center of the Milky Way

Visible Near Infrared

NIR Visible

• Hey Mr B, get out the NIR camera – make them look spooky!

• Veins – See Through Sun Glasses – Weird Eyes - In the dark

Visible NIR FIR

Horsehead Nebula in Orion

Visible Light - VIS From low frequency to

high frequency

RedOrange Yellow Green Blue Indigo Violet

“The colors of the rainbow”

R-M-FIR-NIR-ROYGBIV-UV-X-Gamma

• UltraViolet – UV– SunBurn!– Blacklights

• The sun in UV The Earth in UV

•

R-M-FIR-NIR-ROYGBIV-UV-X-Gamma

• X-Rays– Can go through soft things – stopped by

metals and bones– Can cause cancer or other damage if too

many x-rays are received– Don’t make it through the atmosphere

•

R-M-FIR-NIR-ROYGBIV-UV-X-Gamma

• Gamma Rays– Very high energy– Don’t make it through the atmosphere

• Gamma Rays come from the nucleus of atoms as they rearrange themselves.

• NOTE – Electromagnetic Radiation and Radioactivity Radiation are two separate things! – only in Gamma rays do they come together.

R-M-FIR-NIR-ROYGBIV-UV-X-GammaThe Moon

Gamma Ray Burst

• Other “Radiation” –– Cosmic rays– Radioactivity

• Alpha rays / Alpha particles = He nucleus +2

• Beta rays / Beta particles = high speed electrons e-

• Gamma rays – given off by nuclear reactions

•

R-M-FIR-NIR-ROYGBIV-UV-X-Gamma

The Milky Way in Different Colors of Light

• The following image shows our view of the Milky Way Galaxy from Radio waves to Gamma Rays.

• It looks a little different in each “color” because each is “seeing” different processes.

• Questions??

DisclaimerAloha

I put together these power points for use in my science classes.You may use them in your classes.

Some images are public domain, some are used under the fair-use provisions of the copyright law, some are mine. Copyright is retained by the owners!

Ted Brattstrom