1. White Light & Electromagnetic Spectrum

2. What is Radiation? Energy that is transmitted from one place to another by electromagnetic waves Heat, UV rays (sunburn), radio waves, etc. Properties: Can travel through space and matter. Can be many different size wavelengths. All travel the same speed.

3. How Fast Does Light Travel? 300,000 km/sec 186,000 mi/sec

4. What is the Visible Spectrum Bands of different colors of light : R O Y G B I V

5. What is a Prism? A prism breaks light into the spectrum (rainbow) What is visible light? –Light visible to the human eye, colors of the rainbow What is a spectroscope? –Instrument used to study light emitted by an object. What is a wavelength? –The distance between two successive wave crests or troughs

6. White Light & Astronomers Video (4:45)Video Astronomers study the different colors emitted (given off) by stars and galaxies to learn things about stars –Composition – is the star made of hydrogen? VERY HOTCOOL –Temperature – is the star VERY HOT or COOL? –Movement of star – is it moving away or toward us?

7. What is a Light Year? distanceThe distance light travels in one year. The “unit” astronomers often use to discuss the distance stars are away from Earth… 9,460,800,000,000 kilometers 5,865,696,000,000 milesLight travels 9,460,800,000,000 kilometers in one year – that’s 5,865,696,000,000 miles in one year 129,045,312,000,000 milesSo – if a star is 22 light years from Earth…how many miles away is it? 129,045,312,000,000 miles

8. Visible or White Light All colors combined form white light R O Y G B I VThose colors: R O Y G B I V –Red –Orange –Yellow –Green –Blue –Indigo –Violet Longest Shortest

9. What is the Electromagnetic Spectrum? The arrangement of radiation (electromagnetic radiation) by wavelength Gamma Rays X-Rays Ultra-violet Visible Light Infrared Microwaves Radio Waves Shortest wavelength, most energy, most lethal Longest wavelength, least energetic

10. What’s the Point?