Presentation on theme: "“Seeing” the Invisible Exploring the Electromagnetic Spectrum Re cord the following questions from the class set reading in your composition book leaving."— Presentation transcript:
“Seeing” the Invisible Exploring the Electromagnetic Spectrum Re cord the following questions from the class set reading in your composition book leaving spaces between each question. 1.What is the electromagnetic spectrum? 2.What can we learn from studying light? 3.How can we get a complete picture of our universe? 4.Why Send Telescopes into Space? Alternating Partner Read: Odd numbered sections are read aloud to the partner who listens and answers the question in their composition books. Switch roles on the even numbered questions. Share answers with each other and the class
Designing your Vocabulary foldable Observe the following demo: 1.Lay 4 pieces of unlined paper on top of each other 2.Slide back each of the pages so there is ~1 cm showing of each shorter edge of the page 3.Fold the packet so that you now have 8 flaps with a small edge for labeling 4.Staple on the fold using the long stapler.
Electromagnetic Radiation (The title for the front of your foldable) Definition: Inside the front cover: a stream of photons (packets of energy), each traveling in a wave-like pattern, moving at the speed of light. Label each of your 1 cm edges: 1.Radio Waves: have photons with the lowest energy 2.Microwaves: have a little more energy than radio waves, 3.Infrared: has more energy as does each of the following 4.Visible Light 5.Ultraviolet 6.X-Rays 7.Gamma Rays: have photons with the most energy
Sketch a model of the Electromagnetic spectrum on the inside cover This is also in the class reading
Another Model of the Spectrum
Electromagnetic Spectrum The full range of frequencies, from radio waves to gamma rays, that characterizes lightfrequencies The electromagnetic spectrum can be expressed in terms of energy, wavelength, or frequency. Each way of thinking about the EM spectrum is related to the others in a precise mathematical way.electromagnetic spectrum
Wavelength and Frequency important vocabulary –inside cover of your foldable For any kind of wave there exists a simple relationship between wavelength and frequency. The wavelength (a) is measured as the distance between two successive crests in a wave. The frequency is the number of wave crests that pass a given point in space each second. (b has a higher frequency that a)
What is a wave? A wave is defined as any disturbance which travels with time from one point in space to another. Demo#1: Place water in a clear lid. Tap the water to observe water waves. Add a cork to observe how it moves in the waves. The cork bobs up and down as the waves move along the surface of the water. Waves that travel with this type of motion (water and light) are called transverse waves. Demo #2 …the slinky or a rope!
Radio (include the following information for each wave) Emitted by –Astronomical Objects –Radio Station transmitters Detected by –Ground based radio telescopes –Radios
What can block radio waves?? Try this demonstration: Turn on a radio Wrap the radio in a cloth…can you still hear the music? Wrap the radio in a piece of paper…can you still hear the music? Wrap the radio in a metal wire mesh…can you still hear the music? What do you think is happening to the radio waves when wrapped in a metal?
Infrared Emitted by –Sun and stars –TV Remote Controls –Food Warming Lights –Everything at room temp or above Detected by –Infrared Cameras –TVs, VCRs, –Your skin
Visible Emitted by –The sun and other astronomical objects –Laser pointers –Light bulbs Detected by –Cameras (film or digital) –Human eyes –Plants (red light) –Telescopes
Herschel’s Experiment –Discovered the make up of visible Light –In 1800, Herschel places his control thermometer just outside the red end of the spectrum –Result: The outside thermometer registered the highest temperature
Ultraviolet Emitted by –Tanning booths (A) –The sun (A) –Black light bulbs (B) –UV lamps Detected by –Space based UV detectors –UV Cameras –Flying insects (flies)
X-ray Emitted by –Astronomical objects –X-ray machines…discovered in 1895 by Wilhelm Conrad Roentgen. He didn’t really understand the unusual rays so he used the letter "x" to describe the rays because in Algebra "x" refers to an unknown - CAT scan machines…uses multiple x-ray beams projected at many angles –Older televisions –Radioactive minerals –Airport luggage scanners Detected by –Space based X-ray detectors –X-ray film –CCD detectors
Chandra X-ray Observatory Chandra is designed to observe X-rays from high energy regions of the universe, such as the remnants of exploded stars. The most sophisticated observatory built to date. Deployed by the Space Shuttle Columbia on July 23, 1999, Chandra X-ray Observatory
XMM Newton Its name derives from its three X- ray telescopes, each containing 58 high-precision concentric mirrors. mirrors
Gamma Ray Emitted by –Radioactive materials –Exploding nuclear weapons –Gamma-ray bursts –Black holes –Solar flares Detected by –Gamma detectors and astronomical satellites –Medical imaging detectors
On to Exploring the Electromagnetic spectrum web sites. Complete your foldable by adding illustrations and information you find interesting as you explore some excellent web sites. Be original and be creative!