Presentation on theme: "What Wavelength Was That?"— Presentation transcript:
1What Wavelength Was That? Examining the Electromagnetic Spectrumwith Hands-On Activities
2Electromagnetic Spectrum The full range of frequencies, from radio waves to gamma rays, that characterizes lightThe 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.The wavelength equals the speed of light divided by the frequency or lambda = c / nu
3Electromagnetic Radiation Electromagnetic radiation can be described in terms of a stream of photons, each traveling in a wave-like pattern, moving at the speed of light and carrying some amount of energy.The only difference between radio waves, visible light, and gamma-rays is the energy of the photons. Radio waves have photons with low energies, microwaves have a little more energy than radio waves, infrared has still more, then visible, ultraviolet, X-rays, and gamma-rays.
6Scaling the Spectrum Activity Helps to explain the electromagnetic spectrum and dispels some of the common misconceptions.Paper and pencil project that requires the use of math skills as well.
7Wavelength and Frequency For any kind of wave there exists a simple relationship between wavelength and frequency.The wavelength is measured as the distance between two successive crests in a wave. The frequency is the number of wave crests that pass a a given point in space each second.
8Understanding WavesThe traditional “slinky lab” as well as other activities to help understand waves.An activity that allows students to experiment with waves-longitudinal and transverse.Found in “Waves Light Up the Universe” Booklet
9Radio (Low Frequency & Very High Frequency) Emitted byAstronomical ObjectsRadio Station transmittersDetected byGround based radio telescopesRadios
10Umbrella Receiver Demo Students discover a method of collecting radio frequencies by using an umbrella receiver.
11Microwave Emitted by: Detected by Gas clouds collapsing into stars Microwave OvensRadar StationsCell PhonesDetected byMicrowave TelescopesFood (heated)Cell phonesRadar systems)
12Infrared (Near and Thermal) Emitted bySun and stars (Near)TV Remote ControlsFood Warming Lights (Thermal)Everything at room temp or aboveDetected byInfrared CamerasTVs, VCRs,Your skin
13Herschel’s Experiment Discovered Invisible LightIn 1800, Herschel places his control thermometer just outside the red end of the spectrumResult: The outside thermometer registered the highest temperature
14Conducting Herschel’s Experiment Set up of Box Design for Conducting the Herschel Experiment.
15Conducting Hershel’s Experiment Place a sheet of white paper inside a cardboard boxTape three thermometers together and place inside boxCut a small notch in the top of the box and position a glass prism so that the spectrum is projected inside the boxArrange the thermometers so that one is just outside the red end of the spectrum, with no visible light falling on it
16Visible Emitted by Detected by The sun and other astronomical objects Laser pointersLight bulbsDetected byCameras (film or digital)Human eyesPlants (red light)Telescopes
17Roy G. Biv ActivityStudents will discover and verify the relationship between the Wavelength and Frequency of the EMS.Students compare the wavelength and frequencies of three colors of the visible light portion on the spectrum.
18Red Sky – Blue SkyA demonstration used to illustrate how the gases in the atmosphere scatter some wavelengths of visible light more than others.
19Ultraviolet Emitted by Detected by Tanning booths (A) The sun (A) Black light bulbs (B)UV lampsDetected bySpace based UV detectorsUV CamerasFlying insects (flies)
20X-ray Emitted by Detected by Astronomical objects X-ray machines CAT scan machinesOlder televisionsRadioactive mineralsAirport luggage scannersDetected bySpace based X-ray detectorsX-ray filmCCD detectors
21Chandra 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
22Gamma Ray Emitted by Detected by Radioactive materials Exploding nuclear weaponsGamma-ray burstsSolar flaresDetected byGamma detectors and astronomical satellitesMedical imaging detectors
23Sources of g-ray Emission • Black holes• Active Galaxies• Pulsars• Diffuse emission• SupernovaeGamma-ray bursts• Unidentified
24Source/Detector Activity Students identify sources (emitters) and detectors of the various wavelengths of the EMS.Students also have the opportunity to experiment with shields –or types of materials that prevent the transmission of wavelengths.
25Exploring the EMS with NASA Missions RadioInfraredVisibleUVX-rayGamma rayEnergy(eV)MAPASTRO-E2SwiftSWASGLASTGALEXChandraRXTEHETE-2CHIPSCon-XINTEGRALXMM-Newton