The Invisible UniverseSources & Detectors

of Invisible Light

NEIU NASA Endeavour Program

Electromagnetic Spectrum

• The full range of frequencies, from radio waves to gamma rays, that characterizes light

• 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.

• The wavelength equals the speed of light divided by the frequency.

Electromagnetic 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.

Wavelength 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.

Radio(Low Frequency & Very High Frequency)

• Emitted by– Astronomical Objects– Radio Station

transmitters

• Detected by– Ground based radio

telescopes– Radios

Microwave

• Emitted by:– Gas clouds collapsing

into stars– Microwave Ovens– Radar Stations– Cell Phones

• Detected by– Microwave Telescopes– Food (heated)– Cell phones– Radar systems)

Infrared(Near and Thermal)

• Emitted by– Sun and stars (Near)– TV Remote Controls– Food Warming Lights

(Thermal)– 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

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– CAT scan machines– Older televisions– Radioactive minerals– Airport luggage scanners

• Detected by– Space based X-ray

detectors– X-ray film– CCD detectors

Gamma Ray

• Emitted by– Radioactive materials– Exploding nuclear

weapons– Gamma-ray bursts– Solar flares

• Detected by– Gamma detectors and

astronomical satellites– Medical imaging detectors

Sources of Gamma-ray Emission

• Black holes• Active Galaxies• Pulsars• Diffuse emission• Supernovae• Gamma-ray bursts• Unidentified

Source/Detector Activity

• Identify sources (emitters) and detectors of the various wavelengths of the EMS.

• Experiment with:– shields –types of materials that prevent the

transmission of wavelengths– Transmitters – materials that do not prevent

the transmission of wavelengths

Our Exploration Stations

• Visible Light– Neon– Flashlights

• Radio – Walkie Talkies– Remote Control Vehicle

• Infrared– Remote Controls– Heat Lamp

• Ultraviolet– UV Light

What did we learn?

Question: What property of the materials we tested caused radio waves to be blocked?

Question: Are all the plastics we tested translucent/transparent to infrared light?

Question: If someone had no sunscreen while at the beach what could they cover their face with to keep from getting sun burned by UV light?

Exploring the EMS withNASA Missions

ASTRO-E2

Chandra

CHIPS Con-X

GALEXGLAST

HETE-2

INTEGRAL

MAP

RXTE

SWAS

XMM-Newton

Swift

Energy (eV)

Radio Infrared Visible UV X-ray Gamma ray

And the universe for that matter!

Windows through Atmosphere

NASA’s Views

• Studying the Universe:

http://www.lhsgems.org/IUTour.html

Source of Activities

• GEMS Guide: The Invisible Universe. – www.lhsgems.org

• www.epo.sonoma.edu• http://adc.gsfc.nasa.gov/mw/mmw_product.html• http://coolcosmos.ipac.caltech.edu/

cosmic_classroom/multiwavelength_astronomy/multiwavelength_museum/sun.html

• Studying the Universe:

http://www.lhsgems.org/IUTour.html

More Information

• Swift - http://swift.sonoma.edu

• GLAST – http://glast.sonoma.edu

• XMM Newton - http://xmm.sonoma.edu• NASA EPO @ SSU –

http://epo.sonoma.edu• Space Mysteries –

http://mystery.sonoma.edu