Transcript Electromagnetic Waves
By Dakota Morse, Alex Pollard, and Alex Mang
General Info
Frequency: 300,000,000Hz 300,000,000,000Hz Wavelength: 0.001m to 1m On Electromagnetic Spectrum: Between Radio waves and Infrared waves
Uses: Radar
•
RA
dio
D
etecting
A
nd
R
anging • A radar device detects the range, direction, and speed of moving and stopped objects, using microwaves.
• • • How it works: An antenna transmitter emits microwaves. These microwaves, upon contact, will scatter (and slightly change wavelength and frequency if the object is moving), and some will return to the receiver on the antenna.
The received waves, in knowing the changes in wavelength and frequency, and knowing the speed at which the microwaves returned, allow us to see distance, speed, and location.
Uses: Microwave Oven
• A Microwave Oven cooks and heats food via electromagnetic radiation, specifically microwaves.
• How it works: • A Magnetron inside the oven emits microwaves onto the food, which excites water and other polarized molecules within the food, and heats it up. The molecules excite because the microwaves transfer energy.
Uses: GPS Device
• Global Positioning System Device • A navigation tool, a GPS device supplies accurate time information and your location anywhere on the earth, rain or shine.
• How it works: • You have a personal GPS device, an antenna. This GPS device transmits microwaves in all directions, which four of many satellites in space receive. These satellites record how long it took for the signal to reach them, and use the time information to determine distance from the satellite. These distances are all collaborated in order to triangulate your location on the globe.
Uses: Telecommunication
• Radio waves can be used for telecommunication.
• How?: • Sound is equivalent to a pulse in the air. This pulse is encoded into an electromagnetic pulse, many time microwaves, then they are converted back into sound waves that we hear.
Uses: Spectroscopy
• Spectroscopy is the study on the interactions between matter, radiation, and wavelengths.
• How?: • Microwave radiation is used in electron paramagnetic resonance tests, which provides information on unpaired electrons in chemicals.
Medical Information
• No person or animal can see microwaves, though we can convert microwaves to visible light using technology. Alhough invisible, they can still be dangerous after a long time; short exposures may not be too damaging.
• Prolonged exposure to microwaves is carcinogenic, it mutates the cells and may cause cancer, after a prolonged exposure.
• Many many microwaves on your skin excites your skin, and causes burns. Large amounts of microwaves may also cause cataracts in your eyes, a cataract is like a cloud on your eye lens.
Discovery of the Microwave
• Heinrich Hertz conducted experiments to measure the length and velocity of microwaves in 1885-1889.
• He saw the vibrations and susceptibility to reflection and refraction are like light, and discovered that light, heat, and all were types of electromagnetic radiation.
QuickTime™ and a TIFF (Uncompressed) decompressor are needed to see this picture.
Bibliography
• • • • • • • • • • • • Microwave Background. Digital image. Web.
Radio Antenna. Digital image. Web.
Light Spectrum. Digital image. Web.
Satellite. Digital image. Web.
"How Radio Communication Works." National Radio Astronomy Observatory (NRAO): Look Deeper. Web. 11 May 2010.
"The Electromagnetic Spectrum: Microwaves." C L a R a . N E T - Customer Index. Web. 07 May 2010.
Clock. Digital image. Web.