RADIO WAVES

HOW THEY ARE MADE

• When a direct electrical current is applied and removed repeatedly the current will change polarity and direction, creating radio waves
• They can also occur naturally through lightning and other phenomenons

WAVELENGTH

• 3 kHz - 300 GHz
• 0.04 inches - 62 miles
• Distance from sea level to the start of outer space

FREQUENCY

• Extremely low:
• Very low: 3-30 kHz
• Medium: 300kHz - 3MHz
• Ultra High: 300 MHz - 3 GHz
• Extremely high: 30-300 GHz

HOW THEY HARM US

• This EMR can be harmful, because the body's skin is transparent to radio waves. Which means that can allow the EMR to get deeper into the body which can cause damage, and potentially skin cancer.

HOW CAN THEY HELP US?

Radios
Electricity flows through an antenna vibrating it up and down producing radio waves, They travel at the speed of light to a receiver antenna (radio) and vibrate the same way creating the music and voices you hear

Cellphones
When you send a text it creates a radio wave that moves at the speed of light to a tower and then to the other persons phone when they receive the text

TELEVISION

• Television is a 3 part invention:
• The tv camera which turns the sound and picture into a signal. The tv transmitter which sends the signal out through the air to the tv receiver which captures the signal and turns it back into picture and sound.

FUN FACTS

• Carries sounds, but is actually faster than the speed of sound.
• Radio waves can bounce of electric conductors
• They have the longest wavelength in electromagnetic spectrum.
• Anything that is somewhat warm give off some radio waves.

SOURCES

• Cellphonessaftey.org
• Livescience.com
• Quota.com
• Interferencetechnology.com
• apecsec.org
• arguing.northwestern.edu