Using and Understanding Electro Magnetic Radiation

Devices that we use every day and take for granted are often the result of more than 100 years of scientific experimentation.  It was James Clerk Maxwell who wrote in 1865, a mathematical equation that predicted radiation forms that were not discovered until much later.  Today, we use infrared and microwave radation to communicate wirelesslywith many different forms of computer devices. It was Maxwell who linked the wavelength (in meters) to the frequency of the transmission ( in cycles per second -- 1 Hertz is one cycle per second )  An international committee of engineers now regulates how different frequencies are used in communication and medical equipment.

  • This chart reveals the extraordinary power of Maxwell's equations.  He proposed that visible light was an electromagnetic event.  His mathematical equation showed that a wide variety of electromagnetic phenonema were just different forms of the same radiation.
  • This radiation has a frequency and a wavelength.
  • It was a group of Australian scientists who developed a method of using the 2.4 GHz frequency for use in WiFi devices.
  • Very fast mobile phone networks known as 5G use the 28 gigahertz bandwith.

 
  • In this Arduino sensor, the antenna is able to transmit and detect objects moving by using a Doppler technique.
  • Doppler is a mathematical method for measuring the movement of an object towards the sensor. 
  • The device uses a microwave radiation wavelength.  Some devices can detect movement in another room.
  • Infrared devices use the EMR wavelength that is longer than visible light and shorter than microwave EMR ( electromagnetic radiation )
  • They do not work when blocked by solid objects.

Tasks and Activities

  1. Why is the scientist James Clerk Maxwell celebrated? ( please do not copy or paste an Internet definition )
  2. EMR ( electromagnetic radiation ) is often defined by w-------- and f---------- ( fill in the missing words )
  3. What is the problem with using infrared frequencies for communication with electronic devices?  (Hint! Read the dot points above)

 

  
  1. What is the frequency range of radio waves?   ( Hint! Look at the EMR chart above )

Don't forget to email your choices/answers to Mr. Widmer by the end of this week.  Keep a copy of that email in your Google Docs folder.