NASA: These ideas reach your brain via electrical impulses, a dancing ray of electrons behind your computer screen, and the miracle of vision. Countless unheard radio voices and unseen images are passing through your body as you read this screen. From the force fields that shape our universe to the force fields that bind together the particles that make up your physical body, electromagnetics is the main fabric from which our physical being is woven.

 

 

 

 

 

 

DoD: Let's begin with some of the unique characteristics of the electromagnetic spectrum. We human beings cannot perceive it --- we cannot see it, taste it, hear it, smell it or feel it. Yet our everyday lives are tremendously affected by our use of the spectrum.
I'm talking about television, cellular telephones, weather satellites, cruise missiles, microwave ovens, the air traffic control system, police radars, tornado tracking Doppler radars, MRIs [magnetic resonance images], baby monitors, command and control systems, car radios, pagers and reconnaissance/strike systems.Through our toolmaking creativity, we have taken an intangible resource, the electromagnetic spectrum, and developed systems and devices that have immense tangible impact on our society and our national security.