The Electromagnetic Spectrum
| wavelength
mid-range values (no need to learn these) frequency |
1234567type1234567 | made by
(all are made by the sun and other stars) |
detected by | used for | ||
|
long 10 m high 30 MHz |
radio | transmitters | long wire aerials
TV aerials short wire aerials |
+ tuning and detector circuits | radio sets
TV sets mobile phones |
|
| 3 mm
1011 Hz |
microwave | klystrons
communications satellites |
water in food or body
cells
dish aerials |
cookers
satellite TV, GPS, military |
||
|
10 mm
3 x 1013 Hz |
infra-red | hot bodies | infra-red film
some nerve cells |
heating | ||
|
500 nm
6 x 1014 Hz |
visible
this is actually a rather narrow band of the spectrum (look at the surrounding frequency values), but the need to squeeze in seven colours makes it look wider. |
R | lamps
LEDs |
eyes
film, CCDs |
seeing
imaging (entertainment industry) |
|
| O | ||||||
| Y | ||||||
| G | ||||||
| B | ||||||
| I | ||||||
| V | ||||||
| 100 nm
3 x 1015 Hz |
ultra-violet | u.v. lamps | skin
certain plastics film |
contracting skin cancer
setting plastics, inks, etc imaging |
||
| 1 nm
3 x 1017 Hz |
X-rays | X-ray tubes | film | medical diagnosis | ||
| short
10 pm high 3 x 1019 Hz |
g-rays | radioactive nuclei | photomultipliers | sterilisation
mechanical fault analysis radiation therapy |
||