Part B · Applications and exposure Light and the electromagnetic spectrum mind map

Radio to IR

• Radio: Oscillating charges transmit; receiving aerial signal changes
• Microwaves: Communications / satellites and food heating
• Infrared: Heating, remotes, thermal imaging; warm bodies emit IR
• Atmosphere: Transmission varies by band; some telescopes need space

Uses and risks

• Visible / UV: Vision / imaging; UV fluorescence / disinfection; eyes / skin risks
• X-rays / gamma: Absorption contrast / tracers / sterilisation; controlled exposure
• Damage: Ionisation / DNA damage; dose matters; non-ionising can heat
• Protection: Appropriate shielding, distance and exposure time; balance benefit

Connections

• Radio to IR → Uses and risks: Different bands have useful effects and potential exposure risks.
• Uses and risks → Radio to IR: Non-ionising radiation can still cause heating damage.