A radio telescope's dish is wider than a house. A dentist's X-ray plate is smaller than your palm. Each instrument is built around one band of the spectrum.
Each application uses the band whose waves suit its job. This lesson pairs the common applications with their bands.
Radio waves: broadcasting to radios and televisions, and radio telescopes collecting radio waves from space.
Microwaves: microwave ovens heating food, and links up to satellites.
Infrared: thermal imaging cameras, and television remote controls.
Visible light: eyes, and ordinary cameras.
Ultraviolet: sterilizing lamps, and lamps that make security marks glow.
X-rays: imaging through soft material, like teeth and airport luggage.
Gamma rays: killing tumor cells, and sterilizing medical equipment.
A security scanner at an airport shows the inside of a closed backpack on a screen. Which band does it use?
The scanner images through soft material.
Imaging through soft material is the X-ray job.
X-rays.
An orbiting observatory collects waves many meters long coming from space. Which band does it collect?
Waves many meters long sit in the radio band.
Collecting radio waves from space is the radio telescope's job.
Radio waves.
A broadcast tower sends programs out to car radios across a city. Which band does it use?
A television remote control sends its signal from a small emitter on its front edge. Which band does it use?
A clinic machine images the bones inside a wrist. Which band does it use?
A lamp at a theme park entrance makes hand stamps glow in the dark. Which band does the lamp use?
A ground station sends a signal up to a weather satellite. Which band does it use?
A hospital machine aims radiation at a tumor to kill its cells. Which band does it use?
A kitchen appliance heats leftovers in two minutes by sending waves into the food. Which band does it use?
Which of these instruments uses ultraviolet?
Night-vision goggles image animals in full darkness, the way a thermal camera does. Which band do they detect?