Wavelength Modern astronomy uses telescopes that do not need to reflect or refract light.
A radio telescope uses radio waves to produce visual images of distant objects. Radio telescopes detect radio waves coming from space. The waves are reflected by a concave dish on the telescope. The dish focuses the waves onto a receiver, where they are converted into a digital form to produce an image of the object being viewed.
Radio telescopes have two advantages over light telescopes: z z
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The 32 m radio telescope at the National Space Centre in Midleton, County Cork
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Radio telescopes work at any time of the day. Light telescopes can only be used at night.
Radio waves can be transmitted and received in cloudy weather. You cannot use a light telescope in cloudy conditions.
Waves
A wave transfers energy from one point to another. It does this through vibrations.
Waves have many uses. For example, food can be heated using microwaves and cancerous tumours can be treated with gamma rays. We can hear people speak thanks to sound waves that travel through the air and we can surf on water waves.
Good vibrations
A person who is having a period of success is often described as ‘riding on the crest of a wave’. Link this phrase to the features of waves.
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Learn more about sound waves in the Physical World 19.4 Wavelength (m)
Crest Amplitude (m) Learning Intentions
In this topic we are learning to: zz
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Describe the properties of waves. Consider the uses of radio telescopes.
