P1- 1.1

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P1- 1.1- INFRARED RADIATION

- We can use special cameras to 'see' animals and people in the dark

- The cameras detect INFRARED RADIATION

- Every object emits infrared radiation

- THE HOTTER AN OBJECT IS THE MORE INFRARED RADIATION IT EMITS IN A GIVEN TIME

- RADIO WAVES, MICROWAVES, INFRARED RADIATION AND VISIBLE LIGHT are all parts of the ELECTROMAGNETIC SPECTRUM

- Electromagnetic waves are electric and magnetic waves that travel through space

Energy from the sun:

-The sun emits all types of electromagnetic radiation

- The earths atmosphere blocks most of the radiation that would harm us, but doesn't block radiation from the sun.

The greenhouse effect:

The earths atmosphere acts like a greenhouse made of glass. In a greenhouse:

-Short wavelength infrared radiation (and light) from the sun can pass through the glass to warm the objects inside the greenhouse

- Infrared radiation from theses warm objects is trapped inside by the glass because the objects emit infrared radiation of longer wavelengths that cant pass through the glass

Greenhouse gases:

Water vapour, methane, and carbon dioxide

These gases trap the heat causing GLOBAL WARMING.