Light - IR - 11-14
This collection explores Infra-Red light, suitable for ages 11-14
About Infra-Red Light:
Infrared (IR) is invisible radiant energy, electromagnetic radiation with longer wavelengths than those of visible light, extending from the nominal red edge of the visible spectrum at 700 nanometers (frequency 430 THz) to 1 mm (300 GHz). Most of the thermal radiation emitted by objects near room temperature is infrared.
Infrared radiation was discovered in 1800 by astronomer Sir William Herschel, who discovered a type of invisible radiation in the spectrum lower in energy than red light, by means of its effect upon a thermometer. Slightly more than half of the total energy from the Sun was eventually found to arrive on Earth in the form of infrared. The balance between absorbed and emitted infrared radiation has a critical effect on Earth's climate.
Resources in this collection:
- Invisible Wavelengths: This Teaching Astronomy and Space video clip, from the Institute of Physics (IOP), Teachers TV and the Science and Technology Facilities Council (STFC), shows a simple demonstration to illustrate wavelengths of radiation that are invisible to the human eye, but which can be detected using a camera phone or digital camera. The camera of a mobile phone or digital camera can detect wavelengths near infrared. These are the wavelengths used by remote controls for televisions and other consumer electronics. Whilst the human eye cannot detect the wavelength, pressing the control buttons will show as a flashing emitter on the remote control.
- The Electromagnetic Spectrum:
In this Teaching Astronomy and Space video, from the Institute of Physics (IOP), Teachers TV and the Science and Technology Facilities Council (STFC), Tim O'Brien and astrophysicist Chris North explain how astronomers use radiation from across the electromagnetic spectrum. They demonstrate how Jodrell Bank and the Herschel Space Observatory use radio waves and infra-red to reveal the hidden secrets of the universe.
