Tell about Infrared ?

cience textbooks say we can’t see infrared light. Like X-rays and radio waves, infrared light waves are outside the visual spectrum. But an international team of researchers has found that under certain conditions, the retina can sense infrared light after all.

We use infrared cameras to help us see things. NASA scientists use infrared to help predict weather. Rescue workers use them to find people who need help.

Since the primary source of infrared radiation is heat or thermal radiation, any object which has a temperature radiates in the infrared.

The eye can detect light at wavelengths in the visual spectrum. Other wavelengths, such as infrared and ultraviolet, are supposed to be invisible to the human eye, but Washington University scientists have found that under certain conditions, it’s possible for us to see otherwise invisible infrared light.

Using cells from the retinas of mice and people, and powerful lasers that emit pulses of infrared light, the researchers found that when laser light pulses rapidly, light-sensing cells in the retina sometimes get a double hit of infrared energy.

Even objects that we think of as being very cold, such as an ice cube, emit infrared. When an object is not quite hot enough to radiate visible light, it will emit most of its energy in the infrared.

The research was initiated after scientists on the research team reported seeing occasional flashes of green light while working with an infrared laser.

To make infrared pictures, we can use special cameras and film that detect differences in temperature, and then assign different brightness or false colors to them. This provides a picture that our eyes can interpret.

Humans may not be able to see infrared light, but did you know that snakes in the pit viper family, like rattlesnakes, have sensory "pits", which are used to image infrared light?

This allows the snake to detect warm blooded animals, even in dark burrows! Snakes with 2 sensory pits are even thought to have some depth perception in the infrared.

This allows the snake to detect warm blooded animals, even in dark burrows! Snakes with 2 sensory pits are even thought to have some depth perception in the infrared.

Many things besides people and animals emit infrared light - the Earth, the Sun, and far away things like stars and galaxies do also! For a view from Earth orbit, whether we are looking out into space or down at Earth, we can use instruments on board satellites.

We know that many things emit infrared light. But many things also reflect infrared light, particularly near infrared light. Near infrared radiation is not related to the temperature of the object being photographed - unless the object is very, very hot.