We can see everything through visible light. This allows us to distinguish different wavelengths of light by comparing the colors. Each color has its own wavelengths.
Violet, for instance, can be seen at 0.4 microns light wavelengths. The wavelength of yellow light is 0.6 microns. Reddish colors, on the other side, start at 0.65-micron wavelengths.
Your eyes cannot see light at 0.7-micron wavelengths. These wavelengths are called infrared light and can be measured at 0.7 microns up to 0.1 millimeters. To know more about infrared light therapy, you can check over here.
Infrared light is 1000 times more powerful than visible light. It's like the light that comes from the remote control to change the TV channels. You'll get the idea.
Infrared light wavelengths are longer for hot objects around us than for other objects. This should explain why thermal infrared light wavelengths from hot objects, such as soldering iron hot metal pieces, are not visible to us.
Today, scientists rely on many devices to detect and measure infrared light. Astronomical cameras can pick up different types of light than regular telescopes.
Infrared radiation has the same properties as visible light, so it is similar to visible light in its origins and types. It can also be focused, reflected, and aligned like a regular light. This allows it to be polarized. There are many applications.