Is IR light emitted, rather than reflected? When I look at an object in the sunlight, I'm looking at photons reflected back from the object.  But if I wear infrared goggles and look at an object in the dark, am I looking at photons that are emitted by the object itself, rather than reflected?   This is explained briefly in Tales of the Quantum.  As I understand, the warmer the object is, the more the atoms vibrate. Atoms are made of +protons and -electrons.  These charged particle vibrations create waves in the electromagnetic field which are photons of IR light.
Edit: From Wikipedia on Thermography: "All objects above the absolute zero temperature emit infrared radiation. Hence, an excellent way to measure thermal variations is to use an infrared vision device..."
So it specifically says "emit infrared radiation"  Is this emitted from the vibration of charged protons and electrons?  And would increased vibration of these particles, caused by increased heat, thereby increase the IR emissions?
 A: "Infrared" covers a wide band of wavelengths, everything from about 0.8 um at the long-wavelength limit of human vision to the 1-mm limit of conventional radio-frequencies. An object at 310 K (typical human body temperature) has its peak emission at about 10 um. However, detectors for this wavelength are much more expensive than those for shorter "near-IR" wavelengths closer to the visible band.
Typically infrared night-vision goggles contain an LED light source (essentially, an IR flashlight), and you are seeing photons from this source reflected off the object you are viewing.
Other night vision goggles don't contain a light source; they simply use a very sensitive detector and amplify the received signal to allow imaging in dim conditions. This type of goggles won't work in complete darkness. Again they would be detecting visible and IR light reflected off the objects from other sources.
It is also possible to design an imaging system that detects the longer wavelengths (9-15 um) emitted by objects at typical temperatures themselves. This is usually called thermal imaging or thermography rather than night vision.
