eli5 why is the infra red part of the spectrum warm?

Question

eli5 why is the infra red part of the spectrum warm?

In: 3

Answer 1

The other answers are correct but there is perhaps another aspect. Light (including infra red) has energy. If that energy gets absorbed then the object gets hot. A white object will reflect almost all the visible light but (because of physics) will absorb almost all the IR light. So to heat most objects it is more efficient to use IR light.