However, some materials are opaque to visible light. This means that most of the visible light that hits them is absorbed or reflected, and very little passes through. Examples include:
* Metals: Gold, silver, copper
* Thick wood: Oak, mahogany
* Concrete: A common building material
* Many plastics: Dark, dense plastics
It's important to remember that even these materials will allow some light to pass through, even if it's just a tiny amount. For example, a thin sheet of metal might be opaque to visible light, but it will still allow some infrared radiation to pass through.
Here's a more complete picture:
* Opaque: Very little light passes through.
* Translucent: Some light passes through, but objects are not clearly visible. (Example: frosted glass)
* Transparent: Most light passes through, and objects are clearly visible. (Example: clear glass)
So, while there's no material that completely blocks all light, there are materials that block most of the light we can see.
