: If white objects reflect all forms of light, how come they don’t act as mirrors?
In: 0
A couple of reasons. First of all, mirrors don’t just reflect light; they reflect *images.* That is, the light that hits a mirror doesn’t diffuse and scatter in many directions. Some of this has to do with very smooth surfaces on mirrors’ reflective surfaces. A piece of paper reflects light that hits it, but it won’t bounce all the light equally in the same direction due to its material properties and surface texture.
The other issue worth considering in your question, though, is that white objects *don’t* actually reflect all forms of light in the first place. They reflect wavelengths of light that look white to us, but we’re talking about a visual spectrum that’s particular to human eyes in specific conditions. That white piece of paper doesn’t reflect X-rays, microwaves and infrared light equally, and neither do mirrors. In fact, mirrors can be made of different materials in order to favor the reflection of specific portions of the electromagnetic spectrum. (Think of the James Webb Space Telescope’s gold mirrors, which are especially good for reflecting infrared light.) In other words, there’s a lot more to mirrors than just the range of light they reflect, and white objects aren’t perfectly reflective to all wavelengths of light.
They’re not necessarily smooth, meaning instead of just reflecting light back at a single angle, which would lead to an actual image being reflected, they just scatter it every which way.
It’s because they don’t reflect the light straight back. They scatter it in all directions, which is also why they look white from multiple angles, and not just the angle of reflection in relation to the light.
There are two things at play. The first is “do you reflect all the light”, the second is “what direction do you reflect in”. A mirror reflects the light coming in in the same direction, so you can see an image. A white surface reflects light in lots of different directions, so you don’t get a sharp image. Think about flattening out a disco ball. If you make the little mirrors point in slightly different directions, you won’t get a clean picture, but instead will get lots of little pictures all jumbled together. As you make those mirrors tiny, the jumbled images become so small you can’t make them out any more and just get a white surface.
It depends on the surface condition of the object. A well polished material will act as a mirror regardless of the color it is. A rough and ragged material will scatter light no matter what color it is.
It depends on the surface condition of the object. A well polished material will act as a mirror regardless of the color it is. A rough and ragged material will scatter light no matter what color it is.
There are two main types of light reflection. Direct reflection and diffuse reflection.
Direct reflection is what a mirror does. Light reflects off the surface at the opposite angle from which it came (angle of incidence equals angle of reflection). Thus, we can see an image when we look at a mirror.
A white surface (like paper) has the property of diffuse reflection. It reflects the light in all directions, pretty much equally. The result of this is a ‘normal’ looking object, not a mirror.
There are two things at play. The first is “do you reflect all the light”, the second is “what direction do you reflect in”. A mirror reflects the light coming in in the same direction, so you can see an image. A white surface reflects light in lots of different directions, so you don’t get a sharp image. Think about flattening out a disco ball. If you make the little mirrors point in slightly different directions, you won’t get a clean picture, but instead will get lots of little pictures all jumbled together. As you make those mirrors tiny, the jumbled images become so small you can’t make them out any more and just get a white surface.
A couple of reasons. First of all, mirrors don’t just reflect light; they reflect *images.* That is, the light that hits a mirror doesn’t diffuse and scatter in many directions. Some of this has to do with very smooth surfaces on mirrors’ reflective surfaces. A piece of paper reflects light that hits it, but it won’t bounce all the light equally in the same direction due to its material properties and surface texture.
The other issue worth considering in your question, though, is that white objects *don’t* actually reflect all forms of light in the first place. They reflect wavelengths of light that look white to us, but we’re talking about a visual spectrum that’s particular to human eyes in specific conditions. That white piece of paper doesn’t reflect X-rays, microwaves and infrared light equally, and neither do mirrors. In fact, mirrors can be made of different materials in order to favor the reflection of specific portions of the electromagnetic spectrum. (Think of the James Webb Space Telescope’s gold mirrors, which are especially good for reflecting infrared light.) In other words, there’s a lot more to mirrors than just the range of light they reflect, and white objects aren’t perfectly reflective to all wavelengths of light.
A couple of reasons. First of all, mirrors don’t just reflect light; they reflect *images.* That is, the light that hits a mirror doesn’t diffuse and scatter in many directions. Some of this has to do with very smooth surfaces on mirrors’ reflective surfaces. A piece of paper reflects light that hits it, but it won’t bounce all the light equally in the same direction due to its material properties and surface texture.
The other issue worth considering in your question, though, is that white objects *don’t* actually reflect all forms of light in the first place. They reflect wavelengths of light that look white to us, but we’re talking about a visual spectrum that’s particular to human eyes in specific conditions. That white piece of paper doesn’t reflect X-rays, microwaves and infrared light equally, and neither do mirrors. In fact, mirrors can be made of different materials in order to favor the reflection of specific portions of the electromagnetic spectrum. (Think of the James Webb Space Telescope’s gold mirrors, which are especially good for reflecting infrared light.) In other words, there’s a lot more to mirrors than just the range of light they reflect, and white objects aren’t perfectly reflective to all wavelengths of light.
Latest Answers