Reflection and refraction: the same thing at the atomic level?

In summary, the conversation discusses the concept of color and how it is perceived through the interaction of light with different mediums. The atmosphere is considered to be colorless, but it appears blue due to Rayleigh scattering, which is the scattering of blue light more than red light. The discussion also touches on the idea of reflection and how it applies to solids and individual atoms. Ultimately, it is agreed that reflection is not an accurate term to describe the interactions of light with atoms.
  • #1
AcesHigh
15
0
I got cornered in a discussion on the internet... I am not sure if I am right or not (I thought I was when I started). If you guys here tell me I am wrong, I have no problem admitting if I am indeed wrong

person1 said:
The atmosphere is colourless, you are seeing blue because the length of the waves which is percepted as blue are scattered the most in the atmosphere, because blue has the shortest waves (easy to scatter)

It's all about perception, but the atmosphere is still colourless no matter in what way the light scatters.
It's like saying a glass pyramid is coloured blue just because you are standing in the blue light spectrum looking at the pyramid.
AcesHigh said:
But Person 1... there is no such thing as objects having color. Everything in the world is colorless and what you see is refracted light. Everything is atoms (which are mostly empty) with light waves reflecting at electrons. Depending on the distribution of the atoms, light will get scattered and reflected in different ways and wavelenghts, and what you see are those different wavelenghts of light. Same as with the atmosphere.

Person 2 said:
Refraction =/= reflection. The atmosphere is colorless because it does not reflect any light, regardless of refraction.

The point being, observational evidence falls below experimental in the hierarchy of evidence, and many times contradicts the latter. If I find a burnt matchstick on the ground next to a mound of ash, it does not mean the matchstick was used to light a fire there.

AcesHigh said:
at the atomic level, it´s the same thing.

Whenever light interacts with a medium, (reflection or refraction) the interaction is an electron from the medium absorbing the photon and re-emitting it. There's a very good book on this by Richard Feynman called QED: The Strange Theory of Light and Matter

Person 2 said:
And how does light absorption with no re-emission fit into your explanation? This will surely stimulate your nugget.
Regardless of the atomic interactions, what you stated is a totally moot point in this discussion that addresses nothing. All gases are colorless at STP and even under these alternate environments. Blue sky appears due to Rayleigh scattering while at the same instance a non-blue sky is visible under Mie scattering. That should be indicative of the fact that the atmosphere is colorless. Can't say the same about a solid object such as wood or cement that reflects a constant color of light no matter what angle it is observed from.
This is why observational evidence alone is not considered solid evidence in modern day scientific literature.
first... person 2 said "Refraction =/= reflection. The atmosphere is colorless because it does not reflect any light, regardless of refraction.".

Does atmosphere really does not reflect any light? It seems to me that at atomic level, Rayleigh Scattering is reflection of light between atoms. Due to different medium, the APPARENT velocity of light is different, but between the atoms, it´s still the same old constant C. What changes is the length of the path light travels to get across the medium.

Isn´t it?
 
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  • #2
AcesHigh said:
Does atmosphere really does not reflect any light?
Not in the way solids can do that as coherent effect of the whole surface.
AcesHigh said:
Due to different medium, the APPARENT velocity of light is different, but between the atoms, it´s still the same old constant C.
"Speed of light in between atoms" is not well-defined for atom spacings smaller than the wavelength of light.

The atmosphere scatters blue light more than red light. If you look close to the sun at sunset or sunrise, you'll see red. Does that make the atmosphere red?
 
  • #3
mfb said:
Not in the way solids can do that as coherent effect of the whole surface.

yes, I understand that... but that is when we think "as a whole". When we think about the atmosphere as atoms, aren´t the atoms in the atmosphere reflecting the light?
The atmosphere scatters blue light more than red light. If you look close to the sun at sunset or sunrise, you'll see red. Does that make the atmosphere red?

no. But does seeing a red cup makes that cup red? As far as I understand, that cup is not red, it´s just reflecting more red light. From some angles and IF there is red light component falling unto it. If you shine a blue light unto it, it´won´t be red anymore. Also near the borders of the cup, it will reflect light differently, in a more cohesive way, so that you see highlights or reflections in other colors (like blue or white)
 
  • #4
The atmosphere as a whole reflects about 30% of the incoming light (from the sun).
See "albedo".
 
  • #5
AcesHigh said:
yes, I understand that... but that is when we think "as a whole". When we think about the atmosphere as atoms, aren´t the atoms in the atmosphere reflecting the light?
Solids are more than a collection of individual atoms. You cannot explain properties of solids by looking at isolated atoms.
For the atmosphere, that works, sure.
nasu said:
The atmosphere as a whole reflects about 30% of the incoming light (from the sun).
See "albedo".
Well, "reflection" - it's not like a mirror. It scatters light, some of it leaves Earth without reaching the ground.
 
  • #6
Reflection is not limited to specular reflection. A piece of paper reflects light but is not a mirror.

But I agree that reflection does not properly apply to atoms.
 

Related to Reflection and refraction: the same thing at the atomic level?

1. What is reflection and refraction?

Reflection and refraction are both related to the way light behaves when it encounters a boundary between two different materials. Reflection is the bouncing back of light when it hits a surface, while refraction is the bending of light as it passes through a material.

2. Are reflection and refraction the same thing at the atomic level?

No, reflection and refraction are not the same thing at the atomic level. At the atomic level, reflection occurs when light interacts with the outer electrons of an atom and is reflected back in the same direction. Refraction, on the other hand, is caused by the change in speed of light as it passes through different materials, due to interactions with the atoms and molecules of the material.

3. How do reflection and refraction differ from each other?

Aside from occurring at different levels (atomic vs macroscopic), reflection and refraction also have different properties. Reflection results in a mirror-like image, while refraction causes the bending and distortion of an image. Additionally, the amount of light reflected and refracted depends on the angle of incidence and the properties of the materials involved.

4. What is the importance of understanding reflection and refraction at the atomic level?

Understanding reflection and refraction at the atomic level is crucial in many fields, such as optics, materials science, and even biology. It allows scientists to manipulate and control the behavior of light, leading to advancements in technologies such as lenses, microscopes, and fiber optics.

5. Can reflection and refraction be observed in other types of waves?

Yes, reflection and refraction can also occur with other types of waves, such as sound waves and water waves. The principles of reflection and refraction remain the same, but the behavior of the waves may differ due to the different properties of the materials they encounter.

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