Light reflecting colours from surfaces

How does science work? And what's all this about quantum mechanics?

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attofishpi
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Light reflecting colours from surfaces

Post by attofishpi » Mon May 27, 2019 11:53 pm

Ok hopefully someone can answer this!

So as far as I am aware, when we see an object that is red this means all the wavelengths of light (assume from the Sun) have been absorbed by the surface of the object apart from the wavelength of 'red'...

My question is, does this mean that the light has been absorbed by electron(s) and these electrons have changed their valence shell to a different energy state and emitted a photon at the 'red' wavelength?

Further - thus this would mean all the colours have different atomic structures - what happened to all the other wavelengths that got absorbed - did they get absorbed by the electrons within the object? - I guess this is radiated as heat??

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RCSaunders
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Re: Light reflecting colours from surfaces

Post by RCSaunders » Tue May 28, 2019 3:01 am

attofishpi wrote:
Mon May 27, 2019 11:53 pm
Ok hopefully someone can answer this!

So as far as I am aware, when we see an object that is red this means all the wavelengths of light (assume from the Sun) have been absorbed by the surface of the object apart from the wavelength of 'red'...
This may be true for a pure red, but most colors are usually combinations of reflected light frequencies.
attofishpi wrote:
Mon May 27, 2019 11:53 pm
My question is, does this mean that the light has been absorbed by electron(s) and these electrons have changed their valence shell to a different energy state and emitted a photon at the 'red' wavelength?
The color seen is simply the combination of colors of light that have not been absorbed. They are not absord and then re-emitted. The one's that are absorbed become heat.
attofishpi wrote:
Mon May 27, 2019 11:53 pm
Further - thus this would mean all the colours have different atomic structures - what happened to all the other wavelengths that got absorbed - did they get absorbed by the electrons within the object? - I guess this is radiated as heat??
It is only the frequency at which electrons within the reflecting object vibrate that determines which frequencies of light are absorbed and are turned into heat, not atomic structure.

Please see this link which will clarify the nature of color that is seen: About Colors It is written in the context of HTML, but pertains to all color whether reflected, transmitted, or generated (as in computer and television screens).

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attofishpi
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Re: Light reflecting colours from surfaces

Post by attofishpi » Tue May 28, 2019 6:45 am

RCSaunders wrote:
Tue May 28, 2019 3:01 am
attofishpi wrote:
Mon May 27, 2019 11:53 pm
Ok hopefully someone can answer this!

So as far as I am aware, when we see an object that is red this means all the wavelengths of light (assume from the Sun) have been absorbed by the surface of the object apart from the wavelength of 'red'...
This may be true for a pure red, but most colors are usually combinations of reflected light frequencies.
attofishpi wrote:
Mon May 27, 2019 11:53 pm
My question is, does this mean that the light has been absorbed by electron(s) and these electrons have changed their valence shell to a different energy state and emitted a photon at the 'red' wavelength?
The color seen is simply the combination of colors of light that have not been absorbed. They are not absord and then re-emitted. The one's that are absorbed become heat.
attofishpi wrote:
Mon May 27, 2019 11:53 pm
Further - thus this would mean all the colours have different atomic structures - what happened to all the other wavelengths that got absorbed - did they get absorbed by the electrons within the object? - I guess this is radiated as heat??
It is only the frequency at which electrons within the reflecting object vibrate that determines which frequencies of light are absorbed and are turned into heat, not atomic structure.

Please see this link which will clarify the nature of color that is seen: About Colors It is written in the context of HTML, but pertains to all color whether reflected, transmitted, or generated (as in computer and television screens).
Thanks for the reply. I now need to question - how this 'red' wavelength(s) of light bounces from the surface - does it indeed just bounce? ..as in no interaction with the electrons or nucleus of the atoms (when i say NO interaction - i mean, it has no effect on the surface atoms) ?

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RCSaunders
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Re: Light reflecting colours from surfaces

Post by RCSaunders » Tue May 28, 2019 3:53 pm

attofishpi wrote:
Tue May 28, 2019 6:45 am
I now need to question - how this 'red' wavelength(s) of light bounces from the surface - does it indeed just bounce? ..as in no interaction with the electrons or nucleus of the atoms (when i say NO interaction - i mean, it has no effect on the surface atoms) ?
It does have an effect on the electrons. This description from Wikipedia might help. I think you'll find the entire article there inetersting.
Mechanism
File:Reflection of a quantum particle.webmPlay media
2D simulation: reflection of a quantum particle. White blur represents the probability distribution of finding a particle in a given place if measured.

In classical electrodynamics, light is considered as an electromagnetic wave, which is described by Maxwell's equations. Light waves incident on a material induce small oscillations of polarisation in the individual atoms (or oscillation of electrons, in metals), causing each particle to radiate a small secondary wave in all directions, like a dipole antenna. All these waves add up to give specular reflection and refraction, according to the Huygens–Fresnel principle.

In the case of dielectrics such as glass, the electric field of the light acts on the electrons in the material, and the moving electrons generate fields and become new radiators. The refracted light in the glass is the combination of the forward radiation of the electrons and the incident light. The reflected light is the combination of the backward radiation of all of the electrons.

In metals, electrons with no binding energy are called free electrons. When these electrons oscillate with the incident light, the phase difference between their radiation field and the incident field is π (180°), so the forward radiation cancels the incident light, and backward radiation is just the reflected light.

Light–matter interaction in terms of photons is a topic of quantum electrodynamics, and is described in detail by Richard Feynman in his popular book QED: The Strange Theory of Light and Matter.

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Re: Light reflecting colours from surfaces

Post by Scott Mayers » Tue May 28, 2019 4:51 pm

attofishpi wrote:
Mon May 27, 2019 11:53 pm
Ok hopefully someone can answer this!

So as far as I am aware, when we see an object that is red this means all the wavelengths of light (assume from the Sun) have been absorbed by the surface of the object apart from the wavelength of 'red'...

My question is, does this mean that the light has been absorbed by electron(s) and these electrons have changed their valence shell to a different energy state and emitted a photon at the 'red' wavelength?

Further - thus this would mean all the colours have different atomic structures - what happened to all the other wavelengths that got absorbed - did they get absorbed by the electrons within the object? - I guess this is radiated as heat??
The wavelengths are first absorbed before being 'bounced' back out. The wavelength absorption relates directly to the orbital and how we determines what the actual orbitals are.

I personally think that light cannot exist PRIOR to atoms such that excited atoms create light in the first place, not the other way around as the Big Bang version incorporates in their theory, but can be wrong in part. The wavelengths of light are then products of electrons OF a particular sized orbital of particular atoms first created by strong collisions in the center of a star.

So yes to your question. When an electron gets 'crowded' by pressure of many atoms and electrons, eventually the pressure is released by re-emitting that quantity of energy sufficient to enable the atom to become stable again. The released energy becomes light based upon where it was located at one orbital it didn't belong back to its stable orbital.

To the 'further' part, I'd reverse that: the different atomic structures DEFINE what the light's source came from. One created, its wavelength fits with the kinds of atoms and/or the sized orbitals of other atoms that map to the same shape and size of WHEN it was formed that can then reverse the order in relatively colder matter of the same types. The set of wavelengths created by hydrogen atoms, for instance, can be best absorbed by hydrogen atoms (of the same energy when created) or to other atoms that when 'cooler' match the original energized hydrogen atoms at the center of the stars when created.

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Re: Light reflecting colours from surfaces

Post by attofishpi » Wed May 29, 2019 5:51 am

RCSaunders: - Thanks for the info - really interesting will have a read of the Wiki article when I have spare time!

Scott Mayers wrote:
Tue May 28, 2019 4:51 pm
To the 'further' part, I'd reverse that: the different atomic structures DEFINE what the light's source came from. One created, its wavelength fits with the kinds of atoms and/or the sized orbitals of other atoms that map to the same shape and size of WHEN it was formed that can then reverse the order in relatively colder matter of the same types. The set of wavelengths created by hydrogen atoms, for instance, can be best absorbed by hydrogen atoms (of the same energy when created) or to other atoms that when 'cooler' match the original energized hydrogen atoms at the center of the stars when created.
Wow, if that's correct - really interesting!

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Re: Light reflecting colours from surfaces

Post by gaffo » Wed Jun 19, 2019 4:48 am

attofishpi wrote:
Mon May 27, 2019 11:53 pm
Ok hopefully someone can answer this!

So as far as I am aware, when we see an object that is red this means all the wavelengths of light (assume from the Sun) have been absorbed by the surface of the object apart from the wavelength of 'red'...
yes
attofishpi wrote:
Mon May 27, 2019 11:53 pm
My question is, does this mean that the light has been absorbed by electron(s) and these electrons have changed their valence shell to a different energy state
yes

attofishpi wrote:
Mon May 27, 2019 11:53 pm
and emitted a photon at the 'red' wavelength?
nope. there are of materials that do emit light after recieving it.

like "glow in the dark paint/plastics - their light emitence is more generally "White" - greenish actually.

there is not reason to think that there is no material (maybe not discovered yet?) that might emit "Red" also after recieving white light, but i do not know of such a material.


........but back to the non-exceptions of non glow in the dark materials,

most materials as you said prior do not emit light after recieving it, they instead absorb the full light spectrum - except the light you see as thier color (which is the light they "reject" and see as that materials color)...the rest of the colors are absorbed by the material as HEAT.

that is what a black cloth is hotter hours later than a white clothe (say at nigh - when both were exposed to light) - former absorbed the light and converted it to heat, the latter reflected it.

its why dumb arabs were black burkas, smart ones wear white head dress. lol.

ISIS flag is black too.

lol.


attofishpi wrote:
Mon May 27, 2019 11:53 pm
Further - thus this would mean all the colours have different atomic structures

E= MC2

colors are energy, not matter so not atomic (unless you want to talk about the Fusion Bomb (thank you Teller ;-/.....which i dont think you do - i.e. matter and energy are "one" per the above equation, but only in extreme enviroments can to convert one to the other and vise versa and per your inquiry i think this particular concept is not your intent via my understanding of your post here).


in otherwords, per my understanding of your inquiry, no, colors do not have atomic structures, but they do affect atomic structures (almost always in the form of heating up the material that is exposed to them - and in rare cases (depending fully upon the nature of the material) make the material "glow" refer to "Glow in the dark" stuff.

of course there is other forms of "glow in the dark" - like Radium clocks and aircraft dials - they were common 100-50 yrs ago - not know due to health hazards - they had the similar "glow" as today's materials, but from their own "self atomic decay" of radium to (not sure to what element (when radioactive elements decay they emit light and at the same time transmute to another lighter element) - i have a chemistry 3/4 decree eons ago,............anyone here know what element Radium decays to after emitting light?.

attofishpi wrote:
Mon May 27, 2019 11:53 pm
- what happened to all the other wavelengths that got absorbed -


converted to heat!

and why black material gets hotter than white material!

attofishpi wrote:
Mon May 27, 2019 11:53 pm
did they get absorbed by the electrons within the object? - I guess this is radiated as heat??
YES EXACTLY!

thanks for post, love science questions! ;-)................I've not forgotten about you, my value my word and shall read the link you provided now 3 weeks ago. thanks for your patience on that particular.

you have my word, so i've commited myself to it!

gaffo
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Re: Light reflecting colours from surfaces

Post by gaffo » Wed Jun 19, 2019 4:55 am

attofishpi wrote:
Tue May 28, 2019 6:45 am
RCSaunders wrote:
Tue May 28, 2019 3:01 am
attofishpi wrote:
Mon May 27, 2019 11:53 pm
Ok hopefully someone can answer this!

So as far as I am aware, when we see an object that is red this means all the wavelengths of light (assume from the Sun) have been absorbed by the surface of the object apart from the wavelength of 'red'...
This may be true for a pure red, but most colors are usually combinations of reflected light frequencies.
attofishpi wrote:
Mon May 27, 2019 11:53 pm
My question is, does this mean that the light has been absorbed by electron(s) and these electrons have changed their valence shell to a different energy state and emitted a photon at the 'red' wavelength?
The color seen is simply the combination of colors of light that have not been absorbed. They are not absord and then re-emitted. The one's that are absorbed become heat.
attofishpi wrote:
Mon May 27, 2019 11:53 pm
Further - thus this would mean all the colours have different atomic structures - what happened to all the other wavelengths that got absorbed - did they get absorbed by the electrons within the object? - I guess this is radiated as heat??
It is only the frequency at which electrons within the reflecting object vibrate that determines which frequencies of light are absorbed and are turned into heat, not atomic structure.

Please see this link which will clarify the nature of color that is seen: About Colors It is written in the context of HTML, but pertains to all color whether reflected, transmitted, or generated (as in computer and television screens).
Thanks for the reply. I now need to question - how this 'red' wavelength(s) of light bounces from the surface - does it indeed just bounce? ..as in no interaction with the electrons or nucleus of the atoms (when i say NO interaction - i mean, it has no effect on the surface atoms) ?
i assume it bounces.

except in the rare case of a material that may or may not exist that will emit "red" when exposed to light.

refer to glow in the dark material, which i know of only emits only greenish-white,

so ya, AFIAK it just bounces from the material to your eyes (i.e. all spectrum of light is absorbed, except Red,. which bounces to your eyes for you to se the material as red).

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Re: Light reflecting colours from surfaces

Post by zoey » Thu Nov 07, 2019 11:46 am

I was reading about changing structure to change colors using the peacock tail as a biomimicry example. As more of these technologies are introduced, physics textbooks need to be updated with such stuff. This is exciting for younger people and keeps the subject fresh.

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