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Thread: what happens with the atoms, while reflection of light?

  1. #1 what happens with the atoms, while reflection of light? 
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    what happens with the atoms, while there is reflection of light? What happens with the electrons or protons, are they reflecting the light and how?


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    Nothing happens to the atoms when light is reflected. It is when light is absorbed that the atoms change. In brief, the atoms acquire the energy. The effect may be either to excite electrons or to change the rotational states or vibrational states of molecular bonds.

    I think you are really talking about the mechanism of light reflection and that you want to know whether an individual atom plays a part. If that is your question, I will simply say that classical theory does not need atomic theory to explain reflection. Individual atoms are not considered.


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    Quote Originally Posted by SteveF
    Nothing happens to the atoms when light is reflected. It is when light is absorbed that the atoms change. In brief, the atoms acquire the energy. The effect may be either to excite electrons or to change the rotational states or vibrational states of molecular bonds.

    I think you are really talking about the mechanism of light reflection and that you want to know whether an individual atom plays a part. If that is your question, I will simply say that classical theory does not need atomic theory to explain reflection. Individual atoms are not considered.
    But lets say the electrons, are they opposing of the electromagnetic field, and they reflect the light somehow?
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    An electron in an atom follow simple magnetic laws, although one can also argue Einsteins SR explanation for EM into this, anyway. The atoms have a net charge and so do the electrons, this causes the electrons to 'orbit' the nucleus with all the positive charge. I don't understand what you mean when you say 'opposing the electromagnetic field'.

    Photons are created when a moving electric current creates a magnetic field and vice versa depending on how fast or the distance the current and field, oscillations etc occur, which result in photons having more energy. How can an electron 'oppose' the electromagnetic field, if it itself is a part of that field?

    Photons collide with electrons. Depending on how much energy the electron absorbs, depends on what type of EM radiation you get. If you are reffering to 'reflecting', electrons hardly absorb energy and pass it back in more or less the same frequency of energy it had before hitting the electron. This usually happens because light hitting electrons which reflect, those electrons usually have a full energy level, such as water.
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    Quote Originally Posted by svwillmer
    An electron in an atom follow simple magnetic laws, although one can also argue Einsteins SR explanation for EM into this, anyway. The atoms have a net charge and so do the electrons, this causes the electrons to 'orbit' the nucleus with all the positive charge. I don't understand what you mean when you say 'opposing the electromagnetic field'.

    Photons are created when a moving electric current creates a magnetic field and vice versa depending on how fast or the distance the current and field, oscillations etc occur, which result in photons having more energy. How can an electron 'oppose' the electromagnetic field, if it itself is a part of that field?

    Photons collide with electrons. Depending on how much energy the electron absorbs, depends on what type of EM radiation you get. If you are reffering to 'reflecting', electrons hardly absorb energy and pass it back in more or less the same frequency of energy it had before hitting the electron. This usually happens because light hitting electrons which reflect, those electrons usually have a full energy level, such as water.
    So, the electrons receive the energy, and they can jump in next orbital level, so when they get back, they release that energy. And we see that effect as reflection of light?
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    Yes thats it! .
    "If you wish to make an apple pie from scratch, you must first invent the universe". - Carl Sagan
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    Quote Originally Posted by svwillmer
    Yes thats it! .
    Ok, thank you very much. I appreciate your efforts for trying to help me. Thanks.
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    Well, on a more physical level, allot of what determines whether or not an object reflects light is determined by the surface texture. Take a piano gloss black finish for example; as you sand it down, your aren't changing the chemical content or anything, your are only taking out the micro valleys and imperfections until you eventually have the entire surface evenly reflecting the light, which allows it to appear as a mirror.

    Just thought I'd add that.
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    Do you talk about the light or lights heat resp. warmth? Sorry if this sounds nerdy, but your question was quite interesting,
    and, under circumstances, to differ light, warmth and/or maybe energy additionally to me was appearing as to be taking us
    closer to the issue. Sorry again I, honestly, don't want to crack your thread in some way.

    Steve
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    why the concave mirror reflects the light like this?

    Why not in the other way?
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    The sun keeps Mercury as it's best friend............."just show me who I am........reflect me, like Mercury should".

    I AM THINKING THEN that on the level of the ATOM, which most scientidsts take the sun to be, no greater molecular structure than the atom (hats off to you guys)____that on the level of the atom, we approach the situation similarly...............that there is a miniscule sun we have yet to access without getting burnt.
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    scientist 91,

    Hello,

    which other way?

    Steve
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    Quote Originally Posted by Steve Miller
    scientist 91,

    Hello,

    which other way?

    Steve
    I mean why the electrons reflect the light in such direction? Why they don't reflect the light in opposite direction or in angle of 90 degrees?
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    Because they don't know you, right?

    Otherwise, you have a problem.........one that makes you feel small.
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    Quote Originally Posted by scientist91
    Quote Originally Posted by Steve Miller
    scientist 91,

    Hello,

    which other way?

    Steve
    I mean why the electrons reflect the light in such direction? Why they don't reflect the light in opposite direction or in angle of 90 degrees?
    The reflection depends on the mirror. Other mirror with other concavity, other angels at them
    your light was reflected.
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    Quote Originally Posted by Steve Miller
    Quote Originally Posted by scientist91
    Quote Originally Posted by Steve Miller
    scientist 91,

    Hello,

    which other way?

    Steve
    I mean why the electrons reflect the light in such direction? Why they don't reflect the light in opposite direction or in angle of 90 degrees?
    The reflection depends on the mirror. Other mirror with other concavity, other angels at them
    your light was reflected.
    Do it depends from the electrons? Can you give me some example, what happens with the electrons?
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    Do electrons act independently, or must they be excited?
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    What electron? The mirror was said to reflect light. An electron will move as the particle holding
    the electron does. Therefore, the reflecting angle should be instable or variable. Especially as the
    light just went on, or, as the lights intensity increases or decreases. That's all not the case.

    The angels are only bound to the mirrors concavity.
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    Quote Originally Posted by scientist91
    I mean why the electrons reflect the light in such direction? Why they don't reflect the light in opposite direction or in angle of 90 degrees?
    The Law of Reflection. The angle of incidence (incoming angle), is the angle measured from the Normal, which is orthogonal to the surface of the mirror, and equals the angle of reflection (outgoing angle) from the Normal.

    http://www.glenbrook.k12.il.us/gbssc...ln/u13l1c.html
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    Quote Originally Posted by Steve Miller
    What electron? The mirror was said to reflect light. An electron will move as the particle holding
    the electron does. Therefore, the reflecting angle should be instable or variable. Especially as the
    light just went on, or, as the lights intensity increases or decreases. That's all not the case.

    The angels are only bound to the mirrors concavity.
    "as the particle holding the electron does"
    What's that?
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    ion or atom or molecule (if being seen as one in this context )
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    Quote Originally Posted by Steve Miller
    ion or atom or molecule (if being seen as one in this context )
    I read from one article: "An electron absorbs the energy of the photon and sends it back out the way it came in (reflection)" But I mean why the angle is not 90 degrees? Why it is not reflecting the light in same direction as it had received?
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    Initially you asked about the electron.
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    Can the electron speak for itself?
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    Quote Originally Posted by Steve Miller
    Initially you asked about the electron.
    Is it law, is it unexplainable why they reflect the light in such direction?
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    Quote Originally Posted by maxHeadroom
    Can the electron speak for itself?
    Sure. In rime.
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    Quote Originally Posted by scientist91
    Quote Originally Posted by Steve Miller
    Initially you asked about the electron.
    Is it law, is it unexplainable why they reflect the light in such direction?
    HELLO! Did you read the link I provided?
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    Quote Originally Posted by scientist91
    Quote Originally Posted by Steve Miller
    Initially you asked about the electron.
    Is it law, is it unexplainable why they reflect the light in such direction?
    Who?
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    The question is wrong, then.
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    Quote Originally Posted by (Q)
    Quote Originally Posted by scientist91
    Quote Originally Posted by Steve Miller
    Initially you asked about the electron.
    Is it law, is it unexplainable why they reflect the light in such direction?
    HELLO! Did you read the link I provided?
    YEss, but it is just law. It doesn't say anything about the electrons or protons.
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    Quote Originally Posted by scientist91
    YEss, but it is just law. It doesn't say anything about the electrons or protons.
    But, it answers your question about the angle of reflection.
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    Quote Originally Posted by (Q)
    Quote Originally Posted by scientist91
    YEss, but it is just law. It doesn't say anything about the electrons or protons.
    But, it answers your question about the angle of reflection.
    Why the electron is emitting the light in angle like that? Because it is moving?
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    Did I understand your concern inadequately? The electron emits light? Back in the mirror? Yes?
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    Quote Originally Posted by Steve Miller
    Did I understand your concern inadequately? The electron emits light? Back in the mirror? Yes?
    I asked why the electron reflects the light in such an angle. The reflection works, when the electrons receives the light and than emit it.
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    Quote Originally Posted by scientist91
    Quote Originally Posted by Steve Miller
    Did I understand your concern inadequately? The electron emits light? Back in the mirror? Yes?
    I asked why the electron reflects the light in such an angle. The reflection works, when the electrons receives the light and than emit it.
    No kidding here (not seriously the least). When light was emitted, the object that was the source of the light would emit light. So far my understanding goes the least. You don't regard the electron to be the source of light and not partially also? Meaning, the electron reflects inflowing light and adds light additionally as a light source? No. Only reflecting. Or do you think the electron will process inflowing light in some way however?
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    Quote Originally Posted by scientist91
    I asked why the electron reflects the light in such an angle. The reflection works, when the electrons receives the light and than emit it.
    Each individual photon's emission will be random, however the overall numbers of photons interacting will average out to be the classical large scale reflective angle we measure according to the law.
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    Quote Originally Posted by (Q)
    Quote Originally Posted by scientist91
    I asked why the electron reflects the light in such an angle. The reflection works, when the electrons receives the light and than emit it.
    Each individual photon's emission will be random, however the overall numbers of photons interacting will average out to be the classical large scale reflective angle we measure according to the law.
    But why they reflect the light by that angle?
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    Anybody knows?
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    Electrons don't emit light.
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    Electrons don't emit light.
    Huh? They absorb a photon, jump to a higher orbital, re-emit the photon and then fall back to the original orbital. What do you think happens?

    Q said:
    Each individual photon's emission will be random, however the overall numbers of photons interacting will average out to be the classical large scale reflective angle we measure according to the law.
    What problem do you have with this, scientist91?
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    Quote Originally Posted by KALSTER
    Electrons don't emit light.
    Huh? They absorb a photon, jump to a higher orbital, re-emit the photon and then fall back to the original orbital. What do you think happens?
    Don't know. I never heard they do.
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    Quote Originally Posted by KALSTER
    Electrons don't emit light.
    Huh? They absorb a photon, jump to a higher orbital, re-emit the photon and then fall back to the original orbital. What do you think happens?

    Q said:
    Each individual photon's emission will be random, however the overall numbers of photons interacting will average out to be the classical large scale reflective angle we measure according to the law.
    What problem do you have with this, scientist91?
    I have problem with the angle. Why they reflect the light in such an angle, like the law of reflection?
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    Quote Originally Posted by scientist91
    I have problem with the angle. Why they reflect the light in such an angle, like the law of reflection?
    For a single photon that may disperse in a random direction, we find this to be merely a representation of understanding the mechanics, but cannot explain reflection on a larger scale. However, when gazillions of photons moving together in one direction and then reflecting has conservation of momentum running parallel along the beam, which then follows the classical law of reflection.
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    Quote Originally Posted by (Q)
    Quote Originally Posted by scientist91
    I have problem with the angle. Why they reflect the light in such an angle, like the law of reflection?
    For a single photon that may disperse in a random direction, we find this to be merely a representation of understanding the mechanics, but cannot explain reflection on a larger scale. However, when gazillions of photons moving together in one direction and then reflecting has conservation of momentum running parallel along the beam, which then follows the classical law of reflection.
    Hmm. Momentum is not conserved in the direction normal to the reflecting surface, unless one considers that the momentum is imparted to the mirror. But then why could not the momentum be imparted to the mirror in a parallel direction as well?
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    We breathe.

    yET DO WE reaaaaly wonder about how we are able to do that without thanking the ones who made our livlihood possible?

    Am I wrong?

    hooooowwwwww wrong?
    \
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    Max.

    Max..........

    They want to find a specific answer, not a drama.
    Does a theory of everything therefore need to be purely theoretical and only account for the known laws and forces in handling the improbability of fortune telling?

    the www feature below can explain it better.
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    What have the conservation of momentum, here to do?
    I have read this from wikipedia:
    The law of reflection arises from diffraction of a plane wave (with small wavelength) on a flat boundary: when the boundary size is much larger than the wavelength then electrons of the boundary are seen oscillating exactly in phase only from one direction — the specular direction. If a mirror becomes very small (comparable to the wavelength), the law of reflection no longer holds and the behaviour of light is more complicated.
    but unfortunately I couldn't understand it/
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    Electrons of light bouncing on the mirror are meant? Or electrons within the mirrors surface?
    Or both (that would be pretty clever )?
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    Quote Originally Posted by Steve Miller
    Electrons of light bouncing on the mirror are meant? Or electrons within the mirrors surface?
    Or both (that would be pretty clever )?
    Here is the article. I think it is talking about the electrons within the mirrors surface. But what is it about? Could you explain me, please?
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    You could write to the articles author.
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    Quote Originally Posted by Steve Miller
    You could write to the articles author.
    If you know please help, if you don't please don't ruin this thread.
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    When light is reflected, the energy is absorbed and released, or it the electromagnetic waves are reflected without absorbing the light?
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    I would say reflected only.
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    Is this correct? Does the atoms begin to emit waves in all directions?
    http://www.telescope-optics.net/reflection.htm
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    Incident light does not pervade the surface of the mirror and was reflected. Like playing billiard.
    A ball hits the board and was 'reflected' same way as hitting. Light was reflected since pervading
    the mirrors surface failed.

    The article says, light again was emitted from the atoms electron orbit. I assume while electrons
    are hovering at the outermost distance from the atoms center electrons are considered to reflect
    light. Further on, the article(s author ) regards them the closest particles at the mirrors surface
    boundaries, so to speak.
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    I know that light is reflected because of the fact that electrons don't need extra energy. Also is it correct that the electromagnetic field of the electrons is oppositing the electromagnetic wave?
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    Since when electrons do sport an electromagnetic field? That's new to me. Please explain.
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    The Law of Reflection. The angle of incidence (incoming angle), is the angle measured from the Normal, which is orthogonal to the surface of the mirror, and equals the angle of reflection (outgoing angle) from the Normal.
    This makes sense to me.

    I think scientist91 wants to know the reason for such an angle. I think the billards example works best.

    When you have such a concave mirror lets think about it.

    It come in at a angle of 60 degrees relative to the parallel it will leave at an 60 degree angle relative to the surface of the mirror. this depends on how concave it is. The original picture would be easiest to explain it with.

    http://en.wikipedia.org/wiki/Law_of_reflection

    the first one on that page is the best I can find just imagine it was concave the beem of light that hits in the very middle will be reflected right back at the source if the source is perpendicular to the plane of the surface.
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    So the wave is first absorbed and than released? Or it is just reflected?
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    What this means?
    When surface imperfections are smaller than the wavelength of the incident light (as in the case of a mirror), virtually all of the light is reflected equally
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    is reflection of light: "an electron absorbs the energy of the photon and sends it back out the way it came in?"
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    Quote Originally Posted by scientist91
    is reflection of light: "an electron absorbs the energy of the photon and sends it back out the way it came in?"
    The electrons absorb and re-emit the photons in the above manner. The angles average out according to probabilities to produce the observed angle.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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    Quote Originally Posted by KALSTER
    Quote Originally Posted by scientist91
    is reflection of light: "an electron absorbs the energy of the photon and sends it back out the way it came in?"
    The electrons absorb and re-emit the photons in the above manner. The angles average out according to probabilities to produce the observed angle.
    But why they absorb it, when they re-emit it?
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    From what I can understand you are confusing the photoexcitation/electron relaxation, and reflection of photons.

    Earlier you talked of an electron absorbing a photon, moving up n energy levels (orbitals/shells/whatever you want to call them) then as a result of being unstable, the electron decays back to the orginal shell, re-emitting the photon as light. This is photoexcitation then electron relaxation of an electron, and requires the incident photon energy E=hf to be the same or more as the excitation energy (ie difference between the shells).

    [as a side note this is related to how x-rays are produced]

    Reflection is caused when the electron or atom absorbs then very quickly re-emitts the photon, not changing the state of the atom (ie the shell in this instance). The photon is re-emitted because the atom is not stable with this energy. It therefore re-emitts the photon without having changed the QUANTUM STATE of the atom. (It will however change the kinetic energy (ie temperature) of it).

    The exact angle of photon release is a Quantum Mechanical result. Putting it [sort of] simply, it is calculated from a complicated diffential equation which produces a probability function of different angles. The overall sum of these probabilities for the angles gives rise to the previously stated law of reflection.

    PS: The photoelectric effect is not really related to reflection, this is where the electron absorbs a photon and is excited so much that it breaks free of the atom's restraints, hence ionising it .
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    Quote Originally Posted by Cynapse
    From what I can understand you are confusing the photoexcitation/electron relaxation, and reflection of photons.

    Earlier you talked of an electron absorbing a photon, moving up n energy levels (orbitals/shells/whatever you want to call them) then as a result of being unstable, the electron decays back to the orginal shell, re-emitting the photon as light. This is photoexcitation then electron relaxation of an electron, and requires the incident photon energy E=hf to be the same or more as the excitation energy (ie difference between the shells).

    [as a side note this is related to how x-rays are produced]

    Reflection is caused when the electron or atom absorbs then very quickly re-emitts the photon, not changing the state of the atom (ie the shell in this instance). The photon is re-emitted because the atom is not stable with this energy. It therefore re-emitts the photon without having changed the QUANTUM STATE of the atom. (It will however change the kinetic energy (ie temperature) of it).

    The exact angle of photon release is a Quantum Mechanical result. Putting it [sort of] simply, it is calculated from a complicated diffential equation which produces a probability function of different angles. The overall sum of these probabilities for the angles gives rise to the previously stated law of reflection.

    PS: The photoelectric effect is not really related to reflection, this is where the electron absorbs a photon and is excited so much that it breaks free of the atom's restraints, hence ionising it .
    What is in fact reflection? Receiving energy and than re-emitting that energy?
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    Yes it is, but it is NOT recieving energy and exciting electrons. It is just a near instantaneous absorption and re-emmission of EM energy.
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    Quote Originally Posted by Cynapse
    Yes it is, but it is NOT recieving energy and exciting electrons. It is just a near instantaneous absorption and re-emmission of EM energy.
    Re-emittion in whole directions around the electron, or in just one direction?
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    I think what you have to think about is how do you know the photon has gone in any direction until it interracts with something to say it has gone in that direction...
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    Quote Originally Posted by Cynapse
    I think what you have to think about is how do you know the photon has gone in any direction until it interracts with something to say it has gone in that direction...
    And why the angle of incidence is same with the angle of reflection?
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    Quote Originally Posted by scientist91
    Quote Originally Posted by Cynapse
    I think what you have to think about is how do you know the photon has gone in any direction until it interracts with something to say it has gone in that direction...
    And why the angle of incidence is same with the angle of reflection?
    I don't mean to be, er, mean, but you have been asking the same questions over and over again. Did you forget or are you doing this on purpose?
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  72. #71  
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    Quote Originally Posted by KALSTER
    Quote Originally Posted by scientist91
    Quote Originally Posted by Cynapse
    I think what you have to think about is how do you know the photon has gone in any direction until it interracts with something to say it has gone in that direction...
    And why the angle of incidence is same with the angle of reflection?
    I don't mean to be, er, mean, but you have been asking the same questions over and over again. Did you forget or are you doing this on purpose?
    I am asking the same question over and over again, because I actually didn't get any concrete answer and thanks for your efforts to help me.
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    It is a quantum result. Do you know anything about QM?
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    Quote Originally Posted by Cynapse
    It is a quantum result. Do you know anything about QM?
    Look, I am still confused all about this. Can anybody explain what actually happens, when there is reflaction of light, are the electrons inside of the material also transmitting energy?
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    Reflection is caused when the PHONON absorbs then very quickly re-emitts the photon, not changing the state of any atom. The photon is re-emitted because there is no phonon mode in the solid which resonantes with that freqency of light.

    Ignore my previous post about electron absorbtion. This is not what reflection is.
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    Quote Originally Posted by Cynapse
    Reflection is caused when the PHONON absorbs then very quickly re-emitts the photon, not changing the state of any atom. The photon is re-emitted because there is no phonon mode in the solid which resonantes with that freqency of light.

    Ignore my previous post about electron absorbtion. This is not what reflection is.
    And do the photon is released in whole directions (like the wave?
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    this is why i asked if you know about QM. the wave function itself is released in all directions and you cant say but the photon will only have been proved to go in ONE direction after another an observation.
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    Quote Originally Posted by Cynapse
    this is why i asked if you know about QM. the wave function itself is released in all directions and you cant say but the photon will only have been proved to go in ONE direction after another an observation.
    Ok I understand now thanks.
    So when refraction happens, should the wave go in "above" and "below" direction like the simulation I provided? I think the phonons in the 2-nd medium (the internal structure) should also release waves in both directions (up and down), right??
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    no. in the picture the lines accross the wave indicate the wave front. This is like stoping all of the photons and drawing a straight line accross them. ie it is perpendicular to the actual wave. In fact what you call above and below is all a beam of lots of photons with a width that you can see. The only wave there is the arrow, which as you can see goes in in on direction at one point and comes out in one direction to one point. If you were to draw this non-simplistically there would be lots and lots of arrows across the beam width.
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    Quote Originally Posted by Cynapse
    no. in the picture the lines accross the wave indicate the wave front. This is like stoping all of the photons and drawing a straight line accross them. ie it is perpendicular to the actual wave. In fact what you call above and below is all a beam of lots of photons with a width that you can see. The only wave there is the arrow, which as you can see goes in in on direction at one point and comes out in one direction to one point. If you were to draw this non-simplistically there would be lots and lots of arrows across the beam width.
    I understand that. But I ask you, are there are also waves released from the internal structure, so I can cross several lines? Are the waves real, or they are just a way to describe the reflection?
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    Yes when the photons are absorbed they are re-emitted by the phonons so and the re-emitted photons travel as waves.
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  82. #81  
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    Quote Originally Posted by Cynapse
    Yes when the photons are absorbed they are re-emitted by the phonons so and the re-emitted photons travel as waves.
    Circular waves, like on the simulation or what shape?
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    Yeah simplistically treating the light as a continuous wave (and not a stream of individual photons) it will appear as in the pic.
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  84. #83  
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    Quote Originally Posted by Cynapse
    Yeah simplistically treating the light as a continuous wave (and not a stream of individual photons) it will appear as in the pic.
    So actually, the circular waves are the EM waves of the light?
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    Yes but then you have to forget about individual photons.
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    Quote Originally Posted by Cynapse
    Yes but then you have to forget about individual photons.
    Are there individual photons, actually, in reality??
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    Yes. They are what light waves are made of.
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  88. #87  
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    Quote Originally Posted by Cynapse
    Yes. They are what light waves are made of.
    So I can image one wave (if I cross tangent line) like one photon, right?
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    Yeah the line is the path of the photon (but remember this is only if it is detected to have gone down this path).
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    If the light is first refracted, and then, do it travel among the internal material? Do the internal material reflects this light?
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    some is. It depends on the crystal latice phonon it his. If it is an idealy transparrent medium it won't but this doesn't exist so yes some will be reflected. most reflection will take place at a change of medium though.
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  92. #91  
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    Quote Originally Posted by Cynapse
    some is. It depends on the crystal latice phonon it his. If it is an idealy transparrent medium it won't but this doesn't exist so yes some will be reflected. most reflection will take place at a change of medium though.
    But if we look at the Huygen's principle, it will always reflect light. Like on this picture.
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    But with your part it isn't reflecting off anything, there is no change in medium...
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  94. #93  
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    Quote Originally Posted by Cynapse
    But with your part it isn't reflecting off anything, there is no change in medium...
    What happens with the light, after the interaction with the surface?
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    Cynapse?
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    have already answered.
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  97. #96  
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    Quote Originally Posted by Cynapse
    have already answered.
    Why sometimes, if I touch the glass balloon around the light bulb, it is hot?
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    because not all of the photons are re-emmitted by the phonons,, some go towards heating the medium.
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    I would guess most of the heat that heats up the bulb in an incandescent lamp is coming from the joule heating of the filament conducted to the bulb surface by the inert gas that fills the bulb.
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    Quote Originally Posted by Harold14370
    I would guess most of the heat that heats up the bulb in an incandescent lamp is coming from the joule heating of the filament conducted to the bulb surface by the inert gas that fills the bulb.
    Can you tell me why if light interacts with surface of water, some of the light is reflected, and some refracted, why it is not all reflected?
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