Photon = quanta of energy.................... Ummm what does that really mean?

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why06

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<p>Okay I know a quanta is the smallest part of something in a sense.</p><p>Ex: When something is quantized it is made up of multiples a specific size or capacity. Sort of like the charge of a battery i simply multiples of the charges of single electrons. Or as a bar of iron is composed of multiples of Iron atoms.</p><p>Now Im not asking what "quanta" refers to, but more importantly what energy refers too? Essentially is a photon the smallest form of energy? Than what is energy? </p><p><strong>And since when is energy represented as a particle</strong><img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-undecided.gif" border="0" alt="Undecided" title="Undecided" />??? </p><p>&nbsp;</p><p>This has always puzzled me and I used to think it was a stupid question to ask since everyone who said the word "photon" acted as if it was so easy to understand. However I am setting aside my shame in the hope of procurring the knowlege to rectify my bemusement. <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-tongue-out.gif" border="0" alt="Tongue out" title="Tongue out" /> </p> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>
 
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DrRocket

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Okay I know a quanta is the smallest part of something in a sense.Ex: When something is quantized it is made up of multiples a specific size or capacity. Sort of like the charge of a battery i simply multiples of the charges of single electrons. Or as a bar of iron is composed of multiples of Iron atoms.Now Im not asking what "quanta" refers to, but more importantly what energy refers too? Essentially is a photon the smallest form of energy? Than what is energy? And since when is energy represented as a particle??? &nbsp;This has always puzzled me and I used to think it was a stupid question to ask since everyone who said the word "photon" acted as if it was so easy to understand. However I am setting aside my shame in the hope of procurring the knowlege to rectify my bemusement. <br />Posted by why06</DIV></p><p>Einstein received the Nobel prize for an explanation of the photoelectric effect.&nbsp; The photoelectric effect involves shining light on a substance which then emits electrons. The kinetic energy of the electrons can be measure.&nbsp; Basically what was found was that increasing the intensity of the light increased the number of electrons emitted, but did not change the kinetic energy of the individual electrons.&nbsp; Changing the frequency of the light changed the kinetic energy of the individual electrons, with higher frequency light giving higher energy electrons.&nbsp; The explanation for this is that light is carried by particles called photons and the energy of an individual photon is given the the relation that energy is equal to a constant (Planck's constant) times the frequency.&nbsp; An individual photon is often called a "quanta" of light.&nbsp; Light is carried by this particle called the photon.&nbsp; However, the photon, while most definitely a particle, is not just a little marble.&nbsp; It is a rather complicated gadget that often behaves as though it were a wave.</p><p>Energy per se is not a particle -- it is in fact a concept and not a sensible "thing".&nbsp; However, it is a calculable quantity and quantum theory tells us that it comes in discrete units.&nbsp; There are forms of energy other than photons so it is wrong to associate all energy with photons, and that might be the source of some of your confusion.&nbsp; Energy is the ability to do work, and results from the application of force over a distance.&nbsp; So for instance when a photon is absorbed by an electron in an atom the result is the electron rising to a higher energy orbit, essentially having the negatively charged electron being pulled away from the attracting positively charged nucleus (a force acting orver a distance) reflecting increased energy.</p><p>If you would like to learn a little more, there is a little book taken from some lectures of Richard Feynman for a general lay audience called QED.&nbsp; It is a much simplified explanation of Quantun Electrodynamics by the master of the field.&nbsp; <br /></p> <div class="Discussion_UserSignature"> </div>
 
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billslugg

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<p>why06</p><p>The photon is a carrier of energy. It can be any size. Regardless of size, it is always a certain exact amount. You are sort of asking: "Is a bucket the smallest container?" Well, it depends on how big the bucket is.&nbsp;</p><p>Same thing goes with photons. An EM wave at several thousand kilometers wavelength is usefull for talking to submarines. It can pass through darn near anything, including seawater. Only problem is you have to talk REAL slow.&nbsp;</p><p>How about the 10^13 eV photon detected by Auger? This particle is so powerfull that&nbsp; it can interact with a "normal" photon to produce an electron-positron pair. Whoa Dude! Something out of nothing! Who woulda thunk?&nbsp;</p> <div class="Discussion_UserSignature"> <p> </p><p> </p> </div>
 
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why06

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The explanation for this is that light is carried by particles called photons and the energy of an individual photon is given the the relation that energy is equal to a constant (Planck's constant) times the frequency.</DIV>&nbsp; </p><p>&nbsp;Okay so essentially a&nbsp; photon is equal to Planks constant "h" but this is then multiplied by its frequency to produce a final energy level. </p><p>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>An individual photon is often called a "quanta" of light.&nbsp; Light is carried by this particle called the photon.&nbsp; However, the photon, while most definitely a particle, is not just a little marble.&nbsp; It is a rather complicated gadget that often behaves as though it were a wave.Energy per se is not a particle -- it is in fact a concept and not a sensible "thing".</DIV></p><p>So a photon is a "quanta of light" I see that is quite different from calling it a "quanta of energy." What I find more interesting is the way you explained energy. <strong>"Energy per se is not a particle -- it is in fact a concept and not a sensible "thing""</strong> So energy is can be described as a concept that explains observations. Sort of how the idea of their being energy levels in atoms explain how light can be emitted and other phenomenon that goes on between atoms. </p><p>&nbsp; Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>However, it is a calculable quantity and quantum theory tells us that it comes in discrete units.&nbsp; There are forms of energy other than photons so it is wrong to associate all energy with photons, and that might be the source of some of your confusion.&nbsp; Energy is the ability to do work, and results from the application of force over a distance.&nbsp; So for instance when a photon is absorbed by an electron in an atom the result is the electron rising to a higher energy orbit, essentially having the negatively charged electron being pulled away from the attracting positively charged nucleus (a force acting orver a distance) reflecting increased energy.If you would like to learn a little more, there is a little book taken from some lectures of Richard Feynman for a general lay audience called QED.&nbsp; It is a much simplified explanation of Quantun Electrodynamics by the master of the field.&nbsp; <br /> Posted by DrRocket</DIV></p><p>Thanks for the referance to that book. I'll see if I can find it. And thanks for the insight.&nbsp;</p> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>
 
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why06

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>How about the 10^13 eV photon detected by Auger? This particle is so powerfull that&nbsp; it can interact with a "normal" photon to produce an electron-positron pair. Whoa Dude! Something out of nothing! Who woulda thunk?&nbsp; <br /> Posted by billslugg</DIV></p><p>Wow. now that just doesn't make sense. It this an real life example of a direct energy to matter conversion?&nbsp;</p> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>
 
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drwayne

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Wow. now that just doesn't make sense. It this an real life example of a direct energy to matter conversion?&nbsp; <br />Posted by why06</DIV></p><p>Check out the term "pair production".&nbsp; If you have enough energy to "buy" the rest mass of an electron and a positron - you can have them.</p><p>Wayne<br /></p> <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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DrRocket

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Check out the term "pair production".&nbsp; If you have enough energy to "buy" the rest mass of an electron and a positron - you can have them.Wayne <br />Posted by drwayne</DIV></p><p>I must be missing something here.&nbsp; </p><p>I calculate that the rest mass of the electron, 9.109 E -31 kg, is about 511,000 eV or 8.19 E -14 J.&nbsp; That may be quite a bit of energy in a particle, but it is not much compared to what it takes to run a light bulb for a second, and in terms of economics not even a penny at usual electric rates.&nbsp; <br /></p> <div class="Discussion_UserSignature"> </div>
 
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lildreamer

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Check out the term "pair production".&nbsp; If you have enough energy to "buy" the rest mass of an electron and a positron - you can have them.Wayne <br />Posted by drwayne</DIV><br /><br />so this concept of quanta really falls on values of Planck's constants and C.</p><p>technically there could be particles smaller than plank's length but because we use light in the measurement, anything smaller than light can be missed. That's where the theory portion of quantum mechanics really starts to get interesting - no?&nbsp;</p><p>so here's the true question how do we measure an event smaller than a photon?</p><p>Plus if I show my ignorance on the subject for give me but I think its an interesting question never the less....</p> <div class="Discussion_UserSignature"> </div>
 
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why06

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>so this concept of quanta really falls on values of Planck's constants and C.technically there could be particles smaller than plank's length but because we use light in the measurement, anything smaller than light can be missed. That's where the theory portion of quantum mechanics really starts to get interesting - no?&nbsp;<font size="2"><strong><font color="#ff0000">so here's the true question how do we measure an event smaller than a photon?</font></strong></font>Plus if I show my ignorance on the subject for give me but I think its an interesting question never the less.... <br /> Posted by lildreamer</DIV></p><p>Exactly! I assume that when you say measure you are not refering to size or length, but measuring energy levels. How would one measure the energy level of something less than a photon. Its like the "how long is the coast of britian question?" If any of you have some experience on chaos you might realize that the coast can be infinitely long depending on the size of ruler used to measure it and the accuracy of the measurements. <strong>What is a photon made out of?&nbsp;</strong></p><p>No seriously. not EM waves since those are merely conceptual. I want to know what a "<strong><em>quanta of light</em></strong>" is just as I know that a quanta of iron is an atom of iron which is made out of protons and nuetrons and electrons which are made out of quarks and so on and so on. I'll start off. A photon which is composed of..... so on and so on </p> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>
 
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drwayne

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>so this concept of quanta really falls on values of Planck's constants and C.technically there could be particles smaller than plank's length but because we use light in the measurement, anything smaller than light can be missed. That's where the theory portion of quantum mechanics really starts to get interesting - no?&nbsp;so here's the true question how do we measure an event smaller than a photon?Plus if I show my ignorance on the subject for give me but I think its an interesting question never the less.... <br />Posted by lildreamer</DIV></p><p>I am not sure what you mean by "smaller than light", are you implying a lower limit to the wavelength of light?</p><p>Wayne</p> <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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lildreamer

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<p><span style="font-size:7.5pt;font-family:Verdana"><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I am not sure what you mean by "smaller than light", are you implying a lower limit to the wavelength of light?Wayne <br />Posted by drwayne</DIV></span></p><p><span style="font-size:7.5pt;font-family:Verdana">the theoretical value for the smallest particle for us to detect &nbsp;is based on planck's constant and C. A photon is the smallest packet or quanta of energy that we can and do perceive to exist in this universe. That's our "ruler" so to speak. </span></p><p><span style="font-size:7.5pt;font-family:Verdana">Can we have a better resolution than a packet of light/photon. Do we have the ability to measure an event smaller than light?</span></p><p><span><font color="#ff0000">planck length 1.616&nbsp;252(81)&nbsp;x&nbsp;10<sup>-35</sup> m</font></span></p><p><span><font color="#ff0000">planck time 5.391&nbsp;24(27)&nbsp;x&nbsp;10<sup>-44</sup> s</font> </span></p><p><strong></strong><strong><span style="font-weight:normal;font-size:7.5pt;font-family:Verdana">are considered to be the lowest possible values that are the basic properties of our "space.</span></strong></p><p><strong></strong><strong><span style="font-weight:normal;font-size:7.5pt;font-family:Verdana">I was thinking of the double slit experiment where light is has been described to behave as both particle and wave. </span></strong><strong><span style="font-weight:normal;font-size:7.5pt;font-family:Verdana">My opinion is we say&nbsp;wave only because the resolution that we can perceive only allows us to see the event as a wave but not as a particle.</span></strong></p><p><strong><span style="font-weight:normal;font-size:7.5pt;font-family:Verdana">&nbsp;If we can perceive events as discrete packets of plank's time would not the idea of wave disappear and we see light for what it is a particle? </span></strong></p><p><strong><span style="font-weight:normal;font-size:7.5pt;font-family:Verdana">Would we not be able to see "energy" or "fields" as discrete packets as well?</span></strong> </p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>
 
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DrRocket

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Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>the theoretical value for the smallest particle for us to detect &nbsp;is based on planck's constant and C. A photon is the smallest packet or quanta of energy that we can and do perceive to exist in this universe. That's our "ruler" so to speak. Can we have a better resolution than a packet of light/photon. Do we have the ability to measure an event smaller than light?planck length 1.616&nbsp;252(81)&nbsp;x&nbsp;10-35 mplanck time 5.391&nbsp;24(27)&nbsp;x&nbsp;10-44 s are considered to be the lowest possible values that are the basic properties of our "space"I was thinking of the double slit experiment where light is has been described to behave as both particle and wave. My opinion is we say&nbsp;wave only because the resolution that we can perceive only allows us to see the event as a wave but not as a particle. If we can perceive events as discrete packets of plank's time would not the idea of wave disappear and we see light for what it is a particle? Would we not be able to see "energy" or "fields" as discrete packets as well? &nbsp; <br />Posted by lildreamer</DIV><br /> <div class="Discussion_UserSignature"> </div>
 
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drwayne

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Exactly! I assume that when you say measure you are not refering to size or length, but measuring energy levels. How would one measure the energy level of something less than a photon. Its like the "how long is the coast of britian question?" If any of you have some experience on chaos you might realize that the coast can be infinitely long depending on the size of ruler used to measure it and the accuracy of the measurements. What is a photon made out of?&nbsp;No seriously. not EM waves since those are merely conceptual. I want to know what a "quanta of light" is just as I know that a quanta of iron is an atom of iron which is made out of protons and nuetrons and electrons which are made out of quarks and so on and so on. I'll start off. A photon which is composed of..... so on and so on <br />Posted by why06</DIV></p><p>The question is even harder than that.&nbsp; Is a photon "real"?&nbsp; One can easily view a photon as a point particle with no mass&nbsp;that is a "packet" for carrying various properties, or, possibly, just information about what we can know about the properties.&nbsp; A mathematical construct of our knowlege of the state estimate for light.</p><p>Is this point particle a real particle, or&nbsp;is it a cconstruct that, in certain circumstances of measurement - just act like a real particle?</p><p>Wayne</p><p>Wayne</p><p><br /><br />&nbsp;</p> <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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why06

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>the theoretical value for the smallest particle for us to detect &nbsp;is based on planck's constant and C. A photon is the smallest packet or quanta of energy that we can and do perceive to exist in this universe. That's our "ruler" so to speak. Can we have a better resolution than a packet of light/photon. Do we have the ability to measure an event smaller than light?planck length 1.616&nbsp;252(81)&nbsp;x&nbsp;10-35 mplanck time 5.391&nbsp;24(27)&nbsp;x&nbsp;10-44 s are considered to be the lowest possible values that are the basic properties of our "space"I was thinking of the double slit experiment where light is has been described to behave as both particle and wave. My opinion is we say&nbsp;wave only because the resolution that we can perceive only allows us to see the event as a wave but not as a particle. If we can perceive events as discrete packets of plank's time would not the idea of wave disappear and we see light for what it is a particle? Would we not be able to see "energy" or "fields" as discrete packets as well? &nbsp; <br /> Posted by lildreamer</DIV></p><p>Are you saying that plank constant is not the smallest amount of energy, but perhaps the minimum required amt of energy for a particle to have any effect on other objects possessing mass?</p><p>Perhaps a photon has reached this minimum energy requirement to cause effects on mass. In this case could wavelength be nothing more than the density of energy in a photon and the photoelectric effect be a result of <strong>impulse ?</strong></p> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>
 
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drwayne

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>the theoretical value for the smallest particle for us to detect &nbsp;is based on planck's constant and C. A photon is the smallest packet or quanta of energy that we can and do perceive to exist in this universe. <br />Posted by lildreamer</DIV></p><p>&nbsp;A couple of point related to this</p><p>(1) A photon very well may have no physical "size", so referring to it as the smallest in dimension *may* not have meaning.</p><p>(2) A photon, or light of varying wavelengths is just a means for transporting energy about.&nbsp; One can think of as an exchange particle.</p><p>I get the impression that you are looking at a photon as a sort of - least significant bit of energy.&nbsp; (Or the upper limit of my IQ, whichever is lower)</p><p>Wayne<br /></p> <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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DrRocket

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>the theoretical value for the smallest particle for us to detect &nbsp;is based on planck's constant and C. A photon is the smallest packet or quanta of energy that we can and do perceive to exist in this universe. That's our "ruler" so to speak. Can we have a better resolution than a packet of light/photon. Do we have the ability to measure an event smaller than light?planck length 1.616&nbsp;252(81)&nbsp;x&nbsp;10-35 mplanck time 5.391&nbsp;24(27)&nbsp;x&nbsp;10-44 s are considered to be the lowest possible values that are the basic properties of our "space.I was thinking of the double slit experiment where light is has been described to behave as both particle and wave. My opinion is we say&nbsp;wave only because the resolution that we can perceive only allows us to see the event as a wave but not as a particle.&nbsp;If we can perceive events as discrete packets of plank's time would not the idea of wave disappear and we see light for what it is a particle? Would we not be able to see "energy" or "fields" as discrete packets as well? &nbsp; <br />Posted by lildreamer</DIV></p><p>Sorry about the earlier blip -- computer hiccupped.</p><p>You are right on the edge of some questions that are not resolved.&nbsp; </p><p>When you start to talk about the "size" of elementary particles, things get thorny.&nbsp; As far as is known the electron is a point -- a no-kidding Euclidean point.&nbsp; No size, no volume at all.&nbsp; This poses a bit of a problem.&nbsp; If you calculate the energy required to put a charge into zero volume, you find that it is infinite.&nbsp; Yes, that is a problem.&nbsp; No, we do not have a resolution.&nbsp; The entire field of quantum electrodynamics has a problem with infinities.&nbsp; In the case of quantum electrodynamics they are dealt with via a rather mysterious process known as "renormalization".&nbsp; Calculations using the renormalization process turn out to be in astoundingly close agreement with experimental measurement.&nbsp; However, the process does not have a firm mathematical justification.&nbsp; Renormalization is a key to development of other quantum field theories (as you observed there is a role for quantization with regard to fields).&nbsp; It is the inability to generalize renormalization to the gravitational field that has prevented the development of a theory of quantum gravity and unifying general relativity with quantum theory.</p><p>&nbsp;With regard to "detecting something smaller that light", I think a more precise statement of the question is needed.&nbsp; Photons are also thought to be point particles, so one cannot even in principle talk about anything smaller (what would be smaller than a single point ?)&nbsp; On the other hand if you look at light as a wave, and ask whether we can detect a particle smaller than the wavelength of visible light, the answer is yes.&nbsp; Massive particles can also be thought of as waves.&nbsp; DeBroglie developed that concept.&nbsp; Electrons of a given energy also have an associated wavelength and it is usually smaller than that of visible light.&nbsp; That is why electron microscopes are used to provide images with resolution of features smaller than the wavelength of visible light.</p><p>&nbsp;You might want to take a read through Feynman's little book "QED".&nbsp; Light is a particle.&nbsp; It is not, however, a little marble and exhibits wavelike characteristics under certain circumstances.&nbsp; You might also want to take a look at a book "More than One Mystery."&nbsp; There is pretty neat set of pictures there showing the interference pattern of the classic double slit experiment, using electrons in this case, being build up one particle at a time -- an example of wave behavior comiing from discrete particles.</p> <div class="Discussion_UserSignature"> </div>
 
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lildreamer

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp;A couple of point related to this(1) A photon very well may have no physical "size", so referring to it as the smallest in dimension *may* not have meaning.(2) A photon, or light of varying wavelengths is just a means for transporting energy about.&nbsp; One can think of as an exchange particle.<font color="#ff0000">I get the impression that you are looking at a photon as a sort of - least significant bit of energy.&nbsp; (Or the upper limit of my IQ, whichever is lower)Wayne <br /></font>Posted by drwayne</DIV></p><p><font color="#ff0000">I get the impression that you are looking at a photon as a sort of - least significant bit of energy.&nbsp; (Or the upper limit of my IQ, whichever is lower)Wayne </font><br /><img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-laughing.gif" border="0" alt="Laughing" title="Laughing" />&nbsp;I nearly fell off my chair....</p><p>yes to answer your questions ....</p><p>another&nbsp;reason&nbsp;I was thinking&nbsp;is when we experience a stream of water coming from a faucet - our experience is misleading. Only when we insert another frame of reference do we see the stream as a distinct packet of events...so if we can get a frame of reference smaller than light in my opinion it would open up the universe to greater level of scrutiny...</p><p>therefore getting back to WHY06 question Photon=quanta of energy, yes and no..... dohhh<img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-yell.gif" border="0" alt="Yell" title="Yell" /><br /></p> <div class="Discussion_UserSignature"> </div>
 
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lildreamer

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Sorry about the earlier blip -- computer hiccupped.You are right on the edge of some questions that are not resolved.&nbsp; ..............Mystery."&nbsp; There is pretty neat set of pictures there showing the interference pattern of the classic double slit experiment, using electrons in this case, being build up one particle at a time -- an example of wave behavior comiing from discrete particles. <br />Posted by DrRocket</DIV></p><p>reduced for berivity sake...</p><p>thankyou&nbsp; I will look into those...</p> <div class="Discussion_UserSignature"> </div>
 
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drwayne

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Sorry about the earlier blip -- computer hiccupped.You are right on the edge of some questions that are not resolved.&nbsp; When you start to talk about the "size" of elementary particles, things get thorny.&nbsp; As far as is known the electron is a point -- a no-kidding Euclidean point.&nbsp; No size, no volume at all.&nbsp; This poses a bit of a problem.&nbsp; If you calculate the energy required to put a charge into zero volume, you find that it is infinite.&nbsp; Yes, that is a problem.&nbsp; No, we do not have a resolution.&nbsp; The entire field of quantum electrodynamics has a problem with infinities.&nbsp; In the case of quantum electrodynamics they are dealt with via a rather mysterious process known as "renormalization".&nbsp; Calculations using the renormalization process turn out to be in astoundingly close agreement with experimental measurement.&nbsp; However, the process does not have a firm mathematical justification.&nbsp; Renormalization is a key to development of other quantum field theories (as you observed there is a role for quantization with regard to fields).&nbsp; It is the inability to generalize renormalization to the gravitational field that has prevented the development of a theory of quantum gravity and unifying general relativity with quantum theory.&nbsp;With regard to "detecting something smaller that light", I think a more precise statement of the question is needed.&nbsp; Photons are also thought to be point particles, so one cannot even in principle talk about anything smaller (what would be smaller than a single point ?)&nbsp; On the other hand if you look at light as a wave, and ask whether we can detect a particle smaller than the wavelength of visible light, the answer is yes.&nbsp; Massive particles can also be thought of as waves.&nbsp; DeBroglie developed that concept.&nbsp; Electrons of a given energy also have an associated wavelength and it is usually smaller than that of visible light.&nbsp; That is why electron microscopes are used to provide images with resolution of features smaller than the wavelength of visible light.&nbsp;You might want to take a read through Feynman's little book "QED".&nbsp; Light is a particle.&nbsp; It is not, however, a little marble and exhibits wavelike characteristics under certain circumstances.&nbsp; You might also want to take a look at a book "More than One Mystery."&nbsp; There is pretty neat set of pictures there showing the interference pattern of the classic double slit experiment, using electrons in this case, being build up one particle at a time -- an example of wave behavior comiing from discrete particles. <br />Posted by DrRocket</DIV></p><p>Thanks for the flashbacks to the course I took in "Selected Topics in Quantum Mechanics" that covered, among other things, renormalization.&nbsp; I should never have passed that course.&nbsp; :(</p><p>I worked with a graduate student many years ago who was working on developing estimates of "inertial" mass of electrons, if such truly exists.</p><p>It is not always clear that the mathematical descriptions we come up with for things represent the things themselves, or are simply a mathematical construct.&nbsp; (Or represent what we can know about the system)</p><p>Wayne</p><p><br /><br />&nbsp;</p> <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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DrRocket

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<p>
Thanks for the flashbacks to the course I took in "Selected Topics in Quantum Mechanics" that covered, among other things, renormalization.&nbsp; I should never have passed that course.&nbsp;</p><p>I have been waiting for&nbsp;years to hear a mathematically rigorous description of the renormalization process.&nbsp; I will probably&nbsp;have to wait many more.&nbsp; Until such exists I wonder if anyone should have passed the course.&nbsp; I heard a rumor many years ago that maybe Singer at MIT had figured out what was going on -- something about tensor products of Hilbert spaces -- but I never heard another word on that score.&nbsp; I am absolutely amazed that such accurate predictions can be made using a process that defies clear mathematical definition.&nbsp; </p><p>&nbsp;:(I worked with a graduate student many years ago who was working on developing estimates of "inertial" mass of electrons, if such truly exists.</p><p>Not sure what you mean by "inertial" mass of the electron here.&nbsp; I thought the rest mass was pretty well known (9.109 E-31 Kg is the figure that I have and that I used in the earlier post).&nbsp;&nbsp;They only time I have run into the term "inertial" mass was in the context of the work&nbsp;showing that the "inertial" mass m&nbsp;used in Newtons F=d(mv)/dt &nbsp;is the same as the "gravitational" mass that occurs in the law of universal gravitation.&nbsp; If those ever turn out to be different we are in for quite a shock.&nbsp; </p><p>It is not always clear that the mathematical descriptions we come up with for things represent the things themselves, or are simply a mathematical construct.&nbsp; </p><p>I think in the realm of quantum mechanics, we are having more trouble with language than with the mathematics.&nbsp; "Particles" and "waves" at that level are not like marbles and ripples on the water.&nbsp; I think that it is only the mathematics that allows us to do anything sensible.&nbsp; There is enough&nbsp;difficulty in trying to deal with questions about the "size" of point particle&nbsp;like and electron or a photon&nbsp;--&nbsp;next we'll have to&nbsp;describe how hard it&nbsp;is on a Rockwell scale.&nbsp; Feynman summed it up nicely "... no one understands quantum mechanics."&nbsp; The whole area of interpretation of quantum mechanics and "collapsing of the wave functdion"&nbsp;gets mired up in our lack of understanding and shortcomings of the language to even formulate sensible questions.</p> <div class="Discussion_UserSignature"> </div>
 
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drwayne

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Not sure what you mean by "inertial" mass of the electron here.&nbsp;&nbsp; <br />Posted by DrRocket</DIV></p><p>There apparently was a theory with the electron that was being worked at the time that sought to make a differentiation between what I will refer to loosely as inertial mass, or, even more sloppily - "stuff mass" and some sort of (and this will lower your estimate of my intelligence to zero) "mass due to energy equivilancy" - non-mass that acted like mass.</p><p>I have to admit, at the time, my focus was on spending hours downstairs with the ESR spectrometer looking at organic single crystals.</p><p>Wayne</p> <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>
 
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why06

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>There apparently was a theory with the electron that was being worked at the time that sought to make a differentiation between what I will refer to loosely as inertial mass, or, even more sloppily - "stuff mass" and some sort of (and this will lower your estimate of my intelligence to zero) "mass due to energy equivilancy" - non-mass that acted like mass.I have to admit, at the time, my focus was on spending hours downstairs with the ESR spectrometer looking at organic single crystals.Wayne <br /> Posted by drwayne</DIV></p><p>Well be sides the wacky terminology I think I get what your saying. Correct me if I'm wrong, but does "non mass that acts like mass" refer to something like a EM wave or photon that has no mass, but can interact with objects as if it has mass?</p><p>I have no idea what&nbsp; "inertial mass" (related to inertia?<img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-undecided.gif" border="0" alt="Undecided" title="Undecided" width="14" height="14" />) or "stuff mass" (related to stuff <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-tongue-out.gif" border="0" alt="Tongue out" title="Tongue out" width="18" height="18" />) could refer to? &nbsp;</p> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>
 
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derekmcd

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Well be sides the wacky terminology I think I get what your saying. Correct me if I'm wrong, but does "non mass that acts like mass" refer to something like a EM wave or photon that has no mass, but can interact with objects as if it has mass?I have no idea what&nbsp; "inertial mass" (related to inertia?) or "stuff mass" (related to stuff ) could refer to? &nbsp; <br /> Posted by why06</DIV></p><p>&nbsp;</p><p>I think "non mass that acts like mass" is referring to relativistic mass. &nbsp;Mass is defined by the amount of force required to accelerate a particle (or object). &nbsp;A particle in motion has kinetic energy with adds to its mass (the more kinetic energy a particle has, the harder it is to accelerate it and is said to have more mass). &nbsp;The particles rest mass never changes, though. &nbsp;The reason a photon or EM wave interacts with massive gravitational objects has nothing to do with the photons relativistic mass (or momentum), but rather the geometry of space.</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>
 
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why06

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<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Mass is defined by the amount of force required to accelerate a particle (or object). [/quote] </p><p>Seriously ?</p><p>
The reason a photon or EM wave interacts with massive gravitational objects has nothing to do with the photons relativistic mass (or momentum), but rather the geometry of space. <br /></DIV></p><p>Photons can also interact with small objects, not just black holes. This interaction is not due to the geometry of space.&nbsp;</p> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>
 
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derekmcd

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<p>Yes, seriously. &nbsp;I think in the context of this discussion of particles and mass, the mass of the particle is nothing more (or less) than the total energy of said particle.</p><p>&nbsp;</p><p>I may have misinterpreted your statement:</p><p><span style="font-weight:bold" class="Apple-style-span">"</span><span style="border-collapse:collapse;font-size:12px" class="Apple-style-span"><span style="font-weight:bold" class="Apple-style-span">Correct me if I'm wrong, but does "non mass that acts like mass" refer to something like a EM wave or photon that has no mass, but can interact with objects as if it has mass?"</span><span style="border-collapse:separate;font-size:10px" class="Apple-style-span">&nbsp;</span></span></p><p>I assumed you were talking about gravitational interactions (i.e. gravitational lensing).&nbsp;</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>
 
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