Deepak Kapur Posted June 23, 2014 Share Posted June 23, 2014 Consider the instant of time when a photon is born.... now, divide this instant of time into small intervals each measuring plank time... what is the speed of the photon in first such instant?... c or less or zero or whatever..... Link to comment Share on other sites More sharing options...
xyzt Posted June 23, 2014 Share Posted June 23, 2014 Consider the instant of time when a photon is born.... now, divide this instant of time into small intervals each measuring plank time... what is the speed of the photon in first such instant?... c or less or zero or whatever..... You don't get it, do you? The speed of the photon is "c". Link to comment Share on other sites More sharing options...
Delta1212 Posted June 23, 2014 Share Posted June 23, 2014 Consider the instant of time when a photon is born.... now, divide this instant of time into small intervals each measuring plank time... what is the speed of the photon in first such instant?... c or less or zero or whatever..... The photon always moves at c. Link to comment Share on other sites More sharing options...
Deepak Kapur Posted June 24, 2014 Author Share Posted June 24, 2014 @ xyzt are u gettin angry at me?....plz don't....I might be a silent heart patient..... @ everybody When an electron is pregnant with a photon....what is the speed of the photon inside an electron and in which direction.... Link to comment Share on other sites More sharing options...
Mordred Posted June 24, 2014 Share Posted June 24, 2014 (edited) When an electron is pregnant with a photon....what is the speed of the photon inside an electron and in which direction.... electrons have kids? what exciting parents. now seriously when a photon is absorbed by an electron, it is completely destroyed. All its energy is imparted to the electron, which instantly jumps to a new energy level. The photon itself ceases to be. The opposite happens when an electron emits a photon. The photon is not selected from a "well" of photons living in the atom; it is created instantaneously out of the vacuum. The electron in the high energy level is instantly converted into a lower energy-level electron and a photon. There is no in-between state where the photon is being constructed. It instantly pops into existence electrons surround the nucleus of an atom, occupying different energy levels. To move from a lower to a higher energy level, an electron must gain energy. Oppositely, to move from a higher to a lower energy level, an electron must give up energy so its meaningless to describe a pregnant electron lol. ( no offense but I'll probably chuckle over that statement for some time) Edited June 24, 2014 by Mordred 1 Link to comment Share on other sites More sharing options...
Deepak Kapur Posted June 24, 2014 Author Share Posted June 24, 2014 @ mordred... Plz explain the word 'instantaneously'. 1. When you say something is insantaneously created, does it mean the 'time lag' between the creation and the 'cause of creation' is infinitely small- even smaller than the plank time? 2. Does it mean that 'instantaneous creation' talks of the 'undefined', because time intervals below plank time are not defined in the current scientific paradigm? BTW, I also entertained by the question of the pregnant electron, that 'arose instantaneously' in my mind.... Link to comment Share on other sites More sharing options...
Mordred Posted June 24, 2014 Share Posted June 24, 2014 no measurable time delay, Link to comment Share on other sites More sharing options...
Deepak Kapur Posted June 24, 2014 Author Share Posted June 24, 2014 @ mordred.... thanks for an elaborate answer...... Link to comment Share on other sites More sharing options...
swansont Posted June 24, 2014 Share Posted June 24, 2014 When an electron is pregnant with a photon....what is the speed of the photon inside an electron and in which direction.... You model of the system doesn't agree with what we observe. photons do not gestate within electrons, and electrons on their own never emit electrons. Systems (e.g. atoms) can emit photons. We often say the electron is excited, but that's just shorthand; the entire system is in an excited state. The change is seen in the electron, however, since its mass is so small. now seriously when a photon is absorbed by an electron, it is completely destroyed. All its energy is imparted to the electron, which instantly jumps to a new energy level. The photon itself ceases to be. The opposite happens when an electron emits a photon. The photon is not selected from a "well" of photons living in the atom; it is created instantaneously out of the vacuum. The electron in the high energy level is instantly converted into a lower energy-level electron and a photon. There is no in-between state where the photon is being constructed. It instantly pops into existence electrons surround the nucleus of an atom, occupying different energy levels. To move from a lower to a higher energy level, an electron must gain energy. Oppositely, to move from a higher to a lower energy level, an electron must give up energy "Instantly" is a tad problematic. How would one measure this? Link to comment Share on other sites More sharing options...
Mordred Posted June 24, 2014 Share Posted June 24, 2014 yeah it was bad wording that's why I altered it to no measurable time delay Link to comment Share on other sites More sharing options...
Delta1212 Posted June 24, 2014 Share Posted June 24, 2014 I don't think it even matters to the point whether there is a delay between the "cause of creation" and the "act of creation." The photon's existence is a binary proposition. It either exists or it does not. There is no half a photon. If the photon exists, its speed is c. There is no point at which the photon both exists and is not moving at c. 2 Link to comment Share on other sites More sharing options...
Deepak Kapur Posted June 25, 2014 Author Share Posted June 25, 2014 @ swansont... When a system (atom) emits a photon, where is the photon prior to its emittance...what is its speed...and in which direction... Link to comment Share on other sites More sharing options...
Strange Posted June 25, 2014 Share Posted June 25, 2014 @ swansont... When a system (atom) emits a photon, where is the photon prior to its emittance...what is its speed...and in which direction... It doesn't exist. Link to comment Share on other sites More sharing options...
Deepak Kapur Posted June 25, 2014 Author Share Posted June 25, 2014 @ strange... When a system emits an electron, where is it prior to its emittance? ok....I get the answer...... It doesn't exist! Link to comment Share on other sites More sharing options...
Strange Posted June 25, 2014 Share Posted June 25, 2014 Exactly, the photon is created when the system loses energy as electromagnetic radiation. Link to comment Share on other sites More sharing options...
swansont Posted June 25, 2014 Share Posted June 25, 2014 Photon number is not subject to conservation — they can be created and annihilated. They are an excitation of the electromagnetic field. That excitation can exist or not exist. If there is no excitation of the field, there is no photon. Electrons, on the other hand, are subject to number conservation laws. You can't simply destroy an electron. You need an antiparticle if you want to do that, and to create an anti-electron (positron), you'll also create an electron, so you'll be left with an electron at the end of it all. Link to comment Share on other sites More sharing options...
Deepak Kapur Posted June 25, 2014 Author Share Posted June 25, 2014 It seems exitation of the electromagnetic field is beyond time- it doesn't require time to happen.... Link to comment Share on other sites More sharing options...
Strange Posted June 25, 2014 Share Posted June 25, 2014 It seems exitation of the electromagnetic field is beyond time- it doesn't require time to happen.... I think it does: at one time there is no photon, later there is. There are many factors that affect the time taken for an excited atom to emit a photn, but it can be calculated. http://en.wikipedia.org/wiki/Spontaneous_emission Link to comment Share on other sites More sharing options...
robinpike Posted June 25, 2014 Share Posted June 25, 2014 when a photon is absorbed by an electron, it is completely destroyed. All its energy is imparted to the electron, which instantly jumps to a new energy level. The photon itself ceases to be. The opposite happens when an electron emits a photon. The photon is not selected from a "well" of photons living in the atom; it is created instantaneously out of the vacuum. The electron in the high energy level is instantly converted into a lower energy-level electron and a photon. There is no in-between state where the photon is being constructed. It instantly pops into existence electrons surround the nucleus of an atom, occupying different energy levels. To move from a lower to a higher energy level, an electron must gain energy. Oppositely, to move from a higher to a lower energy level, an electron must give up energy How do we know that the electron 'instantly' jumps to a new energy level when it absorbs and destroys the photon? And what if the photon is not exactly of the same energy as the electron's allowed orbitals? Assuming that the electron has mass, can someone describe the process of how this absorption and instant 'jump' works. And like-wise, how do we know that the photon is created 'instantly' by the electron - and why 'out of the vacuum'? Link to comment Share on other sites More sharing options...
Deepak Kapur Posted June 25, 2014 Author Share Posted June 25, 2014 @ strange Do you mean to say that the time required for the exitation of the EM field is always greater than the plank time... Even if such is the case, the exitation cannot happen if the time below the plank time hasn't been traversed first... So, do you want to say that 'to hell with below plank time', we are concerned with the exitation that happens at or above plank time? Link to comment Share on other sites More sharing options...
Strange Posted June 25, 2014 Share Posted June 25, 2014 Do you mean to say that the time required for the exitation of the EM field is always greater than the plank time... I didn't mention Planck time. How do we know that the electron 'instantly' jumps to a new energy level when it absorbs and destroys the photon? And what if the photon is not exactly of the same energy as the electron's allowed orbitals? Assuming that the electron has mass, can someone describe the process of how this absorption and instant 'jump' works. And like-wise, how do we know that the photon is created 'instantly' by the electron - and why 'out of the vacuum'? I have a vague recollection of an experiment that measured (an upper limit on) the time for an electron to absorb the photon's energy. I doubt I could find it again, though... But the important point is that photons are indivisible quanta. If the photon has less energy than required to "kick" the electron up to the next energy level, then it will have no effect; you can't do it with one photon after another, for example. This is basically what Einstein got his Nobel Prize for. Link to comment Share on other sites More sharing options...
robinpike Posted June 25, 2014 Share Posted June 25, 2014 What happens if the photon has more energy than is needed for the electron to go from the electron's lowest energy level to its second energy level, but not enough energy to get the electron to its third energy level? Does the electron still jump to the second energy level, but only absorb part of the photon's energy? Link to comment Share on other sites More sharing options...
Deepak Kapur Posted June 25, 2014 Author Share Posted June 25, 2014 @ strange... u r not getting the point......plank time has to come in EVERY activity... Link to comment Share on other sites More sharing options...
swansont Posted June 25, 2014 Share Posted June 25, 2014 As I pointed out, and as Mordred agreed, the process should not be described as occurring instantaneously. What happens if the photon has more energy than is needed for the electron to go from the electron's lowest energy level to its second energy level, but not enough energy to get the electron to its third energy level? Does the electron still jump to the second energy level, but only absorb part of the photon's energy? The photon is not absorbed. You'd run into all sorts of selection rule (i.e. conservation law) problems if that were to occur. @ strange...u r not getting the point......plank time has to come in EVERY activity... Um, no. Why do you think this is so? Link to comment Share on other sites More sharing options...
robinpike Posted June 25, 2014 Share Posted June 25, 2014 The photon is not absorbed. You'd run into all sorts of selection rule (i.e. conservation law) problems if that were to occur. Are we able to describe what happens when the photon goes inside the atom? Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now