General Relativity.

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Re: Light and Energy
I don't think that intensity of light and energy of a photon have anything to do with each other because energy is merely an attribute frequency, not intensity. As for answering Ben's question, no clue here, good one though.

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do you know nothing of chemistry or physics? intensity of light produced by any reaction has a direct relation to the amount of energy given off.

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The intensity of light is a measure of the number of photons arriving in unit time. The energy of each one is dependent on the frequency of each photon.

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therefore the intensity of light has a direct correlation to the energy of a photon.

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I may have a very, very low intensity beam of xrays with a photon or 3 arriving per second and a very, very intense beam of yellow light with gajillions of photons arriving each second. However the energy in one xray photon will be several (don't remember the ratio) times that of one photon.

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the energy, or wavelength, of a photon determines the frequency of the light. the frequency of light determines the intensity of how we see that light. but the higher or lower the frequency doesnt always mean a more or less visible intense light. it entrails a more or less actual intensity. there are other aspects to light than what we see with our own eyes. photons all move at the speed of light. but depending on the wavelength of the photon, we see it differently. there is a small spectrum of light that we can view, everything else is invisible to us. that is why an x-ray would appear to be weaker, but is in fact very intense.File:Atmospheric electromagnetic transmittance or opacity.jpg - Wikipedia

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There are two concepts of intensity; one is independent of US, independent of our ability to SEE the light with our very own eyes. That is the sense in which intenisity is being used here (we are, after all, talking physics here). You're talking PSYCHOPHYSICS. PSYCHOPHYSICS is different, Roy. This thread is not about General Relativity in Psychophysics. It's about General Relativity.

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i know that, thats what i was saying in my post. it seemed to me that madeofstarstuff was talking about how we see light. i was trying to say that how we see light is not how all light actally is. so basically you and i are in agreement.please re-read my post with how it pertains to the two subjects:
"the energy, or wavelength, of a photon determines the frequency of the light (physics). the frequency of light determines the intensity of how we see that light (psychophysics). but the higher or lower the frequency doesnt always mean a more or less visible intense light (psychophysics). it entails a more or less actual intensity (physics). there are other aspects to light than what we see with our own eyes(ppsychophysics). photons all move at the speed of light(physics). but depending on the wavelength of the photon, we see it differently(psycophysics). there is a small spectrum of light that we can view, everything else is invisible to us(anatomy . that is why an x-ray would appear to be weaker, but is in fact very intense."

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First off no one knows what energy is.
Secondly the energy is a result of the affects the photons have on matter. IE: electrons making quantum jumps within the valances. The greater the frequency the greater the excitation of atoms, which gives off the energy as heat and light.
The element affected will determine what jumps and this will determine what color the light is.
Amplitude will determine how bright this light is.
Of course this could all be wrong as I am drawing on 30 year old information.

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i think you're pretty much right. but brightness is a part of psychophysics. there is photon intensity, which relates to the frequency, but it can only be viewed as brightness in the visible spectrum. a gamma ray has the most intensity, but we cannot see it because the wavelengths are too small.

just to clear some things up, i think none of us really completely understand photons, including me.from wikipedia:
"In physics, the photon is a quantum of the electromagnetic field, for instance light...The photon is one of the elementary particles. Its interactions with electrons and atomic nuclei account for a great many of the features of matter, such as the existence and stability of atoms, molecules, and solids. These interactions are studied in quantum electrodynamics (QED), which is the oldest part of the Standard Model of particle physics.In some respects a photon acts as a particle, for instance when registered by the light sensitive device in a camera. In other respects, a photon acts like a wave, as when passing through the optics in a camera. According to the so-called wave-particle duality in quantum physics, it is natural for the photon to display either aspect of its nature, according to the circumstances. Normally, light is formed from a large number of photons, with the intensity or brightness related to the number of them. At low intensity, it requires very sensitive instruments, used in astronomy or spectroscopy, for instance, to detect the individual photons..."Photon - Wikipediaas for ben's question, after reading this article i think i can shed some light on the subject (no pun intended)

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If the frequency of light is really just a statement about it's probability amplitude, then how is it that light's energy is related to it's frequency? It seems pretty straightforward to say that light's energy is then related to it's probability amplitude (and how often that little complex vector is spinning). Why would faster spinning of that little vector mean higher energy?

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The frequency of light is a "measurement of the number of times that a repeated event occurs per unit time,"(1) or the measurement of oscillations per second, in the usual case. the frequency of a photon is inversely proportional to the wavelength; the higher the frequency, the shorter the wavelength. The wavelength is the length between a crest and the next crest of a wave, or the "distance between repeating units of a wave pattern."(2) The amplitude of a wave is the "magnitude of the maximum disturbance in the medium during one wave cycle," (3) or the 'height' of a wave on a graph.a diagram depicting the wavelength, frequency and amplitude: 1) Frequency - Wikipedia
2) Wavelength - Wikipedia
3) Amplitude - Wikipedia

i think i see what you are saying. i dont really know much about photons, but in my work with sound waves, the amplitude does correspond to the energy, or the volume of a sound. i would assume the same goes for light. also, it takes more energy to create a higher amplitude.none of these terms correspond to how many photons there are in a light wave, though. the frequency, amplitude, and wavelength can all be applied to a single photon or many photons. say a single photon is travelling through space. we observe the photon and see that its oscillations repeat every one second, therefore it has a frequecy of 1Hz. Its wavelength can be determined by dividing the speed of the wave type (here, the speed of light) by the frequency of the wave (here, 1Hz). The amplitude is a bit more difficult, but it basically measures the energy of the wave. Intensity of a wave is the average fluctuation of energy through time. It is the energy per unit volume divided by the velocity of that energy.Intensity - WikipediaThis message has been edited by RoyLennigan, 09-28-2005 11:55 AM

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What is the volume of a photon? It seems intuitively obvious that a single photon should have an amplitude. Most things in this realm, however, go against some level of intuition. I just don't see, given the results of the photoelectric effect, how intensity/amplitude should differ between one photon of one frequency and any other photon of any other frequency? I further conclude that the energy of a photon is independent of its intensity/amplitude?

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analogous to sound, the 'volume' of a photon would be the amplitude, or the energy of the wave/particle. a single photon does have amplitude, just as many photons have amplitude. intensity and amplitude (in physics) are entirely different things. amplitude relates to how much energy the wave has, while intensity relates to the overall fluctuation of that energy per unit of time. i don't really know how the amplitude of one frequency differs from another. from what i've read it would seem that two different frequencies could have the same amplitude, yet have different intensities. the energy of a photon is definately not independant of its amplitude, seeing as amplitude is just a unit for measurement of energy.

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If amplitude and intensity are synonymous in your usage here, then you have to adopt a different understanding of light due to the results of Einstein's work on the photoelectric effect.

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amplitude and intensity are not synonymous, especially in my usage here. in my previous posts i was ignorant to the definition of intensity in physics, but i have since read into it."In physics, the word "intensity" is not synonymous with "strength", "amplitude", or "level", as it sometimes is in colloquial speech."intensity is a measure of the time-averaged energy flux. To find the intensity, take the energy density (that is, the energy per unit volume) and multiply it by the velocity at which the energy is moving. The resulting vector has the units of power divided by area (i.e. watt/m)."Intensity - Wikipedia

would this diagram refer to what you are talking about, 1.61803?

but you've got to understand that all these terms do not 'determine' an aspect of the wave. they are all measurements of certain aspects of the wave. the energy of a photon is not dependant upon its frequency, but rather the other way around. the amplitude, and frequency both depend on the energy of a single photon of the wave. the intensity depends on the energy of the entire wave, or source.about the site specifying that energy of a wave is dependant upon frequency only; well like i said. the energy is not dependant, but the other way around. and for the other part; amplitude is a measure of an aspect of the wave that corresponds to the amount of energy it has. when you turn up the volume on your speakers, you are increasing the amplitude of the sound wave they are producing, but you aren't changing the frequency of the notes being played. it works the same way with light.the last picture is sort of misleading because it is not in 3D. refer to the link in 1.61803's post after mine, message 42. electric fields and magnetic fields are at perpendicular angles.photons are grouped together that have the same frequency, amplitude, and wavelength; they all come from the same source, and have the same properties. the measurement that differentiates is intensity. intensity measures the energy per unit volume (volume=space) multiplied by the velocity. so it measures the overall energy of the entire wave, which varies depending on the number of photons. intesity is measured in watts, perhaps you can relate that to something familiar This message has been edited by RoyLennigan, 09-29-2005 02:08 AM

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How about, the frequency of a photon is a byproduct of its energy. Is that better wording or more accurate?

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yes, much better.

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But what I am trying to say is that you can't increase the amplitude of an individual photon because every individual photon's amplitude is the same regardless of the frequency. If you want more amplitude, you add more photons, which, in turn, increases the intensity of the light.

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amplitude is determined by the energy leaving the source as an interaction between the electric field and magnetic field. this energy then travels with individual photons. altogether, that energy would be the intensity (energy/unit volume * velocity). i think the only way the amplitude of a photon ever changes is when energy is lost in collisions. but if you added more photons then it would have a greater intensity, but they have to come from somewhere. i dont know if adding more photons affects the amplitude of the wave at all, because amplitude is a scalar, it measures the distance that the wave displaces. i would think, therefore, that amplitude only relates to the energy of each photon, not the overall energy. i know that you can measure the amplitude of one single photon, and you can also measure the amplitude of a group of photons from the same source, acting as a continuous wave.

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I'm not so sure about this. White light isn't composed of a bunch of photons all having the various characteristics you mention of white light. I think it is a bunch of photons of all different frequencies, and consequently colors, that make it appear white, as white is an amalgam of all colors. These can be separated, as I'm sure you know, through diffraction. Your statement is only true, as I understand it, for a coherent light source, i.e. laser.

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yes, of course, thats why i said it applies to a group of photons from the same source. white light is only white because we cannot differentiate all the different frequencies it consists of.

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All of these things being said, I maintain that the frequency of a photon is directly related to its energy and that the energy of an individual photon only changes for changing frequeincies. The amplitude of a photon of any frequency is the same, and intensity is a measure of photons (smallest possible packet of energy still related only to frequency) per unit time and related squarely to amplitude. I have seen no evidence contrary to this, only more evidence corroborating this. You have provided insight, but only relating the wave properties of photons to sound, which doesn't seem totally analogous. Perhaps there is something lost in the translation of thinking about photons as sound waves.

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frequency is related to the amount of energy in that, in a period of time, a higher frequency will carry more energy than a lower frequency. but the actual amount of energy carried by a photon is measured by amplitude. think of microwaves. the frequency of a microwave is less than that of visible light. but then how does it cook your food so fast? well, the particles have a greater amplitude. the same frequency can have different amplitudes, it depends on the source it is coming from. In fact, frequency, amplitude, wavelength, and intensity all depend on the source of the light. the same source produces the same frequency, amplitude, wavelength, and intensity, unless that source itself changes (chemically).all waves in nature are analagous, and the information i have been giving is information directly on photons. the only info about sound i have given is from my own experience. try looking at a wider variety of sites, specifically ones that are more professional.

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This is not true. The formula E=hf determines the energy of a photon based on the frequency of light. This energy is delivered in a packet, a quantum. There is no mention of any period of time going by.

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frequency is measured by oscillations per unit of time. how is that not mentioning time? the way i see it, a higher frequency has more oscillations, that means the 'waves' of the electric field and the magnetic field are closer together. this means that the packets of energy are closer together. therefore more energy would be transfered in one second of a 2Hz wave than in one second of a 1Hz wave. am i right?can you break down that equation for me? E is energy i presume, f for frequency, but what is h?btw, madeofstarstuff, sorry if i come off as condescending at all, its just my way of getting people to think more. believe me, this debate has made me learn a lot more about light than i previously did.This message has been edited by RoyLennigan, 09-30-2005 12:55 AM

yeah i've read a little bit about planck's constant. its just hard to remember so much, especially when i've learned most of it in the last few days. the two slits experiments is a pretty easy way to show wave-particle duality, but it seemed more and more clear to me as i studied this how wave-particle duality worked. i don't know if thats from naivete of the subject or what. early in my investigations i saw how frequency was the amount of oscillations, or number of crests in the wave, per second. then what 1.61803 said made me realize that these oscillations are the movement of a photon and some other particle (what would be the particle for the magnetic field?) later i saw a diagram (A) that made me think of particles along a wave path. it seems to me like the two types of particles are revolving around each other at 90 degree angles to their direction of movement.your second paragraph seems to further my premise that amplitude is the energy carried by individual photons, or packets as you put it, and not the entire group.This message has been edited by RoyLennigan, 09-30-2005 11:46 AM

JustinC, can you look back at message 37 posted by 1.61803 and how that corresponds to your post about how the properties of light cannot be described as both wave and particle?