Piano Forum
Non Piano Board => Anything but piano => Topic started by: m1469 on November 04, 2007, 04:59:47 PM
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hee hee... I can't help myself. I am currently very curious and need to know.
How does it actually come about ? I mean, why does the sun *shine*, for example ?
I know there is some kind of "power" or movement or force involved, and there must be some heat ... but, why does this produce something that causes us to be able to see ? And this causes me to wonder, how are light and vision related ? I think they are deeply related, actually. And, what is a true vision then ?
I know that colors are within light, but they don't actually *cause* light, right ? How does it all relate ?
An observation -- darkness does not seem to be anything but the absence of light, and therefore does not seem to have a distinct origin, a distinct value, a distinct function, nor distinct properties (separate from what would be related to "the absence of light") . Furthermore, I think that darkness does not actually give any value to or subtract any value from light, at least not in an objective sense -- it does not change the properties of light. Similarly, 2+2 = 5 being wrong (nor distinct origin, no distinct value, no distinct function, no distinct properites of its own) does not make 2+2 = 4 any more true, the value of the truth doesn't change based on anything but itself.
Okay. Bye bye ;D
PS -- What is the nature (or purpose (?)) of light ?
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Ligth is nor a vibration of energy, nor a particle. I read the most recent researches on it and it is a concept that human brain can not conceive, at the same level as the universe having no beginning. Light is "something" and does not in any way depend in vision. Our eyes simply capts the light, and transforms it into the image that is in front of us in the brain. Ligth does contain vibrations, and the frequency of this vibration is color in itself. Darkness is nothing but a human concept, that represents, indeed, absence of ligth. Darkness is nothing in itself ... Your assumptions are based on the wrong fact that darkness would be something ... it is not! You are in fact mixing ligth and darkness :P In what you're saying, that light would have to be related to vision, you are assuming that ligth is nothing but a concept we interpret with our eyes ... wich is wrong. Ligth is something in itself and does not need anything to exist. Darkness tough IS nothing, and needs the eye to exist: it is nothing, and when we see nothing we have to put a word on it : "darkness".
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I know that colors are within light, but they don't actually *cause* light, right ? How does it all relate ?
Get a nice bit of white card, cut it into a circle and colour it in with the colours of the spectrum.
Then put it on the end of a powerdrill and spin it around very quickly.
Cool experiment.
Thal
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My anus :)
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Your anus is the origin of light?
I did not know that old chap.
Thal :o
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You don't want to know what I go through to make nights happen.
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I always thought the sun shone out of your arse ;D
Thal
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I went to the planeterium the other day. It was super cool. I plan on reading many books on Space and the universe. About to read a briefer history of time which i bought today. I ope tis a good read.
Gotta get more stuff off the net.
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Light. A moment of watching the sky, the sun, the stars. A moment of hearing a dog bark. A moment in time. Maybe I will soon see the light of the comet Holmes which is currently visible according to the daily news. I hope so :). Light. A hope that everything after all will be fine. Light means so much to me. But darkness does as well. Darkness is nothing "bad" to me. It's "absence of light", okay. But I *love* to sleep or meditate or just *be* in complete darkness, focus myself, be just myself, be completely quiet, refind myself and everything. Darkness can be so "enlightening" and recreative.
Just a few thoughts :)
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You should have been a poet old chap.
Perhaps you are and i did not know.
Thal
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You should have been a poet old chap.
Perhaps you are and i did not know.
Thal
hee hee ;D
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Light is energy, particles called photons. Its the smallest unit of energy we know now, i think. The reason we can see Light is because photons are vibrating, creating a wave moving in all directions, which produced color. These wavelengths reflect off other objects, exposing those wavelengths (energy [photons] hitting electrons excitens it, releasing its photons inorder to stablize itself, which creates a wavelength of color we can observe). You can try this yourself infact, im not sure exactly how. I remember seeing a reflection of the color of my shirt when Light was hiting it one day. You can also try a more advanced version of thise, something i did in chemistry, heat some element (not a pure element, thats dangerous) and its electrons will be excited, exposing its wavelengths/colors (releasing photons).
Darkness is the absense of Light, but not the absense of energy. You could have a small box in a dark room, its absent in Light, but not absent in energy. Any form of matter contains energy, so nothing has no energy (this doesnt' include space, i've read something about it being dark matter (or something like that)). I guess the way to look at this is kenetic energy and potention energy, a box has potential energy because it has energy, its just not really doing anything, but set it on fire and it turns into kenetic energy.
I may be a bit wrong about the electron/photon energy thing, I took chemistry last year and really didn't pay attention, but this is the basic idea.
I don't understand that last paragraph mayla. And asking the purpose of light is like asking the purpose of life, i think. Its just the same, theres no real significance in our lives, or in energy for that matter.
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Light is energy, particles called photons.
Where do the photons go, when they run against a wall? Okay, they are reflected in some cases. But if the wall is black, they know it and vanish immediately :D
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If they run into something black, they get obsorbed? thats why a black car or something gets hot when its left out in the sun, and black is a color, its a collection of all colors isn't it? I wonder what maylas talking about, darkness or nothing-- ness?
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Where do the photons go, when they run against a wall? Okay, they are reflected in some cases. But if the wall is black, they know it and vanish immediately :D
If they run into something black, they get obsorbed? thats why a black car or something gets hot when its left out in the sun, and black is a color, its a collection of all colors isn't it? I wonder what maylas talking about, darkness or nothing-- ness?
Light is energy, particles called photons. Its the smallest unit of energy we know now, i think. The reason we can see Light is because photons are vibrating, creating a wave moving in all directions, which produced color. These wavelengths reflect off other objects, exposing those wavelengths (energy [photons] hitting electrons excitens it, releasing its photons inorder to stablize itself, which creates a wavelength of color we can observe). You can try this yourself infact, im not sure exactly how. I remember seeing a reflection of the color of my shirt when Light was hiting it one day. You can also try a more advanced version of thise, something i did in chemistry, heat some element (not a pure element, thats dangerous) and its electrons will be excited, exposing its wavelengths/colors (releasing photons).
Darkness is the absense of Light, but not the absense of energy. You could have a small box in a dark room, its absent in Light, but not absent in energy. Any form of matter contains energy, so nothing has no energy (this doesnt' include space, i've read something about it being dark matter (or something like that)). I guess the way to look at this is kenetic energy and potention energy, a box has potential energy because it has energy, its just not really doing anything, but set it on fire and it turns into kenetic energy.
I may be a bit wrong about the electron/photon energy thing, I took chemistry last year and really didn't pay attention, but this is the basic idea.
I don't understand that last paragraph mayla. And asking the purpose of light is like asking the purpose of life, i think. Its just the same, theres no real significance in our lives, or in energy for that matter.
You all are missing some points. Valor, you are rigth on some points, but your facts have been disproved : recent searches proved that photons are NOT particules, NOR energy, but something else human brains can't conceive. Some kind of a mix of the two. Those studies are one month or two old. Okay as of what light does when hitting black things ... didn't you guys read what I wrote on what color is ? Color is only how high the frequency of the light is. If you see a surface as black, it's BECAUSE that surface absorbs lots of light, instead of reflecting it. That's why everything black exposed to light will be hotter than something white. It's not because it's black that light gets absorbed, it's because light is absorbed, it's black. The more a surface will reflect light at it's full speed, the brightest the color of that surface will be. Of course, the constitution/strenght of the light will affect the color as well ... that's why things change color(to the eye) when they are outside, inside, under different lights.
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... Valor, you are rigth on some points, but your facts have been disproved : recent searches proved that photons are NOT particules, NOR energy, but something else human brains can't conceive. Some kind of a mix of the two...
Seriously? Oh god, so why is my school teaching all this old junk? Im going to do some research... Can you tell me where you got that information, thierry?
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It's not because it's black that light gets absorbed, it's because light is absorbed, it's black.
Okay, that sounds logical.
Now, where are the photons after they got absorbed? Do they vaporize?
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Seriously? Oh god, so why is my school teaching all this old junk? Im going to do some research... Can you tell me where you got that information, thierry?
Well you are not 100% wrong, it's just not exactly right. It was in an actuality scientific magazine, and it was some university research group that recently discovered that ... it's in french tough.
Okay, that sounds logical.
Now, where are the photons after they got absorbed? Do they vaporize?
As I told you we can not conceive what exactly light is basically, it's just over our heads ... so how could we know if that kind of thing can disapear or how it can change/evolve etc. My guess on this is that the material absorbs the actual energy of light, thus heating, and for the rest, we do not even know what is the rest ;D So it's kinda ambiguous ... altough i'm just reasoning logical on this, i followed a little astronomy class in college that's where my knowledge on light comes from(nothing too deep or w/e), and plus I read the recent experiments, so I got to know the origins of light are even less clear than before lol. So w/e, maybe some people know better answers as to what actually happens when it gets absorbed.
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If you think thats confusing, just think about what happens when light gets sucked into a black hole. sounds almost the same as light being obsorbed by dark things right? We know that energy or light can't just disapear though, because matter/energy cannot be destroyed or created.
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If you think thats confusing, just think about what happens when light gets sucked into a black hole. sounds almost the same as light being obsorbed by dark things right? We know that energy or light can't just disapear though, because matter/energy cannot be destroyed or created.
I had the chance to study black holes a lot, and it's absolutely fascinating. No it's not the same thing at all in fact. The absorbtion of a black thing is just plain normal, every that gets in contact with light absorbs it, at least in parts. Darker objects just absorb it more. In the case of a black hole, it just eats everything that is in his range. When light is absorbed by a black thing, it stays light or w/e, but anything a black hole eats, in fact BECOMES the black hole. Anything that goes into it's range is simply compact mass, without any kind of organisation. There is no atomic structure in black holes, the gravity is too important for it to exist. It's pure, compact mass without any kind of possible(known) organisation. If there still is a structure, it's WAY smaller than anything mankind ever explored.
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This has been most enlightening.
I've enjoyed Thierry's posts, especially the part about darkness.
I noticed, however, that the responses so far have been really answering another question: What is light? m1469 asked, What is the origin of light?
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origin of light is mass itself :)
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As I told you we can not conceive what exactly light is basically, it's just over our heads ...
Umm. Well not quite.
There are things that can be approximated with common language, but to really understand requires a specialized language. Light is one of those.
Is it a particle or a wave? Neither, those are just metaphors. What it is can be described fairly exactly and precisely.
I could tell you, and I would NOT have to kill you. Hee, hee, the old joke is wrong this time.
The problem is simply that to understand it takes math most of you haven't had. And trying to learn that math, well yeah that might kill you. <g>
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Isnt light like packages of waves?
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You all are missing some points. Valor, you are rigth on some points, but your facts have been disproved : recent searches proved that photons are NOT particules, NOR energy, but something else human brains can't conceive. Some kind of a mix of the two. Those studies are one month or two old. Okay as of what light does when hitting black things ... didn't you guys read what I wrote on what color is ? Color is only how high the frequency of the light is. If you see a surface as black, it's BECAUSE that surface absorbs lots of light, instead of reflecting it. That's why everything black exposed to light will be hotter than something white. It's not because it's black that light gets absorbed, it's because light is absorbed, it's black. The more a surface will reflect light at it's full speed, the brightest the color of that surface will be. Of course, the constitution/strenght of the light will affect the color as well ... that's why things change color(to the eye) when they are outside, inside, under different lights.
Where did you find these researches? Could you give me a source or publication?
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The more a surface will reflect light at it's full speed, the brightest the color of that surface will be. Of course, the constitution/strenght of the light will affect the color as well ... that's why things change color(to the eye) when they are outside, inside, under different lights.
Light at full speed? Is there something like light at 'half speed' then or didnt i understand einsteins laws correctly :p .
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Light as I understand it isn't going to have one universal origin as it depends if a source is present. It is a biproduct of whatever chemical reactions are taking place along with heat, and as the light energy released can not be destoryed is not to say that it is a constant concrete ideal as it can change into other forms of energy. So stars are our main sources of light so the origin I suppose relates back to the creation of the universe and the creation of the elements involved in the neccessary chemical reactions.
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Photons are particles and waves.
The idea that a particle cannot be a wave and vice versa is one based on our flawed common sense that arises of our very limited experience of reality. The human brain can perfectly conceive this. It just doesn't seem to make sense if you look at it with a view biased by our personal experiences.
Of course both are human concepts and already limited and bound by our daily experiences, which the world of photons is not part of. But photons behave both like particles and as waves. So why can't it be both?
This has been known by roughly 100 years already.
And yes, light is quantized. So they are packets of energy. They always move through vacuum at the same speed, light speed or c. They have a frequency, the frequency of the wave, and an intensity. The more intense light is, the more packets. The higher the frequency, so lower wave length, the more energy the photon has.
The origin of electromagnetic radiation is the big bang, of course. But, photons are just packets of energy. Photons are appear and disappear in and out of nothing continuously. If you look at a lamp the photons that it radiates only come into being when the warmth energy in the glow thread of the lamp are converted into photons. Before that, the photon does not exist.
Feynman had a famous story about that his father wanted to know where the photon came from. His father new that objects radiate out photons but he didn't understand what the origin of those photons were. Feynman tried to explain this to him by talking in terms of 'word bags'. If you saw a word then the word also appears out of nothing. You don't have 'word bags' and you don't have to fear running out of the word 'apple' because your word bag for 'apple' becomes empty. The word just appears the moment you pronounce it.
Same with photons. Atoms don't have 'photon bags'. The photon just appears out of nothing when the energy is being converted.
Electrons move into a lower energy orbital and the energy that this makes available is turned into an energy packet of the appropriate energy level. So by looking at the frequency of light you can figure out stuff about the orbitals. And if you know orbitals you can figure out which atom we are talking about.
Our bodies also radiate photons. The thing is that they are not within the visible spectrum. They are of course in the infrared spectrum. Everyone has seen pictures of 'infrared humans'. You radiate more photons from your eyes than from your nose. The nose is cold. And the eyes don't have bone blocking warmth. Yes, you are basically seeing warmth.
Metal objects that are very hot start to glow. They radiate in the visible spectrum. All this is called blackbody radiation.
Radiation is different from reflection. Even in a totally dark room with a total lack of 'light' our bodies generate electromagnetic radiation out of nothing. And a creature like a snake, some of which can see a little in the IR spectrum, can see that we are glowing with light.
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My anus :)
No.
God's anus.
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The fact that it is unconceivable to a human brain came from the article itself, based on the lastest tests. I understand your skepticity, but it's not just a mix of wave and particle. Yes the photon does exist as something similar to a particle, and it does vibrate, but what it is exactly, nobody can conceive(and that's a quote from the actual article, from scientists who studied maths and physics all there life and are specialists of light). If you think you can conceive better than them, you should go take their place. What you spoke about as to "known since 100 years" is what was known BEFORE that experiment, and that's the point of everything. Since this experiment, we can tell it's NONE of the two: nor a particle, nor a wave, that's what this recent experience proved. The source, I don't know it there is an internet one, but it was in a science actuality magazine (a french one) : Science&Vie (the september 2007 edition). So you can see those works are quite recent. And that's why it's inconceivable by the brain : it's not both at the same time, it's none of the two. The particle/wave duality is the only thing we found to get a humanly understandable concept, that's it that's all.
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Unless that article refutes that what has been taught for the last 100 years I am correct and that article is not.
And if that article actually refutes our understanding of the photon that we had the last 100 years then that strong claim requires strong evidence and not just a quotation of an obscure French science magazine.
You have to understand that 'particle' and 'wave' are concepts that come from our macroscopic world. And in 'our world' the one rules out the other. On the subatomic level this is just not true. All matter behaves both as a wave and as a particle.
And actually, so does your baseball or football. It's just that on the macro scale the wave-like behavior becomes insignificant because the Planck constant is so small.
You can calculate the wavelengths of macroscopic objects. But their mass is so large so that their momentum is always large enough to make their de Broglie wavelengths way smaller than even the most accurate of experiments one can conceive could detect.
This has been mainstream quantum mechanics for the last 100 years. All forms of matter in the standard model are referred to as 'particles' and all particles have a wave nature. That's the core of quantum mechanics.
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It's not a "quote from an obscure french science magazine", it's a top notch actuality magazine, and it DOES refute what has been taught over the last 100 years. The complete article describes the whole huge experience they succeeded to do recently(the experience was impossible before), and exactly why does it refutes what has been taught for 100 years. The experience was done by Jean-Francois Roch, from a random school, and by Philippe Grangier and Alain Aspect, both from the Orsay institute of optics, one specialist of atomic optics and the other specialist in quantic optics ... they both did this huge experience in wich they could observe single photons and whatever it's very very long to explain, but they just did a before impossible-to-do experience and proved the photon was none of the two.
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You guys should be more open about things, this is just like back then when people wouldn't except when the world was round when it actually is? We haven't discovered everything in the world, they're just theories.
https://www.groupsrv.com/science/about208467.html
is this the article you were talking about Thierry?
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Nah, that's just one of many experiments that confirm something that has been expected from the 'beginning'.
If there is really a revolution about to happen in physics I will wait for the real scientists to inform me about it. I just can't take your word for it.
In the mean time I will inform people about the current views on light. Now, almost certainly this view is incorrect. But it's by far the best we have.
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Well, to all practical intents and purposes light is an electromagnetic wave. Yes, it is also a particle phenomenon and let's not even get started on how electromagnetic waves propagate in a vacuum, wave/particle duality, blah blah - let's just do the basic, day-to-day physics stuff that scientists and engineers work with because they know in most practical situations it will give a sensible answer (I am qualified by education as a physicist and by experience as an engineer so I'm not making this up).
Light is a wave, and colours are different frequencies of waves. White light is 'noisy' - all the frequencies in the visible spectrum (which is about an octave wide, no more) together. Vision is receptors in the back of the eye responding to this wave and telling the brain about it. That's all. At frequencies below those of light, electromagnetic waves are variously infra-red, X-rays, microwaves and radio waves - it's all the same thing.
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Nah, that's just one of many experiments that confirm something that has been expected from the 'beginning'.
If there is really a revolution about to happen in physics I will wait for the real scientists to inform me about it. I just can't take your word for it.
In the mean time I will inform people about the current views on light. Now, almost certainly this view is incorrect. But it's by far the best we have.
That, is PART of the experiment that proved that photons are nor waves nor particles. Jean-francois Roch did do this experiment, but he teamed with the guys at Orsay institute to actually do the rest of the experiment. It's not my word, and they are not "fake" scientists. Why did it not revolutionize physics ? Because we didn't discover what it IS, we only discovered what it is NOT. It won't change anything in practical engineering or w/e ... it's just a step forward.
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That, is PART of the experiment that proved that photons are nor waves nor particles. Jean-francois Roch did do this experiment, but he teamed with the guys at Orsay institute to actually do the rest of the experiment. It's not my word, and they are not "fake" scientists. Why did it not revolutionize physics ? Because we didn't discover what it IS, we only discovered what it is NOT. It won't change anything in practical engineering or w/e ... it's just a step forward.
I believe the original article is here https://www.sciencemag.org/cgi/content/full/315/5814/966. The conclusion is, quoting the very last line of the article, "Once more, we find that nature behaves in agreement with the predictions of quantum mechanics even in surprising situations where a tension with relativity seems to appear". The essential point here is that standard quantum mechanics, exactly as it has been taught at every university for the last 70 years, has been confirmed once again. In other words, one can think of photons as particles, with their motion described by a wave function (which determines the probability of finding the particle at any point in space) - it is exactly this which is called "wave-particle duality", and which was confirmed by the French group of physicists. So, as far as our understanding of light is concerned, its origin, its behavior, its properties, its particle or wave-like nature, etc., this experiment says NOTHING NEW - it just CONFIRMS the OLD picture.
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Postscript to my post of last night: all this stuff about wave/particle duality, the fact that we can't 'visualise' photons or whatever, simply conceals the fact that we can't properly visualise anything that small. Scientists resort to maths and don't even _try_ to visualise these things.
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You both are not getting the point, you should read the COMPLETE article, because YES your quote is right, and it is said exactly the way in my article ... that same article wich says that the wave/particle duality is no more than the only way we can represent this thing, and that says humans can not understand what he exactly is. For me tough the article doesn't concludes this way, it's right in the middle(the quote you mentioned) ... quoted EXACTLY from the VERY SAME article in french(I'll translate afterwards):
"une fois encore, on observe que la nature se comporte en accord avec les prédictions de la mécanique quantique,même dans une situation surprenante" (that's the one you quoted) ... and the law of quantum mechanics they are talking about is not that it IS a wave/particle duality ... it's only the fact that the photon doesn't know what awaits him further ... and what is the very last line : "La réalité quantique est tout autre, et nous force à concevoir que le "quanton" (c'est-à-dire un photon ou tout autre particule élémentaire)n'est pas"à la fois une onde et corpuscule", mais plutôt ni l'une ni l'autre! Il est autre chose, que le cerveau humain ne peut probablement pas comprendre, et qu'il assimile selon les cas aux notions d'onde et de particule, les seuls moyens que l'on a trouvés pour s'en faire une image... La réalisation de l'expérience de Wheeler en est une nouvelle preuve éclatante."
Now for those who do not understand french, translation :
"the quantic reality is something else, and we are obligated to conceive that the "quanton"** (wich means a photon or any other elemantary particle) is not "at the same time a wave and a particle", but actually none of the two ! It's something else, that the human brain can probably not understand, and he assimilates it as the wave/particle duality, the only way we found out to be able to conceive an image out of it. The realisation of the Wheeler experiment is a spectacular new proof."
If you still tell me it IS the wave/particle duality, you are worse than muslim extremists...
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We are worse than Muslim extremists? Lol...
I give up.
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but, why does this produce something that causes us to be able to see ? And this causes me to wonder, how are light and vision related ? I think they are deeply related, actually. And, what is a true vision then ?
You're asking some of your questions from the wrong pov. The sun doesn't shine in a way such that eyes can see it, it's the reverse, something about us means we 'see' [and thus perceive] a particular part of the spectrum.
It's because we, and thus our eyes, evolved on a planet near a star that has a peak radiation in that part of the spectrum. Hence our eyes now see, and what, as a result, we call visible light [the atmosphere blocks parts of the sun's radiation as well, so that will have been significant too, no doubt]
So, it isn't the light that is special [compared with other parts of the spectrum] it's us and the circumstances in which we happened to evolve that were.
Bats see objects by bouncing sound off them and interpreting / perceiving their surroundings from what they hear. Our eyes are sensitive to the radiation [in various different ways that wikipedia / google will tell you much better than I will] which is bouncing off things all around us [and being emitted by some too] and our brains interpret that input to give us our perception that we call sight.
Aside from that, light isn't particularly special compared with other parts of the spectrum that aren't visible.
[That said, the various parts of the spectrum do differ when they interact with surfaces - which is why we can xray ourselves. This is another function of the wavelength, but it's also related to the intensity of the radiation and the composition of the surface it hits [or doesn't hit in the cases where it travels straight through :) ]
As for what causes the sun to shine, very basically, gravity collapses the sun's matter to the point where fusion begins [and this causes an outward pressure, the size of a star is, more or less, the balance between gravity and that outward pressure caused by the reactions inside. When a star runs out of fuel this changes, as a function of its mass] These reactions inside the star radiate energy, which eventually leaves the surface and, some of which, we see as visible light. 'Visible' is really to do with the temperature, e.g you can feel a baby radiates heat, because they are warm, yes? But you don't see them glow. If you put an iron bar in a fire eventually you see it glow.
I know that colors are within light, but they don't actually *cause* light, right ? How does it all relate ?
Colours relate to different wavelengths of the visible [i.e the bit we call light] spectrum.
It's our perception [and the fact we have cones in our eyes that are sensitive to different wavelengths] that sees colours. For objects that are reflecting light, we see their colour as the wavelength(s) they reflect when light hits them.
So it's probably better to say the light is of a particular colour, rather than colours are within light. For sunlight though, as you might have seen in a rainbow or prism, the light is made up of more than one wavelength. This spectrum of colours in the sunlight relates to the makeup of the sun, it's temperature and things like that. Scientists use the spectrum of distant stars to find out the same information.
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"the quantic reality is something else, and we are obligated to conceive that the "quanton"** (wich means a photon or any other elemantary particle) is not "at the same time a wave and a particle", but actually none of the two ! It's something else, that the human brain can probably not understand
That's true anyway. Science is like semiotics: signs for the reality behind the signs.
The muslim extremists will probably disagree, but you just need a man in a white lab coat and they believe everything. Ignorants :P
As i understand it, it cannot *be* a duality (wave/particle, as it is a contradiction). In a way it can, but that's anothe story.
On the subatomic level this is just not true.
But you can't draw a line, and say here's the subatomic level, here not.
Everything is *approximative* in nature. Fact. Therefore wave particle do not become the same thing, but approximate each other. Eliminating Inaccuracy and becoming mathematically exact creates theories which cover only part of reality, such as quantum theory and the theory of relativity.
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What seems to be true based on personal experiences in this macro world is obviously wrong on the sub atomic level.
And then we discover that even on the macroscopic level there is wave particle duality.
You have to understand that what we are understanding as particle behavior and wave behavior is purely arbitrarily based on what we humans think is particle behavior and wave behavior. And this is based on the very limited level of reality we live in.
In the end it just turns out that nature doesn't care about these distinctions and that all particles also behave like waves. Yes, you can say that that means they are neither. But that is our common sense bias. Fact is that mathematically particles, both on the subatomic and on the macroscopic level, all behave like what we traditionally call 'wave behavior'.
Wave-particle duality is a mathematical truism in science today. One may argue that this violates our conventional understanding of what waves and particles are and how they are different from each other. But this is just classical thinking and arguing about semantics.
In modern science there is no more conflict between particle nature and wave nature. We now understand that when energy is quantized it has to show both natures at the same time. And we know this is true for every particle of matter. The double slit experiment first showed us that this is true. And we know that observing or detecting collapses the wave function.
Yes, in the classical sense a photon is neither a particle or a wave. Even matter is neither of them, IN the classical sense.
But in quantum mechanical modern science our understanding is different. Particle vs wave turned out to be a false dichotomy. Just like nature vs nurture and mind vs body.
And about things making sense. Of course they don't make sense. How can they? If a scientific theory makes sense you can be sure it's wrong.
Our brains evolved under natural selection. And that means it is adapted to function and comprehend things on a very limited time scale and size scale. Because we don't live longer than 100 years we can't comprehend time scales larger than a 100 years. Because we can't see it we can't comprehend of sizes larger than 100 kilometer or smaller than .1 millimeter. If we could that would be a miracle because it can't be explained since this ability would gain us no benefit when it comes to natural selection. A gene that allows us to comprehend such a time would never have been selected for.
Therefore, science that deals with the very small or large both in size and time should not make any sense to us. And it doesn't. But still, just as we can calculate with numbers larger than 100 years or 100 kilometer, so we can do math regarding particles like electrons and photons. The math does not go above our heads.
My body is also both a particle and a wave. I can calculate the wave length of my body. And it's real. But because of the numbers I put in the particle nature will dominate greatly over the wave nature of my body. The wavelength of my body will be much smaller than the (classical) radius of an electron.
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But in quantum mechanical modern science our understanding is different. Particle vs wave turned out to be a false dichotomy. Just like nature vs nurture and mind vs body.
Yes. A difference has been made where there is no difference.
However, you know the definitions of particle, you know the definition of wave, being both is per definition a contradiction. It is *real* that matter behaves like both, but if you ask what it *is*, i wouldn't call it a particle/wave duality. It is that for us, but it is not that in reality.
Now you could perfectly say that this could be said about virtually everything, and you're right. ;D It's not necessarily reality as such what concerns humans. Still, a better explanation should be found to make the nature of the duality, it's behaviour and it's place in nature clear and easily understandable.
Our brains evolved under natural selection. And that means it is adapted to function and comprehend things on a very limited time scale and size scale.
I don't believe that. Humans are part of the universe. There's as much truth in humans as there is in anything else, in any other species, form of life, and everything that is matter.
I mean imagine an organism specialized to comprehend cosmic processes, they would complain not being able to understand what's going on on planets, and probably need a microscope to see us ;D
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There are no official general definitions of 'particles' and 'waves' in physics.
Scientific theories all handle with clear specific definitions of clear and specific waves or particles.
Then there are everyday dictionary definitions.
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Thierry - that quote you helpfully give is only saying what quantum physicists have been saying for at least 3 decades. I was taught _exactly_ that (waves/particles are at one time neither and both) in undergraduate physics in 1982 and it clearly wasn't entirely novel then. All that's happened since then is that more and more experiments have been devised and performed that prove it.
Well, that's not _all_ that's happened - other bits of physics have been sorted out, many details have been added to quantum theory, communism has collapsed in Russia etc. - but you get my drift....
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Because we don't live longer than 100 years we can't comprehend time scales larger than a 100 years. Because we can't see it we can't comprehend of sizes larger than 100 kilometer or smaller than .1 millimeter. If we could that would be a miracle because it can't be explained since this ability would gain us no benefit when it comes to natural selection.
AHAHAHAHAHAH. Speak for yourself and your uncreative primitive spongebrain that can only absorb and regurgitate pre-existing knowledge. Me and my homie Einstein are going to go discuss what it feels like to be miracles. Feels good. Feels real good. ohhhh yeah
Seriously. You are so frickin wrong about this one that it's disgusting.
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There are no official general definitions of 'particles' and 'waves' in physics.
Physics, being a science rather than a philosophy is experiments, observations and maths. You can't debate physics with forum posts written in English. It's de facto futile to try.
What you're debating is, more or less, the media and layman book output of various journalists, wikipedia and, perhaps, a few sound bites from actual physicists and possibly one or two introductory physics / science lectures.
Useful for answering m1469's questions, and to get some media attention for physics, but it's no more the actual physics than reading the dictionary definition of maths or one of the BBC articles like 'boffin cracks Fermat's theorem' is actually maths.
e.g one example of the difference. Here on the BBC the kind of stuff you see 'debated' in forums, from Hawking :-
https://news.bbc.co.uk/1/hi/sci/tech/3897989.stm - from this you'll find no end of forum debates using the language in this article, especially the bit where Hawking says he was wrong.
However, the actual physics, the real paper that he based these talks on has a summary that defies the idea that any of the media articles actually put forward the physics itself in a way that could fool someone into believing they now understood Hawking's physics.
The question of whether information is lost in black holes is investigated using Euclidean path integrals. The formation and evaporation of black holes is regarded as a scattering problem with all measurements being made at infinity. This seems to be well formulated only in asymptotically AdS spacetimes. The path integral over metrics with trivial topology is unitary and information preserving. On the other hand, the path integral over metrics with non-trivial topologies leads to correlation functions that decay to zero. Thus at late times only the unitary information preserving path integrals over trivial topologies will contribute. Elementary quantum gravity interactions do not lose information or quantum coherence.
Let alone the content, which isn't particularly difficult as these go, it nevertheless imo shows the fallacies and futility in these debates.
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fallacies and futility in these debates
Actually, I find that the really great scientists - Hawking, Feynmann, Gerzon etc. - can give at least some sense of what these things are about in words that the 'layman' to understand.
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If someone seems to have misunderstood a part of mainstream science I can only but try and help explain it and correct them.
I don't really feel like burrowing them in math. Plus, that won't help anyway.
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Actually, I find that the really great scientists - Hawking, Feynmann, Gerzon etc. - can give at least some sense of what these things are about in words that the 'layman' to understand.
If you want to really understand it, you have to do the math.
If you're content with getting the sense of it, and maybe leaving a couple of contradictions, the layman language is good enough fo 99% of us.
For m1469's purpose, three oversimplifications:
Light is commonly emitted when an electron drops from a higher energy orbit to a lower one, and gives up the extra energy as light. What frequency light is emitted depends on how far it dropped.
For us to see color the light has to hit the three primary color receptors we have in the eye, and these are blue, red, and green. (NOT what you were taught in art class). I have fewer than average red cones, so I am mildly color blind like a lot of males. Then the brain puts together the signals from the three types of cones and you perceive a color.
When light hits something it is absorbed and re-emitted through the same process. If it hits an opaque solid like a brick it is emitted backwards. If it hits glass it is emitted forward from molecule to molecule till it comes out the other end. If it hits a mirror it is emitted backward in phase.
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Actually, I find that the really great scientists - Hawking, Feynmann, Gerzon etc. - can give at least some sense of what these things are about in words that the 'layman' to understand.
Hawking already has written good-to-read and well illustrated books like 'the universe in a nutshell'. Though, physics IS complicated, you cant just write down nonsense so retards can understand it. For example light, you need a decent knowledge of how molecules are build, how electrones behave and even something of Einsteins E=mc2 how mass, energy and light interact. And lots of other biological stuff how the eye translates lightreflections of items to understandable pulses for your brains. I wont even start about wave/partical duality lol.
Light is hard, not something for your 'layman' to understand :p
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Actually, there is a lot of math in physics that is surprisingly simple.
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The maths might be simple, but most people dont have the 'freedom of mind' to combine that math with reality. They want stuff visualised before they can understand it, but how can you visualise stuff like duality or the concept of 'time'?
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The maths might be simple, but most people dont have the 'freedom of mind' to combine that math with reality. They want stuff visualised before they can understand it, but how can you visualise stuff like duality or the concept of 'time'?
That is a subtly profound comment.
For physicists, and we engineers, and a number of other technical types, somewhere in the education process math BECOMES reality. There is one-to-one correspondence with reality. Math is "necessary and sufficient."
We forget that for most of the world math is parallel to reality, and not really required at all. Math is neither necessary nor sufficient. And if you're part of that population, you just aren't going to believe me.
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Actually, I find that the really great scientists - Hawking, Feynmann, Gerzon etc. - can give at least some sense of what these things are about in words that the 'layman' to understand.
Indeed. Hence the popularity some of their books have. But not enough to actually make someone really understand and actually do something useful with the science or make a valid argument about which experiment / theorist or paper is correct.
For that you need to either use the model to make predictions, make observations, do experiments to test predictions or come up with modifications to current theory to explain discrepancies.
So you are making precisely my point. Any buffoon can read Black holes and baby universes or Brief history and (mis)understand it. I did that, I'm sure from the sales figures a lot more did, although I suspect more copies went unread. Give the ones that fancy they understand it, a copy of Hawking / Ellis the Large scale structure of space-time and ask them if it's correct.
For Feynman it's not even worth bothering with someone who claims to understand it, unless they're well on their way towards their own Nobel Prize.
If some layman claims to understand Feynman, they are claiming to be better than Feynman did himself. In truth, they probably can't spell his name properly.
But of course, those videos on the web https://vega.org.uk/video/subseries/8 are worth watching because physics and science in general is a fascinating subject for scientists and laymen alike.
Once something is known - or is the currently accepted pov, as you note, it's easy to explain, in layman terms, what was done and what it means, in prose. This is as profound as saying, once a proof is known in maths you can google for it or even, the more perverse, that maths is easy. Of course maths is relatively easy when someone else has figured it all out for us.
This is the equiv to that IQ test where you keep resending your answers until you get top marks, or have someone else point out the pattern - then it's easy - of course it is. The tricky part is getting top marks yourself, and then coming up with something new, where you can't check your answers against the teachers sheet, or on a website, at the end.
It's like Feynman's story of Fritz Houtermans telling his girlfriend he knew why stars shine - at the time that was something - he was the only one that did. The other day at the OU someone explained it, in precisely the layman terms you make with your point, to my 8 year old. Yes it's kid's stuff.
The QI effect works too. This is that pretty much everything everyone knows is, in fact, not actually the case. For example, Hawking talks in his popular books / lectures about an expanding universe [mentioning Einstein and his cosmological constant / steady state mistake along the way], but not one where the expansion is accelerating [because at the time that wasn't known]
Now, whatever conclusions / experiments and theories will advance from this observation about the expansion is science. That's what makes the subject fascinating and interesting from a layman pov - the work of scientists. Some will soon know all about it, and how easy the maths is, because they they know about google and wikipedia. You see scientists aren't as computer literate as them :D
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Not all science is easily explainable. There is still a large cash prize for anyone who can write a summary of general relativity that is accessible to the layman. I studied General Relativity in the third year of a maths degree, and the mathematical concepts involved are really difficult.
Of course maths is relatively easy when someone else has figured it all out for us.
I thoroughly disagree with this. Lots of maths is never easy. Reading mathematical research papers is massively time consuming. A 20 page paper is liable to take a fortnight to read and much longer to understand fully. Even just the statement of a result (ignoring the proof) can take days to figure out what it actually means, even for someone highly educated in the subject. Trust me on this, I'm a recovering mathematician ;D
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leahcim is just attempting to make fun of someone.
E=mc^2 is a first degree polynomial.
The relation between energy and matter could be so much more complex. Yet it isn't. Why should it be simple and elegant like it is? Of course this kind of relation makes sense. But why would it have to make sense?
E of m could be a crazy function with discontinuity and infinities all over the place. It could take 60 different variables rather than 1.
The only way it would be simpler is with E=m. It's extremely puzzling and interesting to wonder about why this math is so simple. And pointless, of course. At least, so it seems.
That is the point I was trying to make.
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leahcim is just attempting to make fun of someone.
Oops! I should've noticed :-[
E=mc^2 is a remarkably simple formula, although understanding that formula is more central to Einstein's Special Relativity, which is considerably easier than General Relativity.
You do realise of course that it couldn't possibly just be E=m, the units don't match up on both sides of that equation. (Good ol' dimensional analysis ;D)
I agree that it is puzzling and interesting, but it is far from pointless. That equation led to the atom bomb, amongst other things....
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E=mc^2 is the most famous equation in the world, yet it has zero application for 99.9999% of us, and it doesn't matter that most of us don't really understand it.
On the other hand, the lesser known F=ma affects every single one of our lives all day long, and deserves to become famous.
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E=mc^2 is the most famous equation in the world, yet it has zero application for 99.9999% of us
Well, you might think that, but if you get any of your electricity from nuclear power you're wrong!
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Oops! I should've noticed :-[
No I wasn't. That wasn't sarcasm. It is, in general, /relatively/ easier to understand a proof than to come up with it in the first place.
Markedly so. But that wasn't saying maths is easy.
If you're a mathematician then I can't see how you disagree. Otherwise why did you bother reading other papers? You'd be better writing your own new proofs, getting the medals and the cash prizes and leaving the difficult task of reading what you'd written to others :)
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I see your point now. I thought you were saying that once someone has proved a result, then it is easy for all to understand. Which is not the case, some proofs are horrendous. But yes, it is (usually - but not always) much easier to try to understand someone else's proof than to write your own.
I'm a (former) mathematician. Have just finished a PhD, but am now in the process of trying to sell my soul and move out of academia into the real world. Do you have a maths background then?
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Do you have a maths background then?
No, comprehensive education in Nottingham. I didn't even learn to shoot though.
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Hehe. I did my PhD in Nottingham! Ghetto represent :P
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m1469, your question is interesting, although not really answerable by anyone. There have been some nice explanations of wave/particle duality and photons, and how light is reflected/ absorbed.
The origin of all light is unknown, maybe the Big Bang! (Or Genesis, if you lean that way.)
Whether light does indeed exist without an observer is not so obvious. (Photons are emitted by atoms when electrons jump energy levels, but just what are photons without something to sense them??) Certainly color only exists to an observer, and is an outcome of receptors interpreting particular wavelengths (Like pitch in music--just wavelengths of energy until somebody hears them).
Interestingly, if you shine a flashlight into a completely black room, you will see NO light!
A Buddhist view of light equates it with universal "consciousness" --light infuses the universe and makes it coherent, just as consciousness infuses everything (to some degree), resulting in levels of awareness. These levels are of course very, very different whether you have a human brain and nervous system, or you are a mushroom. :)
Teresa
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a
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A Buddhist view of light equates it with universal "consciousness" --light infuses the universe and makes it coherent, just as consciousness infuses everything (to some degree), resulting in levels of awareness. These levels are of course very, very different whether you have a human brain and nervous system, or you are a mushroom. :)
Teresa
Some of the Buddhist view may be metaphorical, but not all, as this story about the Dalai Lama illustrates.
He believed, based on religious doctrine, that the moon emits its own light. When it was explained to him that science says the moon actually just reflects light, he asked for evidence. An astronomer showed him shadows in the craters. He accepted the evidence and changed his mind.
I would suspect adherents of many religions would have the opposite response.
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This thread is like physics 101, where every poster gets an F
Excuse me, evrything I said in my post is true.
Teresa
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Photons are emitted by atoms when electrons jump energy levels, but just what are photons without something to sense them?
They would still be photons.
Doh.
This is not a difficult concept.
What happens when there are only two people left in the universe, and one of them closes her eyes? Does the sun go to half power?
I think an F was generous. Perhaps you can defend your assertions or the authority with which you pronounce them.
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They would still be photons.
Doh.
This is not a difficult concept.
What happens when there are only two people left in the universe, and one of them closes her eyes? Does the sun go to half power?
I think an F was generous. Perhaps you can defend your assertions or the authority with which you pronounce them.
I think you've missed the point here. Science assumes this, but obviously it cannot prove it. There is not a single piece of data about the behaviour of unobserved photons. Not one. Anything science tells you about them is an assumption based in the assumed truthood of their theories, and not based on experimental data, as science is supposed to be.
It depends how much you are willing to trust science beyond the empirical results. Besides, if you have an understanding of quantum mechanics, you'll know that when we're not observing very small particles really really crazy things start to happen to them. Would they still be photons? Who can say. I know several (actively researching) quantum gravitists, and I think they would probably sit on the fence. A good scientist rarely accepts any assumption without first questioning it.
I'm assuming Teresa's question deliberately nods at the ol' 'tree falls in the forest' question. I think philosophy of science is wonderful, but I'm going to stop typing before I turn this into an essay.
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I think you've missed the point here. Science assumes this, but obviously it cannot prove it. There is not a single piece of data about the behaviour of unobserved photons. Not one. Anything science tells you about them is an assumption based in the assumed truthood of their theories, and not based on experimental data, as science is supposed to be.
It depends how much you are willing to trust science beyond the empirical results. Besides, if you have an understanding of quantum mechanics, you'll know that when we're not observing very small particles really really crazy things start to happen to them. Would they still be photons? Who can say. I know several (actively researching) quantum gravitists, and I think they would probably sit on the fence. A good scientist rarely accepts any assumption without first questioning it.
I'm assuming Teresa's question deliberately nods at the ol' 'tree falls in the forest' question. I think philosophy of science is wonderful, but I'm going to stop typing before I turn this into an essay.
Exactly. These particles have attributes when they are measured, but quantum physicists agree that they are in some sort of limbo when they are not. They have a lot of possible explanations for this strange behavior--Bohr's Copenhagen (the particles don't exist until measured), Wheeler's many-worlds (they follow all paths in multiple universes), Feynman's sum-over-histories, Einstein's feeling that quantum theory was an incomplete description--and now we have string theory and other newer hypotheses that attempt to explain it--but as Feynman said, nobody really understands it.
As for the Buddhist idea I mentioned, the idea of light/consciousness infusing the universe is quite compatible with many of quantum physic's quandaries, such as Bell's theorem of action-at-a-distance.
Teresa
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Exactly. These particles have attributes when they are measured, but quantum physicists agree that they are in some sort of limbo when they are not.
I think you are generalizing from concepts you don't really understand, and conflating physics and philosophy.
In the universe there are roughly one billion galaxies, each containing a billion stars, some with planets.
None of them care whether Teresa observes or not. While some religions teach that all of this was created just for man, man's influence seems to be less than predicted.
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Timothy, you shouldn't berate Teresa when it is you who is out of your depth in terms of understanding of physics. The observer is massively important in physics, not just philosophy. The introduction of an mid-way observer to a quantum-level experiment drastically changes the result. If this is your first introduction to quantum mechanics (QM) you will think I'm wrong, but I suggest you read up 'the two slit experiment'.
https://en.wikipedia.org/wiki/Two_slit_experiment#Quantum_version_of_experiment
The results are so counter-intuitive that it is really difficult to believe, but there has been thousands of experiments to back them up. This is accepted mainstream scientific theory.
Also as currently there is no accepted 'theory of everything' (string theory is refuted by many as pseudo-religious) you should not jump from from particles on a quantum level (photons) to massive phenomena such as stars, galaxies and planets, as the same rules do not apply. One is covered by QM, the other by General Relativity. These theories are vastly different.
Interesting point arises here. If you happened to read last week's New Scientist, there was a fascinating article about how we could have massively shortened the lifespan of the universe when we measured its rate of expansion. This is hardly accepted theory, but is definitely not without some merit. So maybe these stars do care about Teresa observing them after all......
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So maybe these stars do care about Teresa observing them after all......
You could be right if she is talking QM. I think she is not, this feels much more like postmodernism to me, but I will leave it to you.
If you read her wording carefully I think you'd have to agree I'm technically correct but I don't want to get hung up on a semantic detail.
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I see your point. Her comment was overly strong. I would go so far to say '....may exist in some sort of limbo....'
Anyway, I feel I've hijacked this thread for long enough now, so I'll retire to my geeky little corner. :)
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You could be right if she is talking QM. I think she is not, this feels much more like postmodernism to me, but I will leave it to you.
If you read her wording carefully I think you'd have to agree I'm technically correct but I don't want to get hung up on a semantic detail.
I was talking about QM. I don't know how my comment, which referred to Bohr, Einstein, Feynman, Wheeler and Bell could possibly be construed as "postmodernist". Those were physicists' interpretations of quantum theory observations. (bob pi's line about The stars "caring" about me observing them is obviously just a teleological /metaphorical comment on the indeterminacy of quatum phenomena until they are observed. And thanks, bob, for coming to my defense.)
Subatomic particles apparently have no attributes until observed. Einstein did not believe this, (He subscribed to your viewpoint that there is an objective reality that is there whether it is measured or not) and thus called quantum theory "incomplete". Other physicists have disagreed.
But none of what I was discussing is New Age woo-woo, it is basic QT. I mentioned Buddhism, which of course is not postmodernist, but 2500 years old. It is a philosophy, I grant you that. Their idea of a universal connectedness or onenness is compatible with Bell's Theorem which involves faster-than-light influence of one particle on another. If everything that exists is a manifestation of the same universal field, it could be compatible with QM.
When you talk about some people believing the universe was created for man, that is either (a) religion, or (b) the "strong version" of the Anthropic Principle. I didn't say that, nor do I believe it. And it really has nothing to do with quantum indeterminacy.
Teresa
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I think you've missed the point here. Science assumes this, but obviously it cannot prove it. There is not a single piece of data about the behaviour of unobserved photons. Not one. Anything science tells you about them is an assumption based in the assumed truthood of their theories, and not based on experimental data, as science is supposed to be.
It depends how much you are willing to trust science beyond the empirical results. Besides, if you have an understanding of quantum mechanics, you'll know that when we're not observing very small particles really really crazy things start to happen to them. Would they still be photons? Who can say. I know several (actively researching) quantum gravitists, and I think they would probably sit on the fence. A good scientist rarely accepts any assumption without first questioning it.
I'm assuming Teresa's question deliberately nods at the ol' 'tree falls in the forest' question. I think philosophy of science is wonderful, but I'm going to stop typing before I turn this into an essay.
One of the most enlighted post I heard from a scientific! Congrats on this !
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One of the most enlighted post I heard from a scientific! Congrats on this !
Why thank you ;D <insert really bad pun about origin of light/being enlightened here> ;D