Luminous Landscape Forum
The Art of Photography => But is it Art? => Topic started by: farbschlurf on November 18, 2017, 02:11:32 pm
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When your pictures are printed on a shopping bag ... :-\
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At least it isn’t *da Vinci’s Salvator Mundi. ;D
-Dave-
*Allegedly, that is. I gather the painting started as a Leonardo but may not have been completed by him, and at any rate has had a lotta work done to it over the centuries.
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At least it isn’t *da Vinci’s Salvator Mundi. ;D
-Dave-
*Allegedly, that is. I gather the painting started as a Leonardo but may not have been completed by him, and at any rate has had a lotta work done to it over the centuries.
Money is blind.
Rob
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Can you just imagine what a half-decent image by Leonardo would go for?
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Can you just imagine what a half-decent image by Leonardo would go for?
No, but a helluva lot more than one by yours truly ever will!
:-)
Rob
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I think I'll choose one of my own lesser images and offer a single print for sale for a half billion dollars. 8)
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I think I'll choose one of my own lesser images and offer a single print for sale for a half billion dollars. 8)
Huh! I heard about that print and the poison-pen killer hidden under the mount at the back!
One tiny question: is the list on archival support?
Rob
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Huh! I heard about that print and the poison-pen killer hidden under the mount at the back!
One tiny question: is the list on archival support?
Rob
The list should remain archivally intact, until it is placed in any light strong enough to read it, when it will fade completely in approximately 1 microsecond.
So I hope your check is in the mail, Rob.
Eric
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The list should remain archivally intact, until it is placed in any light strong enough to read it, when it will fade completely in approximately 1 microsecond.
My neutrino scanning gizmo doesn’t need no stinkin’ light. All your list are belong to me! ;)
-Dave-
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Can you just imagine what a half-decent image by Leonardo would go for?
Image?
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Image?
Leonardo was a multimedia dude!
-Dave-
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Leonardo was a multimedia dude!
-Dave-
His videos seemed a bit weak to me, and his tweets just never got off the ground, IMHO. 8)
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His videos seemed a bit weak to me, and his tweets just never got off the ground, IMHO. 8)
Lame Instagram too. In 7 years only one (http://comfortpit.com/leonardo-da-vinci-procrastination/) pic, and that one's a focus test.
-Dave-
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Lame Instagram too. In 7 years only one (http://comfortpit.com/leonardo-da-vinci-procrastination/) pic, and that one's a focus test.
-Dave-
Thanks for the link; I enjoyed most of it until it became obvious that the writer, too, had no idea when to quit. Or he was being smart, and proving his point without writing so.
Regarding "Adoration..." I have to say that I hold a different opinion: I think the artist was simply developing a new genre, a new style of graphic representation - almost an entirely new school of it. Perhaps it isn't unfinished at all, but very much completed in the new style. I like the concept a lot - almost photographic in the digital sense, because as we all know, a digital picture need never end (be completed), which is also its own greatest failure: the temptation to mess yet further is almost irresitible, if only because it's cheap and eminently undoable which, of course, is not the case with a wet print unless you include ferri in the afterwork... oh yeah, the new school of painting scored because its main man did resist temptation and stopped before going over the edge. It was the entire point.
(As my fading hope about Brexit, and its dreadful effect on my savings and my pension. Yep, I notice because of constant currency exchange needs stuffing it in my face; those still in the UK have escaped nothing: they just don't notice it yet in the sense of its true attribution and implications because the exchanging is being done, invisibly, by somebody else on their behalf: they think in terms of nebulous concepts such as inflation, full employment etc. and buzz words such as hard or soft Brexit without really seeing the inescapable damage already done to the finance and business sectors that fuel everything else. They expected instant measurements to prove or disprove...)
The Mona Lisa must have known: it's in her face.
Feel much brighter now, off to make a Nescaf' and suck on a biscuit.
;-)
Rob
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My guitar (or keyboard) playing these days consists almost entirely of messing about 'til I come up with a chord progression or rhythmic pattern or fragment of melody I like. Then I play it 'til the playing becomes a matter of muscle memory. At that point it might develop into something more, or it might not. Years and decades ago I'd feel compelled to turn such things into fully formed pieces, but now I don't care one way or the other. Making a new thing, even if it's just a fragment, is a satisfying end in itself.
My guess is Leonardo started the "Adoration" with something more conventional in mind. Whether he stopped working on it because he got stuck or bored or distracted, or because he felt he'd made something fresh & new & done…dunno. I do feel it's a glorious work as it is.
As for the other thing ;) grievance and loathing are powerful motivators, often superseding economic concerns. (Come to think of it, this likely applies to artists as much as anyone else.) Will the slower & longer-term drip of diminishing financial health be enough to overcome the immediate endorphin rush of being given political permission to despise? For anyone suckered by the scam in the first place, probably not.
-Dave-
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My guitar (or keyboard) playing these days consists almost entirely of messing about 'til I come up with a chord progression or rhythmic pattern or fragment of melody I like. Then I play it 'til the playing becomes a matter of muscle memory. At that point it might develop into something more, or it might not. Years and decades ago I'd feel compelled to turn such things into fully formed pieces, but now I don't care one way or the other. Making a new thing, even if it's just a fragment, is a satisfying end in itself.
My guess is Leonardo started the "Adoration" with something more conventional in mind. Whether he stopped working on it because he got stuck or bored or distracted, or because he felt he'd made something fresh & new & done…dunno. I do feel it's a glorious work as it is.
As for the other thing ;) grievance and loathing are powerful motivators, often superseding economic concerns. (Come to think of it, this likely applies to artists as much as anyone else.) Will the slower & longer-term drip of diminishing financial health be enough to overcome the immediate endorphin rush of being given political permission to despise? For anyone suckered by the scam in the first place, probably not.
-Dave-
I can understand that sense of racing ahead into the new: in a certain sense, it's part of keeping interest alive and functioning. It has its reflection in non-pro photography: once you know that you really can do what you want to do, then you are faced with the prospect of Groundhog Day. Perhaps the only rescue from terminal boredom is changing to radically different self-imposed themes - as mentioned in another thread recently.
It's opposite can be found in pro life, where if you get known for something, you may get bored with it, but it puts bread on the table, which is the thing upon which the rest of the game depends. In fact, you may well find pleasure in distilling that style down to its essentials, and discovering just how that can be done.
On the other: some day you must experience the UK's best-selling tabloids. No, perhaps not. But they do have the power to form opinion, just like the so-called social media sites... it's why all governments court such "journalists" as best they can. I do wonder, though, whether one should really and fully blame the journos: they all have jobs to safeguard. Is there a free press?
Rob
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On the other: some day you must experience the UK's best-selling tabloids. No, perhaps not. But they do have the power to form opinion, just like the so-called social media sites... it's why all governments court such "journalists" as best they can. I do wonder, though, whether one should really and fully blame the journos: they all have jobs to safeguard. Is there a free press?
I get a little of the UK's best :) from my Scots & English cousins. Don't want any more than that! The equivalents here are mostly *TV stations rather than print media. One of my dad's former engineering protégés, with whom I keep in periodic touch, is forever complaining about people glued to their smartgizmos and websites and social media platforms…while spending most of his afternoons & evenings glued to his idiot box propaganda conduit of choice.
There will always be pathogens. It's up to us to develop antibodies. Or succumb.
-Dave-
*And radio
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Dave, if you want a sort of ersatz version of our musical culture during the 1960s pirate radio period, here's a link to Radio Caroline (on 199! as they would announce) which ended up being two different transmitting boats moored outwith the 12mile limit of UK territorial waters - one serving the south and the other the north.
https://tunein.com/radio/Radio-Caroline-Flashback-s249564/
Rob
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Rob, I got to hear Radio Caroline in summer 1964, though I don't remember it per se. It was only many years later while talking with one of my cousins that she sparked a memory of the two of us dancing around to the music playing in her older sister's flat. "Radio Caroline on 199!" she said with a laugh.
I'll give the link a listen when I'm back home.
-Dave-
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Rob, I got to hear Radio Caroline in summer 1964, though I don't remember it per se. It was only many years later while talking with one of my cousins that she sparked a memory of the two of us dancing around to the music playing in her older sister's flat. "Radio Caroline on 199!" she said with a laugh.
I'll give the link a listen when I'm back home.
-Dave-
Yep, an enchanted era, if you were doing the right things! That was the problem: those things were ever difficult to break into, but if you could, the magic could be real enough.
Of course, the DJs doing their stuff on the link don't have the original silly, excited charm of, say, Tony Blackburn and his dog - probably fake - Arnold, who'd offer the lonely listener a friendly bark now and then. I say lonely, because photography was, essentially, a solitary occupation where you had moments of high-voltage collaboration followed by eons of work in the darkroom, mostly by yourself and the aural friends you switched on. Got me through many a cold night, where all I craved was getting home and into my bed. I think I enjoyed it, though.
Rob
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There's a podcast about the history of Hollywood movie making called You Must Remember This (http://www.youmustrememberthispodcast.com). It's thematic, with multiple episodes devoted to each theme. The latest series of eps was "Bela and Boris," centered around the careers of Bela Lugosi and Boris Karloff. I've gotten in the habit of listening to it while setting up guitars, to the point that I'll put off adjusting a neck, doing a restring, etc. until a new episode shows up in the queue. And when the podcast is between series, like now, I feel downright awkward tweaking a guitar without being accompanied by Karina Longworth's voice. :D
-Dave-
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There's a podcast about the history of Hollywood movie making called You Must Remember This (http://www.youmustrememberthispodcast.com). It's thematic, with multiple episodes devoted to each theme. The latest series of eps was "Bela and Boris," centered around the careers of Bela Lugosi and Boris Karloff. I've gotten in the habit of listening to it while setting up guitars, to the point that I'll put off adjusting a neck, doing a restring, etc. until a new episode shows up in the queue. And when the podcast is between series, like now, I feel downright awkward tweaking a guitar without being accompanied by Karina Longworth's voice. :D
-Dave-
David, that's worthy of an entire thread! Unfortunately, being the time of year, I have to devote my morning to another bout of bookkeeping, where I have to judge whether there's enough cash in the local bank to handle the car insurance, the next set of Community Dues for where I live, and a host of other end-of-year payments that fall into place. Seems that no sooner have I done it for one year but it's time for the next. There is absolutely no doubt that the older one gets the faster time does move. I don't think it's relative - I think it is factually so. Quite how the different speeds mesh in this so-called reality we inhabit I know not; guess it's all part of the grand mystery of life. Which zone the driver of that Amtrak train was in, doing 130kph in a 50kph zone, I know not. Fortunately my zones affect mainly just myself.
My fiscal exercise reveals, yet again, how dumb has been Brexit and its direct, exchange rates effect upon my financial health; for any to imagine its impact impinges only upon those living abroad, then they must also assume their own life on their little island is totally self-contained, that there is no dependency upon foreign trade whatsover. I bet many think just that. Maybe over 50% thinks just that; the same 50% that imagines it is now going to be even more of a trading nation. Talk about confusing contradiction!
Rob
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One of the fun things you can do with Special Relativity is perform thought experiments that highlight how weird the cosmos actually is. You and a friend are travelling towards each other on parallel train rails at the same very high speed. A significant percentage of light speed in fact. You're on a souped-up solar system-spanning section of Tokyo's Tōkaidō Shinkansen railway. As your trains get closer you can use super-duper telescopes to see each other. You look at your friend through your scope while waving and you see her or him looking back and also waving.
But your friend seems to be waving in slow motion, as though underwater. She or he smiles at you and the smile also seems to happen in slow motion. In the language of physics you're travelling at a relativistic speed and the slow motion you're observing is known as time dilation. But your friend's waving is a blur of sped-up motion as are her or his other movements.
Now switch to your friend's perspective. She or he is looking through a scope as your trains get closer and seeing you wave and smile. Your waving and smiling in slow motion also appears to your friend as a blur of motion. Now how can this be? If you see your friend moving slower faster relative to you, shouldn't your friend see you moving faster slower relative to her or him? In this case, no. You and your friend are both travelling fast enough that from both your perspectives the rest of the observable universe has slowed down sped up. This effect was first tested experimentally with atomic clocks in the early 1970s and has been confirmed by all such experiments to date. Our GPS system needs to compensate for it in order to work properly.
-Dave-
[Edit: corrections after a quick chat with a friend who's accustomed to my neophyte mistakes. "Ummm…you're giving an example of time contraction to explain time dilation." The part about atomic clocks and GPS is true but not as relevant as I'd thought, thus now also crossed out. I'll shut up now. ;D]
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One of the fun things you can do with Special Relativity is perform thought experiments that highlight how weird the cosmos actually is. You and a friend are travelling towards each other on parallel train rails at the same very high speed. A significant percentage of light speed in fact. You're on a souped-up solar system-spanning section of Tokyo's Tōkaidō Shinkansen railway. As your trains get closer you can use super-duper telescopes to see each other. You look at your friend through your scope while waving and you see her or him looking back and also waving. But your friend seems to be waving in slow motion, as though underwater. She or he smiles at you and the smile also seems to happen in slow motion. In the language of physics you're travelling at a relativistic speed and the slow motion you're observing is known as time dilation.
Now switch to your friend's perspective. She or he is looking through a scope as your trains get closer and seeing you wave and smile. You're waving and smiling in slow motion. Now how can this be? If you see your friend moving slower relative to you, shouldn't your friend see you moving faster relative to her or him? In this case, no. You and your friend are both travelling fast enough that from both your perspectives the rest of the observable universe has slowed down. Time dilation was first tested experimentally with atomic clocks in the early 1970s and has been confirmed by all such experiments to date. Our GPS system needs to compensate for relativistic effects in order to work properly.
-Dave-
That's because the relativistic "effects" are merely a direct result of the math involved. We use the math to predict the effects, we came up with the math because we observed those effects. The math is build on the premiss of a fixed speed of light and everything else either goes to infinity or to zero to compensate for that premiss. Like for example "we need an infinite amount of energy to accelerate a small mass to nearly the speed of light".
The far more problematic issue with the thought experiments is the reference frame: the math helps to convert from the observer to the observed, but it implies a third reference frame within which you and the friend are travelling in known directions...???
But here is an even more intriguing question for you:
if we consider the speed of light as fixed, then what is actually causing red shift to occur?
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I have absolutely no idea about the physics of it - my wife would have enjoyed this concept, especially if chemistry could be brought into the equation (she loved maths too) but I can tell you this: the more I am exposed to such ideas the more convinced I become that we are indeed creatures of a creator power.
In my mind, life seems just too complex, too brilliantly designed throughout the different species, and beyond that into the rest of what surrounds us and makes up what we are aware of in existence ever to have been accident. Much closer to home, I think of the circuitous paths that led me and my better-half to meet and go on to create our own little dynasty ever to be able to think of it as chance. Chance would have stopped us ever getting together that way - others had the same conscious wishes regarding us but to no avail. It's another way of saying that what will be will be, but the obverse of that is that what is not never can be. So yes, I believe in a grander design than my own. Call it God, call it whatever name is convenient for the time and place, but for me it's very real. Better yet, it brings comfort for the long run. I think this is but a staging post, a stop on the way.
Rob
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But here is an even more intriguing question for you:
if we consider the speed of light as fixed, then what is actually causing red shift to occur?
The Purkinje shift, but in polarised light, of course. Everybody knows that.
:-)
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I have absolutely no idea about the physics of it - my wife would have enjoyed this concept, especially if chemistry could be brought into the equation (she loved maths too) but I can tell you this: the more I am exposed to such ideas the more convinced I become that we are indeed creatures of a creator power.
In my mind, life seems just too complex, too brilliantly designed throughout the different species, and beyond that into the rest of what surrounds us and makes up what we are aware of in existence ever to have been accident. Much closer to home, I think of the circuitous paths that led me and my better-half to meet and go on to create our own little dynasty ever to be able to think of it as chance. Chance would have stopped us ever getting together that way - others had the same conscious wishes regarding us but to no avail. It's another way of saying that what will be will be, but the obverse of that is that what is not never can be. So yes, I believe in a grander design than my own. Call it God, call it whatever name is convenient for the time and place, but for me it's very real. Better yet, it brings comfort for the long run. I think this is but a staging post, a stop on the way.
Rob
For me the presence of a higher something is evident in this; every once in a while, not too often fortunately, you pass by a complete stranger and look them in the eye, however briefly, and you know with absolute certainty throughout the core of your being that you already know that person, that you are connected. Sometimes there is acknowledgement, almost as if you both want to say "hey, good to see you too!" but you don't say that because it would be an extraordinarily awkward thing to say of course.
That's what I like about EVFs. You'll never run into that problem while taking pictures...
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But here is an even more intriguing question for you:
if we consider the speed of light as fixed, then what is actually causing red shift to occur?
Light speed isn't really fixed. What we refer to as the "speed of light" is the maximum speed that anything can travel in space. Massless objects like photons can go faster than anything with mass. (As far as we know.) But light can and does travel slower when interfered with. It interacts with mass. In the lab it can be slowed to a crawl by sending it through a superfluid.
Red shifting is a result of lengthening wavelengths rather than reducing velocity, though the same interaction/interference may result in both. Temporarily in terms of velocity, less so in terms of wavelength.
-Dave-
Disclaimer: I know a handful of astrophysicists, one of 'em quite well. But I'm certainly not one myself.
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Red shifting is a result of lengthening wavelengths rather than reducing velocity, though the same interaction/interference may result in both. Temporarily in terms of velocity, less so in terms of wavelength.
The duration of detection. An interesting concept if you think about it, since we are on a photography forum.
Does it take less time to detect a blue photon as opposed to a red photon?
Or is it the duration of detection that determines the color we assign to it?
Does a photon perhaps always hold the same amount of energy, just compressed into a shorter length of time?
Is the duration of creation relevant? If the source is moving away from us, does the duration of creation increase relative to us as observer?
And in case you're wondering, yes, those are relativistic thought experiments that keep me awake at night. Or the questions come up when I'm already awake. Don't know. I have a cause & effect issue clearly...
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The far more problematic issue with the thought experiments is the reference frame: the math helps to convert from the observer to the observed, but it implies a third reference frame within which you and the friend are travelling in known directions...???
Neglected to put this in earlier… In Special Relativity the idea of a fixed reference frame, a background against which everything else can be observed and measured, is tossed out. In its place you get a fixed parameter, the "speed of light," which is the same in all reference frames. It's this fixed speed limit that leads to the time dilation effect observed by the rail travellers. Different degrees of it will be observed depending on how fast the travellers are going relative to each other.
None of this may be fundamental, but in our macroscopic realm it's holding up so far.
-Dave-
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Does it take less time to detect a blue photon as opposed to a red photon?
Or is it the duration of detection that determines the color we assign to it?
Does a photon perhaps always hold the same amount of energy, just compressed into a shorter length of time?
You can think of a single light wave as always containing the same total amount of energy, packed into a tiny length (gamma ray) or a long one (radio frequency) or something in between. I'd think shorter wavelengths would correlate with longer duration since they pack more punch. Radio photons are zipping through us continuously, unnoticed, while the same amount of gamma photons would turn us into pulp pretty quickly.
Don't quote me on any of this. :)
-Dave-
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But your friend seems to be waving in slow motion, as though underwater.
Is this the right way around? travelling toward each other, there will be a blue doppler shift, so the waving (which is after all just a low frequency oscillator) will be sped up... no? A simple way of thinking of it is that she needs to fit in the same number of waves while approaching, but the early waves take longer to arrive and the whole waving performance is therefore squeezed into a smaller time window.
The time dilation effect would be seen if you were watching your friend zoom past you while you were on the platform, so that her velocity vector would be instantaneously orthogonal to the line of sight between you. You'd also see it (as a general relativistic effect) if she was zooming into a black hole... because you never actually get to see her go over the event horizon, her last actions while approaching it get stretched out over a very long time.
And yes, GPS uses both special AND general relativistic corrections: the first to allow for the speed of the satellites, the second for the earth's gravitation field being smaller at the altitude of the satellite.
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if we consider the speed of light as fixed, then what is actually causing red shift to occur?
It's *because* it is fixed. The number of wave crests coming past you is invariant, so to fix up the relationship between the rate at which they are being generated in one frame and seen in another, the frequency of passing them has to change.
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It's *because* it is fixed. The number of wave crests coming past you is invariant, so to fix up the relationship between the rate at which they are being generated in one frame and seen in another, the frequency of passing them has to change.
But that suggests a longitudinal wave which probably isn't applicable in the first place, but even so: regardless of how fast the source is moving towards or away from you, the photons will move towards you with the speed of light. So, if the observer frame is a frame at rest, then how come they still perceive a shift?
Considering the known dimensions, it would be reasonable to assume that a photon represents a single ripple with a specific duration. If a source is moving away from us (or is under gravitational stress) the duration seems to increase for the observer and thus the light seems to shift to red.
In the classical model it may also be the case that the electron jump becomes larger on one side of an atom and shorter on the other. Electrons have mass so they will experience inertia relative to the acceleration meaning they no longer make perfect circles, but slight ovals.
Again, this is not something i should be thinking about considering i prefer to sleep well.
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This is getting more interesting by the minute, but sadly, it's all way above my cranium; better check out before I hit a red light too. However, I shall enjoy the spectacle of debate from the platform - or the railroad if there is no station with cafeteria available.
:-(
Rob
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But that suggests a longitudinal wave ... reasonable to assume that a photon represents a single ripple with a specific duration. If a source is moving away from us (or is under gravitational stress) the duration seems to increase for the observer ... electron jump becomes larger on one side of an atom and shorter on the other. Electrons have mass so they will experience inertia relative to the acceleration meaning they no longer make perfect circles, but slight ovals.
Oscar I'm sorry, but do you know what any of these words mean? It's really not possible to think clearly when you just have a stew of undefined words. You are mixing up quantum and relativisitic physics, mechanical and EM wave ideas...
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Oscar I'm sorry, but do you know what any of these words mean? It's really not possible to think clearly when you just have a stew of undefined words. You are mixing up quantum and relativisitic physics, mechanical and EM wave ideas...
Which explains the menopause, which I've experience at least twice in my life.
The first one had me wanting to sell our house to buy a boat and live in it, in the Mediterranean; the second had me selling off my twin 'blads, lenses etc. to go 6x7. In the first instance, my wife saved us; in the second, she claimed not to care about photography any more, and probably wished I'd forget about it too. She was right the first time, probably the second time as well, but she failed to insist.
Like I wrote before, she was into the sciences. I think I preferred to dabble in metaphysics of my own construction.
Rob
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So far I think Rob C's posts have given me a better understanding of special relativity than anybody else's posts. ::)
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So far I think Rob C's posts have given me a better understanding of special relativity than anybody else's posts. ::)
You should hear him on quantum mechanics!
;-)
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Is this the right way around? travelling toward each other, there will be a blue doppler shift, so the waving (which is after all just a low frequency oscillator) will be sped up... no?
Yep, I got it backwards. "Again," as my friend Kate noted when I ran it by her. :)
-Dave-
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Oscar I'm sorry, but do you know what any of these words mean?
Of course not, why do you think this keeps me from sound sleep?
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You should hear him on quantum mechanics!
;-)
No, Keith, for that one needs the combined efforts and collected reminiscences of David Bailey and the late, great Brian Duffy. Oh! What a Lovely War was where the mechanics really came together, with his, Bailey's, initial investment being sold off to another punter, making Bailey the only one to come out of it unscathed. I believe Duffy clung on, perhaps just to prove his mucked mistaken, but that takes more detective work than I could finance at short notice. One of the Attenboroughs was involved, not the one famed for life in the wild. Which might seem a bit ambiguous, now that I think about it. Perhaps both habitats were/are a bit wild...
For deeper clarification, dig this:
https://www.youtube.com/watch?v=dMWHi-SPEf0
:-)
Rob
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Ok, I'll attempt my two paragraph explanation of special relativity.
Suppose you have a stick, 1 metre long. You lay it on the ground pointing straight away from you. So you could also describe it as stick that goes from here, 1m forward. However if turn a little bit, it nows goes mostly forward, but a bit to the side. Our brains see this as quite ordinary, and if we wanted to do it with maths we'd say that in one reference frame the stick went to the point (1,0) and in the other to (cos(theta), sin(theta)). What is important is that 1²+0²=cos²(theta)+sin²(theta)=1... the length of the stick doesn't change, I'm just looking at it from a different angle.
The idea of space time is that different speeds are just moving through space-time at a different angle: if you position (x) doesn't change as t increases, we say you are stationary... tilt things over a bit and x increases in proportion to t. That means you are moving. In fact it turns out that the invariant is not x²+y² as it is in the spatial directions, but x²-t² (or x²+y²+z²-t² in full). If you observe something from different reference frames, you rotate a bit between t and x, but x²-t² stays constant. The corresponding rotation functions are cosh(v/c) and sinh(v/c) instead of cos(theta) and sin(theta), and the time dilation and length contraction effects come from applying them like a rotation.
And that's it.
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Shit, Graham, if you'd just stated that at the begining, there'd be no confusion: everyone would have understood right away.
Rob
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Perhaps i should restate my confusion with red/blue shift.
I'm on earth looking into the night sky with a very expensive telescope and a fancy spectroscope. For simplicity's sake we will assume the earth fixed in space and a galaxy i'm observing is moving with considerable speed straight towards me.
I detect blue shift.
Somebody tells me, yes, that's a doppler effect, no different than the higher pitch of sound from a sound source that is travelling towards you.
Except, i realise, that can't be the case, because:
A: there is no "carrier" for light in a vacuum as there is for sound pressure waves in air.
B: no matter how fast the galaxy is travelling towards me, the light will still reach me with the speed of light which we assume as fixed.
Because the speed of the photons reaching me is fixed, the speed of throughs and peaks in the wave, if that would be applicable, don't change for me as observer, unless time is somehow compressed in the photon itself.
So, the question remains: what causes the shift?
Does this make my confusion any clearer? :-\
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Since I'm color-deficient, does that mean that blue-shift and red-shift don't apply to me? ???
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Since I'm color-deficient, does that mean that blue-shift and red-shift don't apply to me? ???
Thinking this question through, Eric, I'm inclined to conclude that just as long as your green credentials are strong enough, you can safely disregard the reds and the blues.
Just avoid fossil fuels and all will be well with the continuum.
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Oscar, in your example you'll see lightwaves emitted by an object coming toward you at high speed as shorter (blueshifted) compared to what you'd see if the object were moving slower or not at all. It's a relative rather than absolute thing.
-Dave-
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Oscar, in your example you'll see lightwaves emitted by an object coming toward you at high speed as shorter (blueshifted) compared to what you'd see if the object were moving slower or not at all. It's a relative rather than absolute thing.
-Dave-
I know, i already mentioned that i would detect a blue shift, but the question is: what's causing the shift? The speed of the photons (relative to me) doesn't change, regardless of how fast the source is moving (relative to me) when the photons are emitted.
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Because the "speed of light" is an upper limit on velocity, you can't add the speed of the source emitting light (the galaxy in your example) to the speed of the light itself and get a faster speed. Instead what happens is that the light coming from the approaching galaxy appears compressed in wavelength (that is, blueshifted) compared to if the galaxy were standing still relative to us. Spectrographic studies of galaxies show this effect. In some cases the rotation of a galaxy around its own center will result in blueshifted light from the part rotating toward us and redshifted light from the part rotating away from us.
-Dave-
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Because the "speed of light" is an upper limit on velocity, you can't add the speed of the source emitting light (the galaxy in your example) to the speed of the light itself and get a faster speed. Instead what happens is that the light coming from the approaching galaxy appears compressed in wavelength (that is, blueshifted) compared to if the galaxy were standing still relative to us. Spectrographic studies of galaxies show this effect. In some cases the rotation of a galaxy around its own center will result in blueshifted light from the part rotating toward us and redshifted light from the part rotating away from us.
-Dave-
Yep, and the fact that we can see the galaxy side-to-side, regardless of which direction it rotates, tells us something else: the photons emitted are always emitted at the speed of light. Their speed towards us is not influenced by the speedvector of the source. Even if the source is moving away from us, you don't have to subtract that speed. The photon still travels with maximum lightspeed towards us after emission. Which perhaps isn't as strange as it seems since they don't have mass and therefore the speed of the source isn't transferred to the photon by impuls or other conventional earth physics.
So, the questions becomes:
1. how is the photon created
2. what causes the photon to be compressed/expanded?
The problem of course is, this being relativistic, that neither the source, nor the observer is moving as far as the photon is concerned.
Something happens during the exact moment of creation that influences the (perception of) the photon.
Some possibilities:
If the duration of creation of a photon is always fixed, then the movement of the galaxy relative to me changes that duration in my perception. So that could cause a shift. Though this doesn't quite explain why there is such a thing as gravitational shift.
If the creation of a photon is influenced by the size of an electron jump (classical model) then perhaps the electrons are moving in a non-circular cloud around their atom core. This would happen in a gravitation field, or when the atom has been under acceleration.
Whatever happens during creation, the same thing should happen in reverse during the detection of the photon. If both me and the galaxy are moving at considerable speed in the same direction, I would not see any shifts. In fact, I would be unable to tell we are both moving.
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I know, i already mentioned that i would detect a blue shift, but the question is: what's causing the shift? The speed of the photons (relative to me) doesn't change, regardless of how fast the source is moving (relative to me) when the photons are emitted.
What do you mean by "cause"? You are looking at them differently, so they look different. That's all. Same as looking at a stick from a different angle, that's how it is.
Another way of saying it is: "because it's a necessary consequence of a universe where everyone sees the speed of light as the same"
What you might find you mean by "cause" is: "please explain this to me in a way that fits with my intuition", ie in a way that doesn't require you to change how you think things work. Can't do that... your intuition is wrong, it needs to be re-trained. But it's a MUCH less violent mental re-configuration than quantum mechanics ("If you think you understand it, then you don't understand it" - Paul Dirac)