Unrelative Relativity Part 2

Discussion in 'Physics & Math' started by Prosoothus, Jun 12, 2002.

  1. Prosoothus Registered Senior Member

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    Crisp,

    You should be carefull with your beliefs, they are VERY unscientific.

    Let me remind you, the reason that science has made so much progress in the last three hundred years, is the result of standardization. By standardization I mean that all people observing a phenomena agree that the properties of that phenomena are the same, even though those same properties are being perceived differently by every observer.

    Without taking into consideration the absolute values of these phenomena, there would be NO progress in science.

    Example: If one observer assumes that the Sun goes around the Earth and another observer assumes that the Earth goes around the Sun, and both agree that they are both correct, would a formula for gravity ever have been created that is correct in both cases???

    The fact is is that science does not care about observers or the perceptions of the observers. Science only deals with "real" values, not the illusions that observers may be perceiving. For example, if I look up at the Sun, and according to me the sun is 2 inches wide, my value of 2 inches will not be included in any scientific formulas because it is not a "real" value, it's a "perceived value". Einstein tried to force philosophy into science by implying that all "perceived" values are real values, and unfortunately the scientific community accepted it.

    You and James R have this faulty belief, because the two of you are not breaking your ideas down into the least common denominator. To stress my point, here's a question for both you and James:

    You have the most fundemental subatomic particle (the particle that everything else is made of) sitting relatively stationairy in space. The particle has a quantum of mass of one (since it's the fundamental particle). An observer flies toward the particle at .90c. What is the mass of the particle???

    1) The mass of the particle remains one quantum. The observer, because of his speed, "percieves" the particle to have 2.29 quantums of mass.

    2) The particle sees the observer so it "pretends" to have 2.29 quantums of mass in order to confuse the observer.

    3) The particle has one quantum of mass, and 2.29 quantums of mass at the same time. It's mass is also all other values because there are infinite frames of reference. (Let me remind you that if you choose this option it means that the particle does not exist, because in order for it to exist, it must have an absolute mass).

    So, Crisp and James, which is the correct answer 1,2, or 3?

    Tom
     
    Last edited: Jul 11, 2002
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  3. James R Just this guy, you know? Staff Member

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    Option 3 is correct. The caveat you place on it is wrong.
     
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  5. Prosoothus Registered Senior Member

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    James R,

    First, how can the quantum mass of the particle be fractional??

    Secondly, if the particle has different masses at the same time, how does the particle know which mass to let the moving observer observe?? Does the particle have to know the speed of the observer in order to give the observer the "correct" mass for the observers frame of reference? How is the particle supposed to know how fast the observer is travelling? If there are two observers, moving at different speeds, does the particle have to try twice as hard in order to give a unique "mass" for each observer??

    Tom
     
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  7. c'est moi all is energy and entropy Registered Senior Member

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    Crisp, I read your response and will answer later on. (Having a heavy head coming back from work.)
     
  8. Crisp Gone 4ever Registered Senior Member

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    Again, some thoughts...

    Hi Tom,

    You also seem to be in favour of an absolute underlying reality. I agree that this would simplify a lot of things, but I don't think that there is such a thing. These idea's are not very unscientific. There is no science involved in answering that kind of questions, only philosophy.

    "By standardization I mean that all people observing a phenomena agree that the properties of that phenomena are the same, even though those same properties are being perceived differently by every observer."

    I disagree, this has totally nothing to do with the progress of science but with the transformation of measurements between different observers. Even before Einstein (because I know deep below this discussion is about relativity

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    ) it was known that different observers can see different phenomena. The simplest example being a single charge: for an observer moving along with the charge, there is only an electrical field. A "stationary" observer sees a moving charge, and hence has to conclude that there is not only an electrical field of that charge, but also a magnetic field produced by the moving charge. The moving observer is totally unaware of this field however. This "paradox" is resolved by the Lorentz transformations in Maxwell's theory of relativity (this is pre-1900 science).

    I can't see any way how you can disagree with this example (that there are different effects depending on your point of view). A moving charge does induce a magnetic field, and a charge by itself creates an electric field. There is no "absolute" truth in this scenario, both observers are right (unless we want to throw the universality of the rules of physics for every observer overboard).

    "Example: If one observer assumes that the Sun goes around the Earth and another observer assumes that the Earth goes around the Sun, and both agree that they are both correct, would a formula for gravity ever have been created that is correct in both cases???"

    Ok, I know what you want to say, but for the record I'd like to state that the example does not apply. Yes, a formula that is correct in both cases has been created: F = K<sub>g</sub>m<sub>1</sub>m<sub>2</sub> / r<sup>2</sup>. There is no need to know who is orbiting who (it's all a matter of what point of view you want to take). From our perspective, it is completely accurate to say that the sun orbits the earth: after all, we see it move around us. It's just a lot easier to take the frame of reference of the sun and say the earth orbits it. In fact, "orbiting" implies that both objects revolve around eachother.

    And no, I am not going back to pre-Copernican times: all planets revolve around the sun, and not around the earth ofcourse. But taking one planet and the sun seperately and studying that scenario results in one conclusion: there is no way of being able to tell who orbits who: neither one is stationary after all for a third observer (even though the effect of earth's gravitation on the sun is ofcourse neglegible). But I don't want to turn this debate into something that has been settled 500 years ago

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    .

    "... if I look up at the Sun, and according to me the sun is 2 inches wide, my value of 2 inches will not be included in any scientific formulas because it is not a "real" value, it's a "perceived value". "

    How do you know it is not a "real" value but a "perceived value" ? In principle there is only one way to find that out, and that is to walk towards the sun, take out your ruler and start measuring the real diameter. Until you do, there is no way to make that distinction. But then ofcourse your perspective (frame of reference) also changes. I'll get back to this...

    "You have the most fundemental subatomic particle...
    ....So, Crisp and James, which is the correct answer 1,2, or 3?"


    The correct answer is 3, for reasons you are aware of (yes that pesky theory of relativity again). Is it the "real" answer, i.e. the one that corresponds to reality ? (and that is ofcourse what this is all about). I think it is.

    Allow me to get back to your 2-inch sun example. You say that the sun is 2 inches in diameter. Are you wrong ? Are we allowed to make fun of you because you think so

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    ? No: from our perspective, our point of view/frame of reference, the sun is in fact only two inches tall. For us, that is reality. But ofcourse we know that this isn't the "correct" answer, the sun is quite a bit larger (1.400.000 km in diameter). However, what we forget to mention is that this is only true for an observer standing on the sun, i.e. from the sun's frame of reference.

    The example is perhaps a bit ridicule and far-fetched, but I think it illustrates what I mean: it's all a matter of what frame of reference you are looking at. For common things like the sun, cars on the highway, ... we always forget to mention what frame of reference we are talking about, because it is trivially assumed by the context. When you are cruising on the highway, your car is not moving at 120 km/h: it is moving at 0 km/h from your perspective! It is only moving at 120 km/h for an observer that is stationary with respect to the road.

    The same goes for the "quantum mass" particle (even though I have troubles with quantized mass, but let's put that aside for a moment). The particle is not trying hard to have 1 quantum mass for itself and 2.29 quantum masses for a moving observer. Both are true, only in their respective frames of reference.

    That's why I think there is not one "truth" or reality: when I say that my car moves at 0 km/h for me, then I am not lying or being inaccurate. When I say it moves at 120 km/h for someone next to the road, I am also correct.

    This dependence of frame of reference makes me believe that there every frame of reference has its own reality. You can't say that all the other observers are liars, because from their perspective, they are only describing reality as they perceive it, and it is the only way they can perceive it (without taking another frame of reference).


    c'est moi,

    Looking forward to your reply.


    Bye!

    Crisp
     
  9. overdoze human Registered Senior Member

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    It's all theoretical

    I totally understand you Crisp and JamesR, when you say it doesn't matter how one interprets the math as long as the math works out.

    However, I think implicitly Tom and Kevin (and me) try to delve a little deeper, that's all.

    That is to say, the universe didn't have to be relative. There seems to be no inherent reason why different inertial reference frames shouldn't derive different physical laws. However, relativity is what is observed, of course, so the question is why. One way of answering the question is, "who cares; it's just the way it is". Historically, and scientifically, that has not been a very fruitful approach.

    On the other hand, if relativity itself can be derived from a simpler basis then we have at least a potential explanation for why relativity holds. It's all a matter of simplicity; if we can eliminate relativity as a fundamental axiom, we've reduced our set of premises. Ockham would approve.
     
  10. Prosoothus Registered Senior Member

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    Crisp,

    I see you forgot to take into consideration the centrifugal force of the Sun in the Sun's orbit around the Earth.

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    You and James don't understand what the two of you are saying. There are only two explanations to the theoretical experiment I have illustrated:

    1) The mass of the particle does not change. The observer only perceives a change in the mass of the particle due to his high speed(Why: I don't know, yet). This is the simplist and most logical explanation because the mass of the particle is constant, therefore the value of it's mass does not have to change based on the speed of its observers.

    2) The mass of the particle is in reality different for every observer(This is what you and James are claiming). This would first have to mean that the particle can have a whole range of mass at the same time, which is very illogical. Next it would also mean that the particle, while having a whole range of mass, would also have to give a unique mass value to every observer at the same time, which is even more illogical. Finally, the particle would have to know the speed of every observer, in order to give every observer a unique mass, while at the same time, giving two different unique mass values to two different observers, which are in the same line of sight, if the observers are travelling at different speeds.

    Please correct me if I'm wrong, but I find that case 2 is impossible. I also can find no way that a multiple-mass particle can give an observer a unique mass without knowing the speed of the observer.

    If you or James have a different explanation for your beliefs, please share.

    Tom
     
    Last edited: Jul 12, 2002
  11. Crisp Gone 4ever Registered Senior Member

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    Hi all,

    Overdoze,

    "There seems to be no inherent reason why different inertial reference frames shouldn't derive different physical laws."

    It is a fundamental assumption in science that the laws of physics are the same for every intertial observer. An apple falls down to earth here, so it also falls down in China. If we don't take this assumption into account, then you can wipe (the scientific part of) your bookshelf clean right now, because then it is completely useless to perform science (repeatability is no longer true then for example). Hence it is not an attitude of "well, it just happens to be that way": it is a necessary requirement to perform science.

    Tom,

    You seem to believe that it is on the particle's side that something changes that magically gives rise to different masses for different observers. This is not correct, nothing changes on the particle's side - it is at the observer's side where the measurement is performed. All James and I are saying is that the relative speed of an observer influences the measurement that observer performs. That is basically your explanation number one.

    What James and I add, is that because an observer can never tell what the "real" (or stationary) mass is without changing his frame of reference, well, then that is reality for that observer.

    Bye!

    Crisp
     
  12. Prosoothus Registered Senior Member

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    Crisp,

    From your post, you seem to admit that "reality" and "reality for the observer" may be two different things.

    James, on the other hand, believes that "reality" and "reality for the observer" are the same thing. James believes, just like Einstein did, that there is no "reality" that is independent of observers. And that every "reality" for every observer is as real as the "reality" for any other observer.

    My argument is that I believe that there is a reality seperate from any observation. Only an observer that is everywhere at the same time, can percieve this reality accurately(by the way, science attempts to be this all-seeing observer by standardizing all physical properties in the universe). All other observers perceiving this reality will see illusions based on their location and their speed. Even though these observers may not be able to perceive this reality in certain cases, it does not mean that the reality does not exist, or that it can't be indirectly perceived by the observers by using mathematical transformations.

    Tom
     
  13. Prosoothus Registered Senior Member

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    Crisp,

    After rereading your posts, you seem to be contradicting yourself.

    You first said:

    Answer 3 was:

    3) The particle has one quantum of mass, and 2.29 quantums of mass at the same time. It's mass is also all other values because there are infinite frames of reference.

    However, then you said:

    Explanation one was:

    1) The mass of the particle does not change. The observer only perceives a change in the mass of the particle due to his high speed(Why: I don't know, yet). This is the simplist and most logical explanation because the mass of the particle is constant, therefore the value of it's mass does not have to change based on the speed of its observers.

    Which one is it?

    Tom
     
  14. Crisp Gone 4ever Registered Senior Member

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    Some corrections...

    Hi Tom,

    "From your post, you seem to admit that "reality" and "reality for the observer" may be two different things."

    Well, then I formulated it in an unfortunate way, because I do believe that for one observer there is only one reality, and that there is no absolute or general "reality".

    "After rereading your posts, you seem to be contradicting yourself...

    3) The particle has one quantum of mass, and 2.29 quantums of mass at the same time. It's mass is also all other values because there are infinite frames of reference.

    1) The mass of the particle does not change. The observer only perceives a change in the mass of the particle due to his high speed"


    I can see where the confusion arises. Allow me to add some words to your two answers to stress how I interpreted them:

    3) The particle has one quantum of mass, and 2.29 quantums of mass at the same time for the two seperate observers. It's mass is also all other values because there are infinite frames of reference and each frame of reference measures one of those possible masses.

    1) The mass of the particle does not change in its own frame of reference. The observer only perceives a change in the mass of the particle due to his high speed and for the observer, his reality is defined by his own measurements.

    The "own frame of reference" is important, because from what I have understood from your replies, you seem to think that James and I claim that the mass changes in the particle's frame of reference, depending on who is looking at it. That's ofcourse not what happens (even though measurements can do have an influence on a system, but we'd better not descend towards the quantum measurement path).

    Bye!

    Crisp
     
  15. Prosoothus Registered Senior Member

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    Crisp,

    You seem to be tip-toeing in order to avoid the obvious.

    1) You keep claiming that the "perceived" mass of the particle is dependent on the speed of the observer, but then you claim that the particle does not have an absolute mass that would appear to change for the observer. Are you saying that if there are no observers, the particle would cease to exist, or do you think that certain properties of a particle exist whether there is an observer or not? If these properties exist, shouldn't they have absolute values of some kind? In other words, does the particle exist, or is it just in the observers imagination? Which properties of the particle do you consider to be absolute in order for the particle to exist?

    2) You and James have such a limited view of the properties of observers. You assume that an observer must be at x,y,z in spatial coordinates, t in time, and v as his speed. What if the observer isn't at a specific "point" but rather occupies an entire area, or even the entire universe. If there was an observer that exists everywhere in the universe at the same time, what would they perceive? Would the particle's mass equal 1 or 2.29 quantums to this universal observer?

    Isn't science actually this all-seeing observer? Isn't the reason scientists convert relative measurements to absolute measurements so that it applies to an all-seeing observer? Wouldn't this observer's perception be reality, since it's not corrupted and tainted by the illusions of space or time that other relative observers are affected by?? Since this observer sees everything, from every point of view, doesn't that mean that everything it sees must exist, and therefore must have absolute properties?

    Tom
     
    Last edited: Jul 12, 2002
  16. Crisp Gone 4ever Registered Senior Member

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    No tip-toeing involved

    Hi Tom,

    "1) Are you saying that if there are no observers, the particle would cease to exist, or do you think that certain properties of a particle exist whether there is an observer or not? Which properties of the particle do you consider to be absolute in order for the particle to exist?"

    From the moment you have a particle, you always have at least one frame of reference, namely the one of the particle itself. What you would call "absolute properties" is what I would call "properties with respect to the particle's frame of reference". Properties that are listed in tables, like solar mass, sun diameter, ... are all properties from the frame of reference of the sun. One should not regard them as "absolute" properties of some kind.

    The only thing that I would call absolute is the fact that the particle exists. All other properties (like mass, energy, speed, momentum) are relative to the observer.

    "2) You and James have such a limited view of the properties of observers. You assume that an observer must be at x,y,z in spatial coordinates, t in time, and v as his speed."

    Yes, that is the mathematical definition of an observer: the location of one point (the origin of the frame of reference of that observer) defines from what perspective that observer looks at the world around him.

    "What if the observer isn't at a specific "point" but rather occupies an entire area, or even the entire universe. If there was an observer that exists everywhere in the universe at the same time, what would they perceive? Would the particle's mass equal 1 or 2.29 quantums to this universal observer?"

    If we assume that the particle is at rest for that observer, then I would say 1 "quantum mass". But don't let this answer mislead you, a spatially spread out observer is ill-defined. Because of the point-like structure of events, described by coordinates (t,x,y,z) , you are obliged to take a point-like observer aswell (who describes himself by the point event (0,0,0,0)). A spread out observer cannot define himself in his own frame of reference, so I think that it would be very difficult to define another event from that perspective

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    .

    Let me conclude by summarizing what I think defines reality. You have an observer (or frame of reference if you prefer that word) that is located in a point in spacetime. He labels himself as being event (0,0,0,0), and describes all other events by coordinates (t,x,y,z). The observer perceives these events, and because of several fundamental limitations, e.g.
    - that he cannot change his frame of reference since that would involve describing another observer
    - finite transmission speed of signals
    he cannot decide whether what he perceives is "real" or not. For him, there is no way to distinguish between what he perceives and what might be some form of underlying reality. As a matter of fact, his measurements will tell him that what he perceives is reality, and hence he cannot conclude otherwise than to say that it his measurements are reality. What the observer should take into account is that other observers might measure other properties, and that for them, reality might be different. But nevertheless, all observers are right, since they can all reproduce their measurement and find the same outcome over and over again. This is exactly what relativity is all about: you cannot be wrong, since everybody is telling the truth

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    .

    Bye!

    Crisp
     
  17. overdoze human Registered Senior Member

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    It is an assumption borne out by observation. If observation contradicted this assumption, then this assumption wouldn't be fundamental to science. Question is, why is this assumption borne out by observation.

    I would have to wipe the bookshelf if the universe was not in fact relativistic. But it is, so the books stay. The question is, why is the universe relativistic as opposed to not?

    As for repeatability, who says? What if in an alternate universe ether was detectable and you could measure absolute velocity. Then you could use that measurement to compensate for relative motion and still arrive at consistent physical laws. In another alternate universe, you might not be able to directly detect your absolute velocity but still derive consistent physical laws. Of course, these laws would morph as you accelerate in various directions, but then you'd be able to indirectly determine your absolute velocity by deriving the particular set of physical laws for your reference frame and determining your absolute velocity from the particular way your laws are skewed.

    Anyway, there are an infinite number of self-consistent mathematical frameworks, and relativistic is just one of them. So I think it bears questioning why this particular mathematical framework, of all others, is the one applicable to our universe.

    I don't think this statement is justified at all, unless you take observation into account. That is, your statement is not an apriori, self-evident truth; rather it is an empirical conclusion based on measurements. So the question is why shouldn't we try to build a theoretical framework that explains the measurements, rather than just build a superficial one that sits on top of them.
     
  18. Crisp Gone 4ever Registered Senior Member

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    More tricks up my sleeve

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    Hi Overdoze,

    (On the assumption that the laws of physics are the same for every frame of reference)
    "I don't think this statement is justified at all, unless you take observation into account. That is, your statement is not an apriori, self-evident truth; rather it is an empirical conclusion based on measurements. "

    I think it is a requirement, not based on observations. If the laws of physics would not be the same in all frames of reference, then there really is no point in doing science: nobody can verify what you claim since there wouldn't be a transformation that can map your measurements to an arbitrary other frame of reference (and individual transformations for every possible frame of reference is not allowed: that way you are just "fitting" your measurements). For science to be meaningful, you'd have to demand that someone else can verify your claims, and this is (very fundamentally) speaking only possible if physical laws have the same form for every observer. Note that I have nuanced "the same" to "the same form" because there ofcourse are differences between observers. The beauty is that they all map to the same general form (e.g. F = ma in my reference frame transforms to F' = ma' in another frame of reference, possibly with other forces and acceleration)

    I forgot how this assumption is called in science philosophy, but if I remember correctly, it was related to the homogenity of space i.e. that space has the same structure in all directions). A few years ago, some experiments suggested that this assumed homogenity might not be necessarily true on cosmological scales. Even today, where the constancy of physical constants is questioned, observations do not necessarily support the idea that the laws of physics are indeed the same for every observer. That's why I think that the universality of physical laws is not induced by observations, but is rather a rational postulate.

    Bye!

    Crisp
     
  19. overdoze human Registered Senior Member

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    sleeves are overrated

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    Why would you think that? First of all, anyone moving identically to me would be able to verify what I claim. Anyone not moving identically to me would know as much, and so won't be surprised to make different measurements than I. Regardless, who says there wouldn't be a transformation that can map our disparate measurements to the same event? Maybe if we took our relative movement into account, we could arrive at a transformation of my laws into the other guy's laws.

    Imagine a universe where everything is always accelerated and nothing is ever at rest. Would there be no point in doing science in such a universe, even if there was a way of measuring acceleration?

    Not necessarily. If someone knows my laws, they can assume my point of view and apply them, and verify my results.

    Yes. The question is, why.

    Again, this is what we observe. It didn't have to be this way, at least as far as we know. As late as 1900 people believed ether would be detected via electromagnetic experiments.

    I don't think that's a valid argument. The assumption of uniformity was made way before any evidence for anisotropy showed up. Rather than calling it a "rational postulate", I would call it an "empirical fact" or, if you want to take possible cosmological anisotropy into account, an "empirical approximation".
     
  20. James R Just this guy, you know? Staff Member

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    overdoze:

    <i>That is to say, the universe didn't have to be relative. There seems to be no inherent reason why different inertial reference frames shouldn't derive different physical laws.</i>

    We don't know about that yet. We don't know of any such reason so far, but there might be one. It's an open question.

    <i>On the other hand, if relativity itself can be derived from a simpler basis then we have at least a potential explanation for why relativity holds.</i>

    Of course, it's worth remembering that relativity is derived from just two simple assumptions (arguably one). That's a very simple basis already, if you ask me.

    <i>...if we can eliminate relativity as a fundamental axiom, we've reduced our set of premises. Ockham would approve.</i>

    I agree.



    Tom:

    I have a question for you.

    How do you know how tall you should be for different observers looking at you from different distances? What is it that makes you look 6 feet tall to somebody standing next to you and 2 inches tall to somebody standing on a neighbouring hill with a telescope? How do you communicate to them how tall you should look?
     
  21. overdoze human Registered Senior Member

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    No contest. However, the only way to "close" this open question is to go beyond relativity. Relativity itself does not inherently contain the answer.

    It's simple, but I've shown an alternative set of assumptions that's even simpler. And there may exist yet simpler reductions.
     
  22. James R Just this guy, you know? Staff Member

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    Relativity assumptions:

    1. The laws of physics are the same in all inertial reference frames.
    2. The speed of light is constant in an inertial reference frames.

    Actually (2) follows from Maxwell's equations combined with (1), so really there's only one assumption.

    Could you please remind me of your supposedly simpler, alternative set of assumptions?
     
  23. overdoze human Registered Senior Member

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    In a sec. First, let's see why relativity's assumptions are not so simple after all.

    First question, why the same. Second question, in terms of what do we define an inertial frame (this drags in inertia and acceleration as additional basic premises.) Third question, how do inertial frames co-exist and how do they change into each other (it can't avoid depending on a unifying, common universe.)

    This still depends on "inertial reference frames" with all the baggage that entails. Regardless of whether you choose (2) or Maxwell's equations, you still have an additional premise.

    Ok, now for a reminder of those alternative premises:

    <ol>
    <li>There exists a cosmic medium within which all observable events take place</li>
    <li>Within this cosmic medium, the velocity of light is the same in all directions</li>
    </ol>

    (1) is inevitable, and relativity quietly implies it. It's the equivalent of saying "all observers inhabit the same universe." (2) is a basic premise equivalent to the second premise of relativity. In the very least, the premises are sufficient to explain invariance of optical experimental outcomes amongs inertial reference frames. Note there is no mention of physical laws; it is assumed that inertia (and inertial reference frames), as well as the equivalence of physical laws in inertial reference frames, will simply drop out of the definition of the cosmic medium's structure. (2) itself is likely to turn out to be such an emergent phenomenon.
     

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