Newtonian relativity

DaleSpam

Which words am I putting in your mouth? I went to great effort to get you to express your opinion in your own words and to verify that I was correctly understanding you and not putting words in your mouth.

I am only showing you the logical consequences of your own words. Intelligent design assumes that there is an intelligence which caused the biological life we see on earth. Since that is a causal mechanism it qualifies as a scientific assumption under your stated criterion: "Scientific assumptions should take the form of a causal mechanism or a mathematical relation".

Would you like to revise your criterion? (I would recommend it)

russ_watters

Sorry, harry, it doesn't work that way. I gave you one example but what you are saying requires proving the negative in every part of Newton's theory. That is not a reasonable bar. In fact, 'i'm right unless you prove me wrong' is crackpot logic.

Since you claim the assumption has utility, it should be fairly easy to provide one example demonstrating it.

russ_watters

Also, regarding the scientific method: it is a free internet, so you can choose whatever formulation of the scientific method as your personal preference. But you can't cange reality or history with opinion. The reality is that the vast majority of professional scientists require the use of logic and the history is that even Newton's contemporaries agreed. So you can choose to believe in unicorns if you wish, but that choice has no value outside your head.

rbj

so was it a different topic when you said

?



i don't see the difference between absoluteness regarding time intervals (for every observer in every reference frame) and simply following those ticks back in time to some time defined as the origin. who defines the origin and where it is defined is immaterial to Newtonian mechanics (only time differences exist in Newtonian mechanics). but the (ostensible) fact that all of our clocks tick at the same rate, independent of the frame of reference is not immaterial, and, as humans found out a century ago, was a mistaken notion.

the fact that Newton was religious (or an alchemist) is non sequitur. what i thought was the topic was how could have Newton been so "unscientific" to take as an axiom that your clock ticks the same as mine (from my POV) independent of the motion of your clock relative to me. it's mistaken (as we know now), an invalid axiom, but it came from observation of reality in a world where nothing of substance (that people could watch and draw inference from) moved, relative to anything else, at anything close to relativistic speeds.

it would be, as best as i can tell, a perfectly reasonable axiom for Newton and his contemporaries to make. after Michaelson, then it becomes a little more questionable as an axiom. and for Einstein to understand it as he had, purely from thought experiment, does not reflect poorly on Newton's scientific method but only on Einstein's singular genius.

DaleSpam

harrylin, I did notice earlier that you seem to like Popper for your philosophy of science. As you say, it is a matter of taste and philosophy, but you may want to look into his concept of falsifiability. His statements may be something we can both agree on as a premise. One commonality with intelligent design, undetectable unicorns, Lorentz's aether, and Newton's absolute frame is that none of them are falsifiable.

harrylin

Negative experimental results matter just as much; thanks to this discussion which is on another topic, I took Popper out of the book shelve. Anyway, in view of your reaction I won't even mention topics to you that differ from the discussion topic.

harrylin

Sorry Dalespam, but that's wrong again: we are not concerned with an illusionary "absolute truth" of models, instead we are concerned with testing one hypothesis against another; and we already discussed in this thread how this was applied by Newton. If one hypothesis or model predicts observation A and another one predicts observation B, then commonly it's accepted that these hypotheses are falsifiable and can be tested against each other. However, you already disagree on that fundamental point.

DaleSpam

Huh?!? I think we must be talking past each other.

I don't disagree with anything you said, except that Newton's ideas of absolute velocity and position do NOT predict any different observations. Newton was clearly aware of that in his writings, particularly in the Scholium that you cited. That is why those ideas are non-scientific, per my criteria and per Popper's falsifiability criterion.

harrylin

I already clarified that I did not do that; I will thus take it that you talk about yourself.
Nobody here suggest that science is illogical - and I can't help it if you believe in unicorns either! For a last time: please make your case - not just loose remarks - to show that Newton's theoretical development is "illogical". Then your argument can be discussed, just as we discuss the arguments from people who pretend that Einstein's theoretical development is illogical.

harrylin

I have noticed that in many discussions with others I just do not have enough patience or long-windedness (or perhaps just really not enough time!) to clarify things to the point that people finally "get" it, and in such cases it's often you (or ghwellsjr) who, with three times as much posts of double the length, finally manage to make things sufficiently clear to those people. Regretfully you cannot take up that role here, as you are on the other side of the discussion. So, I must simply ask you, what was not clear in my posts #4 and #6? For there I really thought to have:
1. provided the link to Newton's falsification of the model of Galileo-Leibniz, and which he replaced with his own model.
2. pointed out that he thus compared two models, one of which was falsified in favour of the other.
Surely I don't have to explain to you that if Galileo was right, such experiments and many others would falsify Newton's model?

DaleSpam

But neither of those are relevant to the falsifiability of Newtons absolute position and absolute velocity concepts. Falsifiability is intrinsic to a theory and has nothing to do with comparing one theory to another. The fact that Galileo-Leibniz had a theory which was falsified is irrelevant to the question of the falsifiability of Newtons assumption.

Newtons assumption of absolute velocity and absolute position is non falsifiable in it's own right because there is no observation which could disprove it. Therefore it is non scientific according to Poppers criterion. The rest is irrelevant.

Ken G

I'm a bit unclear on exactly what claims are being discussed here. Surely Newton's postulate of absolute time and space were perfectly scientific concepts, and they did indeed turn out to be falsifiable. What's more, it is arguable that they also satisfied Occam's Razor (never perfectly clear, but arguable what that entails), because they were consistent with known observations and explained the shape of water in a spinning bucket in a way that was simpler than other ways (like Mach's principle applied to general relativity). Were there not observational evidence in favor of GR, no one would adopt the latter approach (the approach that spacetime does not have a global a priori geometry, but rather a local geometry that can be expressed in any global coordinate system that expresses the correct local curvature and which responds to the history of the situation rather than being a priori). To me, the real crux of the question of absolute space and time is whether space and time are global or local concepts, and making them global would always seem to be an advantage if it was possible. Newton had only data that suggested it was possible-- we know today it isn't. Locally, the geometry of spacetime is determined by the inertial paths, and that is as close to anything "absolute" as we can get, but it's not particularly clear that being able to identify inertial paths requires that anything be absolute, because there's nothing more absolute about an inertial path than a noninertial one-- you don't know what either are until you have the global solution of the Einstein equations, so you need to know the mass distributions, boundary conditions, history, etc. But once you know all that, a spinning bucket is "absolutely" non-inertial, so I don't think we should say Newton was wrong, merely that his ideas were not sophisticated enough to treat the full situation. What else is new? That's typical of perfectly good science, it doesn't necessarily have anything to do with magic or religion.

DaleSpam

We have been discussing the concepts of absolute space and absolute velocity, but absolute time suffers the same non-falsifiability problem.

Consider two hypothetical universes in which Newton's laws hold. They are identical except that one is 10 m up, 3 m forward, 13 m left, and 5 s later wrt its absolute space and time than the other. What experiment could inhabitants of those universes do in order to determine which universe they were in?

Agreed, but it is not relevant. We agree that there are a class of frames which share the same acceleration. These frames are called inertial frames, they are equivalent for the purposes of Newtonian physics, and they are related to one another via the Galilean transform. What is under dispute is whether or not selecting one of those frames and giving it prefered status in the theory is scientific given the fact that they are experimentally equivalent.

The problem isn't being wrong. You can make a wrong hypothesis and still be doing completely good science. The problem is being unscientific. You may be right and still be unscientific. Newton's concepts of absolute space and absolute velocity are unfalsifiable and therefore unscientific.

This is not to demean Newton, science itself was brand new at the time and the scientific method hadn't been refined like it is today. But we need to recognize that even the greatest scientist of all time (IMO) was a fallible man and not some infallible prophet. He was limited not only by his data and experimental equipment, but also by his philosophical preconceptions. With the added benefit of his genius and several centuries of subsequent study, we should be able to recognize and accept those small limitations.

harrylin

OK then, since you insist to go on making an off-topic claim about my opinion which is the exact opposite of my opinion, I will clarify this in a new thread on your topic.

harrylin

I already remarked that, apparently, no hypothesis about such frames existed; that concept was developed based on Newton's theory. Nothing exists in the world that could have served him as logical basis for a physical model of "inertial frames".
And since you spoke of unicorns: here is a real unicorn that you try, after-the-fact, to impose on Newton: it would not make any sense to propose a space with respect to which one does not have velocity and position!

PS. "What is under dispute is whether or not selecting one of those frames and giving it prefered status in the theory is scientific".
Instead: we have not even discussed that point - and it is a misrepresentation of Newton's hypothesis, he did no such thing. Perhaps this whole discussion was due to a misunderstanding of what Newton was dealing with; but I thought to have clarified that in post no. #35 and, even more, #43

harrylin

It would certainly be unreasonable to demand that every logical consequence of a hypothesis should be falsifiable. And contrary to what you claim, Popper did not agree with your "positivist" thinking, as he called it. Here is how Popper formulated his criterion in chapter 6:

"It must be possible for an empirical scientific system to be refuted by experience".

That was certainly not a mistake of formulation, for earlier, in chapter 4, he elaborated as follows:

"it may be said [..] that I remove the barriers which separate science from metaphysical speculation.
[..]
The older positivists wished to admit, as scientific or legitimate, only those concepts [..] which were [..] 'derived from experience'; [..] that is, which they believed to be logically reducible to elements of sense-experience [...].
Modern positivists [...] wish to admit [..] only those statements which are reducible to elementary [..] statements of experience [..]. I must also reject all these attempts to solve the problem of demarcation. [...] positivists, in their anxiety to annihilate metaphysics, annihilate natural science along with it".

I thus found strong disagreement with your suggestion that since some but not all logical consequences of Newton's "absolute space" model can be verified in their own right, that therefore that model is non-scientific according to Popper's criterion.

harrylin

I agree; and I now came with suggestions for possible causes (positivistic philosophy or a misunderstanding of the status quo at the time of Newton) in the foregoing posts.
Yes indeed, it seems to me that Newton made the simplest assumptions that he could think of and that were consistent with the data that he had.
Well, his way of thinking way was certainly affected by his religion, but not such that it made him illogical, as some people seem to think. And insofar as religion played a role in his creative thinking we should say happily so, as the result was a very useful theory that even today is still in use.