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Rive
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It is a bit of a problem to support that claim with experimental data.russ_watters said:No speed where it and Einstein's formulas give exactly the same result.
It is a bit of a problem to support that claim with experimental data.russ_watters said:No speed where it and Einstein's formulas give exactly the same result.
This might just be a matter of semantics, but I would say, "experimentally equivalent", yes, "approximately equivalent", yes, but "mathematically equivalent", no.Dale said:Newton's velocity addition formula is mathematically equivalent to the SR velocity addition formula for ##v<<c##.
Huh? The statement is purely mathematical. It has nothing at all to do with experiment. That's one of the key points of the entire post.Rive said:It is a bit of a problem to support that claim with experimental data.
@Jarvis323 accurately describes my position.Dale said:I disagree with this. Newton's velocity addition formula is mathematically equivalent to the SR velocity addition formula for ##v<<c##. In fact, it is critical that the SR velocity addition formula reduce to the Newtonian formula in the limit ##v<<c## precisely because we have a lot of data in that limit that supports the Newtonian formula.
That's a problem for me, then. Is there another name for what I describe? To me, the distinction matters because in one case we need to keep looking for a better theory and in the other case we don't.As far as I know, that is not the usual definition. I believe that the usual definition is that the theory's domain of validity is the domain where there is experimental data which validates the theory.
Since I'm not a scientist, I may not have the theory/process of how errors are dealt with correct, but my understanding was that error bars are not hard limits, so there is no binary yes or no or necessarily an equality of two theories. Isn't there still debate about whether the original Michelson Morley experiment was accurate enough to claim a null result? E.G., it was zero within the error bars, but the error bars were pretty wide?There is a lot of experimental data that supports Newtonian physics, including the Newtonian velocity addition. In that domain Newtonian physics is valid (hence domain of validity). SR, to be valid, must also match the established correct predictions of Newtonian physics in that domain.
Note that the precision of an experiment is an important characteristic of the experiment. So the issue is not "we just don't care because it is close enough" but rather than with a certain experimental precision the theories are indistinguishable. They both agree with the data equally. The domain of validity includes not only the experimental velocity but also the experimental precision.
$$\lim_{c \rightarrow \infty} \frac{u+v}{1+uv/c^2}=u+v$$ So I stand by “mathematically equivalent to the SR velocity addition formula for ##v<<c##”Jarvis323 said:This might just be a matter of semantics, but I would say, "experimentally equivalent", yes, "approximately equivalent", yes, but "mathematically equivalent", no.
That's nice. But somewhere down the line it is exactly the experiments what turns math into physics.russ_watters said:the statement is purely mathematical.
For practical reasons, this stands not just for experiments but even for educational levels too.russ_watters said:It also means that for different experiments, Newton's laws have different domains of applicability.
Does adding a condition ##v<<c## really provide the same result as $$\lim_{c \rightarrow \infty}$$ ? I thought ##v<<c## meant "so small the deviation becomes immeasurable."Dale said:$$\lim_{c \rightarrow \infty} \frac{u+v}{1+uv/c^2}=u+v$$ So I stand by “mathematically equivalent to the SR velocity addition formula for ##v<<c##”
I believe the appropriate term here is "asymptotically equivalent" but I don't really care.Jarvis323 said:Of course this is just semantics perhaps, but I would say, "experimentally equivalent", yes, "approximately equivalent", yes, but "mathematically equivalent", no.
If you really mean this then we can equally debate the number of angels who fit on the head of a pin. I know that you understand this but the statement itself is far too categorical.russ_watters said:Huh? The statement is purely mathematical. It has nothing at all to do with experiment. That's one of the key points of the entire post.
I'm an engineer and I recognize that nothing I calculate or measure is exact. It was my understanding that mathematicians deal with exact math and that physicists (scientists) sometimes deal with exact math and sometimes deal with inexact experiments and that the difference matters. I'm honestly baffled that it doesn't appear to be the case - that the line appears to be quite blurry.Rive said:That's nice. But somewhere down the line it is exactly the experiments what turns math into physics.
I'm really not following you.hutchphd said:If you really mean this then we can equally debate the number of angels who fit on the head of a pin. I know that you understand this but the statement itself is far too categorical.
I'm not saying it very well. I really just mean that the behavior of any mathematical theory can be endlessly debated in the realm where the experimental data is not precise enough to differentiate two theories (angels size for instance). It is the hallmark of physics that experimental data always matters and so I disliked the statement categorically.russ_watters said:I'm really not following you.
Agreed. But the impression I'm geting is that scientists do not believe there is enough room in those error margins for another theory, or believe Relativity is exact/correct -- and flip back and forth between the two positions/descriptions. It's a lot more vague than I thought the way scientists think.hutchphd said:I really just mean that the behavior of any mathematical theory can be endlessly debated in the realm where the experimental data is not precise enough to differentiate two theories (angels size for instance).
Well, I don't know because the much less than symbol is not exactly defined as an asymptotic limit. In this case, if you take a limit, then ##v = 0## is probably the appropriate one I guess. Rather than use the concept of a limit, you could just say for ##v=0##.hutchphd said:I believe the appropriate term here is "asymptotically equivalent" but I don't really care.
I am more concerned with the larger question vis.
If you really mean this then we can equally debate the number of angels who fit on the head of a pin. I know that you understand this but the statement itself is far too categorical.
That's more than stretching a point. If "mathematically equivalent" means anything it means they are the same axiomatically (which they are not). Moreover, one system being a special case of the other does not mean they are equivalent. The geometry of circles is not mathematically equivalent to the geometry of ellipses, even though the circle is a special case of the ellipse.Dale said:$$\lim_{c \rightarrow \infty} \frac{u+v}{1+uv/c^2}=u+v$$ So I stand by “mathematically equivalent to the SR velocity addition formula for ##v<<c##”
With physics it is even worse. It takes a lot of metaphysics (philosophy) to accept that we can't deal with 'reality' (whatever it means). We only have experiments, and theories fitting them. So the whole 'real', and 'right' is a kind of alarm bell, since these are just out of physics.russ_watters said:I'm an engineer and I recognize that nothing I calculate or measure is exact.
hutchphd said:And actually quite various as well. I think that was more surprising to me.
Well, where the rubber meets the road, I'm not sure I believe it. There's a 8.5 km supercollider near Geneva, not an 8.5 km Michelson interferometer. There's a reason for that. There's a reason we scoff when someone says they have an idea for a new theory that contradicts Relativity. I don't think it's just that the person isn't qualified to make the claim - I think the reason in both cases is that physicists believe Relativity is Correct. Not "correct within its domain of applicability", but Actually Correct.Rive said:With physics it is even worse. It takes a lot of metaphysics (philosophy) to accept that we can't deal with 'reality' (whatever it means). We only have experiments, and theories fitting them. So the whole 'real', and 'right' is a kind of alarm bell, since these are just out of physics.
If you have only experiments, then how can you decide which theory is 'right' if you can't support the distinction (within a range) with experimental data?
russ_watters said:Agreed. But the impression I'm geting is that scientists do not believe there is enough room in those error margins for another theory, or believe Relativity is exact/correct -- and flip back and forth between the two positions/descriptions. It's a lot more vague than I thought the way scientists think.
seems like everyone who sees that graph thinks they are an expert on Dunning-KrugerDaveE said:Dunning-Kruger comes to mind here.
I have no idea how this relates to the OP's work since we haven't seen it. Even then I probably wouldn't, but y'all might.
I believe that this effect applies to everyone in each knowledge domain. The question is: do we have the self awareness to know where we are on the graph?
“The first principle is that you must not fool yourself — and you are the easiest person to fool.” - R. Feynman
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russ_watters said:not an 8.5 km Michelson interferometer
I certainly could be understanding it wrong, but I have always understood it as a shorthand for the limit as v/c goes to zero.russ_watters said:Does adding a condition ##v<<c## really provide the same result as $$\lim_{c \rightarrow \infty}$$ ? I thought ##v<<c## meant "so small the deviation becomes immeasurable."
That is possible. I tend to use 2., but now that I think of it I am not sure that anyone I have read actually defined it clearly. So 2 is simply what I inferred from context and usage.russ_watters said:I feel like there are three different definitions people use:
1. The domain in which we use it.
2. The domain in which it is proven accurate.
3. The domain in which it is believe to be accurate.
You are right. I have an Insights article about Bayesian inference in science. In my opinion that is the best way to evaluate the evidence without resorting to a binary yes no.russ_watters said:Since I'm not a scientist, I may not have the theory/process of how errors are dealt with correct, but my understanding was that error bars are not hard limits, so there is no binary yes or no or necessarily an equality of two theories.
I think that there are some beyond the standard model theories that differ from SR but live in those error margins.russ_watters said:But the impression I'm geting is that scientists do not believe there is enough room in those error margins for another theory
It does mean that they are equivalent when restricted to that special case. An ellipse is not mathematically equivalent to a circle, but an ellipse with both foci at the same point is.PeroK said:Moreover, one system being a special case of the other does not mean they are equivalent. The geometry of circles is not mathematically equivalent to the geometry of ellipses, even though the circle is a special case of the ellipse.
Yes, which is why the precision of the experiment needs to be part of the specification of the domain. With new portable optical atomic clocks we should be able to do a similar experiment at walking speed.PeroK said:The Hafele-Keating experiment is evidence that Newtonian physics and Relativity are not equivalent, even within what might be expected to be the domain of applicability of Newtonian physics: airline travel.
I think that galactic rotation curves are quite analogous to the Mercury situation. At the time, another planet called Vulcan was proposed as the source of the anomaly. Vulcan was never identified by other means and then GR was developed which explained the anomaly without Vulcan.gmax137 said:Einstein knew about the anomalous precession of the perihelion of Mercury, and was able to accurately calculate the orbit using his new GR. So there is a place in orbital mechanics where "Newton is wrong" so to speak. Do we now have any examples where SR/GR predictions are known to be incorrect, or better said "not quite in accordance with observations"?
Ok, that's what I thought -- rather than say v is so small compared to c it may be zero, you're saying limit as c goes to zero, giving basically the same result. But the "<<" operator of "much less than" is qualitative and really means "too small to measure" or "too small to matter", right?Dale said:I certainly could be understanding it wrong, but I have always understood it as a shorthand for the limit as v/c goes to zero.
In this case since there are two velocities it is equivalent but easier to take the limit as c goes to infinity.
Setting aside whether what you said means what I think you said, my objection is that you added the restriction in the first place. It creates a circular argument: they are mathematically identical in special cases we can specify where they are mathematically equivalent. Ok. In other cases they aren't mathematically equivalent, so let's talk about those. Clearly, one can make calculations using either method for cars driving on a highway and get answers that are different from each other. Not a lot different, but different nonetheless. Whether 100 km/hr satisfies "<< c" and we can safely ignore the difference isn't what matters to me. It matters that they are in, in fact, different.I notice that the people who have been objecting to my language keep on dropping the restriction. The restriction is essential.
This is great, thanks. The abstract talks big-picture motivation, which is what I'm after here:f95toli said:I don't think that is true. There are quite a number of scientists who spend their whole career doing more and more accurate measurements to see if they can spot any difference between their measured values and what is predicted by theory. Some of this work is published in high-impact journals (see https://www.nature.com/articles/s41586-020-2964-7 for a recent example.)
"...consistent with (almost) all experimental results."The standard model of particle physics is remarkably successful because it is consistent with (almost) all experimental results. However, it fails to explain dark matter, dark energy and the imbalance between matter and antimatter in the Universe. Because discrepancies between standard-model predictions and experimental observations may provide evidence of new physics, an accurate evaluation of these predictions requires highly precise values of the fundamental physical constants. Among them, the fine-structure constant
What about certain pieces of physics? Is the speed of light really invariant or is there room for it to vary? Do scientists think that's realistic? Would they have declared it to be the basis for defining units of length if they believed fluctuation was likely?We all know that physics isn't "complete" so it is entirely possible that we will one day find a "more complete" theory which also works in situations where existing physics (including SR) isn't applicable or-assuming we one day find an "error"- is able to predict results with higher accuracy.
Yes, and this is where I perceive the OP goes wrong. It's not the general idea that there could be a new theory that contradicts SR in certain predictions, is better and replaces SR, but rather the likelihood that a person who is almost certainly a layperson could have discovered it.The key here is realising that these situations would have to be either very exotic OR you are trying to calculate something with a precision which is beyond what we can currently measure. So any new theory would still need to explain existing data.
The point is that there does exist such a special case where SR becomes equivalent to Newtonian physics. Not all possible theories have a Newtonian limit at all. Those that do not are invalidated by all of the evidence that validates Newtonian physics. The existence of that limit was critical for establishing relativity as a viable theory.russ_watters said:my objection is that you added the restriction in the first place. It creates a circular argument: they are mathematically identical in special cases we can specify where they are mathematically equivalent.
What matters for the scientific method is whether or not a specific experiment can distinguish between them. That involves not only the predicted difference but also the experimental precision.russ_watters said:Whether 100 km/hr satisfies "<< c" and we can safely ignore the difference isn't what matters to me. It matters that they are in, in fact, different.
russ_watters said:Is this wording really much different from the OP?
"... supported by most experiments..." (this is most concerning to me based on how weak it is worded).
"...contradicts..."
What experimental tests do you have that your theory is valid?georgechen said:Thank you everyone replied to my post. Appreciate your feedbacks. This post was moved by the admin so I mistaken it from being deleted and only see it today.
For update, I already spent several months checking the math and can't find any error since it is simple math. So I will move forward and send the paper just hope someone may be so open-minded that he will at least take a look and not throwing it away immediately.