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Purported Relativity Paradox Resolved

timothy posted about a year and a half ago | from the disappears-in-a-puff-of-logic dept.

Science 128

sciencehabit writes "A purported conflict between the century-old theory of classical electrodynamics and Einstein's theory of special relativity doesn't exist, a chorus of physicists says. Last April, an electrical engineer claimed that the equation that determines the force exerted on an electrically charged particle by electric and magnetic fields — the Lorentz force law — clashes with relativity, the theory that centers on how observers moving at a constant speed relative to one another will view the same events. To prove it, he concocted a simple 'thought experiment' in which the Lorentz force law seemed to lead to a paradox. Now, four physicists independently say that they have resolved the paradox."

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128 comments

Summary of Resolution Ceremony (5, Funny)

CodeBuster (516420) | about a year and a half ago | (#42699347)

The four physicists waived their hands over the box containing Schrödinger's cat while repeating, "omine, omine, omine" before walking away without looking inside and thus the conjecture was false and the paradox is resolved.

Re:Summary of Resolution Ceremony (2, Funny)

Anonymous Coward | about a year and a half ago | (#42699551)

So they refrained from using their hands?

Re:Summary of Resolution Ceremony (3, Funny)

alphatel (1450715) | about a year and a half ago | (#42699679)

So they refrained from using their hands?

They refrained from using thoughts.

Re:Summary of Resolution Ceremony (0)

Anonymous Coward | about a year and a half ago | (#42699781)

"omine, omine, omine"? How is that pronounced? What language is it from? What does it mean?

Re:Summary of Resolution Ceremony (1)

hort_wort (1401963) | about a year ago | (#42703081)

"omine, omine, omine"? How is that pronounced? What language is it from? What does it mean?

Sounds like the poof of smoke the physicist-magicians are using to distract you from seeing the trick.

Re:Summary of Resolution Ceremony (1)

martin-boundary (547041) | about a year and a half ago | (#42705301)

Omine is the Latin word omen in ablative singular case. It could be translated loosely as "from an omen", ie some kind of explicit argument from authority.

However, it's also possible you misheard "omine": There's the word "domine", which is vocative singular, which could be translated as "Hey God, Hear Me!" (dominus = master of the house, but due to historical misuse by the catholic church it also means the christian god).

Dark matter (-1, Troll)

Anonymous Coward | about a year and a half ago | (#42699363)

So, hidden momentum and dark matter... What other concept will we invent to explain we dont know anything?

Re:Dark matter (1)

Anonymous Coward | about a year and a half ago | (#42699785)

RTFA. Unlike dark matter, hidden angular momentum isn't "invented", it follows from the assumptions of special relativity, which are dead simple and already proven beyond doubt.

Re:Dark matter (5, Informative)

buchner.johannes (1139593) | about a year and a half ago | (#42699981)

So, hidden momentum and dark matter... What other concept will we invent to explain we dont know anything?

Dark matter is not an invented concept, it is a name for something we observe. Galaxies just rotate faster than from what is there in normal matter. So something is going on, and this something is called "dark matter", just because it does not produce/interact with light but behaves like a mass.

Now in what way you explain this (new physical laws, new elementary particles) is still an open question. But it's there and needs to be addressed. Dark matter is just the name of the problem.

Re:Dark matter (1)

Junta (36770) | about a year ago | (#42700915)

I think dark matter theory is a bit more presumptive than 'any theory to explain discrepancies between established theory and observed reality with respect to gravity' it specifically hypothesizes some sort of matter as the mechanism. For example there are theories suggesting our accepted model to describe gravity is incomplete and more complex models might explain the discrepancies. Of course the post saying dark matter is 'invented' does unduly trivialize the experimentation that is going on to attempt explanation and the strength of the evidence supporting the theory that it is a sort of matter versus incomplete models of gravity as an explanation for what we observe.

Re:Dark matter (4, Informative)

Omnifarious (11933) | about a year ago | (#42701165)

Observations of the gravitational lensing caused by far away galaxies in the process of merging have distinctly shown concentrations of something that's lensing the light that's not in either of the two galaxies. There are also other observations that kill any possible 'alternate law of gravity' explanations.

I thought these explanations were interesting myself and I've been paying attention to the topic. And there's been a lot of study of these ideas, because you're right, positing a brand new form of matter is a big step. And study leads to experiments. And the experiments have lead to the general consensus is that dark matter has to be something that has mass and doesn't otherwise interact with light (or normal matter) at all.

Re:Dark matter (1)

CrimsonAvenger (580665) | about a year ago | (#42702497)

Photino birds?

Re:Dark matter (1)

Immerman (2627577) | about a year ago | (#42702715)

As an interesting aside, I remember hearing that someone recently analyzed galactic rotation in terms of General Relativity rather than Newtonian gravity and found that the "anomalous" speed curve is actually predicted by the theory (the math is apparently *much* more complicated, which is why it hadn't been attempted before). It's true that there have been other observations of phenomena that also support the Dark Matter hypothesis, but the reality may well be considerably more subtle than the universe containing massive quantities of non-baryonic matter.

Re:Dark matter (0)

Anonymous Coward | about a year ago | (#42703599)

Galaxy rotation curves are one of the things heavily studied by modified gravity theories. Some of them can fit the rotation curves, although there is a question of whether it is over-fitting, and such theories usually fail to match any of the other observations tied to dark matter.

Re:Dark matter (0)

Anonymous Coward | about a year and a half ago | (#42705321)

There are also other observations that kill any possible 'alternate law of gravity' explanations.

Sounds murderous indeed.

But seriously what do you mean? You think gravity is all figured out? Does that mean we have unified the 4 forces? Care to put the matter to rest with some cut & paste, or a link or two?

We have the _effects_ of gravity mostly figured out but how, for example, do you think gravity actually works?

Re:Dark matter (0)

Anonymous Coward | about a year and a half ago | (#42705513)

If dark matter doesn't interact with light, then how does it cause gravitational lensing?

Re:Dark matter (1)

tragedy (27079) | about a year and a half ago | (#42705731)

It interacts gravitationally. What it apparently does not do is emit or absorb light.

Re:Dark matter (2)

lgw (121541) | about a year ago | (#42702579)

You're about 5 years behind the facts on dark matter. The cosmic microwave background radiation studies comfirmed the dark matter hypothesis for galaxy/cluster rotation rates several years ago now.

Dark matter was proposed in the 1930s. At the time it was one of several hypotheses for why rotation rates weren't as expected. But a few years ago the CMBR studies also "observed" dark matter, and the matter/dark matter ratio matched the predictions to a couple of significant digits (which for cosmology is amazing).

The existance of dark matter is now confirmed as much as anything can be in cosmology - the evidence is as strong or srtonger than, say, black holes existing.

Re:Dark matter (0)

Anonymous Coward | about a year ago | (#42700975)

OR, and this is a big OR, our Theory of Gravity is off and needs fixing. I don't say this lightly because our current theory works very well. It is, however, not absolute and is still theory.

Re:Dark matter (1)

Anonymous Coward | about a year ago | (#42701683)

The thing is, there are many teams of physicists working on modified theories of gravities or trying to find new modifications of gravity. So far, none of them work as well as the dark matter theory, and they contradict observations in some way or at some place (or possibly require both dark matter and a modified just gravity). Some of them are even more contrived than creating a new particle, because they have arbitrary distances where things just suddenly change and they have to get that distance by just fitting data. Even some of the physicists working on and promoting such new gravity theories admit they are inelegant or still not as good as dark matter. But they all work on it just to be sure there is not another possibility hidden there.

Re:Dark matter (1)

strikethree (811449) | about a year ago | (#42701437)

Now in what way you explain this (new physical laws, new elementary particles) is still an open question. But it's there and needs to be addressed. Dark matter is just the name of the problem.

Hm. Doesn't calling it Dark Matter strongly imply that it is NOT a new physical law but rather some sort of... substance or particle? Surely you can see how the non-physicist who is curious could be mislead into a narrower interpretation?

Re:Dark matter (1)

DMUTPeregrine (612791) | about a year and a half ago | (#42704615)

Well, a new substance or particle that creates the observed effects of dark matter would very likely require new physics. For example, there is no dark matter candidate particle proposed by the Standard Model, though other theories and modifications of the SM do propose possible DM particles. These would be new physics.

Re:Dark matter (1)

ilguido (1704434) | about a year ago | (#42701655)

Dark matter is not an invented concept, it is a name for something we observe.

It is as observed as Aether or the cosmological constant...

Re:Dark matter (1)

kharchenko (303729) | about a year ago | (#42701949)

Dark matter is not an invented concept, it is a name for something we observe.

Precisely the opposite - it's a name for something we haven't observed. And instead of appropriately referring to it as a paradox, inconsistency, etc. a concept of an entirely new "matter" was conjured up. I might agree with you that it's more likely that something is missing in the estimates of galaxy masses as opposed to physical laws breaking down, but gp is perfectly correct in saying that at this point it's a theoretical (i.e. invented) concept.

Re:Dark matter (1)

Anonymous Coward | about a year ago | (#42702037)

but gp is perfectly correct in saying that at this point it's a theoretical (i.e. invented) concept.

So are quarks. They were invented to try to explain patterns seen in the formation of hadrons, and later used to explain some aspects nuclear structure. We don't observe the quarks directly, but only their interactions and decays. It is still possible we've missed another explanation that doesn't require inventing a whole family of particles.

The only thing that matters in the end is how well the theory agrees with observation. Dark matter is kicking butt here compared to all proposed alternatives. Although it has a ways to go to at same level of say quarks.

Re:Dark matter (2)

lgw (121541) | about a year ago | (#42702625)

Sorry, you're just wrong on this one. In the 1930s, then the hypothesis was new, you would have been correct, but in the past decade measurements of the early universe (via the CMBR) have directly confirmed predictions made by the dark matter hypothesis.

Dark matter is as confirmed as anything else in science that there's not actual engineering built around. Everything in science is a theoretical concept: that's not a useful statement.

Re:Dark matter (1)

StripedCow (776465) | about a year ago | (#42702133)

Of course, the increase in speed from other galaxies is caused by aliens who are trying to fool us so that we don't develop superior knowledge.

In physics, if you have two explanations for a problem, choose the simplest one. If you have only one, well, that must be it.

Re:Dark matter (0)

Anonymous Coward | about a year ago | (#42703275)

The name of the problem is Dark Matter! Dark Matter.... or Dark Energy.
The name of the two main problems are Dark Matter and Dark Energy... and hidden momentum.
Our three main problems are named Dark Matter, Dark Energy, and Hidden Momentum.... and Inflation...
Amongst the names of the main problems are Dark Matter, Dark Energy, Hidden Momentum, and Inflation....
Wait, I'll come in again.

Re:Dark matter (0)

Anonymous Coward | about a year ago | (#42701615)

So, when we find a theory is wrong, we are not supposed to try to come up with new theories to replace them?

It's good to see that ..... (4, Insightful)

thephydes (727739) | about a year and a half ago | (#42699373)

Science is alive and well in at least the Physics community. Whilst I won't even pretend to understand General Relativity, the questioning of it and discussion about those questions is the true essence of science. facts ->theory->more facts->questions->revised theory. Beautiful!

Re:It's good to see that ..... (1)

Anonymous Coward | about a year and a half ago | (#42699491)

This is in the range of a practise problem in special relativity, not something for a scientific paper.

Re:It's good to see that ..... (5, Insightful)

Anonymous Coward | about a year and a half ago | (#42699521)

Science is alive and well in at least the Physics community. Whilst I won't even pretend to understand General Relativity, the questioning of it and discussion about those questions is the true essence of science.

Sigh. General Relativity was not even at question here. Perhaps commenting on Slashdot should require a minimum amount of knowing what one is talking about. AAAHAHAHAHAHAHAHAHHAHAHAHA. Sigh.

At any rate, electrical engineers tend to view parts of Special Relativity in isolation. That makes them easier to handle and "visualize" in some respects, but much harder to deal with interactions. Minkovsky vectors and tensors are what theoretical physicists use instead, grouping several codependent field parts into one entity that can then be transformed as a whole.

So the physicists will most likely just have employed a better mathematical toolbox for resolving the "paradox". I've not actually read the original Einstein papers, but I would not be much surprised if his equations were closer to what Electrical Engineers get to deal with than what Theoretical Physicists do. Shaking out all that tensor stuff is more or less elegant wrapup work.

That sort of approach was, however, at the core of General Relativity, and mastering it took quite a bit more time for Einstein. I seem to remember that he discussed the underpinnings with Hilbert, and Hilbert came up with the general equations independently within something like a week, but retracted his papers out of respect for Einstein doing all the visionary groundwork as well as shouldering the math (though being quite slower at it than well-versed mathematicians).

Re:It's good to see that ..... (2)

maxwell demon (590494) | about a year and a half ago | (#42699559)

I've not actually read the original Einstein papers, but I would not be much surprised if his equations were closer to what Electrical Engineers get to deal with than what Theoretical Physicists do.

Indeed. When Minkowski reformulated it with 4D tensors, Einstein complained that he didn't recognize his own theory any more.

However, for General Relativity, Einstein had to go that path as well, and learned to love the power of it.

Re:It's good to see that ..... (-1, Offtopic)

Janek Kozicki (722688) | about a year and a half ago | (#42699709)

you should register on slashdot. I don't like spending modpoints on anonymous cowards. I modded you up, but since I decided to participate in this discussion, and my modding is lost I might as well reply to you.

Re:It's good to see that ..... (4, Insightful)

EzInKy (115248) | about a year and a half ago | (#42700055)

You worry too much about silly shit. Some of the best and most insightful posts here are from "Anonymous Cowards".

Re:It's good to see that ..... (1)

Janek Kozicki (722688) | about a year ago | (#42703667)

to all three fellows who replied to my comment about ACs: you are absolutely right. I'm sorry and I promise to mod up ACs appropriately. Although they are harder to spot, sometimes :/ And I prefer modding up too, rather than down.

Re:It's good to see that ..... (3, Insightful)

maxwell demon (590494) | about a year and a half ago | (#42700155)

I don't like spending modpoints on anonymous cowards.

Why not? Moderation is done for the sake of the readers, so they can more easily spot posts which may be worth reading. This primary function of moderation is independent of someone posting as AC or not.

Moderation also has secondary effects on the posters, to encourage writing good posts. For logged-in users, it changes their Karma. For ACs, it affects the number of allowed posts that day (and probably also the time until the next post is possible) from the same IP. While the effect is not the same for logged-in posters and ACs (and in particular, for ACs it is no lasting effect), there is an effect on ACs as well. Thus even if you only care about the secondary effects, moderating ACs makes sense.

Re:It's good to see that ..... (1, Offtopic)

smpoole7 (1467717) | about a year and a half ago | (#42700265)

OK, this IS off topic, but it's something I feel strongly about.

When I have mod points, I follow some simple rules. I rarely, if ever, mod someone down. I'd rather mod a good post up.

I always reserve some points just to bump up an AC who does a good job. Some people post AC because they're at work or need/want to remain anonymous, not because they're trolls. (And you didn't need to lose your mod points in this discussion; you could have posted AC yourself, then said, "posting AC 'cause I have points" and then added your name to prove it.)

I want a well-done post that makes me think, even if I strongly disagree with the poster's conclusion. It irritates me when I see someone modded down just because he/she has said something that others might disagree with. (Threads on politics, global warming and gun control come to mind.) If you mod someone down just because they attack your sacred cow, YOU are the one with the small mind ... not THEM.

Re:It's good to see that ..... (0)

Anonymous Coward | about a year and a half ago | (#42699835)

One perfectly reasonable interpretation of Thephydes's post is that he meant "I won't even pretend to understand General Relativity, much less Special Relativity..." So your sighing might be unnecessary.

Re:It's good to see that ..... (0)

Anonymous Coward | about a year ago | (#42703577)

What should be added to this story is that Special Relativity was in many ways born in Electro-Magnetism to the point where many physicists believe Einstein got too much credit. The EM laws for example are completely relativistically invariant to the point where there cannot be any kind of conflict between EM and GR, and the most important early experiments establishing that there is no single preferred reference frame where done in an EM context.
As such this story is non-news. Someone not versed well enough in EM and GR to know what he's talking about asserted there's a conflict even though it has been known that there cannot possibly be such a conflict since day one, since both have been shown mathematically to be fully compatible.

Re:It's good to see that ..... (1)

BitterOak (537666) | about a year ago | (#42703587)

Science is alive and well in at least the Physics community. Whilst I won't even pretend to understand General Relativity, the questioning of it and discussion about those questions is the true essence of science.

Sigh. General Relativity was not even at question here. Perhaps commenting on Slashdot should require a minimum amount of knowing what one is talking about. AAAHAHAHAHAHAHAHAHHAHAHAHA. Sigh.

Wow, somebody took their grumpy pill this morning. Can't a person simply point out that it's great to see issues like this being discussed without someone tearing them apart for confusing the special and general theories of relativity? By the way, I have a Ph.D. in physics. Does that make me qualified to post a reply to your comment?

Re:It's good to see that ..... (0)

Anonymous Coward | about a year and a half ago | (#42705689)

By the way, I have a Ph.D. in physics. Does that make me qualified to post a reply to your comment?

no =D

Re:It's good to see that ..... (0)

BitZtream (692029) | about a year and a half ago | (#42705815)

By the way, I have a Ph.D. in physics.

No. Having a Ph.D. in physics means nothing more than you have a Ph.D. in physics. It does not, contrary to what you assume, mean you know what you're talking about. Having a Ph.D. just means you did the same shit grunt work those before you did so now you've got a certificate from the Good Ole' Boys club saying you did the same shit they did. That is not science, thats Academia and while most associate Academia with knowledge, that is also silly and more often than not, wrong.

A Ph.D. means you paid your dues to the elitist, arrogant and often ignorant Academia club, nothing more.

To be clear, you may very well be qualified to respond, but having a Ph.D. has nothing to do with why. Pointing out you have a Ph.D. actually means its less likely you know what you're talking about and more likely you just wanted to brag about how smart you think you are.

Re:It's good to see that ..... (1)

Anonymous Coward | about a year and a half ago | (#42699635)

/. is the last place I expected to see, "isn't science great" Facebook-type posts.

Re:It's good to see that ..... (0)

Anonymous Coward | about a year and a half ago | (#42700121)

[Like]

Re:It's good to see that ..... (1)

bill_mcgonigle (4333) | about a year and a half ago | (#42700257)

/. is the last place I expected to see, "isn't science great" Facebook-type posts.

Not everybody here is a depressed curmudgeon.

Re:It's good to see that ..... (1)

Anonymous Coward | about a year ago | (#42701733)

Perhaps the previous AC meant that science being great is a given and doesn't need to be stated here.

Re:It's good to see that ..... (2)

rocket rancher (447670) | about a year and a half ago | (#42700219)

Science is alive and well in at least the Physics community. Whilst I won't even pretend to understand General Relativity, the questioning of it and discussion about those questions is the true essence of science. facts ->theory->more facts->questions->revised theory. Beautiful!

Did you mean trueFacts, or goodFacts? Anything can be politicized, even physics. Humans, as a rule, don't care about "facts" when they conflict with personal beliefs. If the algorithm starts with "facts", you are setting up a conflict between trueFacts and goodFacts, which allows personal beliefs to corrupt the entire process. Let me propose a slightly different algorithm that takes personal belief out of the way of the pursuit for knowledge:

model -> hypothesis -> measurement -> failure of hypothesis -> revised model.

Start with a model, not some "fact." A model is just a model. As long as it is empirically adequate, it doesn't require truth with a capital "T" to be useful, so nobody has to get their knickers in a twist over those parts of the model that disgust or terrify them. That's how Galileo and Copernicus got their ideas past the Catholic Church. By insisting they were just models [wikipedia.org] that were more useful [wikipedia.org] to them than the Ptolemaic "truth" endorsed by Rome, they therefore posed no threat to the Church's "facts."

For what it is worth, as a mathematician, I've always chuckled at physicists who think that reality is going to be accessible via mathematics, which is a purely abstract tool. :)

Re:It's good to see that ..... (1)

maxwell demon (590494) | about a year and a half ago | (#42700297)

You have to start with facts because without facts you don't even know that you have something you need a model for. You don't just invent models and then look if you can find something in nature which fits that model. You start with facts you find, and try to make a model which reproduces those facts. You generally try to be compatible with existing models in regimes where those didn't fail, so that would be the first test of your model (well, you might at the very first also do some consistency check). Then you derive predictions from that model and test those predictions with reality. You'll usually start with things which already have been measured, and only after your model has survived that test you start proposing new experiments.

Re:It's good to see that ..... (1)

lgw (121541) | about a year ago | (#42702675)

Starting with "facts" really adds nothing to the process, except perhaps expediency. If a model accurately predicts new measurements it's a good model. If a model accurately fits the set of known measurements ("facts") - that actually means very little! Necessary, but not even close to sufficient. That's the "data mining fallacy", and why people tend to do such a poor job at modelling the stock market.

Re:It's good to see that ..... (1)

maxwell demon (590494) | about a year ago | (#42703135)

Without having facts, you don't even know what to model. If someone told me to model the solar system and I had no facts about the solar system, my model might look like "a=b+c" where a is the a-ness of the solar system, b is the b-ness and c is the c-ness. Of course that has nothing to do at all with the solar system. But I can't know that without any facts about the solar system.

Rationalism vs Empiricism (1)

Tenebrousedge (1226584) | about a year ago | (#42703971)

No, it's not about facts.

It's about epistemologies: How you arrive at those facts. Most scientists follow an empirical empistemology. The rest of the world usually follows a more rational one, or historical (i.e. something is true because a book says so).

A rational epistemology holds that anything that can be proved logically is true. An empiricist holds that anything that can be demonstrated experimentally is true. Some statements can be true in either paradigm, but it can make a big difference as to how you arrive at these conclusions.

And it's not that either is necessarily invalid, or even that they're entirely separable. You have tradeoffs: with rationality, you can prove things that aren't necessarily 'true' in the real world. With empiricism, your truths are only valid to the limits of measurement: there's very little in the way of absolute truth to be had.

The clashes between science and the church were epistemological. Only one of these things can be the ultimate test of knowledge. So far the empiricists are winning if you count the fruits of their works, and the rationalists are winning by sheer numbers.

Re:Rationalism vs Empiricism (1)

rocket rancher (447670) | about a year and a half ago | (#42704901)

I don't think "rational" means what you think it means...there is nothing rational about an epistemology that requires faith to espouse. Faith is the acceptance of truth without evidence. The wikipedia entry for faith and rationality [wikipedia.org] explicitly calls out faith as being incompatible with rational, evidence-based reasoning.

Re:Rationalism vs Empiricism (1)

Tenebrousedge (1226584) | about a year and a half ago | (#42705355)

Actually in the context of epistemology [wikipedia.org] , it means exactly what I said it means. The wikipedia article you refer to conflates rationalism and empiricism, I refer you to my previous post for an explanation of the differences.

You're also ignoring centuries of christian apologists and philosophers, scores of whom were better logicians than either of us: I may single out Descartes and Kant. Faith is an axiom, not necessarily an irrationality. The axioms of Christianity and those of mathematics may differ, but their applicability to the real world is problematic for the exact same reason.

Re:It's good to see that ..... (5, Insightful)

bill_mcgonigle (4333) | about a year and a half ago | (#42700237)

And it's a healthy sign that some random guy can say, "look Special Relativity seems to be broken," and nobody starts screaming about golden idols or anything, but rather four smart guys kindly consider what he has to say and show him where he went wrong. Everybody learns something, egos remain intact, and nobody starts swinging guns. Science FTW.

Re:It's good to see that ..... (1)

Anonymous Coward | about a year ago | (#42701431)

This is actually surprisingly easy to do with physicists in my experience. As long as you are polite, and don't make it look like you are trying to feed your ego by "beating" physicists with no effort, you can sometimes get a remarkable amount of effort and response to questions. In other words, physicists are very nerd-snipe-able, and will before they know it, spend a weekend working on a problem just because of something a student, coworker, or random person said or asked in idle conversation.

Re:It's good to see that ..... (0)

Anonymous Coward | about a year and a half ago | (#42705509)

Where would that occur? Is there a forum you have in mind?

Lorentz invariance (0)

Anonymous Coward | about a year and a half ago | (#42699431)

General relativity cannot clash with the Lorentz force law, because it is based on Lorentz invariance.

Re:Lorentz invariance (1)

wonkey_monkey (2592601) | about a year and a half ago | (#42699547)

Einstein's theory of special relativity

Re:Lorentz invariance (0)

Anonymous Coward | about a year and a half ago | (#42699603)

special relativity can clash even less.

how strange (1)

Anonymous Coward | about a year and a half ago | (#42699575)

How strange that even I understand the "hidden momentum" concept (I think!). Time for a car analogy:
Imagine a car driving past you. At first you're looking at its front, then side, then it rear. So the car actually rotated from your frame of reference, and at the time it was passing right next to you it had an angular momentum.
Since the car was not actually rotating, those physicists call it a "hidden angular momentum".

This electrical engineer claims that such angular momentum is just a kludge concept added on top of relativity, and not real. If my understanding is correct, then he is wrong.

Re:how strange (0)

Anonymous Coward | about a year and a half ago | (#42699607)

He's not as wrong if he comes up with another kludge concept that is better at predicting/explaining stuff.

Re:how strange (1, Flamebait)

expatriot (903070) | about a year and a half ago | (#42699651)

Whenever there are any really tough questions about relativity, the world waits for an electrical engineer to comment. Unfortunately their comments are not correct.

Re:how strange (2, Interesting)

Anonymous Coward | about a year and a half ago | (#42699725)

Well, "hunt the paradox" is a standard exercise in Theoretical Physics 101, special relativity. There are quite a number of them, and not too few involve understandings of "orthogonal" and "simultaneous" and other conceptual geometric invariants that are not actually invariant.

Electrical engineers don't go through that enfuriating and embarrassing spectacle of "ok, what did I take for granted now again" of relativity initiation.

Read original paper (3, Informative)

Janek Kozicki (722688) | about a year and a half ago | (#42699727)

http://prl.aps.org/toc/PRL/v108/i19 [aps.org]

Scroll down to "Trouble with the Lorentz Law of Force: Incompatibility with Special Relativity and Momentum Conservation", there you can get the pdf, if you have university access. Whew, it took me more than 20 minutes to find it. Why those journalists do not include the cited source?!

This paper is actually quite interesting, and I remember my ED teacher complaining about the Lorentz Law incompatibility during his lectures too. Whether "hidden moment" exists or not - maybe is a matter of performing the right experiments :)

And what about the proton radius problem?

Back to middle ages (0)

Anonymous Coward | about a year and a half ago | (#42699769)

Didn't have access. What is this? Scientology? Have to advance in levels of priesthood or something?

Re:Back to middle ages (1)

Janek Kozicki (722688) | about a year and a half ago | (#42699791)

sorry, not all journals are open access, yet. I hope it will be fixed in this decade.

level 1 is Pir8 bouy (1)

cheekyboy (598084) | about a year and a half ago | (#42699899)

What ever means are necessary, in the quest for knowledge, the artificial imaginary made up, invisible laws made by man are just that, big fairy tales that dont exist.

Re:Back to middle ages (0)

Anonymous Coward | about a year and a half ago | (#42700073)

You could, you know, pay to play. Like all other aspects of life.

Re:Back to middle ages (4, Funny)

Zontar The Mindless (9002) | about a year and a half ago | (#42700437)

You could, you know, pay to play. Like all other aspects of life.

I hate being the one to break this to you, but... If your girlfriend is billing you for services rendered, she's not really your girlfriend.

Ah, well... (0)

Anonymous Coward | about a year and a half ago | (#42700521)

When you go on dates with your girlfriend, do you pick up her check?
Do you buy her more gifts than she buys you?

In the overwhelming majority of cases, the answer to both questions is a resounding "yes."

She may not be billing you, but you are definitely paying her.

Re:Ah, well... (1)

Zontar The Mindless (9002) | about a year ago | (#42700985)

Really? Mine makes more than I do (she's an engineer and I'm a writer, go figure), and usually volunteers to pay for "extras" like trips to the cinema and dinners out.

I must be doing it wrong, I suppose.

Re:Ah, well... (0)

Anonymous Coward | about a year ago | (#42702367)

How you got modded up for trolling is anyone's guess, but nobody cares about you or your girlfriend duder.
Either pony up for access to the journal or STFU.

Re:Ah, well... (1)

Zontar The Mindless (9002) | about a year ago | (#42703157)

Meet an old debater's judo throw known as reductio ad absurdem. It's very effective at dispelling ridiculous blanket assertions such as that put forward by the OP.

BTW, given your keen powers of observation, you no doubt noticed that elsewhere in this discussion, I took someone else to task for equating a pay-walled article to some sort of life-and-death matter, and you were able to conclude (correctly) that I don't give a shit whether they charge to read their article or not.

Re:Back to middle ages (3, Informative)

maxwell demon (590494) | about a year and a half ago | (#42700187)

All you have to do to access it is to give them the right amount of money (or to be at an institution which does so, as for example an university).

However, these days many physics articles are also found on arXiv [arxiv.org] so it makes sense to search for the article there. And indeed, this article can be found there. [arxiv.org] The journal reference given there also makes it clear that it is really the same article.

Note that everything on arXiv is Open Access.

Re:Back to middle ages (1)

History's Coming To (1059484) | about a year and a half ago | (#42700231)

Also not that arXiv is not formally peer reviewed, it's a pre-print archive, so the papers have not necessarily been vetted or reviewed in any way, so you do get the odd one which may very well be sociologists trying to get their own back for the Sokal affair, or just plain nutjobbery, it does happen. (In general though, it's the way papers SHOULD be published.)

Re:Back to middle ages (1)

Anonymous Coward | about a year ago | (#42701607)

Just check first to see what journal the final form of the paper was published in (and possibly if there are any public comments or citations), then go look for it on arXiv. It should still be the exact same content. At least in physics, every journal publishing agreement I've seen allows you to release a copy of your paper and give it out, just without the formatting done by the editors of the journal.

Re:Read original paper (1)

Janek Kozicki (722688) | about a year and a half ago | (#42699797)

it is slashdotted now...

Re:Read original paper (0)

0111 1110 (518466) | about a year ago | (#42703669)

Ah. Sometimes denial of service attacks are a good thing then. Locking away pure information in such a way that only rich people from rich countries can view them is so not the way for science to move forward.

Re:Read original paper (3, Informative)

henryteighth (2488844) | about a year and a half ago | (#42700221)

http://arxiv.org/abs/1205.0096 [arxiv.org] Many physics papers are also uploaded to the arxiv where they are freely accessible.

Has nothing to do with physics (2, Interesting)

Anonymous Coward | about a year and a half ago | (#42699733)

Since a paradox is not a feature of the Universe; it is a feature of a limited mind trying to understand the Universe.

Re:Has nothing to do with physics (1)

maxwell demon (590494) | about a year and a half ago | (#42700205)

Since a paradox is not a feature of the Universe; it is a feature of a limited mind trying to understand the Universe.

Physics is all about understanding the universe with our limited mind.

Re:Has nothing to do with physics (1)

Zontar The Mindless (9002) | about a year and a half ago | (#42700455)

Heh. I was actually thinking of your sig when I posted that. :)

Open access links to actual papers (3, Informative)

forand (530402) | about a year and a half ago | (#42699857)

Glad to see that others are noticing that in Physics we are still willing to entertain questioning of the foundations of modern Physics by those outside the field. Another great thing about our field is that most every paper is openly available on one of the abstract services. The original article noting the apparent paradox can be found here [harvard.edu] . While the subsequent discussion can be seen by looking at the papers citing the original, found here [harvard.edu] . Some of the commentaries have yet to be released from their embargo and are thus not yet available but will likely be so soon.

I've discovered a new paradox! (0)

Anonymous Coward | about a year and a half ago | (#42699867)

A purported conflict between the century-old theory of classical electrodynamics and Einstein's theory of special relativity doesn't exist, a chorus of physicists says.

Now, four physicists independently say that they have resolved the paradox.

If the four physicists spoke independently, how are they a chorus?

Re:I've discovered a new paradox! (0)

Anonymous Coward | about a year ago | (#42701805)

If the four physicists spoke independently, how are they a chorus?

chorus: (noun) something sung, or spoken either simultaneously or unanimously by a group of people. E.g., a chorus of "are we there yet" came from the children in the back of the car...

However, if they weren't unanimous, then they would not be a chorus.

Isn't this normal? (0)

Anonymous Coward | about a year and a half ago | (#42699935)

Summary: Engineer misunderstands physics - physicists prove him wrong.

Where's the news?

It's not a paradox (5, Insightful)

mocm (141920) | about a year and a half ago | (#42700041)

if you forget part of the energy-momentum tensor when you transform your coordinates from a stationary into a moving frame of reference.
Special relativity really cannot "clash" with the Lorentz force law, because it is based on the Lorentz invariance of Maxwell's equations. I think a "paradox" like this keeps coming up ever so often in discussions of special relativity, form people who don't understand it. I just don't see how PRL can accept such a paper.
I admit it would make a nice problem for a physics test, but not much more.

Re:It's not a paradox (1)

maxwell demon (590494) | about a year and a half ago | (#42700355)

I just don't see how PRL can accept such a paper.

Simple: The referees they sent it to for peer review didn't understand it either.

Re:It's not a paradox (1)

tinkerton (199273) | about a year and a half ago | (#42700513)

I think your position is too radical. Understanding is more than knowing what the result will be. Understanding is about - to put it in James Maxwell's words - knowing the particular go of it. And that is valid science. The twins paradox in special relativity can easily be dismissed on general principles but that isn't the same as understanding how it goes.

When someone proposes a perpetuum mobile it can instantly be dismissed by slapping a physics law on it, but that is a limited form of understanding. It's legitimate to ask what the actual mobile will do.

Of course, there's still a difference between wanting to know what the actual model will do and concluding that the basic laws are wrong. Then again, often it's hard to be sure that you haven't actually made some approximation that accidentally threw away an important factor.

I first thought this was about the Abraham-Lorentz reaction force. You can sure make some hairy paradoxes with that one.

Re:It's not a paradox (3, Informative)

daaxix (218354) | about a year ago | (#42700567)

Read his paper and his rebuttal. He is basically saying that if the Lorentz law of force is replaced with a more elegant equation (Einstein-Laub), then you naturally obtain the "hidden momentum" terms that are inserted under a covariant transformation. Furthermore, there is another candidate equation, Helmholtz force, which is different but takes care of the "hidden momentum" in a similar way. Predictions in differences in experiments can be made and Mansuripur is attempting to realize these experiments. These experiments will determine if Einstein-Laub is correct or if Helmholtz force is correct. Interestingly, the covariant transformation of the hidden momentum gives a term like the Helmholtz force I believe, so these experiments really should determine who is right.

I really don't see why he is being attacked, his analysis doens't disagree with relativity, it just moves the mathematical terms for the hidden momentum to a different place. What I really find interesting is his claim about the experiments...

What is it with physics? (3, Insightful)

exploder (196936) | about a year and a half ago | (#42700291)

First of all, this post is aimed not at the engineer from the article, but at some of the posters to this story and others like it. What is it about physics in particular that attracts so many uneducated crackpots? It seems to be the sweet spot for cranks on the XKCD spectrum--they don't go all the way over to math, and try to promote their pet tensor analysis theory ("this is how we really should compute the induced map on the cotangent bundle!"), and even less often are we treated to their "revolutionary" theories of hydrocarbon structure or ribosomal protein synthesis.

Nope, they gravitate straight to physics. Is it that concepts are (relatively) familiar, like light, gravity, time, particles, etc? Is it Star Trek? Must drive physicists nuts.

Re:What is it with physics? (1)

ceoyoyo (59147) | about a year ago | (#42700699)

I suspect it's because classical physics is something we're all reasonably familiar with from our everyday experience but modern physics departs from our expectations in many ways. We know our intuition doesn't work very well with tensor analysis or hydrocarbon structure or protein synthesis, but we expect it to work well with bits of matter flying around. Cranks are just people who mistake their intuition, or deeply held beliefs, for "truth."

Re:What is it with physics? (0)

Anonymous Coward | about a year ago | (#42701591)

While there may be some bias and dis-proportionality in what fields crack-pots go into, they are still present across the board in great numbers.

There are quite a few pseudo-mathematicians. Numerous people claim to have found ways to square a circle or trisect an angle using a compass and unmarked rule, even though it has been mathematically proven impossible to do. There are various people with inconsistent claims of how to divide by zero, or calculate the digits of pi (frequently showing they are just playing with floating point numbers with serious rounding errors...), and so on. It is just anecdotal evidence, but a friend from undergrad that went into math gets more cold emails from crack pot theories in math than I do working for a physics department.

There is plenty of stuff on the other side, with various crack pot theories on evolutionary and developmental biology (not counting ID based things). Geology in my experience seems to be a popular field of crack pot work. And you get people in chemistry claiming to have reactions that can cycle and produce a net amount of energy (although sometimes that gets boarder-line physics depending on how to explain it). Not to mention the immense amount of medical and dietary crack-pottery that lacks any experimental evidence and can sometimes hit main stream.

At least for physics though, I think the problem is there are so many analogies and superficial explanations of theories and ideas that people will base their crack-pot theories on, when from the start the watered-down analogy was incomplete already. Even ones with more formal training in some of the basic ideas I've noticed tend to not be familiar with the immense catalog of experiments and data related to some theories. "Yeah, your new theory would be great if the only observations we had were the ones described in that single paragraph in that one pop-sci book... but your theory directly contradicts these twenty other experiments..."

Re:What is it with physics? (1)

noobermin (1950642) | about a year ago | (#42703395)

I'd say it is the philosophical side of physics. Physics, sometimes more than the other sciences focuses on the big picture and hence, meaning of equations and less of plain facts, or at least that's what I gather from the pre-meds I tutor. It's not that meaning isn't important in biology or chemistry, it is just is that with so much information, going too deep into one topic can be a waste of time that misses the point. For physics, depending where you are on the experimental to theoretical spectrum, depth is the point, and thus, one can be philosophical about it (okay, so QED is infrared free, but why would that upset you? What does that mean? How can someone even talk about an electric field so close to, say, a point particle?)

Also, I think it is the sort of things physics talks about--the nature of space and time, the nature of systems in the quantum regimes (schrodinger's cat), it sounds very mystical. Furthermore, it isn't quite easy to understand and for some phenomena, like QM, there are few, everyday analogies one can make to understand it.
So, perhaps this philosophical stuff mixed with the subject matter and served with a side of mystical sounding phenomena sort of attracts the cranks. The fact that quantum mechanics sounds counterintuitive and says (apparently) stuff like "existing and not existing" and "takes a stand only when you are observing" kind of resounds with some mystical cord in their hearts and makes them draw parrallels to eastern mysticism...only now, with science!

I've met some people who are sorta out there, but I usually try to bring them to seeing that a lot of the theories are not dreamnt by some thinker on a cot (that's reserved for mathematics: Kurt Godel), they are the result of real-life experiments: photoelectric effect, Michaelson-Morley...we aren't philosophers, we really are scientists.

Speaking of mathematics, I find mathematics mystifying; I mean, it is the study of thought itself, essentially. I think the reason that math doesn't attract cranks as much (save numerologists, squared-circles, etc) is because mathematics has no direct applications to real-life (ie., it isn't science), and thus, it misses that "nature" crap that physics attracts, although it does sometimes have the thinkers on cots. Therefore, your induced maps on cotangent bundles don't quite sell your books about the nature of time and how your ancient meditation techniques with egyptian oil will help you reach the cosmos (oil available at a low cost with the free coupon insert!). Now, if that bundle happens to be over a spacetime manifold...well, then, you are now somewhere that relates to the real-world (somewhat removed, however ;) ), but now this is physics, not strictly math anymore.

Cognition (1)

hduff (570443) | about a year and a half ago | (#42700363)

Executive Summary
If you have a paradox in a thought experiment, you can think your way out of it.

Re:Cognition (4, Informative)

thegreatemu (1457577) | about a year ago | (#42700993)

Not by any means. For probably the best example, look at the Einstein-Rosen-Podalsky paradox , a simple thought experiment used an attempt to disprove the so-called Copenhagen interpretation of quantum mechanics because it would require the instantaneous transmission of quantum states in such a way that would violate special relativity. People did try to think their way out of it, until Bell's theorem "thought" everyone back into the paradoxical corner - leading to the modern sciences of quantum entanglement.

In fact if you look back, many of the advances in modern physics have come about specifically because of paradoxes arising from thought experiments. See also the ultraviolet catastrophe, or even Schrodinger's cat for that matter.

uniformly accelerating particle radiate? (0)

Anonymous Coward | about a year and a half ago | (#42700485)

This reminds me of another paradox which is still unsolved. Even the experts disagree. Some claim (Feynman) it does not since it would violate relativity, but some (Becker) claim things would still work out. Even QED/QCD/QFT does not provide a conclusive answer to the above. Unfortunately it would take a billion dollar experiment to find out and since no oil is involved that is not going to happen.

Caution (0)

Anonymous Coward | about a year ago | (#42700925)

One of the links leads to mit.

Decision, by default, goes to ... (1)

yusing (216625) | about a year and a half ago | (#42704635)

Mansuripur's papers are readable on Archive.org, while the replies of his critics are on paywalled journals. I do not have 30 or 40 dollars to observe their handwaving. Since he's out in the open, while their supposed 'replies' are hiding behind the bulwarks of protectionist convention, I'm awarding the decision to Mansuripur. All hail Swartz.

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