[fennecfoxen]

The BBC coverage quotes a Lindsay LeBlanc, of the University of Alberta, "a physicist not involved in the study":

"Although these results offer only an analogy to a magnetic monopole, their compatibility with theory reinforces the expectation that this particle will be detected experimentally."

http://www.bbc.co.uk/news/science-environment-25946734

The overall phrasing seems to say that it's still just an analogue of a monopole, but that it's a far more useful analogue in a system that you could do meaningful experiments upon.

[mjburgess]

Physicists tend to be metaphysical sceptics on the whole, meaning that they arent really convinced that the implied objects (/particles/fields/etc.) of physical theories actually exist^. Merely that "something exists which makes the mathematics work". Seeing so many different kinds of math work for the same physical system tends to engender a kind of scepticism towards the "metaphysical power" of mathematics to imply anything ontologically particular about the world.

Now, when it comes to results like this, they are interesting because it doesnt really matter if there are magnetic monopoles if you "just wanted to use a magnetic monopole" - you could create some in supfl. He.

The point is that whatever system enables the math to work is irrelevant to what ever uses theories will have for this math.

Of course it is still practically relevant, because a simple monopole experiment might be extremely expensive/difficult in Supfl. He.

NB^: Pop physicists who wax philosophical on TV shows tend to be sceptics but appear "hardcore realists" for TV.

[weland]

> The point is that whatever system enables the math to work is irrelevant to what ever uses theories will have for this math.

Additional explanation from someone who (also?) used to do research, with papers and all: we actually used objects we knew did not exist to do actual science. By "do not exist" I mean "they are make-believe theoretical objects that do not exist per se, but they are good models for things that do exist".

Science and engineering is full of these things. Holes in transistors: they don't exist, they're actually a certain type of electron shifting their positions in a particular way, but the math would get a lot hairier (at no gain!) if you treated them as electrons. Electrical charges in classic electromagnetism aren't electrons at all -- they're small dots with charge on them, but the math would get a lot hairier (at no gain -- again!) if you didn't treat them like this.

Being able to model a phenomenon is very important, and being able to model it simply is, for lack of a better word, God-given. Phenomenological models (i.e. models that model only the behaviour, not the inner working of a certain phenomenon) are as good as any other model, as long as you bear in mind that they are phenomenological: you can use them to reason about certain effects, but not necessarily about what causes them.

Before anyone jumps in to point out this is bullshit and that there's really more to life, I just want to remind everyone that we've been building buildings and bridges and shit based on a phenomenological model. Classical mechanics knows absolutely shit about how gravity works -- it just tells you useful stuff about what it does -- and I'll personally grab all the beer in the world for someone who finds an actual material point.

[acjohnson55]

Perhaps it's phenomenological models all the way down. If that is, indeed, the case, is a hole significantly less "real" than a mobile electron?

[wbhart]

I guess an electron is "an actual point".

[weland]

But it's not the only charge carrier. To put things in better context, classical electromagnetism actually predates knowledge about the structure of atoms. The charges in its model are very much hypothetical particles, and that's why it only really works at macroscopic scales. Turns out that's actually enough for a lot of things :).

[ocfnash]

As others have pointed out, these are indeed just analogues of (fundamental) monopoles.

IMHO, this is an example of a deliberately-slightly-misleading abstract for a paper. The authors write: "Although analogues of magnetic monopoles have been found [in others' work] there has been no direct experimental observation of Dirac monopoles within a medium described by a quantum field [...]. Here we demonstrate the controlled creation of Dirac monopoles in [...]. Monopoles are identified, in [...]"

If I were a referee for the paper, I would have registered the following objection: When referring to others' work, the authors use the phrase "analogues of monopoles" whereas they reserve the phrases "monopole" and "Dirac monopole" for references to their own. Their terminology seems especially egregious on account of their earlier statement: "The existence of even a single Dirac magnetic monopole would have far-reaching physical consequences, most famously explaining the quantization of electric charge". In fact they too have only discovered analogues of monopoles and the abstract is confusing for non-specialists, as evidenced by this thread.

Nature is a journal that has been known to give in to the temptation to sensationalise so I am not all that surprised.