Thursday, February 16, 2012

"Pinch" Me, I'm Dreaming of "Magnetic Slinkies!"

Silly metaphors require silly titles. Hopefully today we can sort out some astrophysical silliness and come to a better understanding of what is going on from an electrical standpoint. The silliness in question is the "magnetic slinky" that has been metaphorically associated with a molecular cloud in Orion. Put simply, a better physical explanation is the "plasma pinch."

In my introductory post, I exegesis-ized the relationship between... Yes, okay, I know exegesis-ized isn't a word! Sheesh! Fine, I elaborated (some might prefer belabored) the relationship between magnetic fields and electric currents. Hopefully we're all on the same page by now:
"Electric currents are the sole source of magnetic fields in the universe."
Today, we seek to put that notion into practice with a real-world example. Moreover, let's add another bit of electrical physics to the mix.

The topic I want to recap today is an oldie but a goodie. In 2006, astronomers discovered what was subsequently coined a "magnetic slinky" encircling a molecular cloud in Orion. 

But, what does that even mean? Honestly, by itself, not a whole heck of a lot. It's a pretty bad metaphor. Essentially, what was being described is the approximate shape of magnetic 'field lines' encircling the long axis of the molecular cloud. In a later post, I'll cover why we should move away from the concept of talking about 'field lines' (they don't actually exist).

But, again, what does the discovery actually tell us about what's going on? For that I'll actually grab a slightly better quote from the press release:
"The magnetic field lines are like stretched rubber bands; the tension squeezes the cloud into its filamentary shape."
Ahh, action words! Something happened. Finally, we're getting somewhere! Though, the metaphysics is still terrible, since magnetic 'field lines' do not exist thus cannot have 'tension' and cannot 'squeeze' anything. But at least we have some idea now of what has been observed. Something is causing the compression of the molecular cloud into a filamentary shape. It's a start...

So, what do we know? We know there's a 'cloud' out in space. We know that a magnetic field is involved. We know that the cloud is being compressed. We know that the magnetic field is implicated somehow in compressing the cloud.

So, what's actually going on?

Let's back up and head back to the basics. We've already said that magnetic fields are produced by electric currents, because electric currents of some character are the sole source of magnetic fields in the universe.

When a current flows, a magnetic field is generated around it. It can be visualized as a straight line (current, I) surrounded by concentric circles (magnetic field, B).
But, this universe is messy and things are never quite that simple. When a current flows and generates a magnetic field, the magnetic field can also interact back with the current that created it, constricting the current. As the current is constricted the magnetic field increases.
Original Caption: Fig. 10: Physics of the Z-pinch: A current (orange) generates a magnetic field (blue), which causes the current to pinch inwards along the axis by way of the Biot-Savart F = I × B force. This amplifies the magnetic field and accelerates the pinch, heating the plasma and causing it to radiate X-rays (red).
This feedback continues until magnetic pressure reaches equilibrium with the gas pressure in the compressed conductor. This is known as the 'pinch effect.'

Are there any accessible examples of the pinch effect? Yes. But we'll get to those in a moment.

First let's back up one more time and discuss discharge regimes. In a plasma, there are three basic regimes. One might call them 'intensities' of discharge.
  • Dark Discharge
    This regimes is termed a dark discharge because although a current flows, generally, the discharge remains invisible to the eye.
  • Glow Discharge
    The glow discharge regime owes its name to the fact that the plasma is luminous. The gas glows because the electron energy and number density are high enough to generate visible light by excitation collisions.
  • Arc Discharge
    Beyond the glow discharge is the arc discharge regime. Particle energies and current density are higher. The increased current produces an associated increased magnetic field which pinch the current into a filamentary shape. Arc discharges are also known to emit copiously across the electromagnetic spectrum.
So, are there any examples of the pinch effect? Yes!

In the glow mode, one need look only as far as a novelty 'plasma lamp' or 'lightning globe' as they are affectionately known:

Discharge streamers emanate through low density ionized gases (plasma) from a central electrode, compressed into filamentary forms by way of the pinch effect.

In the arc discharge regime, we can easily point to lightning:

The discharge channel is clearly compressed into a filament with a very small radius. Lightning also emits brightly in the visible range and indeed across much of the EM spectrum from radio to x-rays.

Now you know! The pinch effect can be reasonably easily understood and is useful for understanding several relatively mundane processes here on Earth. But, what about in the cosmos at large?

It is this author's opinion that what's good for the goose is good for the gander. What holds true here on Earth in the lab and in nature should also apply to the cosmos. so, we come full circle back to the original inquiry: the molecular cloud in Orion.

To recap what we know: there is a filamentary cloud of material; it is being compressed into its filamentary shape; magnetic fields are involved somehow.

We also know that magnetic fields find their genesis in electric currents and can be visualized as field lines wrapped around the central axis of the current.
Original caption: The Orion Molecular Cloud superimposed on the Orion constellation, with the orange star Betelgeuse at the top corner and Rigel at the bottom. The inset shows the Slinky-like coils of the helical magnetic field surrounding the filamentary cloud. (Credit: Saxton, Dame, Hartmann, Thaddeus; NRAO/AUI/NSF)
Diagram shows azimuthal magnetic field (B)
as concentric circles around central current (I).
So, based on what we know of the nature of magnetic fields and the pinch effect, do we have enough information to make an anecdotal case for a hypothesis on what's really going on here? I think we do.

An electric current flowing along the length of the filamentary cloud would generate a magnetic field azimuthal to the cloud (wrapped the short way around the filament). Such a magnetic field could interact back with the current flowing through the cloud causing it to 'pinch' or compress into the observed filamentary shape. Not unlike the filamentary tendrils observed in a plasma lamp (above).

Thus, rather simply, we can back-infer from the magnetic field of the filament, its shape and the implication that the magnetic field is involved in compressing the cloud into its filamentary shape that there is a plausible possibility that a current is flowing there, which would reproduce the features observed.

Would the solution be as simple as drawing a line down the middle of the "magnetic slinky" along the long axis and labeling it (I) denoting a current flowing there (as an analogy to the current [I] vs. magnetic field [B] diagram, above)?

I suggest that it is incumbent upon astronomers to perform some follow up observations and/or modeling to investigate this simple, testable proposition. Moreover, if this hypothesis is found plausible or even probable in this instance, this observation and hypothesis could easily be applied to a number of other structures demonstrating filamentary shapes and strongly associated magnetic fields.

Another pertinent example that jumps to mind is the "Strongest Electrical Current in the Universe" recently derived from observations in an extremely similar manner (by first observing Faraday rotation indicating the presence of a magnetic field then modeling the system to determine the characteristic of the current driving it).

One wonders somewhat emphatically whether all similar jets (such as the "largest stellar jet" stretching over 400 trillion kilometers recently found in the Large Magellanic Cloud or Herbig-Haro objects, generally) may share common features, including an electrical character heretofore not widely acknowledged.

I'd love to see a rigorous investigation with the potential to investigate this very simple hypothesis.

If the above examples are tackled and an answer in the affirmative is obtained, perhaps this hypothesis can then be extended to the investigation of the entire filamentary cosmic web of stars, galaxies and galaxy clusters.

Are any astronomers brave enough to undertake a rigorous voyage of discovery into this wild new frontier? The exploration won't be without its challenges. But the bounties may far outweigh the perils.

Wednesday, February 15, 2012

Exploding Circuits: A New 'Magnetic Reconnection'?

Has a minor update about ongoing plasma research just confirmed a decades old idea about the physical origin of 'magnetic reconnection'? The notion of 'snapping' and 'merging' magnetic field lines may be a thing of the past, replaced by an old theory: exploding electric circuits (exploding double layers).

Breaking news promises to revolutionize our understanding of such processes as magnetic substorms and solar flares wherein an unknown process (commonly referred to as 'magnetic reconnection') releases vast amounts of energy very quickly. And by revolution, I mean that it promises to take us a step backward.

"Wait, backward? How can that possibly be a good thing?" you might ask.


It's a long story about a quiet row in astrophysics that nobody likes to talk about... But, this is my blog, so "out with it!"

There is an unstated or very quietly stated assumption in astrophysics that electric currents can't exist in space (except when they're shown to exist by actual observations; how embarrassing!), or if they do exist they don't do anything of note (well, okay, there's that one jet that's the largest electric current in the universe; "but other than that, what's electricity done for me lately?"). And even if electricity does do interesting things out there, gravity is still king so n'yah!

Unfortunately, this notion has straight-jacketed astrophysics, astronomy, magnetospheric physics, heliospheric physics, etc. In terminology, if nothing else. It's a rather queer situation. Astronomers will tell you they 'factor in electric currents,' on the one hand, and then they'll couch things in terms of 'magnetic reconnection' in such a way as to make you think they have no clue about how electricity and magnetism work, on the other..

Why is this bad? Well, there's the notion of the 'pseudo-pedagogical concept.' Why are you giving me a blank look? Ohh right... Not a philosopher. Okay, in layman's terms, sometimes when one starts using a certain set of terminology and ideas to refer to something else (as a sort of analogical placeholder), one starts believing that the placeholder one has invented is equivalent to the actual thing one was referring to and stops thinking in terms of the original idea at all.

So, what is 'magnetic reconnection?' Up until today, it was pretty fair to say 'nobody knows.' That is, in this particular case, a certain formalism has crept in whereby astronomers and astrophysicists seem to prefer talking in terms of magnetic fields and magnetic field lines.

Although some of us think it's bad, it's also somewhat understandable. Here's why: 1) magnetic fields are easier to detect. 2) Magnetic fields can be easier to work with mathematically.

So, it's certainly easier (if lazier) to talk in terms of the thing we can 'see' and treat mathematically with less effort.

But, getting back to the question of 'what is magnetic reconnection,' it arises out of the observation of certain events in space. In particular, 'magnetic reconnection' is a process of interest in solar flares and the magnetic substorms in our magnetosphere that spark the auroras. What we see is that during substorms, the magnetic field changes in particular ways. At the same time vast amount of energy are released very quickly. The relationship between the magnetic field changes and the energy release is what is not well understood and underpins the idea of magnetic reconnection. We'll return to that in a moment.

Now, a magnetic field is visualized using magnetic 'field lines' kind of like the ones you see with bar magnets and iron filings. Though in the case of field line diagrams the lines serve a specific purpose: denoting magnetic field strength and direction. They are a visual tool and that is all.

That brings us to another problem: reification.

I know, another philosophy word. Basically, it means taking some abstract thing and making the mistake of thinking it's a real thing.

In this case, it seems that some astronomers and physicists have goofed and think that 'field lines' are real. They are not. They are lines on a page. There is not a material object (such as a thread, wire, rope or sheet) in 3-dimensional space corresponding to that line. The line merely represents the strength and direction (sometimes thought of as a 'vector') of the force felt by a charged particle placed at that location in the field. Nothing more or less.

So, they've associated observed energy release with observed magnetic field topology changes (changes in the shape of the field lines) and have come to the conclusion that it's the magnetic 'field lines' that are doing something, and in the process energy is released. That is, 'field lines' are thought to be 'twisting,' 'coiling,' 'breaking' and 'reconnecting.' In point of fact that is not even possible, because they do not exist. Morever, magnetic fields are solenoidal (continuous). What does that mean? It means, for one thing, that field lines are ALWAYS drawn as complete loops (except where they run off the page, and then only if the same number of line return to the page as left the page) and cannot 'break,' let alone then 'reconnect' without violating Maxwell's equations.
"...fields are solenoidal: that is, they never begin or end..."
But, there are still observations for which to account... And, account for them we must if science is ever to progress to completion. So, where does that leave us?

We know that magnetic field topology changes and we know that copious energy is released at approximately the same time. But we also know that field lines do not exist and can't break or reconnect. This should also give us a clue that field lines are not themselves a primary mover and shaker. It's hard for things that don't exist to do much of anything. Nonetheless things get done... 

So, how do we reconcile this conundrum?

While magnetic field lines do not exist, they are helpful visual aids to determine properties of that which does exist, namely magnetic fields (keeping in mind that magnetic fields are actually the expression of a force felt between electric currents).

Hopefully you have already read my very first post. If not: stop what you're doing; don't read any further; read that post first. I'll wait. I'm not going anywhere. I'm just a blog post.

Okay, now that we're sure you've read that, my next statement should no longer come as a cognitively dissonant shocker:
Electric currents are the sole source of magnetic fields in the universe.
To quote myself further:
As electric currents produce magnetic fields, any magnetic fields we observe must be produced by electric currents.
Heady stuff, I know! Simple and to the point... Shocking! And we haven't even gotten to the 'A' material yet...

The above reiterated, the bent of the suggestions in the remainder of this post should not be entirely surprising. Hopefully, it's just pretty cool science.

Let's get to the cutting edge research now and then suggest a better metaphysics to replace the tired old dog known as 'magnetic reconnection'!

In the plasma physics lab (as opposed to 'in a giant supercomputer simulation with 30 adjustable variables'), researchers (Moser & Bellan) have studied the physics of jets (electrical discharges) in plasma in order to ascertain the what, when, where, why and how of 'magnetic reconnection.'
"As in all electrical currents, the flowing electrons in the plasma jet generate a magnetic field, which then exerts a force on the plasma. These electromagnetic interactions between the magnetic field and the plasma can cause the jet to writhe and form a rapidly expanding corkscrew. This behavior, called a kink instability, has been studied for nearly 60 years..."

"The jets in the experiment formed 20-centimeter-long coils in just 20 to 25 microseconds. [Moser] also noticed tiny ripples that began appearing on the inner edge of the coil just before the jet broke--the moment when there was a magnetic reconnection."

"...after months of additional experiments, they determined that the kink instability actually spawns a completely different kind of phenomenon, called a Rayleigh-Taylor instability. A Rayleigh-Taylor instability happens when a heavy fluid that sits on top of a light fluid tries to trade places with the light fluid. Ripples form and grow at the interface between the two, allowing the fluids to swap places."

"What Moser and Bellan realized is that the kink instability creates conditions that give rise to a Rayleigh-Taylor instability ... The plasma tries to swap places with the trailing vacuum by forming ripples that then expand--just like when gravity forces a heavy fluid to try to change places with a light fluid underneath."

"While the coil created by the kink instability spans about 20 centimeters, the Rayleigh-Taylor instability is much smaller, making ripples just two centimeters long. Still, those smaller ripples rapidly erode the jet, forcing the electrons to flow faster and faster through a narrowing channel. 'You're basically choking it off,' Bellan explains. Soon, the jet breaks, causing a magnetic reconnection."
This research puts the answer to the 'magnetic reconnection' mystery squarely back into the court of plasma physics.

Basically, what they're saying is that there is a large-scale electric current flowing. That current produces its own magnetic field. If the current and its self-magnetic field are inhomogeneous, an instability can develop (the kink instability; literally, a kink develops in the current filament). Additionally, a smaller-scale Rayleigh-Taylor instability can develop that causes the primary current to 'pinch' (self-constrict) and 'neck off' (similar to what happens in a 'sausage instability' where a current may self-constrict at many locations along its length making it look a bit like Bratwurst links; don't eat it!). In the end, this 'pinch' can completely disrupt the current.

You'd think that would be where the story ends. That's certainly where that article ends. But this post continues a little further. Read on valiant listener! I implied a solution and I'd hate to disappoint.

What happens when you disrupt such a circuit? Is it like a light switch? Not necessarily...

Here I'll turn to an esteemed colleague, Don Scott, who had already some time ago turned his steely electrical engineering eye toward the notion of 'magnetic reconnection' in an old post of his own, wherein he quotes Nobel prize winner Hannes Alfvén:
"'In the case of the instability leading to the extinction of the current, it should be remembered that every electric circuit is explosive in the sense that if we try to disrupt the current, a release of the whole inductive energy at the point of disruption will occur.' - H. Alfvén, Cosmic Plasma, Reidel, Holland, Boston, 1981, p.27."

"Alfvén extrapolated his findings about terrestrial power lines to the study of magnetized cosmic plasma. In the case of the disruption of an electric current within such a plasma, he said, 'If the current disruption is caused by an instability in the plasma, the inductive energy in the circuit will be released in the plasma. … The disruption of a current through a plasma is often caused by a double layer becoming unstable.'"

"Astrophysicists ignore Alfvén's work. They attempt to arrive at a de novo explanation for the release of such energy by embracing the notion that the motion and interaction of magnetic field lines is its root cause. They expound on the (basically false) idea that magnetic fields are 'frozen into' plasma, and by moving and breaking, these lines carry the plasma along and spew it out into space."
So, it would seem that the disruption of a current in plasma isn't quite the same as flipping a light switch. Rather, when the circuit is disrupted, the inductive energy of the circuit explodes out of the point where the circuit is broken.

It is here that we find our impulsive energy release at the same time as the apparent change in the shape of the magnetic field. When a circuit is broken, there is an electrical explosion. Sometimes the explosion of a double layer of separated electrical charges is involved.

In fact, a mechanism such as this was proposed as far back as 1986 or even earlier:
"According to Bostrom (1974) and Akasofu (1977), an explosion of the transverse current in the magnetotail gives an attractive mechanism for the production of magnetic substorms (see Fig. 11). Bostrom has shown that an equivalent magnetic substorm circuit is a way of presenting the substorm model. The onset of a substorm is due to the formation of a double layer, which interrupts the cross-tail current so that it is redirected to the ionosphere."
Although a double layer may not always factor in, the notion of a current disruption and its attendant energy release has apparently circulated for some time. It seems the idea's time has finally come.

The sequence of events appears (in this instance), to this author, to begin with an electric current (as it should since magnetic fields are involved). At some point the current filament develops an instability such as a kink instability. Beyond that the Rayleigh-Taylor instability develops, causing the current to pinch, neck off and break the circuit. At the point of the break in the circuit, the entire inductive energy of the circuit pours out impulsively. Since the underlying current system has changed and a new impulsive event occurs, it would naturally follow that the 'field lines' denoting the magnetic field shape and strength must be redrawn.

Finally, we can return to a valid causal metaphysics based on real-world entities doing things they are well-known to do in the lab (and we should expect no less in space). We now have a pretty good understanding of what's going on. Currents flow. Currents can become unstable. Instability sometimes breaks the circuit. An electrical explosion may occur at the point of the break in the circuit (not unlike the electrical arcs that happen occasionally at power substations). Magnetic fields change when the underlying current system changes. 'Field lines' do nothing.

'Magnetic reconnection' is dead! Plasma physics hath killed it. Long live plasma physics!

Many kind thanks to Bellan and Moser for this innovative work, even though they have never heard of me (to my knowledge, anyway) and have in no way sanctioned or approved this post. So, if anyone must take the blame for this, I shall happily bear full responsibility for my own contributions and pass on responsibility to Don Scott and Hannes Alfvén those portions which I have borrowed in good faith...

Monday, February 13, 2012

Joined at the Hip: Magnetic Fields and Electricity

Hello world. I'm here and this is my obligatory first post! I must here recount my primary exegesis on the relationship between electricity and magnetism. Hopefully you will read and enjoy it before moving on to reading any of my other posts. 

I will, throughout this post, refer to the words of others who have summarized the currently accepted views on classical electrodynamics. Thus, I do not consider the majority of this post to be 'original research,' merely a collated regurgitation of well-stated facts.

Hopefully, by the end of this post, you will believe this simple thesis, as I do: electric currents are the sole source of magnetic fields in the universe.

It seems an outrageously simple statement. Can it be true? Put simply, yes.

For the first and simplest statement of fact, we'll turn to the Hyperphysics site:
"Magnetic fields are produced by electric currents, which can be macroscopic currents in wires, or microscopic currents associated with electrons in atomic orbits."
This is an extraordinarily simple and factual statement. Magnetic fields are produced by electric currents. These can be macroscopic currents in wires or these can be atomic-scale currents where the net collective motion of the electrons around the nuclei of atoms constitutes the 'electric current' (this is relevant primarily for the explanation of 'permanent' magnetism, as in bar magnets or horseshoe magnets).

But, is it correct? Do electric currents produce magnetic fields? Even at the atomic scale?

Let us first consider the general case and then come back to atomic scales and 'permanent' magnets.

Wikipedia seems to be in basic agreement with this non-controversial assessment:
"Electric current [I, above] produces a magnetic field [B, above]. The magnetic field can be visualized as a pattern of circular field lines surrounding the wire."
Expanding on this concept incrementally, one can also relate electric currents and magnetic fields to electric fields:
"An electromagnetic field (also EMF or EM field) is a physical field produced by moving electrically charged objects. ... The field can be viewed as the combination of an electric field and a magnetic field. The electric field is produced by stationary charges, and the magnetic field by moving charges (currents); these two are often described as the sources of the field."
The World Health Organization offers a similar explanation:
"Electric fields are created by differences in voltage: the higher the voltage, the stronger will be the resultant field. Magnetic fields are created when electric current flows: the greater the current, the stronger the magnetic field. An electric field will exist even when there is no current flowing. If current does flow, the strength of the magnetic field will vary with power consumption but the electric field strength will be constant."

"Magnetic fields are created only when the electric current flows."
So, what can we take away from all this? I'll let Richard Fitzpatrick of the University of Texas at Austin summarize it thus (from a course on classical electromagnetism):
"...steady electric and magnetic fields cannot generate themselves. Instead, they have to be generated by stationary charges and steady currents. So, if we come across a steady electric field we know that if we trace the field-lines back we shall eventually find a charge. Likewise, a steady magnetic field implies that there is a steady current flowing somewhere. All of these results follow from vector field theory (i.e., from the general properties of fields in three-dimensional space), prior to any investigation of electromagnetism."
Electric fields originate at one or more charged particles. Electric currents (the net motion of like-charged particles in the same direction or of oppositely charged particles in opposite directions) generate magnetic fields.

A little bit of history from NASA physicists Dr. David P. Stern and Dr. Mauricio Peredo may put these statements into perspective:
"People not familiar with magnetism often view it as a somewhat mysterious property of specially treated iron or steel."

"Out in space there is no magnetic iron, yet magnetism is widespread. For instance, sunspots consist of glowing hot gas, yet they are all intensely magnetic."

"It is all related to electricity."

"Close to 1800 it was found that when the ends of a chemical "battery" were connected by a metal wire, a steady stream of electric charges flowed in that wire and heated it. That flow became known as an electric current. In a simplified view, what happens is that electrons hop from atom to atom in the metal."

"In 1821 Hans Christian Oersted in Denmark found, unexpectedly, that such an electric current caused a compass needle to move. An electric current produced a magnetic force!"

"Andre-Marie Ampère in France soon unraveled the meaning. The fundamental nature of magnetism was not associated with magnetic poles or iron magnets, but with electric currents. The magnetic force was basically a force between electric currents."

"--Two parallel currents in the same direction attract each other.
--Two parallel currents in opposite directions repel each other.

"Here is how this can lead to the notion of magnetic poles. Bend the wires into circles with constant separation:"

"--Two circular currents in the same direction attract each other.
--Two circular currents in opposite directions repel each other.
So, at its simplest, the 'magnetic field' is actually a force felt between electric currents. Electric currents are the source of the magnetic field. The stronger an electric current the stronger its associated magnetic field (or, put another way, the stronger the force felt by another electric current some finite distance away).

But, "what of 'permanent magnets'?" you ask. No measurable current flows along the length of a bar magnet. Certainly this explanation must be false if a magnetic field can be generated without a current flow!

Well, not exactly. It is true that there are no currents flowing from one end of the bar magnet to the other. However, each atom can be considered to constitute its own electric current which generates an associated magnetic field:
"...[according to] the Ampère model, ... all magnetization is due to the effect of microscopic, or atomic, circular bound currents, also called Ampèrian currents, throughout the material. For a uniformly magnetized cylindrical bar magnet, the net effect of the microscopic bound currents is to make the magnet behave as if there is a macroscopic sheet of electric current flowing around the surface, with local flow direction normal to the cylinder axis."
In short, the adjacent portion of currents flowing in the same direction cancel. So, the entire volume inside a magnet effectively cancels mathematically in terms of currents. However, for the outside layer of atoms in the magnet, there are no adjacent currents external to the magnet to cancel them and the magnet as a whole acts as if there is a sheet of current flowing there.

We can return to Richard Fitzpatrick's course on Classical Electrodynamics for an illustration of this idea:
"...atoms consist of negatively charged electrons in orbit around positively charged nuclei. A moving electric charge constitutes an electric current, so there must be a current associated with every electron in an atom. In most atoms, these currents cancel one another out, so that the atom carries zero net current. However, in the atoms of ferromagnetic materials (i.e., iron, cobalt, and nickel) this cancellation is not complete, so these atoms do carry a net current. Usually, the atomic currents are all jumbled up (i.e., they are not aligned in any particular plane) so that they average to zero on a macroscopic scale. However, if a ferromagnetic material is placed in a strong magnetic field then the currents circulating in each atom become aligned such that they flow predominately in the plane perpendicular to the field. In this situation, the currents can combine together to form a macroscopic magnetic field which reinforces the alignment field. In some ferromagnetic materials, the atomic currents remain aligned after the alignment field is switched off, so the macroscopic field generated by these currents also remains. We call such materials permanent magnets."
So, it seems that so-called 'permanent magnets' are merely a special case wherein tiny electric currents at the atomic level add up to an apparent macroscopic magnetic field. So long as the majority of those individual magnetic domains remain aligned, as they do in ferromagnets (metallic permanent magnets), the macroscopic field will persist.

I believe it is not safe to come to our concluding remarks on the subject of the relationship between electricity and magnetism.

Drs. Stern and Peredo conclude their historical piece on magnetic fields succinctly thus:
"In space, on the Sun and in the Earth's core, electric currents are the only source of magnetism." (Emphasis added.)
Professor Richard Fitzpatrick similarly concludes his lecture on why magnetic monopoles do not exist:
"In conclusion, all steady magnetic fields in the Universe are generated by circulating electric currents of some description."
Fitzpatrick further concludes his lecture on the origin of permanent magnetism thus:
"In conclusion, all magnetic fields encountered in nature are generated by circulating currents. There is no fundamental difference between the fields generated by permanent magnets and those generated by currents flowing around conventional electric circuits. In the former, case the currents which generate the fields circulate on the atomic scale, whereas, in the latter case, the currents circulate on a macroscopic scale (i.e., the scale of the circuit)."
Hopefully, at this juncture we have all arrived together at the same non-controversial conclusion. That is to say, the outrageously simple thesis proffered at the outset is in fact correct:
Electric currents are the sole source of magnetic fields in the universe.
This extremely simple understanding forms the basis of this blog. It is here suggested that this basic premise can be used to reverse engineer a new emergent understanding of our universe.

"How so?" you might ask...

Wikipedia, while an imperfect resource, occasionally offers a few salient nuggets, such as this one:
"Electric current can be directly measured with a galvanometer, but this method involves breaking the electrical circuit, which is sometimes inconvenient. Current can also be measured without breaking the circuit by detecting the magnetic field associated with the current."
Why is this important? Well, consider the above statement. If we understand that electric currents generate magnetic fields, that also allows us an avenue of inquiry. If we see a magnetic field but the electric current is inconvenient or impossible to get to, we may examine the characteristics of the magnetic field and work backward to determine characteristics of the electric current that must by definition also be present to drive the observed magnetic field.

So, why is that important with respect to understanding the universe? 

My, my! Quite a lot of questions you've got there... Okay, I'll tell you why this is important. 

Being perfectly frank, everywhere we look in space, it is permeated by large-scale magnetic fields. They have been implicated in everything from star birth to shaping molecular clouds. The earth has a magnetosphere and the solar magnetic field flips every 11 years for reasons heretofore not well understood. Even so-called extremely 'young' galaxies can be permeated by strong magnetic fields.

In point of fact, there is so much 'magnetism' out there that it has led prominent institutions to declare that we live in a 'Magnetic Universe!' However, the source of magnetic fields seem to have eluded researchers and astronomers appear to have thrown up their collective hands in confusion...
"...we now appreciate that understanding the cosmos is impossible without understanding magnetism. [Magnetic fields] play a vital role in key physical processes throughout the universe, from the formation of stars to the evolution of entire galaxies. "

"On the largest scales, much of the universe's mass consists of charged particles, whose movements are completely enslaved by whatever magnetism surrounds them." (Emphasis added.)

"...on the scale of entire clusters of galaxies, only rough measurements of magnetism have so far been made ... on the very largest scales, there have been tentative reports that the entire universe is magnetised."

"Underpinning all this is a serious problem: we simply don't know what created this cosmic magnetism, or how it has maintained its strength over billions of years."
Being blunt for a moment now, if we live in a 'Magnetic Universe' it can be just as easily said that we live in an 'Electric Universe,' keeping in mind that we have reached the point in the curriculum where we should all be on the same page. Electric currents drive magnetic fields.

Where we see all-pervasive large-scale magnetic fields, we should now know that we can reason our way backward and come to the justifiable conclusion that large-scale electric currents must, by definition, also be just as all-pervasive. We can't have one without the other... Large-scale magnetic fields are diagnostic for large-scale electric currents. As electric currents produce magnetic fields, any magnetic fields we observe must be produced by electric currents

It is now incumbent upon astronomy to acknowledge this outrageously simple fact and moreover to consistently apply it to the cosmos. Do I believe it is possible probe the far reaches of the universe to determine whether such currents exist? Yes, unequivocally, though by indirect methods since we cannot physically travel to said far reaches.

I submit as a proof of concept this recent news item predicated on research submitted by radio astronomers to arxiv:
"Researchers at the University of Toronto have found some serious current emanating from a huge cosmic jet 2 billion light years from Earth. At 10^18 amps, the current is the strongest current ever seen, equaling something like a trillion bolts of lightning."
It is clear that cosmic-scale electric currents *do* exist. It is equally clear that they must give rise to magnetic fields.

Certainly, we cannot physically reach the cosmic electric currents themselves with our current level of technology. They are too far away.

However, we can study the magnetic fields we observe out in space in order to intuit the characterization of those electric currents (e.g., using such known concepts as Faraday rotation or the Zeeman effect). For closer objects like the Sun, the Stark effect can give us information about electric fields thereabouts. However, my understanding is that, for objects far out in the cosmos, our ability to resolve fine detail may be insufficient to effectively utilize that effect, which is unfortunate. Sometimes we must make do with the tools we have that do work.

Magnetic fields can be observed far more easily with existing tools than electric currents can (so it is not entirely surprising that the field of astronomy has preferred to speak in terms of magnetism rather than electricity). But, as the above demonstrates, it is entirely possible to make observations and formulate models consistent with an electrical model.

In some regards it simply boils down to metaphysics. Is the universe by and large a gravitational machine, in which case we exclude and safely ignore electrical interactions? Or does the universe also have an electrical character, in which case it would be a mistake to prematurely dismiss considering the implications of electrical interaction (especially since the raw electric force is 36 to 39 order of magnitude greater than the raw gravitational force)?

Clearly, if magnetic fields are pervasive (and they are), the universe must have an electrical character. Which character (gravitational or electrical) is dominant remains to be determined. But, the question is now begged and requires adequate redress from unbiased researchers.

Our universe is awash in plasma. Upward of 99% of the directly observable matter in the universe is in the plasma state. Plasma is a highly conductive medium (electric currents flow easily through it). To ignore the likelihood that electric currents flow in cosmic plasma, driving cosmic magnetic fields, would be foolhardy.

Hopefully I have long since made my case that this investigation is in fact warranted and worthwhile. If you wish to explore this new frontier with me, I hereby welcome you to the journey...