Galactic electric currents vs nuclear fusion

In a Twitter discussion with Ned Nikolov, I discovered that some people believe that the Sun is powered by Galactic electric currents. I don’t even understand how this is meant to work, but that doesn’t really matter since it’s clearly nonsense. A star like the Sun (in fact all stars on the main sequence) are powered by nuclear fusion in their cores; specifically, the fusion of hydrogen into helium.

There are a number of reasons why we know this. One basic issue is that if the Sun were simply radiating gravitational potential energy into space it would have a lifetime of only a few tens of millions of years. We know, however, that the Solar System is about 4.5 billion years old, so this can clearly not be the source of the Sun’s energy. Whatever powers the Sun has to be able to do so for billions of years, and the only known source that can do so is nuclear fusion.

Another factor that I wanted to highlight here (partly because I’ve just been teaching this in one of my classes) is that stars spend most of their lives on what we call the main sequence. While on the main sequence their properties (radius, temperature, luminosity) will remain quite constant. For a star like the Sun, this phase will last for just over 10 billion years. It’s quite interesting (I think) to consider how this is possible.

One reason is that the energy generated in the core of a star doesn’t stream straight out into space; it can takes 10s of thousands of years to go from the core to the surface via a combination of radiative diffusion and convection. A consequence of this is that a star then settles into a state of hydrostatic equilibrium. A self-gravitating system in hydrostatic equilibrium satisifies what is known as the Virial Theorem (which I also discussed in this post).

The Virial Theorem is essentially that twice the total thermal energy in the star plus the gravitational potential energy is zero. Since the total energy is the sum of the total thermal energy and the gravitational potential energy, being in Virial equilibrium means that the total energy is also half the gravitational potential energy, or minus the total thermal energy (i.e., the total energy is negative and has a magnitude equal to the thermal energy). What this means is that if the total energy in the star goes up (becomes less negative) the thermal energy goes down (it cools) and the gravitational potential energy goes up (becomes less negative which can only happen if the star expands). The opposite happens if the total energy in the star were to go down.

So, why does this mean that stars can sustain a roughly stable state for billions of years? Well, the rate at which nuclear fusion generates energy is strongly temperature dependent; it increases dramatically with increasing temperature. Given that the star is in Virial equilibrium, if the fusion rate were to increase, this would increase the total energy in the star and it would expand and cool, and the fusion rate would go back down. If the fusion rate were to go down, this would reduce the total energy in the star and it would contract and heat up, and the fusion rate would go back up.

Therefore, the rate at which energy is generated by nuclear fusion can be kept very constant. That the energy then leaks out slowly means that the star can be kept in a state of hydrostatic equilibrium, with the surface temperature and radius (and hence overall luminosity) also kept constant.

Hence, that stars settle into a state of hydrostatic equilibrium, which results in them satsifying the Virial Theorem, and because the energy generation via nuclear fusion is strongly temperature dependent, leads to stars being able to maintain a roughly constant state for billions of years. I have no idea of how Galactic electric currents are supposed to power stars, but I have no real interest in trying to work out how this is meant to work, and I’m pretty sure it wouldn’t be able to explain the basic properties of stars.

Advertisements
This entry was posted in Science, The philosophy of science, The scientific method and tagged , , , , . Bookmark the permalink.

30 Responses to Galactic electric currents vs nuclear fusion

  1. One reason I wrote this is that I’ve been teaching this in one of my classes and it is (I think) an interesting concept to try and explain. The other reason is that it is also interesting that those who promote this alternative theory for how star’s are powered also reject anthropogenically-driven climate change. In fact, they reject that there is any such thing as a greenhouse effect due to radiatively active gases in the atmosphere.

  2. For those wanting a popular account of our nearest star, Prof. Lucie Green’s “15 Million Degrees: A journey to the centre of the Sun” is excellent. It is wonderful to me how much we have been able to deduce about the innards of stars using the basic physics we know; a million miles from those who offer up boring crank science that takes us nowhere (and along with GHE denial, these people are also, ironically, great proponents of other people applying Popperian Falsificationism!).

  3. jacksmith4tx says:

    I’m quite outside of my field of expertise but in the spirit of the post topic this news is interesting if not directly related.
    https://www.nextbigfuture.com/2018/10/possible-detection-of-new-particles-with-new-physics-in-antarctic.html
    “The Antarctic Impulsive Transient Antenna, or ANITA, has detected two unusual signals.

    ANITA floats on a helium balloon 37000 meters high for a month at a time. It searches for the signals of high-energy particles from space, including lightweight, ghostly particles called neutrinos. Those neutrinos can interact within Antarctica’s ice, producing radio waves that are picked up by ANITA’s antennas.

    It appears to be from extremely energetic neutrinos shooting skyward from within the Earth. But high-energy neutrinos can’t pass through as much material as lower-energy neutrinos can. So although high-energy neutrinos can skim the edges of the planet, they won’t survive a pass straight through.

    Either new high-energy neutrinos have been detected that are less likely to react to the Earth’s matter or there was some kind of error in the analysis.

    Arxiv – The ANITA Anomalous Events as Signatures of a Beyond Standard Model Particle, and Supporting Observations from IceCube

    The ANITA collaboration have reported observation of two anomalous events that appear to be εcr≈0.6 EeV cosmic ray showers emerging from the Earth with exit angles of 27∘ and 35∘, respectively. While EeV-scale upgoing showers have been anticipated as a result of astrophysical tau neutrinos converting to tau leptons during Earth passage, the observed exit angles are much steeper than expected in Standard Model (SM) scenarios. [b]Indeed, under conservative extrapolations of the SM interactions, there is no particle that can propagate through the Earth with probability p>10−6 at these energies and exit angles.[/b] We explore here whether “beyond the Standard Model” (BSM) particles are required to explain the ANITA events, if correctly interpreted, and conclude that they are. Seeking confirmation or refutation of the physical phenomenon of sub-EeV Earth-emergent cosmic rays in data from other facilities, we find support for the reality of the ANITA events, and three candidate analog events, among the Extremely High Energy Northern Track neutrinos of the IceCube Neutrino Observatory. Properties of the implied BSM particle are anticipated, at least in part, by those predicted for the “stau” slepton (τ̃ R) in some supersymmetric models of the fundamental interactions, wherein the stau manifests as the next-to-lowest mass supersymmetric partner particle.”

  4. verytallguy says:

    Cranks will be cranks.

    Half the denial-o-sphere seems to be off on conspiracy theories of novichok poisoning and Syrian had attacks. Anyone would have thought Lewandowsky were right!

    On the energy balance of the sun, it’s a great example of how simple concepts can explain very surprising results.

    It also strikes me that there’s a great story to be told on the discovery of the principles behind the sources of energy known and how that has progressed.

    The sun; the centre of the earth; combustion; muscular; hydro; wind; lightning etc. All are of interest scientifically and those I’m familiar with have great human interest stories too. It’s probably already been done of course.

  5. Vtg,
    Indeed, with some assumptions about energy transport and energy generation in stars, you can analytically determine the basic properties.

  6. Harry Twinotter says:

    Yeah I dug into the Electric Universe stuff a while back. My advice is don’t if you value your brain. EU is really just a weird form of Christian Creation Cosmology. Look up Immanuel Velikovsky.

    Basically the EUers have to reject a lot of science for their crank to work, so it is not surprising they also reject climate change science. They just run a typical “woke” hoax/scam.

  7. Greg Wellman says:

    Funny thing, this post made me remember some wacko from usenet days who was convinced the sun is made of iron. So I googled “iron sun” and discovered that it’s actually part of the whole Electric Universe concept. Yeah, I’m not going down that rathole even for a few laughs.

  8. dikranmarsupial says:

    Didn’t some famous astronomer say something along the lines of a civilisation living on a perpetually cloudy planet would be able to infer the existence of stars from basic physics without having ever seen one?

  9. Pingback: Galactic electric currents vs nuclear fusion — …and Then There’s Physics – THE BIG TIMES

  10. The Very Reverend Jebediah Hypotenuse says:


    Didn’t some famous astronomer say something along the lines of a civilisation living on a perpetually cloudy planet would be able to infer the existence of stars from basic physics without having ever seen one?

    A. S. Eddington, “The Internal Constitution of the Stars“, p. 16.


    We can imagine a physicist on a gas-bound planet who has never heard tell of the stars calculating the ratio of radiation pressure to gas pressure for a series of globes of various sizes, starting, say, with a globe of mass 10 gm., then 100 gm., 100 gm., and so on so that his nth globe contains 10^n gm.

    Regarded as a tussle between matter and aether (gas pressure and radiation pressure) the contest is overly one-sided except between nos 33-35 where we may expect something interesting to happen.

    What “happens” is the stars.

    ATTP link-back:
    https://andthentheresphysics.wordpress.com/2017/08/13/science-its-complicated/#comment-101576

    Of course, a different author also imagined what should happen according to the inhabitants of a planet that had never heard tell of the stars.

  11. dikranmarsupial says:

    That’s the one, thanks!

    As a batsman (of sorts) I have the bad taste to celebrate the achievements of the latter every summer ;o)

  12. A post from this morning where Rog obviously does not understand much about equilibrium processes and gas planets.

    https://tallbloke.wordpress.com/2018/10/04/a-conversation-with-ken-rice-on-the-causes-of-the-greenhouse-effect

    Rog is following the lead of N.Nikolov who I refer to as the #IdealGasBag because of his embarrassing insistence on misapplying the Ideal Gas Law.

  13. Magma says:

    I don’t see how the Galactic Electric Current Sun model can possibly be reconciled with the Iron Sun model.

    (This concerns me about as much as you’d imagine.)

  14. Greg Wellman said:

    “So I googled “iron sun” and discovered that it’s actually part of the whole Electric Universe concept. Yeah, I’m not going down that rathole even for a few laughs.”

    The Iron Sun model due to Oliver Manuel, a favorite of Judith Curry and someone included in a list of climate experts presented to Trump’s Environmental Protection Agency by the Heartland Institute

    This is the rathole you speak of, and it’s not funny at all:
    http://www.mshp.dps.mo.gov/CJ38/OffenderDetails?page=0&column=name&id=1097755

  15. The Very Reverend Jebediah Hypotenuse says:


    I don’t see how the Galactic Electric Current Sun model can possibly be reconciled with the Iron Sun model.

    Easy.
    Iron is a conductor.
    Q.E.D.

    Look – The whole universe is God’s giant plasma globe, OK?


    …Rog obviously does not understand much…

    Obviously, Rog should publish – Cuz if he’s right, he’s (re)discovered a perpetual heat engine.

    Conservation of energy is for silly alarmists.

  16. Dave_Geologist says:

    Strangely, I came across someone elsewhere who seemed convinced that inductive heating of the iron core as the Earth orbits the Sun was a significant factor in slowing the planet’s cooling, in addition to radioactivity (I have also seen latent heat invoked as the solid inner core continues to grow by crystallisation, which seems more reasonable). But (s)he did not appear to be an AGW denier, so crank magnetism is not universal 🙂 . The obvious problem is that the Sun’s magnetic field at the orbit of the Earth must be pretty small compared to Earth’s magnetic field. Otherwise compasses wouldn’t work 😉 . A quick Google suggests that the Sun’s magnetic field at Earth is seven orders of magnitude smaller than Earth’s. I did find a paper suggesting that it could work for some exoplanets, but with very different orbits to Earth’s and with the star’s magnetic field axis highly inclined to the orbital plane. Cool! But can you have a stable, highly inclined dipole in a fast-rotating (3 days) star? Wouldn’t it tend to align with the rotation axis? I wonder if a quadrupole would work, or would breaking the asymmetry break the mechanism? The mechanism seems to be magnetic field variation as the axis sweeps like a lighthouse bean past the planet. So a quadrupole would work, just be less strong. But I would have thought that as you get far away from the star, the quadrupole starts to look like a slightly lumpy dipole.

    Because strong external magnetic fields are necessary to make the induction heating substantial, this mechanism plays a negligible role for modern Solar System objects, with the possible exception of Io, for which the external magnetic field is provided by the tilted dipole field and the fast rotation of Jupiter. The induction heating for Io is comparable to the energy release from radioactive decay

    Maybe Jupiter somehow became conflated with the Sun and Io with Earth? Is that how Internet memes start? 🙂

  17. “Obviously, Rog should publish – Cuz if he’s right, he’s (re)discovered a perpetual heat engine.

    Conservation of energy is for silly alarmists.”

    They have perfected the art of being knowledgeable about some very basic ideas (such as PV=nRT) yet then twisting the laws so their argument appears plausible, but only on the surface. I’s really a mistake to give them any credit at all, because they will use any reinforcement as credential virtue signalling to their followers. Rog in fact is doing it right now.

  18. Dave_Geologist says:

    But I would have thought that as you get far away from the star, the quadrupole starts to look like a slightly lumpy dipole.

    Hmmm… maybe that’s wrong. I’m thinking of geomagnetic anomalies where the full-width half-maximum is proportional to the depth of the source. But that’s on a scale where the Earth is effectively flat. Maybe on a sphere the surface area spreads as fast as the anomaly does. Back to school!

  19. Greg Wellman says:

    Paul Pukite,
    Whoah, I did not know about that! Yeesh, I see why they designated him tier 3. That’s horrific.
    http://journalistatheart.blogspot.com/2011/10/dr-oliver-manuel-arrested-for-multiple.html

  20. David B. Benson says:

    For starters, at least, the Viral Theorem is not required. Just the negative feedback of increased temperature causing fewer “fuses” suffices. The differing feedback delays in different stars explains some of the variable stars, etc.

  21. Andrew E Dessler says:

    A bit of an aside about the philosophy of science: if you want to suggest a new theory for something, you have to show that it explains *more* than the current theory. It’s not enough to say that your theory works as well — it has to work better. So the nutbags who have better theories for how the Sun works or how the greenhouse effect works have to show how their theory solves a problem with mainstream theory. Of course, they can never do this because what they’re peddling is nonsense, but we should hold that up as the standard they have to meet.

  22. David,

    For starters, at least, the Viral Theorem is not required. Just the negative feedback of increased temperature causing fewer “fuses” suffices

    Maybe I misunderstand you, but if the temperature goes up, the fusion rate increases. The reason the being in Virial equilibrium prevents this is that it means that a star has negative heat capacity – if you increase the energy, the temperature goes down.

    Andrew,

    if you want to suggest a new theory for something, you have to show that it explains *more* than the current theory. It’s not enough to say that your theory works as well — it has to work better.

    Indeed. Of course, in this case you have people whose theory is simply fitting curves to some data. It really doesn’t explain anything.

  23. Andrew E Dessler says:

    “A bit of an aside about the philosophy of science: if you want to suggest a new theory for something, you have to show that it explains *more* than the current theory. It’s not enough to say that your theory works as well — it has to work better. So the nutbags who have better theories for how the Sun works or how the greenhouse effect works have to show how their theory solves a problem with mainstream theory. Of course, they can never do this because what they’re peddling is nonsense, but we should hold that up as the standard they have to meet.”

    In recent news, we are seeing this idea being put to the test. DARPA decided to fund a team looking at Quantized Inertia (QI), which is Mike McCulloch’s wide-ranging theory to explain several long-standing issues and which has some amazing potential practical applications. The latter is manifested by the EM Drive, which when you read about the idea sounds a lot like science fiction.

    McCulloch has had a tough go getting stuff published, but now that he now has some research funding and the fact that he and his team knows how to do controlled experiments, they should be able to make some more definitive findings.

  24. izen says:

    The pseudo-science and un-physical concepts in things like the ‘Electric Universe’, and alternatives to General Relativity or Quantum mechanics are a lot less interesting than the question WHY people become fanatically devoted to defending these ideas.

    Unlike the rejection of AGW or Evolution which have the fossil fuel producers and religious dogma to provide morale support, the ‘Flat-Earth’ crankisms have little apparent motivation or justification for the enthusiasm with which they are embraced.

    Beyond a wish to be apart from the mainstream and a memeber of an exclusive group that has the ‘TRUE’ knowledge, unlike all the sheeple that ignorantly accept the dominant dogma.

  25. Greg said:
    “Whoah, I did not know about that! Yeesh, I see why they designated him tier 3. That’s horrific.”

    From a phys.org thread on recent Cassini findings regarding Saturn’s rings and magnetic fields
    https://phys.org/news/2018-10-latest-insights-saturn-weird-magnetic.html

    “Oh I long for the days when the greatest controversy was Oliver Manuel.”

  26. Harry Twinotter says:

    Paul your post does not make any sense.

  27. Harry Twinotter says:

    Izen.

    From what I have seen the EU people have a mix of motivations, but they are more or less united in wanting to reject mainstream science for, well, reasons. If you follow their stuff right to the end (I don’t recommend it), they start producing ideas which are basically voodoo.

    To be honest EU smells like a confidence trick to me, they do make money from their videos, pamphlets and so forth.

    Flat Earthers are Christian Creationists, pure and simple. They want to take the Christian Bible literally (even though they have not caught on to the fact a number of their “truths” are actually mistranslations).

  28. Harry Twinotter said:
    “Paul your post does not make any sense.”
    I don’t know which post you are referring to. I write posts on my own blog. What I do here is write comments.
    https://www.quora.com/Whats-the-difference-between-a-post-and-a-comment

  29. Dave_Geologist says:

    Were you responding to my digression, Paul, into why someone might conflate Jupiter and Io with the Sun and Earth and get an idea in their head that the Earth’c metallic core is kept warm by the Sun’s magnetic field? Which is what you might call casual-passer-by confusion, putting two and two together to make five, rather than the dedicated-crank-with-the-education-to-know-better sort.

    Although having now searched for “the Sun is powered by Galactic electric currents”, I find The Electric Universe Theory.

    The Electric Sun is often attributed to a 1972 article by Ralph Juergens,[1] who acknowledges priority to a 1958 Melvin Cook monograph, and inspiration from Immanuel Velikovsky‘s 1946 monograph, Cosmos Without Gravitation

    Ah, the V-word 😦 .I know it’s a terrible pun, but Crank magnetism, literally as well as figuratively 😉 .

    OMG there’s a whole alternate universe out there. With awards and everything!

    Wallace Thornhill (b. May 2, 1942) earned a degree in physics and electronics at the University of Melbourne, Australia, and began postgraduate studies. Before entering university he had been inspired by Immanuel Velikovsky’s best-selling book, Worlds in Collision…In 2010, the Telesio-Galilei Academy of Science awarded Thornhill (and 9 others) its 2010 Gold Medal

    How did a guy with a physics degree fall for Velikovsky? He’s not just “gone emeritus”; he’s been at is since his early thirties. Of course the TGAS have to name-check Galileo 😦 . I wondered briefly if it was an Ig-type Poe, what with it being run by Jeremy Dunning-Davies. And a Scholar search for Francesco Fucilla turns up [C] La Divina Comedia JG Fucilla – 1948. But no Kruger on the member list. And JDD seems to be a real retired scientist/mathematician, albeit one whose cites per paper are typically between 2 and 4 and whose papers are mostly on ArXiv or ResearchGate so not peer-reviewed. I checked a couple of cites and they were abstracts claiming to overthrow the laws of thermodynamics. So yes, crank magnetism.

    He seems to have gone conspiracy-theory-prone lately

    Information has been suppressed which appears to lead to new solutions for many problems in physics that could benefit the race of man and the Earth upon which we live. … finally provide a clear physical explanation for quantum effects through mathematical articulation of the actual hidden variable underlying quantum theory itself: Consciousness.

    I blame the Illuminati 😉 .

  30. Dave_Geologist says:

    Here’s the link to the Saturn paper. It appears to be open access. Saturn’s magnetic field revealed by the Cassini Grand Finale. The striking thing for me is not the close alignment of Saturn’s field, but how axisymmetric it is. Which has apparently been known and a puzzler for some time. Most Solar System planets and moons which have a magnetic field have a reasonably close alignment of rotation and magnetic axis (10° or less). Uranus and Neptune are different, but there are suggestions their fields have a different origin, e.g. convecting “oceans” rather than a rotating liquid core. Stars too, from a bit of Googling, except for the likes of pulsars which experienced a catastrophic event. There’s a Cowling’s Theorem which says if the field is perfectly axisymmetric and aligned it can’t self-sustain for longer than a few tens of thousands of years. That’s what the article refers to, but it strikes me that’s like the economics papers which assume unreasonable perfection to obtain closed-form solutions. In the real world, even if the net dipole is strongly aligned with the spin axis, there are loads of more complicated things like smaller-scale convection going on, at the level where the field is generated, to break the symmetry. I see there are also suggestions that the field we see may be filtered through a shallower layer like a conducting “ocean”, which smooths and aligns it.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.