The origin and mechanism of sunspots, solar flares and heating of the corona to millions of degrees remains a mystery under the current standard solar model. In the past 95 years several theories were proposed, but none could really explain the origin and how the Sun’s magnetic field is generated.
The first serious theory that tried to solve this problem was introduced by Larmor in 1919. He proposed that the motion of charged particles on the solar surface create magnetic fields, like current flowing in a wire. But this was soon dismissed by T.S Cowling on the grounds that these "dynamo fields" cannot be self-sustaining due to the resistance of the solar gases. In other words, the solar plasma would dissipate the magnetic fields almost as quickly as they tried to form.
Early in the second half of the 20th century, Eugene Parker proposed another solution to the solar magnetic fields. This became known as the "Parker Solar Dynamo Theory". Parker’s theory was based on the idea that currents of charged particles in the convective zone would induce magnetic fields and these fields would rise to the surface. Along the way the magnetic fields would be cyclonically twisted by the Coriolis effects. This process is supposed to form sunspot-like magnetic regions at the surface. Over a full solar cycle these magnetic field regions would merge and form a large-scale solar magnetic field. This theory of Parker’s was followed, or complemented, by the Babcock-Leighton Model.
According to the BL Model the differential rotation of the solar surface would distort the magnetic fields and wrap them more tightly. As a result sunspots would tend to form at higher solar latitudes at the beginning of the cycle and then move steadily to lower latitudes as the cycle progressed. Despite the fact that the Parker theory and the BL Model together could explain some of the sunspot cycle observations, they could not predict the cycle length and more importantly they did not explain in detail how the surface magnetic field was created in the first place. Calculations have also shown that the Sun’s magnetic field cannot be generated in the highly-turbulent convection zone or in the radiative zone.
However, the currently accepted theory suggests that the solar dynamo is divided into two separate processes; the Local Dynamo and the Global Dynamo. The first one is responsible for generating small-scale magnetic features on the solar surface through the flow of charged particles in the granulation convection. The Global Dynamo is responsible for generating and evolving the main features of the Sun (such as sunspots), creating the changes that take place during the solar cycle activities and the overall magnetic polarity of the Sun.
Even still, recent observations by satellites and space observatories have shown that the Dynamo theory is obsolete.
Researchers have found an ideal way to show how heat from the deep interior of the Sun is transferred to its surface. They have created an "MRI" of the Sun’s interior plasma motion.
In order to develop their "MRI" of the Sun’s plasma flows, the researchers used high-resolution images of the Sun’s surface, taken by the Helioseismic and Magnetic Imager (HMI) onboard NASA’S Solar Dynamic Observatory. Using a 16-million pixel camera, HMI analyses motion on the surface of the Sun caused by convection. The invisible plasma motion was calculated using the observed movement of waves on the surface of the Sun.
What the researchers found was more evidence against the reigning physics dogma. The speed of the Sun’s plasma motions were found to be approximately 100 times slower than what theoretical physicists had previously projected based on the current solar model.
"Our current theoretical understanding of magnetic field generation in the Sun relies on these motions being of a certain magnitude," said the Indian scientist, Shravan Hanasoge, a researcher in geoscience at Princeton University. "These convective motions are currently believed to prop up large-scale circulations in the outer third of the Sun that generate magnetic fields. However, our results suggest that convective motions in the Sun are nearly 100 times smaller than these current theoretical expectations. If these motions are indeed that slow in the Sun, then the most widely accepted theory concerning the generation of solar magnetic field is broken, leaving us with no compelling theory to explain its generation of magnetic fields and the need to overhaul our understanding of the physics of the Sun’s interior."
But the dilemma of the Sun’s magnetic field is not only connected to its generation but also to its origin. According to the theory of stellar evolution the Sun, like all stars, is supposed to be formed from a cloud of interstellar gas by the process of the gravitational collapse, and its magnetic field is a remnant of the ancient field acquired by at the time of its formation.
There is no way that the current magnetic field of the Sun, which is the strongest magnetic field compared to any other body in the solar system, can be a remnant of an ancient magnetic field. If this is the case then the primordial surface field must have diffused back out into space in just a few million years. In other words, the vestigial magnetic field should have been carried off by the solar wind and by the ejected plasma (Coronal Mass Ejections).
Astronomers and astrophysicists who study newly formed stars observe very high activity from these young stellar objects. They produce intense flares and other powerful magnetic explosions during their chromospherically-active formative years. Thus, if our star went through the same process, then its ancient magnetic field must have diffused into space in a matter of a few million years after its formation.
Theoretical physicists not only believe that the magnetic field of the Sun is a remnant of the ancient field acquired by it during its formation, but they also believe this primordial field is still trapped within the so-called "Radiative Zone", located 100,000 km below the Sun’s surface. They also think that the strength of this field is over one million Gauss. But this theoretical belief is not supported by any modern space observation. Data from satellites like SOHO use Helioseismometers clearly show that the internal magnetic field cannot be stronger than 30 Gauss.
However, I am not surprised that the Sun’s magnetic field is still a puzzle because the current model cannot explain any basic features of the Sun, let alone the magnetic field. But what can we do? The ruling establishment and scientific authority in advanced notions - not poor and backwards ones - refuse to have an open debate about this crucial issue. They are demanding more money from poor taxpayers to carry on their fusion research, which is based on the current dogma. The money they spent in the last 65 years has been incredible – yet they are still unable to break even.
The input energy spent on generating this hypothetical reaction is still much bigger than the output. More importantly, this reaction cannot be sustained for a sufficient period of time and according to my understanding they will never be able to sustain it.
Written by Jamal S. Shrair
Featured image: In this false-color ultraviolet image, the Sun shows a C3-class solar flare (white area on upper left), a solar tsunami (wave-like structure, upper right) and multiple filaments of plasma following a magnetic field, rising from the stellar surface. Credit: NASA SDO/AIA