At https://phys.org/news/2021-07-unravelling-knotty-problem-sun.html … unravelling a knotty problem of activity on the sun by untwisting and twisting magnetic field lines.
At https://wattsupwiththat.com/2021/07/23/can-we-predict-long-term-solar-va… .. a post by Andy May after an email conversation with Leif Svalgaard, solar physicist. It is described as an argument on the basis they disagree on the amount of influence the sun has on earth's climate. It might be a squall in a teacup – but the comments come thick and fast. Are long term solar variations large enough to affect the earth's climate – more than changes due to human activity. Large scale changes in solar output are determined by visible changes on the face of the sun, now determined as due to the solar magnetic field. These changes are reasonably understood, May alleges. Less well understood are the contributions to solar variability made by the quiet regions of the Sun – known as Q regions. These are the featureless portions of the solar surface, or photosphere. They leave no sun spots or other visible magnetic features. Most of the electromagnetic power of the sun is generated in the Q regions, according to May, in flux tubes too small to detect. They are important because they are so numerous. Sun spots are much larger flux tubes – so large we can easily see them. According to Svalgaard and most solar physicists, by keeping track of sun pots and related features on the photosphere, they can detect all, or most of the solar activity. The reasoning is – we cannot observe any increases, or changes in the Q regions, so they must be insignificant. Who is right?
If the sun was the dominant source of recent warming on the earth, in the 1990s and 2000s, it would have had to increase its output. The IPCC and Svalgaard, prefer one particular model of TSI [reconstruction]. Andy May argues that other TSI composites differ. His point is that TSI reconstructions [of for example the Little Ice Age or the Maunder Minimum] are well supported, because the active regions of the sun can be modelled using sun spot records, fairly accurately. This ignores the Q regions. It is often considered these Q regions are constant and never diverge, or only in a small way. He concludes by saying the sun is much more variable than assumed in most reconstructions. However, various other factors are in play which he does not mention in this post, but are well known to both he and Svalgaard. These include volcanic eruptions and dust accumulated in the atmosphere, as well as the cloud theory of Svensmark. Climate is complicated.
At https://sciencex.com/news/2021-07-electromagnetism-property-spacetime.html … by Lindgren and Liukkonen of Finland – a fascinating read [two pages]. Electromagnetism dominates spacetime – does it have ramifications for science and engineering? Nikola Tesla thought that electromagnetism contains essentially everything in the universe. So, what is the relationship it has with gravitation? They go on to supply one possible explanation – presented as one possible explanation rather than unravelling a knotty problem. Maxwell's equations are key to describing classic electromagnetism. In general relativity, Einstein's field equations are a set of non linear equations describing the metric of how spacetime evolves. They then suggest they are basically the same governing equation – describing both electromagnetism and gravitation. The two things live side by side and are complimentary, might be one way to look at it. Maxwell's equations hide inside Einstein's field equations of general relativity. They describe general relativity as a generalised theory of non linear electromagnetism. Tensions in spacetime manifest themselves as electric and magnetic fields. The electric charge relates to the compressibility properties of spacetime. Electric current is a rebalancing object – transports charge in order to keep spacetime manifold Ricci-flat. They suggest this is aesthetically pleasing as nature seems to strive for harmony, efficiency and simplicity.
Although Maxwell's equations are a condition to keep spacetime Ricci-flat electromagnetic fields do seem to cause curvature in spacetime. A sort of differential geometry such as Weyl curvature, may be at work. Local curving of spacetime in order to preserve volume. A special kind of stretching and bending of spacetime. A rather beautiful way of accommodating electromagnetic properties in space. Simply pointing a finger at the existence of electricity is not enough.
See https://doi.org/10.1088/1742-6596/1956/1/012017 … and https://iopscience.iop.org/article/10.1088/1742-6596/1956/1/012017/pdf