probably related to those, and Paul Vaughan may say some more about that. Now, every couple of hundred years, the sun goes into a funk, as we see from the succession of grand minima over the last millennium. Oort -- Sporer -- Maunder -- Dalton -- and now. So the divergence seen in the plot between ssolar activity and the z-axis curve is the Dalton Minimum, a period of anomalously low solar activity where everything goes 'non-linear' for a while. The 4 black tick marks above the time axis indicate points where the z-axis motion has a 'hiccup' near the solar surface (orange band on the plot is +/- 0.1 solar radii relative to the x,y,z radial distance of the barycentre from the solar centre (which is at around -700,000 km = -70,000km on the left y axis of the plot). Landscheidt noticed that solar activity crashes whenever the radial distance hangs around near the solar surface for more than 3 years or so. (Mechanism unknown). Hence the anomalously low activity 1796-1830 and again around 1970 and again about now. During the Maunde there were three such 'hiccup' periods over 50 years, so its unlikely to be coincidence. ed says: ...Question for you though...what was the justification for creating a TSI floor for sunspot count equals zero? Couldn't find it in his "essay". Is there any data which shows that TSI always drops to the same value for a sunspot equals zero count? I believe the cosmic ray count (oulu)