Carbon dating decay rate

C-14 is produced in the upper atmosphere when nitrogen-14 (N-14) is altered through the effects of cosmic radiation bombardment (a proton is displaced by a neutron effectively changing the nitrogen atom into a carbon isotope).The new isotope is called "radiocarbon" because it is radioactive, though it is not dangerous.These excited neutrons then collide with nitrogen atoms in the atmosphere, changing them into radioactive carbon-14 atoms.CARBON-14 IS ABSORBED (Figure 1b): Plants absorb this carbon-14 during photosynthesis.In 2010, Purdue University published a research paper[1] stating that their researchers had detected slight fluctuations in radioactive isotope decay rates "in synch with the rotation of the sun's core." The article also stated: Has there been any further research on this, and has it been found to affect carbon dating techniques or other archeological dating methods? Graven, "Impact of fossil fuel emissions on atmospheric radiocarbon and various applications of radiocarbon over this century," Proceedings of the National Academy of Sciences 112.31 (2015): 9542-9545.

It seems limited, how can an observer know the state of the decay of a certain molecular structure even 100,000 calendar years ago?

Their job, their very being, is tied up in pushing the boundary of human knowledge.

Very good scientists listen to their inner crackpot but keep it inside until they are very sure that their inner crackpot has revealed something new.

A bit in the other, the rate of fusion drops and the Sun collapses.

Where "A bit" is a few parts in a trillion or less, most likely very much less.