Not perfect clock. Also spots move toward equator as cycle progresses. Part of 22 year solar cycle. 1645-1715 Little IceAge. How sun affects people allows life on Earth photosynthesis sunburns and skin cancer climate connections solar flares cause power outages sometimes Auorae - Northern Lights Will destroy Earth in about 5 billion years.
Carbon never burns.
Si ignites Iron Catastrophe. Collapse and supernova Neutron star and supernova remnant or black hole 6 supernovae in our galaxy in past 1000 years. Pulsars - ice skater analogy. Magnetized rapidly rotating neutron stars. Accretion disk Black holes Information contained on this page does not represent the lecture verbatim.