•Does
lifetime of sun make sense?
–Oldest
rocks on earth ~4 billion years old
–Oldest
rocks in meteorites ~4.5 billion years old
–
•Other
stars with higher/lower luminosity
–Causes
for different luminosity
–Lifetimes
of those stars
–
•Look
for neutrinos from fusion
–Complicated
story – due to neutrino properties
–Example
of how astronomy presents “extreme” conditions