Testing solar fusion model
• 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