In 1930, Georg Joos conducted an experiment using an automated interferometer with arms forged from pressed quartz having very low thermal coefficient of expansion, that took continuous photographic strip recordings of the fringes through dozens of revolutions of the apparatus.
12.
Reducing temperature effects to minimum, I have been monitoring the light spot for few months ( day and night ) from time to time and the maximum offset achieved was less than 1 mm ( perhaps due to temperature slight variation and different thermal coefficients ).
13.
EBR-II had a negative thermal coefficient of reactivity that shut down the reactor when the temperature increased due to loss of the coolant pumps; the time required to heat the large pool of sodium surrounding the reactor provided a sufficient time buffer for the passive decay heat removal system to prevent the EBR-II reactor from melting down.
