he performed an experiment which demonstrated the production of neutral pions and their decay to photon pairs. This experiment utilized the 330 MeV synchrotron and the newly invented scintillation counters. Despite this and other achievements, he was asked to leave the Radiation Lab at Berkeley in 1950, due to his refusal to sign the so-called non-Communist Oath. Steinberger accepted a faculty position at Columbia University in 1950. The newly commissioned meson beam at Nevis Labs provided the tool for several important experiments. Measurements of the production cross-section of pions on various nuclear targets showed that the pion has odd parity. A direct measurement of the production of pions on a liquid hydrogen target, then not a common tool, provided the data needed to show that the pion has spin zero. The same target was used to observe the relatively rare decay of neutral pions to a photon, an electron, and a positron. A related experiment measured the mass difference between the charged and neutral pions based on the angular correlation between the neutral pions produced when the negative pion is captured by the proton in the hydrogen nucleus. Other important experiments studied the angular correlation between electron–positron pairs in neutral pion decays, and established the rare decay of a charged pion to an electron and neutrino; the latter required use of a liquid-hydrogen bubble chamber. Investigations of strange particles During 1954–1955, Steinberger contributed to the development of the bubble chamber with the construction of a 15 cm device for use with the Cosmotron at Brookhaven National Laboratory. The experiment used a pion beam to produce pairs of hadrons with strange quarks to elucidate the puzzling production and decay properties of these particles. In 1956, he used a 30 cm chamber outfitted with three cameras to discover the neutral Sigma hyperon and measure its mass. This observation was important for confirming the existence of the SU(3) flavor symmetry which hypothesizes the existence of the strange quark. An important characteristic of the weak interaction is its violation of parity symmetry. This characteristic was established through the measurement of the spins and parities of many hyperons. Steinberger and his collaborators contributed several such measurements using large (75 cm) liquid-hydrogen bubble chambers and separated hadron beams at Brookhaven. One example is the measurement of the invariant mass distribution of electron–positron pairs produced in the decay of Sigma-zero hyperons to Lambda-zero hyperons. Neutrinos and the