The End of School Desegregation and the Achievement Gap

After nearly five decades of school desegregation mandated by federal courts, school districts throughout the nation are being released from court orders, leading some civil rights proponents to complain that ending school desegregation will deprive minority students of educational benefits. This article argues that ending school desegregation will not have any appreciable impact on the academic achievement of African American students. To the extent that desegregation had academic benefits, those benefits have already occurred. Despite the extensive desegregation of American schools during the 1970s and 1980s, a large black-white achievement gap remains, and there is credible evidence that this gap is due to persistent socioeconomic differences between black and white families

Quantum state preparation and macroscopic entanglement in gravitational-wave detectors

Long-baseline laser-interferometer gravitational-wave detectors are operating at a factor of 10 (in amplitude) above the standard quantum limit (SQL) within a broad frequency band. Such a low classical noise budget has already allowed the creation of a controlled 2.7 kg macroscopic oscillator with an effective eigenfrequency of 150 Hz and an occupation number of 200. This result, along with the prospect for further improvements, heralds the new possibility of experimentally probing macroscopic quantum mechanics (MQM) - quantum mechanical behavior of objects in the realm of everyday experience - using gravitational-wave detectors. In this paper, we provide the mathematical foundation for the first step of a MQM experiment: the preparation of a macroscopic test mass into a nearly minimum-Heisenberg-limited Gaussian quantum state, which is possible if the interferometer's classical noise beats the SQL in a broad frequency band. Our formalism, based on Wiener filtering, allows a straightforward conversion from the classical noise budget of a laser interferometer, in terms of noise spectra, into the strategy for quantum state preparation, and the quality of the prepared state. Using this formalism, we consider how Gaussian entanglement can be built among two macroscopic test masses, and the performance of the planned Advanced LIGO interferometers in quantum-state preparation

The impact of school SES on student achievement: Evidence from U.S. statewide achievement data

After the U.S. Supreme Court restricted the use of race in assigning students to schools, there was a surge in advocacy of school integration based on student socioeconomic status (SES). Benefits of socioeconomic integration have been supported by various studies finding significant effects of school SES on achievement after controlling for individual student SES. This article investigates school SES effects using statewide longitudinal achievement data from several U.S. states. School SES effects nearly vanish after controlling for a student’s prior achievement or, alternatively, controlling for stable differences among students using fixed effects models. The article concludes that large school SES effects often found in cross-sectional studies are artifacts of aggregation and are not a sound basis for SES-based school integration policies