Edited by Pablo G. Debenedetti, Princeton University, Princeton, NJ, and approved February 12, 2021 (received for review December 8, 2020)Under typical conditions on Earth, ice exhibits two distinct polytypes: hexagonal and cubic. Yet, despite its importance to nature (e.g., the atmosphere) and technology (e.g., cryopreservation), the crystallization of liquid water to cubic ice has never been achieved in the laboratory. Here, we show how to design substrates to nucleate desired polytypes of ice, including the elusive cubic ice, and show that the process is controlled by the structure of...…Edited by Pablo G. Debenedetti, Princeton University, Princeton, NJ, and approved February 12, 2021 (received for review December 8, 2020)Under typical conditions on Earth, ice exhibits two distinct polytypes: hexagonal and cubic. Yet, despite its importance to nature (e.g., the atmosphere) and technology (e.g., cryopreservation), the crystallization of liquid water to cubic ice has never been achieved in the laboratory. Here, we show how to design substrates to nucleate desired polytypes of ice, including the elusive cubic ice, and show that the process is controlled by the structure of...WW…

Two dimensionless fundamental physical constants, the fine structure constant α and the proton-to-electron mass ratio , are attributed a particular importance from the point of view of nuclear synthesis, formation of heavy elements, planets, and life-supporting structures. Here, we show that a combination of these two constants results in a new dimensionless constant that provides the upper bound for the speed of sound in condensed phases, vu. We find that , where c is the speed of light in vacuum. We support this result by a large set of experimental data and first-principles computations...…Two dimensionless fundamental physical constants, the fine structure constant α and the proton-to-electron mass ratio , are attributed a particular importance from the point of view of nuclear synthesis, formation of heavy elements, planets, and life-supporting structures. Here, we show that a combination of these two constants results in a new dimensionless constant that provides the upper bound for the speed of sound in condensed phases, vu. We find that , where c is the speed of light in vacuum. We support this result by a large set of experimental data and first-principles computations...WW…

Effect of school...Effect of school closures on mortality from coronavirus disease 2019: old and new predictions;, , , School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, UKCorrespondence to: G J Ackland Objective To replicate and analyse the information available to UK policymakers when the lockdown decision was taken in March 2020 in the United Kingdom.Design Independent calculations using the CovidSim code, which implements Imperial College London’s individual based model, with data available in March 2020 applied to the coronavirus disease 2019 (covid-19)...…Effect of school...Effect of school closures on mortality from coronavirus disease 2019: old and new predictions;, , , School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, UKCorrespondence to: G J Ackland Objective To replicate and analyse the information available to UK policymakers when the lockdown decision was taken in March 2020 in the United Kingdom.Design Independent calculations using the CovidSim code, which implements Imperial College London’s individual based model, with data available in March 2020 applied to the coronavirus disease 2019 (covid-19)...WW…