Optical measurements of the silicon vacuum window with anti-reflective sub-wavelength structure for ASTE Band 10.

For millimeter and submillimeter-wave astronomy, it is highly desirable to have vacuum windows within the receiver cryostat that exhibit low reflection, low loss, and a wide bandpass. The use of antireflective (AR) sub-wavelength structures (SWSs) on substrates has expanded the possibilities for creating new vacuum windows. Recently, a novel method of fabricating AR SWS on a silicon-on-insulator wafer has been proposed, and a vacuum window with a two-layer AR SWS has been developed for use with the Atacama Submillimeter Telescope Experiment Band 10 receiver. To thoroughly assess the characteristics of the silicon window sample, we conducted transmittance measurements using terahertz time-domain spectroscopy, and noise and beam measurements using an Atacama Large Millimeter/submillimeter Array (ALMA) Band 10 receiver. We found that the silicon window sample exhibits characteristics comparable to the quartz window of the ALMA Band 10 receiver. The result strongly encourages applications of AR silicon windows in receivers with wider bandwidths.

Threshold, budget and deadline: beyond the discourse of climate scarcity and control.

Since its inception, the Intergovernmental Panel on Climate Change (IPCC) has always been at the centre of the global climate debate. Its authoritative reports provide cultural resources for public understanding on the challenge of climate change. While the IPCC maintains its perception as a policy-neutral adviser, the IPCC in practice acts as a powerful discursive agent that guides policy debates in a certain direction by enacting influential scientific concepts. These concepts include three prominent metaphors-temperature threshold, carbon budget and climate deadline-that have been widely circulated across science, policy and advocacy. Three metaphors differ on ways in which the risk of climate change is expressed in terms of space and time. But they all constitute the discourse of climate scarcity-the cognitive view of that we have (too) little space and time to stay below a physical limit for avoiding dangerous climate change. This discursive construction of physical scarcity on climate change has significant political and psychological implications. Politically, the scarcity discourse has the risk of increasing a post-political tendency towards managerial control of the global climate ('scarcity of politics'). Psychologically, however, scarcity has a greater risk of generating a 'scarcity mindset' that inhibits our cognitive capacity to imagine human life beyond managing physical scarcity. Under a narrow mindset of scarcity, the future is closed down to the 'point of no return' that, if crossed, is destined to be the end. To go beyond the scarcity discourse, a new discourse of emancipation has to be fostered. Climate change can be reframed not as a common single destination but as a predicament for actively reimagining human life. Such a narrative can expand our imaginative capacity and animate political action while embracing social losses.

Are we ignoring a black elephant in the Anthropocene? Climate change and global pandemic as the crisis in health and equality.

Climate change and coronavirus pandemic are the twin crises in the Anthropocene, the era in which unsustainable growth of human activities has led to a significant change in the global environment. The two crises have also exposed a chronic social illness of our time-a deep, widespread inequality in society. Whilst the circumstances are unfortunate, the pandemic can provide an opportunity for sustainability scientists to focus more on human society and its inequalities, rather than a sole focus on the natural environment. It opens the way for a new normative commitment of science in a time of crises. We suggest three agendas for future climate and sustainability research after the pandemic: (1) focus on health and well-being, (2) moral engagement through empathy, and (3) science of loss for managing grief.

Reconstruction of the boundary between climate science and politics: the IPCC in the Japanese mass media, 1988-2007.

The Intergovernmental Panel on Climate Change (IPCC) plays a significant role in bridging the boundary between climate science and politics. Media coverage is crucial for understanding how climate science is communicated and embedded in society. This study analyzes the discursive construction of the IPCC in three Japanese newspapers from 1988 to 2007 in terms of the science-politics boundary. The results show media discourses engaged in boundary-work which rhetorically separated science and politics, and constructed the iconic image of the IPCC as a pure scientific authority. In the linkages between the global and national arenas of climate change, the media "domesticate" the issue, translating the global nature of climate change into a discourse that suits the national context. We argue that the Japanese media's boundary-work is part of the media domestication that reconstructed the boundary between climate science and politics reflecting the Japanese context.