The case now for air quality & taming the most risky spaces — It’s the middle of 2022, and most folks in the US have given up COVID mitigations. Big conferences, indoor dining. It’s basically over, despite record rates of transmission and new variants on the horizon. Why did people stop every mitigation earlier this year, rather than picking some halfway mark? Well…

Recently, I wrote about practical ways to ventilate for COVID-19, and why this is important. The idea from medical facilities and building scientists is that you want to optimize for “ACH” (or “air changes per hour”). This is a good start, because more air movement is better. But it’s really…

For anyone who lands here in 2023: ASHRAE 241 is now published, and has better advice than this article. We should view ACH (“air changes per hour”) as a good way to ventilate unoccupied spaces. But a room with one person should be ventilated differently than one with 100, so…

Can we use a new kind of UV-C light in occupied spaces? — In 1903, Niels Finsen was awarded the Nobel Prize for using UV-C light for disinfection, originally for lupus. Since then, UV-C has been used in tackling Tuberculosis and MRSA in hospitals. Recent interest in UV-C for COVID-19 has involved disinfecting air (since there is potential for the virus to transmit…

June 3, 2019 To the Committee on Energy, Utilities, and Communications, I write to oppose AB-7, and I hope to convince the committee that permanent DST will wake people up too early throughout the winter, restricting how much they sleep. This pattern is associated with increased cancer, heart disease, diabetes…

We have to stop changing the clocks twice a year, but it’s also important to pick the right schedule when we do it. Thousands of scientists say that Standard Time is better, yet legislators are pushing for permanent DST, anyway. The scientists have shown that seeing light in the morning…

VR glasses are going to affect sleep like nothing we’ve ever seen I took my iPhone 6 and popped it into Google Cardboard. Put the spectrometer where my eyes usually go, and pushed the button. The meter took the reading really fast… 360 lux f.luxometer says that’s 90% as bright as daylight — meaning it can kick your circadian clock two timezones…

They’re good for more than the movies — Dolby just announced their Dolby Vision project. To make movies look better, they’re testing incredibly bright screens—20,000 nits—making so much heat they have to use liquid cooling. Normal screens clock in at just 200-400 nits, so it’s quite a jump. I’m sure the images look splendid, but that’s not why…