I make f.lux (lighting and screens) and do research on sleep and circadian neuroscience, color, and vision. Previously: Picasa (founding CTO), Google, MetaCreations, Microsoft, CMU.https://bsky.app/profile/mherf.bsky.socialhttps://bsky.app/profile/mherf.bsky.social/post/3ml7mb5yt6k2chttps://www.biorxiv.org/content/biorxiv/early/2026/04/30/2026.04.27.721075.full.pdf Interesting preprint [in mice] says that cone bipolar cell "OFF" (the one shared by rods and cones) is responsible for retinal entrainment. The authors suggest that the fade of sunset could help fine-tune retinal clock timing.06 May 2026 21:07 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3ml7mb5yt6k2chttps://bsky.app/profile/mherf.bsky.social/post/3mkaytdxsb22gAI can score 100% in CMU's 15-112, but... "Last January, many students started to use AI on every assignment, only to drop the class once they began receiving low marks on their quizzes and exams. That semester had the highest number of students who dropped the class since teaching the course." https://the-tartan.org/2026/02/09/ais-impact-on-education-at-cmu-and-beyond/24 Apr 2026 17:00 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3mkaytdxsb22ghttps://bsky.app/profile/mherf.bsky.social/post/3mjfipc555s2bIf there was an important guy who posted on social media a lot but "never sleeps" you might be able to figure out that he has started napping a lot recently.13 Apr 2026 18:29 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3mjfipc555s2bhttps://bsky.app/profile/mherf.bsky.social/post/3mgdbmu2c422t"Lunar gravity predicts sleep timing" - bookmarking this lunar rhythms & sleep paper as interesting. It uses a 30-day rhythm but not the 28-day declination rhythm - a claim of "gravity" should probably use the 28-day one, but I think "phase" should follow 30? https://europepmc.org/article/med/4165949105 Mar 2026 17:02 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3mgdbmu2c422thttps://bsky.app/profile/mherf.bsky.social/post/3mfrxmv3ox22lAmazing data here - just 100lux of room light while staying up late seems to delay teens enough that 8000lx of morning bright light delays them further: [contains quote post or other embedded content]26 Feb 2026 19:47 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3mfrxmv3ox22lhttps://bsky.app/profile/mherf.bsky.social/post/3mdbmz5z5zk2kI helped Travis with some moonlight calcs for this paper - our code figures out "how bright compared to moonlight is this light for each species". There is a ton of photometrics and spatial modeling here too: https://www.sciencedirect.com/science/article/pii/S000632072600016925 Jan 2026 21:04 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3mdbmz5z5zk2khttps://bsky.app/profile/mherf.bsky.social/post/3md6t3bobf22uWhen the cold fronts come farther south, I search for the latest in polar vortex research. This time: https://www.npr.org/2026/01/23/nx-s1-5684971/winter-storm-ice-texas-new-england-climate-science24 Jan 2026 18:15 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3md6t3bobf22uhttps://bsky.app/profile/mherf.bsky.social/post/3m73uqn3pzk2jThey try to help teens by pulling out the 10% worst of social media… while leaving the five hours a day of not sleeping or socializing, as if that stuff doesn’t matter.03 Dec 2025 16:26 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3m73uqn3pzk2jhttps://bsky.app/profile/mherf.bsky.social/post/3m73tvstkj22oSome notes on "blue light harms mitochondria" making the rounds this week - a lot of the evidence is VERY indirect like this paper that says mice in blue light gain weight. 1/n https://www.nature.com/articles/s41598-025-89081-203 Dec 2025 16:11 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3m73tvstkj22ohttps://bsky.app/profile/mherf.bsky.social/post/3lxzqdj2zws2aFacial age estimation requires a 5-7 year margin of safety in validation studies, so when the software says you're 23-25 you can be considered 18. Errors are even larger around age 13, so basically useless for distinguishing minors from adults. [contains quote post or other embedded content]04 Sep 2025 18:06 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lxzqdj2zws2ahttps://bsky.app/profile/mherf.bsky.social/post/3lv4qxwfsr22oWe proposed a new metric (mDFD) for blue-blocking glasses. It's based on the sensitivity of melanopsin, log-transformed to resemble optical density: https://tvst.arvojournals.org/article.aspx?articleid=281060029 Jul 2025 18:39 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lv4qxwfsr22ohttps://bsky.app/profile/mherf.bsky.social/post/3lqkwrqznec2oIt's troubling that LLMs do not represent probability distributions *at all* - if you ask a question that should have a normal distribution, it will pick almost the same number every time. Maybe it's the mean, who knows - but it isn't equipped to reason about human populations this way.01 Jun 2025 18:55 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lqkwrqznec2ohttps://bsky.app/profile/mherf.bsky.social/post/3loous2euc22aIt would be cool if AIs only ran on solar because then they’d have circadian rhythm.08 May 2025 21:39 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3loous2euc22ahttps://bsky.app/profile/mherf.bsky.social/post/3lnig66xlr22nAstonishing technical feat here, laser projector that tracks eye movements and stimulates cone cells by kind! In just a few milliseconds of latency. [contains quote post or other embedded content]23 Apr 2025 14:36 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lnig66xlr22nhttps://bsky.app/profile/mherf.bsky.social/post/3lhz4st5ln22tJust received word that ANSI has approved our "flicker" TM, (ANSI/IES TM-39-25), which addresses in delightful detail how flickering lights of all kinds affect people. Congrats to everyone involved with the IES Vision Science Committee.12 Feb 2025 21:33 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lhz4st5ln22thttps://bsky.app/profile/mherf.bsky.social/post/3lg6zdn4vvs25Same concern as this post: PurpleAir (highly rated by AQMD) and IQAir are reporting 500% the AQI of the single reference sensor. This is the "reference" sensor used by everyone near the Palisades fire, and surely it should not be. [contains quote post or other embedded content]20 Jan 2025 18:56 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lg6zdn4vvs25https://bsky.app/profile/mherf.bsky.social/post/3lg2ymyrswc2gGreat article on wildfire smoke, particulates, and VOCs, and how to deal with it: https://scienceexchange.caltech.edu/topics/sustainability/ask-expert-sustainability/wildfire-california-hazards-of-smoke-paul-wennberg19 Jan 2025 04:33 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lg2ymyrswc2ghttps://bsky.app/profile/mherf.bsky.social/post/3lfkmkqsybk2fIf you’re in an area affected by fires, turning up your car’s fan helps with air quality - cabin air filters are pretty decent.12 Jan 2025 16:15 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lfkmkqsybk2fhttps://bsky.app/profile/mherf.bsky.social/post/3lfe3pqd3k22xFriend called me "we've been evacuated from the fires but can't see our security cameras" - tried @tailscale.com on a pi for the first time and they had a VPN in 20 minutes later. Thanks for the free version!10 Jan 2025 01:57 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lfe3pqd3k22xhttps://bsky.app/profile/mherf.bsky.social/post/3lez4yo6fms2oThere should be a privacy panel of regular people who can go deep on privacy-related defaults and explain it. If 90% of them vote yes, you can turn it on by default. e.g., this is pretty defensible IMO (but not obvious why at first glance): https://www.theverge.com/2024/12/29/24331354/ios-18-sending-photos-data-apple-enhanced-visual-search-opt-out-landmark-lookup05 Jan 2025 17:21 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lez4yo6fms2ohttps://bsky.app/profile/mherf.bsky.social/post/3lez3fj7knk2gFirst thought today: that someone would inspect my brain someday, and they would be surprised to find it has a lower-brain bootstrap sequence that can make espresso before the rest of it is awake.05 Jan 2025 16:52 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lez3fj7knk2ghttps://bsky.app/profile/mherf.bsky.social/post/3ldgpw3eb2c2zThe latest on Oura, Fitbit, Apple sleep stages vs PSG! https://ieeexplore.ieee.org/abstract/document/1078059516 Dec 2024 16:14 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3ldgpw3eb2c2zhttps://bsky.app/profile/mherf.bsky.social/post/3lcw7wt42ls2yGreat review [two labs] on current knowledge about LCA (longitudinal chromatic aberration) - LCA for accommodation: if the retinal image has blue fringes where it's out of focus, you should focus closer - Does LCA it have a big role in myopia? Maybe! https://www.annualreviews.org/content/journals/10.1146/annurev-vision-101222-05222810 Dec 2024 02:45 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lcw7wt42ls2yhttps://bsky.app/profile/mherf.bsky.social/post/3lcqi3dsf4k2jReading this study by Danielle Wallace about daily light exposure - men see 50% more (!) bright light (time outdoors) than women. Most of the difference is due to workday (men in blue-collar trades), but some is due to free time. If it's only certain worker populations, may not be true for everyone. https://www.nature.com/articles/s44323-024-00016-y07 Dec 2024 19:55 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lcqi3dsf4k2jhttps://bsky.app/profile/mherf.bsky.social/post/3lcor5akgg22cA trouble with pure chronological feed is the person you really like to hear from, but who posts 100 times in a row.07 Dec 2024 03:32 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lcor5akgg22chttps://bsky.app/profile/mherf.bsky.social/post/3lcigi7h5zc2kLED Christmas lights have tons of flicker (half-rectified=off half the time). Looking for flicker-free Christmas lights on Google makes you think flicker doesn’t exist, or it is the special mode where the lights blink. You have to search “full rectified” or “DC” to find good ones now?04 Dec 2024 15:05 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lcigi7h5zc2khttps://bsky.app/profile/mherf.bsky.social/post/3lcchdizkb22z#1 dictionary search in Wyoming is "chronobiology"? 🤷 https://www.reddit.com/r/Infographics/comments/1h48lw2/most_popular_word_searches_on_dictionarycom_in/02 Dec 2024 06:04 +0000at://did:plc:eoynz36cz24tp672f7bjrmdj/app.bsky.feed.post/3lcchdizkb22z