Michael Herf
@mherf.bsky.social
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.
Facial 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.
Roblox will expand age checks to all users of its communication tools by the end of 2025 using facial age estimation tech, ID verification, and parental consent (Sarah Perez/TechCrunch)
Main Link | Techmeme Permalink
Main Link | Techmeme Permalink
September 4, 2025 at 6:06 PM
Facial 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.
We proposed a new metric (mDFD) for blue-blocking glasses. It's based on the sensitivity of melanopsin, log-transformed to resemble optical density:
tvst.arvojournals.org/article.aspx...
tvst.arvojournals.org/article.aspx...
Optimizing the Potential Utility of Blue-Blocking Glasses for Sleep and Circadian Health | TVST | ARVO Journals
tvst.arvojournals.org
July 29, 2025 at 6:39 PM
We proposed a new metric (mDFD) for blue-blocking glasses. It's based on the sensitivity of melanopsin, log-transformed to resemble optical density:
tvst.arvojournals.org/article.aspx...
tvst.arvojournals.org/article.aspx...
Reposted by Michael Herf
This is the big one: Kennedy is firing the entire #ACIP in a move he says is needed to restore confidence in vaccines.
"It scares me to think of what’s ahead,” Mike Osterholm of CIDRAP told me. www.statnews.com/2025/06/09/r...
"It scares me to think of what’s ahead,” Mike Osterholm of CIDRAP told me. www.statnews.com/2025/06/09/r...
Health secretary RFK Jr. abruptly fires CDC vaccine advisory panel
Health secretary Robert F. Kennedy Jr. has taken the extraordinary step of firing the expert panel that advises the CDC.
www.statnews.com
June 9, 2025 at 9:03 PM
This is the big one: Kennedy is firing the entire #ACIP in a move he says is needed to restore confidence in vaccines.
"It scares me to think of what’s ahead,” Mike Osterholm of CIDRAP told me. www.statnews.com/2025/06/09/r...
"It scares me to think of what’s ahead,” Mike Osterholm of CIDRAP told me. www.statnews.com/2025/06/09/r...
It'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.
June 1, 2025 at 6:55 PM
It'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.
Reposted by Michael Herf
There are 2 previous historical cases of countries destroying their science and universities, crippling them for decades: Lysenkoism in the USSR and Nazi Germany. The Trump administration will be the 3rd.
It's not just budgets but research, institutions, expertise, and training the next generation.
It's not just budgets but research, institutions, expertise, and training the next generation.
May 31, 2025 at 4:43 AM
There are 2 previous historical cases of countries destroying their science and universities, crippling them for decades: Lysenkoism in the USSR and Nazi Germany. The Trump administration will be the 3rd.
It's not just budgets but research, institutions, expertise, and training the next generation.
It's not just budgets but research, institutions, expertise, and training the next generation.
It would be cool if AIs only ran on solar because then they’d have circadian rhythm.
May 8, 2025 at 9:39 PM
It would be cool if AIs only ran on solar because then they’d have circadian rhythm.
Astonishing technical feat here, laser projector that tracks eye movements and stimulates cone cells by kind! In just a few milliseconds of latency.
This paper is the result of >20 yrs of hard work by talented students, postdocs and collaborators, but none more than my co-author Ren Ng and his team in EECS.
1/n
Novel color via stimulation of individual photoreceptors at population scale | Science Advances www.science.org/doi/10.1126/...
1/n
Novel color via stimulation of individual photoreceptors at population scale | Science Advances www.science.org/doi/10.1126/...
Novel color via stimulation of individual photoreceptors at population scale
Image display by cell-by-cell retina stimulation, enabling colors impossible to see under natural viewing.
www.science.org
April 23, 2025 at 2:36 PM
Astonishing technical feat here, laser projector that tracks eye movements and stimulates cone cells by kind! In just a few milliseconds of latency.
Just 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.
February 12, 2025 at 9:33 PM
Just 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.
Same 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.
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.
January 20, 2025 at 6:57 PM
Same 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.
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.
Great article on wildfire smoke, particulates, and VOCs, and how to deal with it:
scienceexchange.caltech.edu/topics/susta...
scienceexchange.caltech.edu/topics/susta...
Ask a Caltech Expert: Paul Wennberg on Environmental Hazards of Smoke
Paul Wennberg discusses the air quality following the 2025 California fires and how to clean homes downwind of the fires.
scienceexchange.caltech.edu
January 19, 2025 at 4:33 AM
Great article on wildfire smoke, particulates, and VOCs, and how to deal with it:
scienceexchange.caltech.edu/topics/susta...
scienceexchange.caltech.edu/topics/susta...
If you’re in an area affected by fires, turning up your car’s fan helps with air quality - cabin air filters are pretty decent.
January 12, 2025 at 4:15 PM
If you’re in an area affected by fires, turning up your car’s fan helps with air quality - cabin air filters are pretty decent.
Friend 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!
January 10, 2025 at 1:57 AM
Friend 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!
There 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):
www.theverge.com/2024/12/29/2...
www.theverge.com/2024/12/29/2...
Is your iPhone sharing photos data with Apple by default?
It is, but you can change it.
www.theverge.com
January 5, 2025 at 5:21 PM
There 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):
www.theverge.com/2024/12/29/2...
www.theverge.com/2024/12/29/2...
First 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.
January 5, 2025 at 4:52 PM
First 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.
Reposted by Michael Herf
Read our new preprint on photic sneezing.
Sneezing in response to bright light exposure: A case study in a photic sneezer https://www.biorxiv.org/content/10.1101/2024.12.11.627890v1
December 15, 2024 at 10:34 AM
Read our new preprint on photic sneezing.
Great 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!
www.annualreviews.org/content/jour...
- 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!
www.annualreviews.org/content/jour...
The Role of Chromatic Aberration in Vision | Annual Reviews
The study of biological optics would be complicated enough if light only came in a single wavelength. However, altering the wavelength (or distribution of wavelengths) of light has multiple effects on...
www.annualreviews.org
December 10, 2024 at 2:45 AM
Great 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!
www.annualreviews.org/content/jour...
- 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!
www.annualreviews.org/content/jour...
Reading 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.
Light exposure differs by sex in the US, with females receiving less bright light - npj Biological Timing and Sleep
npj Biological Timing and Sleep - Light exposure differs by sex in the US, with females receiving less bright light
www.nature.com
December 7, 2024 at 7:55 PM
Reading 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.
A trouble with pure chronological feed is the person you really like to hear from, but who posts 100 times in a row.
December 7, 2024 at 3:32 AM
A trouble with pure chronological feed is the person you really like to hear from, but who posts 100 times in a row.
LED 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?
December 4, 2024 at 3:05 PM
LED 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?
Most popular Word Searches on dictionary.com in each State
www.reddit.com
December 2, 2024 at 6:04 AM
This is the best social network ever
Making a real effort to post things about science not just 1) politics, 2) nonsense, though you can count on those from me.
So…
What is your favorite retinal cell type? I have two. Mueller glia cells (of course) but my real favorite is intrinsically photosensitive retinal ganglion cells.
So…
What is your favorite retinal cell type? I have two. Mueller glia cells (of course) but my real favorite is intrinsically photosensitive retinal ganglion cells.
November 28, 2024 at 8:22 PM
This is the best social network ever
Feeling lucky so many scientists are here, helps me avoid reactive news. As they say in finance, volatility is not return. And online, outrage is not progress.
November 24, 2024 at 4:28 PM
Feeling lucky so many scientists are here, helps me avoid reactive news. As they say in finance, volatility is not return. And online, outrage is not progress.