Michael Herf

👏 Ceiling lamps light up paper but windows light up retinas

illustrating how mDFD can apply directly to a dose-response for a "brighter" light

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...

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.

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'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.

Graphs showing 25 years of budgets for the National Institute of Health, NASA, and the NSF. In all cases, the proposed budget for next year is far, far below any year of the previous quarter century.

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.

Agreeing that we need better names, I would add that it bugs me when people say the human L-cone peak is "red". It looks to me much more like "yellow", and then it's only via L-M opponency that we get the "red" color response?

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.

I am so sorry. 💔

This is a business model problem. Supporting a niche device for a long time is very expensive.

Yet to come, I will post a followup when I have it.

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.

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.

Great article on wildfire smoke, particulates, and VOCs, and how to deal with it:

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.

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!

Is your iPhone sharing photos data with Apple by default? It is, but you can change it.

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...

LLMs train with trillions of tokens to do something akin to “brainstorming” but then we try to do safety/inhibition with a few paragraphs of system prompts? Think about all the corrections you get in high school, it’s more than a paragraph.

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.

Performance of Widely used Consumer Wearables for Sleep Tracking Sleep tracking by consumers is becoming increasingly prevalent, yet few studies have evaluated the accuracy of such devices. We sought to evaluate the accuracy of three devices (Oura Ring Gen3, FitBit...

The latest on Oura, Fitbit, Apple sleep stages vs PSG!

ieeexplore.ieee.org/abstract/doc...

Read our new preprint on photic sneezing.

Is there a way to disable the quippy summaries but keep access to image and other features? The one big toggle seems to control it all.

Interesting - it’s in chick embryos so the light goes through a shell. For humans, light is highly attenuated at depth in tissue, and our newborns take some time to develop circadian rhythm.

The retina does a lot with post-receptoral circuitry even before signals get to the brain. The variety of cells and combinatorics there is substantial. So, it may be that you can get more "spectra" or more "processing" (but not both?) given the basic metabolic needs and connectivity of the retina.

Chickens have 6 cone types! The post-receptoral possibilities alone...

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...

This is great!

32.9 percent of employees had regular outdoor exposure in 2022 : The Economics Daily: U.S. Bureau of Labor Statistics 32.9 percent of workers in 2022 were exposed to the outdoors as a regular part of their job. Among the occupations with the most outdoor exposure are cement masons and concrete finishers, construction...

BLS has a guess about outdoor occupations here, but ones that include a lot of driving would probably qualify for 1000lx also.

www.bls.gov/opub/ted/202...

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

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.