The Journal.
Every essay, review, field note, and interview we've published. New pieces arrive on Tuesdays; full issues close every three months.
Gemini on the Wrist: 31 Nights of Asking My Watch About Coffee — and What Smartwatch Reviews Keep Getting Wrong
At 3:41 on a Tuesday afternoon in August I drank a double-shot flat white — about 125 mg of caffeine, give or take the barista's tamp — then raised my wrist and asked the watch whether that had been a…
I Fed 42 Days of Caffeine Data to Three AI Health Apps. The Hallucinations Weren't the Problem.
The most dangerous thing AI health apps did to me over six weeks was tell me the truth. Not a fabricated sleep score. Not a workout I never did.
When Local Infrastructure Failure Reaches the Kettle: Whanganui, Brown Water, and the Cost of Resident Accountability
A kettle is a poor instrument for testing a water supply, and also the first one most households reach for.
Positive Airway Pressure and Pediatric Sleep Apnea (OSA): What the Mask Is Actually Doing
The advice arrives in the same calm voice every time. Give it two weeks. Children are adaptable — she'll adjust faster than you would.
Caffeine, Radar, and AR Glasses: I Tested Safety Wearables on E-Bikes for Six Weeks
The three-piece safety systems bolted to the concept e-bikes at this autumn's trade shows — radar in the seat tube, a heads-up display in the glasses, a helmet wired to both — are not for sale.
Eight Weeks of Double-Logged Lifts: The Apple Watch Fitness Features in the watchOS 27 Rumors Fix the Wrong Number
Automatic set and rep detection sits at the top of my list of missing Apple Watch fitness features, and after eight weeks of testing I've concluded that shipping it in watchOS 27 will make my watch…
Pillow Evaluation and Testing, With a Ruler: What Four Pillows and Sixteen Nights Told Me
At 11:40 on a Tuesday night I was kneeling on the bedroom floor with a kitchen ruler and a 4.5 kg bag of dog food, which is not where I expected pillow evaluation and testing to enter my life.
Sleep Apnea Detection and the Class I Detour: What Sleep Cycle's Staged Rollout Reveals About Digital Health Market Entry
The advice is well-worn, and it comes from people who have actually done it: clear the highest regulatory bar you can, in the largest market you can, and the commercial questions resolve themselves…
I Bought Bone Conduction Headphones at $70 Off to Wear in Bed. My Partner Heard the Podcast.
The number that got my attention was $70. On September 8 Amazon dropped the Shokz OpenRun Pro to $109.95 against a $179.95 list price, and I bought a pair — not primarily to run in, which is what bone…
I Tested Six Chlorine Bleach Alternatives on Yellowed Sheets: A Laundry Stain Removal Experiment
The pillowcases went first. Four summers into a set of white percale, the two on my side of the bed had a tea-colored shadow along the top hem that survived every ordinary wash — visible in daylight…