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The science and history behind units, measurements, and conversions.
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Why a Unit Conversion Error Destroyed a $327 Million Mars Mission — And Why the US Still Uses Imperial
Food Calories, Thermic Effect, and Why the Label Isn't the Whole Story
Food calorie labels use Atwater values from the 1890s and don't account for the thermic effect of food, the difference between raw and cooked, or gut microbiome variation. Here's what food calories actually measure, why protein delivers fewer net calories than the label suggests, and why individual calorie extraction varies.
Kitchen Temperature: Oven Calibration, Safe Internal Temperatures, and Why Your Oven Lies to You
Consumer ovens can run 10–30°C off their dial setting. Colour and time are indicators; internal temperature is the only reliable doneness test. Here's gas mark to Celsius conversion, food safety internal temperatures, the difference between thermometer types, and why burgers and whole cuts have different safety rules.
Extreme Temperatures: From Blast Furnaces to Quantum Computers to Stellar Classification
Gas turbine blades operate above their own melting point, cooled by internal airflow. Quantum computers run at 15 millikelvin — colder than outer space. Here's industrial thermocouples and pyrometer accuracy, extreme industrial temperatures, cryogenic applications, and how stellar surface temperature determines star colour.
How Property Floor Area Is Measured: GIA, NIA, and Why UK and US Numbers Aren't Comparable
UK properties use Gross Internal Area, US uses Gross Living Area — and the same building measured both ways gives different numbers. Here's GIA vs NIA vs GEA, how Germany and France mandate floor area disclosure differently, how to calculate price per m² for property comparison, and why EPC certificates are the most reliable floor area source.
Scheduling Across Timezones: Finding Overlap Windows, Fair Meeting Rotation, and Async-First Practices
A 9 AM New York meeting is 10 PM in Singapore — and scheduling from headquarters systematically burdens everyone else. Here's how to visualise timezone overlap (or its absence), rotating meeting approaches for fair distribution, the 2-3 week DST gap between US and European transitions, and async-first practices for wide timezone spreads.
Gradients, Roof Pitch, and Ramp Design: Trigonometry in Everyday Construction and Accessibility
A 5% road gradient is a 1:20 slope at 2.86° — three ways to express the same incline. Here's trigonometry in everyday construction: wheelchair ramp compliance angles, roof pitch in degrees vs rise:run, how GPS calculates horizontal distance from slope distance, and the steepest roads in the world.
Scuba Diving Physics: How Pressure Changes Underwater and Why It Creates Both Rules and Risks
At 10 metres underwater, pressure doubles. Every additional 10 metres adds another atmosphere. Here's Boyle's Law and why air spaces squeeze on descent, nitrogen narcosis and partial pressures, decompression sickness mechanics, and what NDL limits mean for recreational divers.
From Sundials to Atomic Clocks: How Timekeeping Precision Enabled GPS Navigation
The second was once 1/86,400 of a day. Now it's defined by caesium atom oscillations — 9,192,631,770 per second — because GPS requires nanosecond timing to achieve metre-level accuracy. Here's the history from sundials to atomic clocks, how GPS trilateration works, and why relativistic corrections are essential.
Clothing Sizes Explained: UK vs US vs EU, Vanity Sizing, and Why You Should Measure Instead
A UK size 12 is not the same as a US size 12, and both have changed over decades due to vanity sizing. Here's how clothing size systems compare internationally, the anthropometric data behind them, why brand-to-brand variation makes labels unreliable, and why measuring in centimetres is the only solution.
How SSDs Work: NAND Flash Types, 3D Stacking, and Why Prices Keep Falling
SSD prices fell from $3.00/GB in 2009 to $0.08/GB in 2024 — driven by NAND cell density improvements. Here's how NAND flash stores data, the SLC/MLC/TLC/QLC endurance trade-off, how 3D NAND stacks hundreds of layers, why NVMe is faster than SATA, and the TBW lifespan calculation.
International Remittances: How Transfer Costs Work and How to Send Money Home for Less
Over $800 billion is sent home by migrant workers each year — with an average 6.2% cost. Here's how transfer fees and hidden exchange rate margins combine, why Wise, Remitly, and Western Union suit different corridors and recipient situations, and why mobile money matters for the 1.4 billion unbanked.
Human Power Output in Sport: FTP, W/kg, How Power Meters Work, and What 400 Watts Means
Professional cyclists sustain 400+ watts — and W/kg (watts per kilogram) determines who wins on climbs. Here's FTP and power training zones, how cycling power meters work, human power output in different sports, and why mechanical efficiency means 250W of cycling burns 850 kcal/hour metabolically.
