Nadia Rahim is a RECATOOLS editorial persona focused on statistics and data literacy: what confidence intervals, averages, correlations and margins of error actually mean, and how they are misquoted. Articles under this byline trace each claim to the primary statistical literature and show the working, so readers can check a number rather than take it on trust.

About this byline

Nadia Rahim is a RECATOOLS editorial persona for statistics and data-literacy coverage. Articles are produced and reviewed under RECATOOLS editorial supervision.

Editorial responsibility for this byline rests with Jeffrey Tan (Tan Seng Fei), RECASYS, Singapore. Our Editorial Policy sets out how sources are reviewed, how AI-assisted workflows are used, and how editorial desks and personas are defined.

154
Articles
Science
Primary beat
Jul 2026
Writing since
~985 min
Total reading
All 154 Science 88 Statistics 46 Sustainability 19 AI & ML 1

Articles · Science Showing 81–88 of 88

Electrician's tools laid out on a bench with a stripped three-core cable showing bare copper conductors.
Science

Why the Voltage-Drop Limit Is Really an Efficiency Limit

The voltage-drop limit in every wiring code reads as a performance rule. The current cancels, so the share of power burned as heat in a cable run is exactly its percentage voltage drop — an identity we verified across 216 combinations. At the three per cent limit a 100-amp circuit dissipates 720 watts into the walls while fully compliant, and on one run we measured the rule removed 354.9 watts of permanent heat.

14 Aug 2026 · 6 min read
Gloved hands closing a vernier caliper around a length of timber, with its scale in view.
Science

Significant Figures: The Digits Your Calculator Invents

We audited our own science calculators against the precision their inputs actually justify. Across 768 multiplications and divisions the significant-figures rule held, failing only 4.4 per cent of the time. Subtraction is where it breaks: 60.8 per cent of 120 cases overstated the answer, and in one worked example the page shows three significant figures when the inputs justify none. The audit also found and fixed a real defect in our own display code.

13 Aug 2026 · 9 min read
A long-exposure photograph of a rocket launch at night, its exhaust drawing a bright curved arc across a starfield above a coastline
Science

Vietnam's First Privately Built Satellites Have a Ride

VinSpace has booked a SpaceX Transporter rideshare for 2027. Coverage calling these Vietnam's first home-built satellites is wrong - state engineers have flown four since 2013. What is new is who is paying.

13 Aug 2026 · 9 min read
Rows of young seedlings in small peat pots on a sunlit sill, lit from behind.
Science

What a Punnett Square Cannot Tell You

The square says three-to-one, and the lesson usually adds that in a family of four, three children will show the trait and one will not. We computed it exactly: that split turns up 42.2 per cent of the time, and 31.6 per cent of such families have no recessive child at all. You would need 120 offspring before the observed ratio reliably matched — a number fit for peas, not people.

12 Aug 2026 · 5 min read
A gibbous Moon photographed against black sky, its cratered surface picked out along the terminator — illustrative; the impact site described here is not visible at this scale.
Science

A Rocket Stage Hit the Moon. South Korea Was Overhead With a Camera.

Danuri made eight passes over the predicted impact point, starting half an hour early, with reference frames taken a month before. That is what makes it a measurement.

11 Aug 2026 · 7 min read
A spacecraft with solar arrays extended, photographed in orbit above a desert coastline — illustrative of an orbiting satellite; this is not MICHIBIKI No. 7.
Science

Japan Launched Its Seventh Navigation Satellite. It Is Flying Six.

MICHIBIKI No. 7 reached orbit on Tuesday morning, completing the launch manifest for a seven-satellite design. QZS-5 was lost in December and is not being replaced.

11 Aug 2026 · 7 min read
Two rows of DIN-rail terminal blocks in a distribution cabinet, with numbered terminals and blue, yellow and green-and-yellow conductors landed on them.
Science

How to Size a Cable: the Six Checks, and the Three People Skip

Picking a cable looks like one lookup — find the current, read the size off a table. That answer is right in a cool plant room and wrong in a tropical riser, in the direction that makes the cable too small. There are six checks, the corrections multiply, and the small-conductor cap is applied after them rather than before. Worked on four real circuits, with both defects this audit found in our own calculators.

9 Aug 2026 · 8 min read
A gloved hand in a lab coat filling a volumetric flask of dark purple solution on a laboratory bench, an analytical balance beside it.
Science

Dilute It Tenfold. The pH Moves One Unit, or None at All.

C1V1 = C2V2 looks like arithmetic but is a physical claim with four assumptions inside it. Dilute a strong acid tenfold and its pH moves by exactly 1.00. Dilute a buffer by the same factor and it moves by exactly 0.00 — because Henderson-Hasselbalch depends on the RATIO of base to acid, and dilution divides both by the same number. What the concentration sets is not the pH but the capacity. And at the bottom of the scale the rule that worked perfectly breaks outright: 10⁻⁸ M hydrochloric acid is not pH 8, because an acid cannot make water alkaline.

8 Aug 2026 · 8 min read
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