What Does a QR Code Actually Store? You Cannot Tell by Looking
Two codes pointing at two different sites differ in 35.6 per cent of their squares — and no human can tell, because nobo...
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How Much RAM Do I Need? Free Memory Is the Wrong Number
On a 17.2 GB laptop running a browser, a container stack and an editor, free memory read 0.06 GB — and nothing was wrong...
Is This Email Really From Them? The Check You Cannot See
The sender name is free text and the address can be forged. The real check happens in DNS before the message reaches you...
Why Is My PDF So Big? It Is Probably a Picture of Text
We built one A4 page both ways and weighed them. As text: 8,256 bytes, with 4,791 searchable characters. The same page s...
What Does Incognito Mode Actually Do? Less Than the Name Suggests
A private window destroys a storage container when you close it — five things go with it, all of them data your own devi...
What Does the Padlock Actually Prove? We Read Six Real Certificates
It certifies that the connection is encrypted and that the name in the address bar matches the certificate. It says noth...
How to Compare Unit Prices When the Shelf Makes It Hard
The large pack is usually cheaper per unit, and checking is one division — but the shelf is arranged so you cannot do it...
What Your A1C Actually Measures, and When It Does Not
A1C estimates average glucose over about three months by measuring what has happened to your red blood cells — so anaemi...
Your Fertile Window Is Six Days, and It Ends at Ovulation
"Ovulation is on day 14" and "ovulation is 14 days before your next period" are repeated as the same fact. They describe...
Why Is My Disk Full? Every Tool Is Answering a Different Question
The same 494 GB drive reports 6 per cent used, 53 per cent used and 56.3 per cent used depending on what you ask — and a...
Should I Pay Off My Loan Early? The Date Matters More Than the Amount
An extra payment does not buy a fixed amount of anything — what it buys depends almost entirely on when you make it. On...
Why Is My Wi-Fi Slow? Usually, It Is Not the Wi-Fi
A page load is five separate stages, and the radio is only involved in one of them. Timed across three real sites, the W...
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