John D. Cook @johndcook - Bluesky Profile

Looking back at Martin Gardner’s RSA article

www.johndcook.com/blog/2025/08...

05.08.2025 13:04 — 👍 2 🔁 0 💬 0 📌 0

Gluons, quarks, letters, and envelopes

www.johndcook.com/blog/2025/03...

17.03.2025 01:28 — 👍 2 🔁 0 💬 0 📌 0

New post: Practical consequences of LLM tokenization details

www.johndcook.com/blog/2025/03...

09.03.2025 14:19 — 👍 2 🔁 0 💬 0 📌 0

Thanks!

16.02.2025 01:46 — 👍 1 🔁 0 💬 0 📌 0

13.02.2025 14:49 — 👍 8 🔁 0 💬 3 📌 0

Polynomial Encounters of the Third Kind

www.johndcook.com/blog/2025/02...

13.02.2025 12:56 — 👍 2 🔁 1 💬 1 📌 0

Does DeepSeek demonstrate that we don’t need as much compute power as we thought?

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03.02.2025 20:04 — 👍 7 🔁 1 💬 0 📌 1

31.01.2025 17:44 — 👍 1 🔁 0 💬 0 📌 0

Protecting Privacy in the Age of AI: A Conversation with John Cook We discuss safeguarding sensitive information in data-intensive industries, the balance of preserving data utility and protecting privacy as AI applications raise new concerns, and methods like differ...

New podcast interview just dropped.

Protecting Privacy in the Age of AI: A Conversation with John Cook

www.trenegy.com/podcast/prot...

16.01.2025 22:07 — 👍 5 🔁 0 💬 0 📌 0

How the day of the week for New Years Day goes through a 28 year cycle.

The green diamonds represent leap years and the blue squares represent ordinary years.

01.01.2025 03:22 — 👍 7 🔁 0 💬 0 📌 0

Modal logic and science fiction

www.johndcook.com/blog/2022/01...

31.12.2024 01:08 — 👍 0 🔁 0 💬 0 📌 0

Unix Time and a Modest Proposal Why Unix time is not exactly what it is often described to be, and a proposal for fixing it.

Unix Time and a Modest Proposal

www.johndcook.com/blog/2024/12...

27.12.2024 18:13 — 👍 3 🔁 1 💬 1 📌 1

Centered triangular numbers are the number of dots in images such as the one below.

The nth centered triangular number equals 1 + 3n(n + 1)/2.

25.12.2024 15:47 — 👍 5 🔁 3 💬 0 📌 0

Most popular posts of 2024

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24.12.2024 15:42 — 👍 6 🔁 1 💬 0 📌 0

Twelve Days of Christmas and tetrahedral numbers How many gifts are there in the song Twelve Days of Christmas? Day 1: 1 gift Day 2: 1 + 2 = 3 gifts Day 3: 1 + 2 + 3 = 6 gifts … Day 12: 1 + 2 + 3 + … + 12 = 78 gifts The number of gifts on day

By the nth day of Christmas, my true love had sent to me n(n+1)(n+2)/6 gifts.

www.johndcook.com/blog/2009/12...

20.12.2024 16:59 — 👍 4 🔁 0 💬 0 📌 0

Intro to interval arithmetic. Applied to cosine iteration.

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19.12.2024 16:13 — 👍 4 🔁 1 💬 0 📌 0

If you press the cosine key on a calculator over and over, you always get stuck on the same number.

This post takes a more sophisticated look at a child’s amusement.

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17.12.2024 18:05 — 👍 10 🔁 1 💬 0 📌 0

A golden hospital gown is an allusion to The Emperor’s New Clothes, except the emperor is somewhere between sumptuously clothed and naked.

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16.12.2024 13:10 — 👍 1 🔁 0 💬 0 📌 0

How many ways can you select six points in the plane so that every subset of three points forms the vertices of an isosceles triangle?

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09.12.2024 14:17 — 👍 5 🔁 0 💬 0 📌 0

Bi-elliptic transfer orbit maneuver Comparing bi-elliptic transfer orbit and the Hohmann transfer orbit. The latter can be more efficient when the target orbit is far larger than the initial orbit.

Bi-elliptic transfer orbit maneuver

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08.12.2024 17:25 — 👍 5 🔁 0 💬 0 📌 0

Connecting powers of two and decibels Powers of two give the approximate significant figures in integer decibels.

Connecting powers of two and decibels

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08.12.2024 02:08 — 👍 4 🔁 0 💬 0 📌 0