Leen Noordzij – This blog is about, business, climate change, culture, economics, physics, education, Fermat, history, innovation, mathematics, politics, quantum mechanics and technology.

When everybody is going in one direction, choose another one.

Groupthink is the end of humanity.

23 Mar 2026Leen NoordzijLeave a Comment

Pythagorean Triples, Goldbach’s Conjecture and De Fermat’s Last Theorem Updated 2026-03-23: New §8 Pythagorean Triples and Rational numbers.

23 Mar 202623 Mar 2026Leen NoordzijLeave a Comment

De beginjaren van de THT, een Terugblik An experiment with Liberal Arts at Twente Institute of Technology. Mijn studie en promotie aan de THT 1964-1973. Updated 2026-03-20, enige aanvullingen o.a. “meer kennis dan inzicht”, pag. 21.

9 Mar 2026Leen NoordzijLeave a Comment

Wiskunde D Online VWO 6 Summary Blok 15-16 Updated 2026-03-09 Toegift uit het verre verleden

6 Mar 2026Leen NoordzijLeave a Comment

Mijn geschiedenis van de haven van Pernis. 1942-1954, de haven, het water en de watersnood. Updated 2026-03-06, artist impressie pag. 33

17 Dec 202517 Dec 2025Leen NoordzijLeave a Comment

Wiskunde D Online VWO 5 Summary Blok 8-14 and Solved Problems Mathematics, Preparation for College, yOUlearn Updated 2025-12-17, edited and figures added

11 Dec 2025Leen NoordzijLeave a Comment

Wiskunde D Online VWO 4, Summary Blok 1-7 and solved Problems Mathematics Preparation for College, yOUlearn Updated Blok 7 2025-12-11 Toegift a serie and a limit page 232

5 Dec 20255 Dec 2025Leen NoordzijLeave a Comment

Ship Hydrodynamics, Ship Propeller Acoustics and Cavitation. Updated 2025-12-05 §4 cavitation and cavitation inception, pages 9 and 10

26 Nov 202526 Nov 2025Leen NoordzijLeave a Comment

De Fermat’s Last Theorem and the margin of De Fermat’s Diophantus The emergence of Format’s Last Theorem from Pythagorean Triples Update: 2025-11-26: §4 edited

13 May 202513 May 2025Leen NoordzijLeave a Comment

From De Fermat to Pythagoras and Back. The emergence of Format’s Last Theorem from Pythagorean Triples Updated 2025-05-13 , footnote 4 added Leen Noordzij,

7 Jan 20257 Jan 2025Leen NoordzijLeave a Comment

de Fermat’s Last Theorem in the marginal line of Diophantus. Updated 2025-01-07 Edited and typos

dr.l.noordzij@leennoordzij.nl