Music Theory

 https://en.wikipedia.org/wiki/Music_theory

https://en.wikipedia.org/wiki/Music_and_mathematics

https://en.wikipedia.org/wiki/The_Geometry_of_Musical_Rhythm

https://en.wikipedia.org/wiki/Tempo

https://en.wikipedia.org/wiki/Metre_(music)

https://en.wikipedia.org/wiki/Lyric_setting

https://en.wikipedia.org/wiki/Metronome

https://en.wikipedia.org/wiki/Metric_modulation

https://en.wikipedia.org/wiki/Bar_(music)

https://en.wikipedia.org/wiki/Beat_(music)

https://en.wikipedia.org/wiki/Duration_(music)

https://en.wikipedia.org/wiki/Glossary_of_music_terminology

Astronomy

Eclipse - lunar/solar

tide

phase of moon

location of moon

angle of sunrise

Solstice / equinox

Analemma

Wright Brothers

 1. "the Wrights calculated they needed an engine that produced at least 8 horsepower and weighed no more than 200 pounds (91 kilograms)."

            No such engine was available in the market, so they designed/and made one

            They choose aluminum... They painted black - so people did not know the metal (avoid copy)

2. Propeller: Navy's propeller designs were "cut and try". 

They used the wind tunnel. 

"propeller was a wing traveling in a spiral course".

"90 pounds of thrust to sustain the Flyer in flight at 24 mph" - "combined thrust of between 120 and 130 pounds at 330 rpm"

3. wind tunnel

4. "a highly unstable but controllable machine" (Like Bicycle, flights too...)

No Patent

Few reasons

1. Altruism and the Public Good
2. Encouraging Innovation
3. Financial Constraints
4. Open-Source Movements

Examples:

1. Wilhelm Conrad Roentgen (X-rays)
2. Nikola Tesla (Alternating Current)
3. Charles Babbage (Difference Engine)
4. Sir Tim Berners-Lee (World Wide Web)
5. Linus Torvalds (Linux)
6. Richard Stallman (Free Software Movement)
7. The Raspberry Pi Foundation (Educational Devices)
8. The Wright Brothers (Airplane)
9. Thomas Edison (Phonograph)
10. Open Source

Marie Curie - "There were no patents. We were working in the interests of science. Radium was not to enrich anyone. Radium... belongs to all people."

Apollo-11

The Virtual AGC Project Gemini — Apollo — Shuttle

Apollo 11 guidance computer Github

Virtual Apollo Guidance Computer Github

DSKY - display/keyboard

AGC - Apollo Guidance Computer

CM - Command Module (Colossus) software

LM - Lunar Module (Luminary) Software

https://www.youtube.com/@CuriousMarc

Sudoku 17

010000009000300800000000600000012400703000000500000000800600000000040020000700050

030600080019000000000020000700000450000031000200000000400800000060500000000000900

052400000000070100000000000000802000300000600090500000106030000000000089700000000

092300000000080100000000000107040000000000065800000000060502000400000700000900000

800000001000950000000000000000070420301600000000000000040000570600308000000000200

030500020010000000000090000607000804200300000500000900700080400000100000000000000

200000500000080000000070000031600000000000470000000800000209030400500000060000001

700400000000000500000000300060000890000250000001000000300000042000006070010080000

081000000000800300000000470400000020060300000000900000700021000000050609000000000

070040000000050000000000060000700208900000400000100000300000150008306000000000090

These are minimal Sudoku puzzles using most distinct numbers