#recmaths — Public Fediverse posts on home.social

Colin the Mathmo @[email protected] · 2026-03-22 · 17:48 UTC

Friday was the equinox, at 14:46 GMT. I didn't get the time, but yesterday, March 21st, I went out to measure our latitude.

I did so on the surrounds of the Port Sunlight Analemmatic Sundial, which seemed appropriate:

https://sundialsoc.org.uk/wp_bridol/pages/S7/S7998.html

I'll write up the technique and do the error analysis later, but with a stick, and director's chair, about 10 pennies, a length of ball chain, and a tape measure, I got a latitude of:

53.343891584 degrees.

Check the page above to see their official value.

I'm fairly pleased with that.

#RecMath #RecMaths #Astronomy #Equinox

#equinox #astronomy #recmaths #recmath

Colin the Mathmo @[email protected] · 2025-10-06 · 16:12 UTC

CW: Puzzle included ... no spoilers please

A friend has sent me an interesting meta-puzzle, but we need to start with the first one.

Attached is a black and white figure divided into four regions. That challenge is to divide the white regions into 2, 3, 4, and 5 congruent pieces.

More explicitly, one of the white regions will be subdivided into 2 congruent regions. Another into 3, and so on.

Can you find a solution?

The second phase will follow later, but I think this is interesting enough in its own right.

Please put solutions and spoilers behind a CW.

PS: Classical methods and constructions only. We're in Puzzle World, not Crypto World.

#RecMaths #RecMath #Math #Maths #MathsPuzzle #MathPuzzle #Geometry #GeometryPuzzle

#geometrypuzzle #geometry #mathpuzzle #mathspuzzle #maths #math

Colin the Mathmo @[email protected] · 2024-12-30 · 13:42 UTC

Continuing the series of videos of #G4G15 :

Sabetta Matsumoto:
Bending Seams - How to Create Couture Curves

https://www.youtube.com/watch?v=vMa6RIi42L4

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)
Please share!

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-11-17 · 09:49 UTC

Continuing the series of videos of #G4G15 :

Bjoern Muetzel - Apollonian Dream

https://www.youtube.com/watch?v=m9PNxh3cEwE

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-11-15 · 20:12 UTC

Continuing the series of videos of #G4G15 :

Spandan Bandyopadhyay:
The Egg Sandwich Problem

https://www.youtube.com/watch?v=vLUBX3q38oQ

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-11-14 · 21:35 UTC

Continuing the series of videos of #G4G15 :

George Hart, Abraham Sharp and the "Sharpohedron"

https://www.youtube.com/watch?v=0K_0vMrZBjc

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-11-14 · 16:15 UTC

Continuing the series of videos of #G4G15 :

Tanya Khovanova: My Favorite Math Jokes

https://www.youtube.com/watch?v=zNQLCR0yz2A

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-11-13 · 20:11 UTC

We continue the series of videos of #G4G15 :

Robin Houston:
Polyhedra Whose Faces Meet at Right-Angles Except on One Edge

https://www.youtube.com/watch?v=eru0lAuqLzU

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-11-10 · 16:45 UTC

Continuing the series of videos of #G4G15 :

Scott Vorthmann: The Virtual Fifty-Nine Icosahedra

https://www.youtube.com/watch?v=NP4PN1tgGvU

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-10-30 · 22:20 UTC

We continue the series of videos of #G4G15 :

This is quite simply astonishing:

Bob Hearn:
The Magnetic Fifty-Nine Icosahedra

https://www.youtube.com/watch?v=pxsT-uavzug&list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x&index=2

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-10-29 · 14:22 UTC

We continue the series of videos of #G4G15 :

Greg Whitehead:
Nerd Sniped by the Hat Tile

https://www.youtube.com/watch?v=paYj4hEIsxk

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-10-27 · 21:55 UTC

We continue the series of videos of #G4G15 :

Amina Buhler-Allen:
Hyperspace Heroes 1: Odd Bedfellows

https://www.youtube.com/watch?v=7Hc9cHwtcQc

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-10-26 · 15:56 UTC

Chaim Goodman-Strauss:
The Hat Aperiodic Monotile

https://www.youtube.com/watch?v=PZw2lFws5oo

Video from #G4G15 ... there's some gorgeous stuff here.

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat

#mathedchat #mathed #mtbos #recmath #recreationalmath #recmaths

Colin the Mathmo @[email protected] · 2024-10-23 · 12:10 UTC

Eric Bates: Passing the Spark

Why do some people seem so natural on camera, while the rest of us feel awkward and inarticulate? This talk delves into the art of speaking to a camera and sharing your skills online...

https://www.youtube.com/watch?v=RWgs7bcpcJI

From the playlist:

https://www.youtube.com/playlist?list=PL5_D5QQxvWKUPpMY3eNV-PrIzh1uHlR8x

All part of the #G4G series of videos:

https://www.youtube.com/@G4GCelebration/playlists

Boosts welcome (if content to do so)

#RecreationalMaths #RecMaths
#RecreationalMath #RecMath
#MTBoS #MathEd #MathEdChat