#recmath — Public Fediverse posts

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

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

UPDATE: My program found a new personal best most delayed palindromic number!

The 25-digit number 1102320000659911613429286 takes 235 iterations before it becomes a 123-digit palindrome.

This beats a former world record set in 2003 by Jason Doucette involving 233 iterations (source: https://jasondoucette.com/worldrecords.html#Most), and is 58 iterations off from the current world record of 293.

#Math #LychrelNumber #MostDelayedPalindromicNumber #Mathematics #RecMath #RecreationalMathematics

Update: New record! After appending random digit after random digit for two days, it eventually found this 31689-digit prime. It's larger than the 148091th number in the Fibonacci sequence, which is also prime.

The tiny white digits on the black background look like TV static when zoomed out!

#Math #Mathematics #PrimeNumbers #Primes #RecreationalMathematics #RecMath

Update: overnight it found a 17828-digit prime number, a new personal best!

I can see why most primes found are found with easy-to-write formulae like (2^p)-1 or (k^2^n)+1. Ttrying to go backwards – coming up with a compact formula to represent a really huge prime made up of random digits like this one, is really tricky.

#Math #Mathematics #PrimeNumbers #Primes #RecreationalMathematics #RecMath

Just for fun, I wrote a Python program to start with a random decimal digit, and keep adding the decimal digit until it reaches a prime number.

I'm excited to share it's found a 10997-digit long prime number, which is my new personal best largest prime! It's larger than the 37th factorial prime (3507!-1) which is 10912 digits.

I'll leave the program running overnight to see if it can find longer ones! :MOULE_Happy:

#Math #Mathematics #PrimeNumbers #Primes #RecreationalMathematics #RecMath

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

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

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

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

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

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

It's Maths Week England !!!!

https://mathsweekengland.co.uk/

#MWE2024 #MWE24 #MathsToday #MathsChat #MathsEd

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

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

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

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

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

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

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

Video from #G4G15 :

John Winston Garth: Cellular Auto-mon

https://www.youtube.com/watch?v=b_VR33eICoc

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

Video from #G4G15 :

Carolyn Yackel:
Depicting Catalan Solids on Temari Balls

https://www.youtube.com/watch?v=FQLdstg4Tiw

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

Video from #G4G15 :

Roy Leban:

Markov Algorithms and Life
https://www.youtube.com/watch?v=ieQdpBgt4DU

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

Video from #G4G15 :

Tom Rokicki:

The Speed of Light in the Game of Life

https://www.youtube.com/watch?v=AWDCNCszn-U

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

Video from #G4G15 :

David Michael Greene:
How Many Gliders Do You Really Need?

https://www.youtube.com/watch?v=W9ZR_4u38a4

Soon to be on 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

Another video from #G4G15 :

Alvy Ray Smith:
What Do the Theory of Computing and the Movies have in Common?

https://www.youtube.com/watch?v=CbXlg3GeIbQ

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

Another video from #G4G15 :

Jorge Nuno Silva:
Lewis Carroll's Game of Logic
https://www.youtube.com/watch?v=n6HZe4SIR60

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

Next video from #G4G15 :

Audrey Nasar:
Symmetry Card Game
https://www.youtube.com/watch?v=mWjUQKoO-OU

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

Next video from #G4G15 :

Jim Propp:
Industrious Dice, or, Pip-Pip Hooray!
https://www.youtube.com/watch?v=dLFr1SqvkQQ

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

Next video from #G4G15 :

Jeanette Shakalli:
FUNDAPROMAT: A Free Source for Math Enthusiasts
https://www.youtube.com/watch?v=pRS-iqJ1-1o

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

Another video from #G4G15 :

John Harris:
Puzzle Variations from a Rod Bentley Text
https://www.youtube.com/watch?v=pRDIOLdQJvE

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

Next video from #G4G15 :

Bill Cheswick:
Paul Erdos' Brain was in Town
https://www.youtube.com/watch?v=XvzAQdjQ4d0

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

Next video from #G4G15 :

Eleftherios Pavlides:
Polymorphic Elastegrity (PE): From Recreational Paper Folding to the Tree of Polymorphisms
https://www.youtube.com/watch?v=qnP6jRtGLyY

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

Video from #G4G15 :

Robert Pope Vermillion: The Impossible 3000.1
https://www.youtube.com/watch?v=Dds2gFpWv8w

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

Inna Zakharevich:
Computing with Paper

https://www.youtube.com/watch?v=G3XU1PSwVRw

A video from #G4G15

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

Video from #G4G15 :

Thomas Draper:
Monoidal Categories for Modelling Physical Systems and Language
https://www.youtube.com/watch?v=3OLr_WAgQuQ

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

Another video from #G4G15 :

Woody Aragon: Sleight of Math
https://www.youtube.com/watch?v=sOmN_0O_E4s

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

It is inevitable as time goes by that we lose people from the #G4G community. This video from #G4G15 remembers some of our most recent losses.

G4G Tributes
https://www.youtube.com/watch?v=bs74-ioxPfI

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

The talks from G4G are recorded and made available ... here's another one from #G4G15 :

Eliza Gallagher, 9x9 Project:
Building Math Identity One Digit at a Time
https://www.youtube.com/watch?v=zrK4uZDrfOk

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

Child's (12) maths teacher gave them the "2024 Challenge" - which is the Four Fours challenge (https://en.wikipedia.org/wiki/Four_fours) with the digits 2, 0, 2 & 4.

Of course I had to give it a go. I tried to keep the digits in that order, red formulae are where I failed.

Any corrections or improvements welcome!

#math #maths #MathsMonday #RecMath #RecreationalMathematics