Simon Blackburn's Avatar

Simon Blackburn

@simonrblackburn.bsky.social

Combinatorics, Algebra, Cryptography. Professor of Pure Mathematics at Royal Holloway University of London. Maths enthusiast. Cat enthusiast. Woking Rail Enthusiast.

396 Followers  |  442 Following  |  105 Posts  |  Joined: 16.10.2023  |  2.3164

Latest posts by simonrblackburn.bsky.social on Bluesky

Post image Post image

Laws of thought: George Boole, influential mathematician, born #OTD 1815; Boolean logic laid foundation for computers & Information Age.
University College Cork

02.11.2025 06:00 โ€” ๐Ÿ‘ 70    ๐Ÿ” 12    ๐Ÿ’ฌ 3    ๐Ÿ“Œ 1
Cartoon of a train passing through a city. In the windows of the train can be seen the little heads of ducks. Caption: "Ducklands Light Railway"

Cartoon of a train passing through a city. In the windows of the train can be seen the little heads of ducks. Caption: "Ducklands Light Railway"

www.worldofmoose.com/collections/...

31.10.2025 10:18 โ€” ๐Ÿ‘ 204    ๐Ÿ” 32    ๐Ÿ’ฌ 4    ๐Ÿ“Œ 2
Print featuring a stylised image of a farmer ploughing a curving field with horses beside large trees

Print featuring a stylised image of a farmer ploughing a curving field with horses beside large trees

Fall of the Leaf, 1934
By printmaker Sybil Andrews (Canadian (born England)
Color linocut on Japanese paper #ReframingWomenPrintmakers

26.10.2025 06:48 โ€” ๐Ÿ‘ 881    ๐Ÿ” 142    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 3
Video thumbnail
24.10.2025 10:49 โ€” ๐Ÿ‘ 914    ๐Ÿ” 171    ๐Ÿ’ฌ 10    ๐Ÿ“Œ 13
a sleepy tuxedo cat

a sleepy tuxedo cat

a circle

a circle

a purrfect circle

24.10.2025 10:49 โ€” ๐Ÿ‘ 1047    ๐Ÿ” 168    ๐Ÿ’ฌ 7    ๐Ÿ“Œ 3
Preview
Time Immemorial turns 750: The Medieval law that froze history at 1189 Youโ€™ve probably heard of the phrase โ€œtime immemorialโ€ as a general term for events that happened a very long time ago, but in fact, it has a specific meaning, and this year is its 750th anniversary.

Youโ€™ve probably heard of the phrase โ€œtime immemorialโ€ as a general term for events that happened a very long time ago, but in fact, it has a specific meaning, and this year is its 750th anniversary.

www.ianvisits.co.uk/articles/tim...

23.10.2025 06:43 โ€” ๐Ÿ‘ 26    ๐Ÿ” 7    ๐Ÿ’ฌ 2    ๐Ÿ“Œ 1

This remains the funniest way to hear about an internet outage, though.

20.10.2025 08:41 โ€” ๐Ÿ‘ 7819    ๐Ÿ” 2370    ๐Ÿ’ฌ 45    ๐Ÿ“Œ 87
Video thumbnail

a very spooky tutorial

18.10.2025 12:53 โ€” ๐Ÿ‘ 1020    ๐Ÿ” 203    ๐Ÿ’ฌ 21    ๐Ÿ“Œ 12

This morning my ChatGPT quota was inexplicably exhausted.

It took a while but I pieced it together. Voice mode somehow got activated when I went to bed.

The bot then engaged in a 10 hour conversation with my snoring dog, answering questions the pup wasnโ€™t asking and praising him for his insight.

18.10.2025 09:04 โ€” ๐Ÿ‘ 3331    ๐Ÿ” 580    ๐Ÿ’ฌ 94    ๐Ÿ“Œ 84

Professors *never* supply information. Students arenโ€™t paying premium prices for โ€˜informationโ€™ at all. How can people who presumably have attended universities misunderstand their role so badly?

16.10.2025 14:16 โ€” ๐Ÿ‘ 178    ๐Ÿ” 47    ๐Ÿ’ฌ 11    ๐Ÿ“Œ 10

Top tip: Cheer up your garden library with some laurel and hardy annuals.

16.10.2025 19:19 โ€” ๐Ÿ‘ 179    ๐Ÿ” 21    ๐Ÿ’ฌ 4    ๐Ÿ“Œ 0
Post image Post image

There is no need for a moral panic about the UK's welfare system.

Far from perfect but recent discourse is nuts

Spending is controlled, not spiralling

Worklessness is near record lows

My column www.ft.com/content/ee67...

15.10.2025 12:35 โ€” ๐Ÿ‘ 759    ๐Ÿ” 441    ๐Ÿ’ฌ 27    ๐Ÿ“Œ 45
A comic strip in six panels. The panels inerlock like a jigsaw with knobs and sockets. Two stick figures walk right to left through all the panels.

Panel 1: Person 1 says "I hear you're working on a new theory."
Panel 2 & 3: Person 2 says: "Yes, I'm calling it the jigsaw model. I think it could change our whole View of reality."
Panel 4: Person 1 says "When Will you publish?:
Panel 5: Person 2 says "But a couple of things are still bothering me." (this piece/panel is a bit squint) 
Panel 6: This piece is rotated ninety degees and fits to the others very badly. Person 2 is saying "Soon. I feel like I'm really close"
A second look at the whole comic shows that the last two panels read in the wrong order because the jigsaw has been put together incorrectly.

A comic strip in six panels. The panels inerlock like a jigsaw with knobs and sockets. Two stick figures walk right to left through all the panels. Panel 1: Person 1 says "I hear you're working on a new theory." Panel 2 & 3: Person 2 says: "Yes, I'm calling it the jigsaw model. I think it could change our whole View of reality." Panel 4: Person 1 says "When Will you publish?: Panel 5: Person 2 says "But a couple of things are still bothering me." (this piece/panel is a bit squint) Panel 6: This piece is rotated ninety degees and fits to the others very badly. Person 2 is saying "Soon. I feel like I'm really close" A second look at the whole comic shows that the last two panels read in the wrong order because the jigsaw has been put together incorrectly.

My cartoon for this weekโ€™s @newscientist.com

12.10.2025 09:25 โ€” ๐Ÿ‘ 1419    ๐Ÿ” 394    ๐Ÿ’ฌ 16    ๐Ÿ“Œ 16

We are realizing that we have no idea what British people think a โ€œflapjackโ€ is.

10.10.2025 22:24 โ€” ๐Ÿ‘ 191    ๐Ÿ” 18    ๐Ÿ’ฌ 38    ๐Ÿ“Œ 26
LinkedIn result for their Pinpoint game: Solved in 2. Today's average: 45461.

LinkedIn result for their Pinpoint game: Solved in 2. Today's average: 45461.

What kind of average are LinkedIn using here? (This is a you-have-five-guesses game.) #MathSky

09.10.2025 13:06 โ€” ๐Ÿ‘ 2    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Just before he died I got to chat to Brian Clemens as part of a press junket for a remaster of The Professionals.

After about 3 polite-but-bored answers I said:

"Okay would you mind if we spent the rest of this talking about 'Bugs'? That show BLEW ME AWAY as a teen."

And he was so happy he cried.

06.10.2025 15:39 โ€” ๐Ÿ‘ 201    ๐Ÿ” 28    ๐Ÿ’ฌ 9    ๐Ÿ“Œ 2
Red mushrooms on a pinecone and pine needle covered ground. Lots of browns. Autumn is lovely.

Red mushrooms on a pinecone and pine needle covered ground. Lots of browns. Autumn is lovely.

Mushrooms seen on Horsell common this morning. Autumn has arrived.

05.10.2025 14:21 โ€” ๐Ÿ‘ 3    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Post image

Billy Bragg has started a โ€˜reclaim the lamppostsโ€™ campaign and is happy to supply these stickers for you to attach to lampposts with flags on. If you want to call the Xenophobes out then send a stamped, self-addressed envelope to Billy Bragg at Bragg Office PO Box 6830, Bridport DT6 9BH

04.10.2025 19:03 โ€” ๐Ÿ‘ 191    ๐Ÿ” 91    ๐Ÿ’ฌ 6    ๐Ÿ“Œ 3
3 smiling people stand in front of the Victorian marvel that is Founders Building, and (out of sight) a couple of floors above a lovely coffee shop.

3 smiling people stand in front of the Victorian marvel that is Founders Building, and (out of sight) a couple of floors above a lovely coffee shop.

Keith Martin and I welcoming combinatorialists Doug Stinson (from Waterloo, Canada) and Maura Paterson (from Birkbeck) to Royal Holloway for the day. It was great to see them!

02.10.2025 13:36 โ€” ๐Ÿ‘ 5    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

One of my favourites is a tangram-like calendar puzzle, such as here: bit.ly/4o1TyXO

01.10.2025 09:58 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
A blue skylight at the centre of an ornate dome in Teatro Massimo, Palermo. A single line bounces around a circle, forming a 7 pointed star. The skylight is surrounded by a beautiful wide gold band, and then by a cream band decorated with dancing figures. This room is famous for its strange accoustic, but it should be famous amongst experimental design theorists.

A blue skylight at the centre of an ornate dome in Teatro Massimo, Palermo. A single line bounces around a circle, forming a 7 pointed star. The skylight is surrounded by a beautiful wide gold band, and then by a cream band decorated with dancing figures. This room is famous for its strange accoustic, but it should be famous amongst experimental design theorists.

I just love it when 2 is coprime to 7!
(Teatro Massimo, Palermo, Sicily.)
#MathSky

29.09.2025 11:13 โ€” ๐Ÿ‘ 6    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Post image

It's all happening for us train enthusiasts (or is it just me?) as today marks 200 years since the Stockton and Darlington Railway opened in 1825 - the birth of the modern railway.
So here are some of the many railway linocuts I have done over the years - too many, I hear you say? Surely notโ€ฆ ๐Ÿ˜‚

27.09.2025 14:59 โ€” ๐Ÿ‘ 433    ๐Ÿ” 106    ๐Ÿ’ฌ 30    ๐Ÿ“Œ 11
The prototype used to develop the Apple 1. The wooden case is adapted from a breadbox (the holes for mounting on a wall and some of the hardware for the sliding cover is still visible), the wiring is hand-soldered, giant Sprague capacitators like yellow soda cans are along the back, and the chips are hand-placed in a grid.

The prototype used to develop the Apple 1. The wooden case is adapted from a breadbox (the holes for mounting on a wall and some of the hardware for the sliding cover is still visible), the wiring is hand-soldered, giant Sprague capacitators like yellow soda cans are along the back, and the chips are hand-placed in a grid.

Apple 1 - Prototype

27.09.2025 12:05 โ€” ๐Ÿ‘ 163    ๐Ÿ” 25    ๐Ÿ’ฌ 3    ๐Ÿ“Œ 3
Post image

This morningโ€™s endeavour in the Peak District. Two minutes of undeniably glorious light. Autumn getting off to a decent start and Iโ€™m trying to get back into the swing of sunrise.

26.09.2025 19:42 โ€” ๐Ÿ‘ 165    ๐Ÿ” 20    ๐Ÿ’ฌ 6    ๐Ÿ“Œ 0
Panel 1
 The shallow end of a swimming pool. A swimmer says "I got tired of hearing About so-called 'Infinity pools', so I created a genuine one. This is my first length". 
"Good luck!" replies an onlooker standing by the steps.

Panels 2-4
The onlooker waits for the swimmer to come back. Time passes. The sun sets and rises. the onlooker ages.
 
 Panel 5
"Impressive." says the onlooker, now old and walking with a stick.

Panel 1 The shallow end of a swimming pool. A swimmer says "I got tired of hearing About so-called 'Infinity pools', so I created a genuine one. This is my first length". "Good luck!" replies an onlooker standing by the steps. Panels 2-4 The onlooker waits for the swimmer to come back. Time passes. The sun sets and rises. the onlooker ages. Panel 5 "Impressive." says the onlooker, now old and walking with a stick.

A recent cartoon for @newscientist.com

p.s. my new book of science cartoons 'Physics for Cats' is out now. Visit www.tomgauld.com for details

26.09.2025 12:49 โ€” ๐Ÿ‘ 577    ๐Ÿ” 125    ๐Ÿ’ฌ 2    ๐Ÿ“Œ 5
Cartoon of five men and a duck in a police lineup. A police officer says to a witness "Do you recognise the person who stole your bread?"

Cartoon of five men and a duck in a police lineup. A police officer says to a witness "Do you recognise the person who stole your bread?"

Line up

www.worldofmoose.com/products/lin...

26.09.2025 11:30 โ€” ๐Ÿ‘ 102    ๐Ÿ” 21    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 1
Preview
Where now for the REF? The Research Excellence Framework has been postponed for three months โ€˜to take stock and ensure alignment with the UK governmentโ€™s priorities and vision for higher educationโ€™. But how radical should t...

Where now for the REF? Five very different views on how radical the changes should be www.timeshighereducation.com/depth/where-...

26.09.2025 10:40 โ€” ๐Ÿ‘ 2    ๐Ÿ” 4    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0

Alt text: Pinpoint LinkedIn game lists 'Subjects in Mathematics'. Combinatorics is pride of place, at the top, just as it deserves.

24.09.2025 15:41 โ€” ๐Ÿ‘ 0    ๐Ÿ” 0    ๐Ÿ’ฌ 0    ๐Ÿ“Œ 0
Post image

Glad to see Maths, and especially Combinatorics, recognised by LinkedIn earlier this week! #MathSky

24.09.2025 15:35 โ€” ๐Ÿ‘ 1    ๐Ÿ” 0    ๐Ÿ’ฌ 1    ๐Ÿ“Œ 0
The former Corus Redcar Steelworks at night

The former Corus Redcar Steelworks at night

The Teesside Steelworks once stretched along the south bank of the River Tees from Middlesbrough to Redcar. At its peak, 91 blast furnaces operated within ten miles, but by the late 1970s only one remained. The Redcar blast furnace, opened in 1979 near the riverโ€™s mouth, was then

22.09.2025 16:24 โ€” ๐Ÿ‘ 34    ๐Ÿ” 6    ๐Ÿ’ฌ 3    ๐Ÿ“Œ 2

@simonrblackburn is following 20 prominent accounts