K. P. Hart
@hartkp.bsky.social
Pythagoras zoekt een nieuwe hoofdredacteur:
www.wiskgenoot.nl/index.php?pa...
www.wiskgenoot.nl/index.php?pa...
Vacature hoofdredacteur Pythagoras
Pythagoras is een Nederlandstalig wiskundetijdschrift dat leerlingen van vwo en havo, en iedereen die jong van geest is, laat kennismaken met de leuke en uitdagende kanten van wiskunde. Het verschijnt...
www.wiskgenoot.nl
November 6, 2025 at 9:45 AM
Pythagoras zoekt een nieuwe hoofdredacteur:
www.wiskgenoot.nl/index.php?pa...
www.wiskgenoot.nl/index.php?pa...
Happy 350th birthday to the integral sign: fa.ewi.tudelft.nl/~hart/37/stu...
fa.ewi.tudelft.nl
October 29, 2025 at 11:04 AM
Happy 350th birthday to the integral sign: fa.ewi.tudelft.nl/~hart/37/stu...
Reposted by K. P. Hart
Farage: epic grifter
October 27, 2025 at 12:45 PM
Farage: epic grifter
Reposted by K. P. Hart
A neat tool I just came across: Viabundus, a digital road map of northern Europe 1350-1650, that lets you calculate contemporary travel routes/times. In 1500, going Amiens → Köln by horse took almost 7 days and 13 toll payments.
#medievalsky
www.landesgeschichte.uni-goettingen.de/handelsstras...
#medievalsky
www.landesgeschichte.uni-goettingen.de/handelsstras...
October 24, 2025 at 10:58 PM
A neat tool I just came across: Viabundus, a digital road map of northern Europe 1350-1650, that lets you calculate contemporary travel routes/times. In 1500, going Amiens → Köln by horse took almost 7 days and 13 toll payments.
#medievalsky
www.landesgeschichte.uni-goettingen.de/handelsstras...
#medievalsky
www.landesgeschichte.uni-goettingen.de/handelsstras...
De verhouding tussen de afstanden Aarde-Zon en Aarde-Maan afschatten. Hoe deed Aristarchus dat?
pyth.eu/aristarchus
pyth.eu/aristarchus
Pythagoras 65-1 | Aristarchus
Aristarchus van Samos bepaalde dat de verhouding tussen de afstanden Aarde-Zon en Aarde-Maan tussen 18 en 20 ligt. Hoe hij dat deed, gaan we hier zien.
pyth.eu
October 18, 2025 at 1:55 PM
De verhouding tussen de afstanden Aarde-Zon en Aarde-Maan afschatten. Hoe deed Aristarchus dat?
pyth.eu/aristarchus
pyth.eu/aristarchus
Connected, locally connected, not path-connected?
Take a Bernstein set:
mathoverflow.net/questions/50...
Take a Bernstein set:
mathoverflow.net/questions/50...
Example of connected, locally connected metric space that isn't path-connected?
I tried to construct a reasonable example for someone, meshing together various sorts of dust, but I either failed or wound up with sets whose separation properties are far too delicate for the stu...
mathoverflow.net
October 11, 2025 at 3:37 PM
Connected, locally connected, not path-connected?
Take a Bernstein set:
mathoverflow.net/questions/50...
Take a Bernstein set:
mathoverflow.net/questions/50...
Reposted by K. P. Hart
“Sommige mannen denken dus echt recht te hebben op het vrouwelijk lichaam en als ze het niet aan mogen raken, dan maken ze er een foto van om zich er dan samen met een roedel andere sukkels online op te verlekkeren.”
'Mannen die op deze sneue manier aan hun trekken komen, zijn afstotelijk'
'Het is vernederend om zonder toestemming op deze manier misbruikt te worden. Mannen die zich hieraan schuldig maken, zijn afstotelijk.'
www.linda.nl
October 8, 2025 at 12:18 PM
“Sommige mannen denken dus echt recht te hebben op het vrouwelijk lichaam en als ze het niet aan mogen raken, dan maken ze er een foto van om zich er dan samen met een roedel andere sukkels online op te verlekkeren.”
Alles wat ik tijdens de Nazomercursus 2025 verteld heb, en meer:
fa.ewi.tudelft.nl/~hart/onderw...
fa.ewi.tudelft.nl/~hart/onderw...
Nazomercurus 2025
fa.ewi.tudelft.nl
September 29, 2025 at 12:46 PM
Alles wat ik tijdens de Nazomercursus 2025 verteld heb, en meer:
fa.ewi.tudelft.nl/~hart/onderw...
fa.ewi.tudelft.nl/~hart/onderw...
Ahh, Samuel Pepys
Samuel Pepys' diary entry for this day in 1665 recalls a stay at Mrs Clerke's house, where he left a surprise (or two) in the chimney...
September 28, 2025 at 6:13 PM
Ahh, Samuel Pepys
Reposted by K. P. Hart
Readers reply: What would happen if politicians actually answered the question?
Readers reply: What would happen if politicians actually answered the question?
The long-running series in which readers answer other readers’ questions tackles what might occur if our elected representatives responded directly to questions put to them …
www.theguardian.com
September 28, 2025 at 5:29 PM
Readers reply: What would happen if politicians actually answered the question?
Reposted by K. P. Hart
Jimmy Kimmel's Monologue now has 14.3 MILLION VIEWS on YouTube.
It would be a shame for you to share it
www.youtube.com/watch?v=c1tj...
It would be a shame for you to share it
www.youtube.com/watch?v=c1tj...
Jimmy Kimmel is Back!
YouTube video by Jimmy Kimmel Live
www.youtube.com
September 24, 2025 at 7:37 PM
Jimmy Kimmel's Monologue now has 14.3 MILLION VIEWS on YouTube.
It would be a shame for you to share it
www.youtube.com/watch?v=c1tj...
It would be a shame for you to share it
www.youtube.com/watch?v=c1tj...
September 27, 2025 at 6:51 AM
Reposted by K. P. Hart
Big news: Internet Archive Europe ( @internetarchive.eu ) has opened its new HQ in Amsterdam! 🎉 A home for preservation, access & shared cultural heritage.
Read coverage from @mariabustillos.com in Flaming Hydra: flaminghydra.com/freedom-and-...
Read coverage from @mariabustillos.com in Flaming Hydra: flaminghydra.com/freedom-and-...
Freedom and Sharing at the Internet Archive Europe
On Friday, in a narrow, cream-painted 17th-century row house facing a wide canal bathed in golden light, the Internet Archive Europe celebrated the opening of its new headquarters in Amsterdam. Around...
flaminghydra.com
September 24, 2025 at 8:00 PM
Big news: Internet Archive Europe ( @internetarchive.eu ) has opened its new HQ in Amsterdam! 🎉 A home for preservation, access & shared cultural heritage.
Read coverage from @mariabustillos.com in Flaming Hydra: flaminghydra.com/freedom-and-...
Read coverage from @mariabustillos.com in Flaming Hydra: flaminghydra.com/freedom-and-...
Reposted by K. P. Hart
To ‘ultra-crepidate’ (19th century) is to lecture others on subjects you know very little about.
September 23, 2025 at 5:11 PM
To ‘ultra-crepidate’ (19th century) is to lecture others on subjects you know very little about.
Nog twee weken ...
platformwiskunde.nl/nazomercursus/
platformwiskunde.nl/nazomercursus/
Nazomercursus - PWN
(Voorheen de vakantiecursus) Nazomercursus 2025 voor wiskundeleraren een gezamenlijke activiteit van de Platforms Wiskunde Nederland en Vlaanderen Datums: Antwerpen: 19 en 20 september, Amsterdam: 26 ...
platformwiskunde.nl
September 7, 2025 at 11:28 AM
Nog twee weken ...
platformwiskunde.nl/nazomercursus/
platformwiskunde.nl/nazomercursus/
I had to laugh: trouble with smart-boards at the TU Delft due to a security up date from Microsh*t.
(Apparently world-wide ...)
(Apparently world-wide ...)
September 3, 2025 at 2:05 PM
I had to laugh: trouble with smart-boards at the TU Delft due to a security up date from Microsh*t.
(Apparently world-wide ...)
(Apparently world-wide ...)
@jonalendering.bsky.social ze zijn er weer
August 30, 2025 at 9:00 AM
@jonalendering.bsky.social ze zijn er weer
Here's a nice regular not completely regular space.
arxiv.org/abs/2508.13325
arxiv.org/abs/2508.13325
An Infinite Library
The purpose of this note is to describe a space that is regular but not completely regular, but only barely so: all closed sets are $G_δ$-sets and every singleton is a zero-set.
arxiv.org
August 20, 2025 at 5:40 PM
Here's a nice regular not completely regular space.
arxiv.org/abs/2508.13325
arxiv.org/abs/2508.13325