Philosophy

(english/german below) **Bitcoin Pizza Dag!** Op 22 mei 2010 betaalde programmeur Laszlo Hanyecz 10.000 BTC voor twee pizza's — de eerste gedocumenteerde aankoop met bitcoin. Hij plaatste een bericht op een forum waarin hij BTC aanbood voor pizza; een andere gebruiker ging akkoord, bestelde de pizza's en leverde ze af. Die transactie werd later bekend als "Bitcoin Pizza Day". Laszlo bewees dat Bitcoin als ruilmiddel gebruikt kan worden. **Sluit je bij ons aan voor pizza-avond bij De Pizzabakkers! (vanaf 18:00)** RSVP zo snel mogelijk; we moeten reserveren bij De Pizzabakkers en er is beperkte plek. Zorg dat je je geladen Lightning-wallet meeneemt! *** **English: Bitcoin Pizza Day!** On May 22, 2010, programmer Laszlo Hanyecz paid 10,000 BTC for two pizzas — the first documented purchase using bitcoin. He posted on a forum offering BTC for pizza; another user accepted, ordering pizzas and delivering them. That trade later became famous as "Bitcoin Pizza Day," Laszlo proved that Bitcoin can be used as a medium of exchange. **Join us for pizza diner at De Pizzabakkers! (from 18:00)** Please RSVP as quick as possible as we need to make a reservation at De Pizzabakkers and there is only limited space. Be sure to bring your loaded lighting wallet along with you! *** **Deutsch: Bitcoin Pizza Tag!** Am 22. Mai 2010 zahlte Programmierer Laszlo Hanyecz 10.000 BTC für zwei Pizzen — der erste dokumentierte Kauf mit Bitcoin. Er postete in einem Forum und bot BTC für Pizza an; ein anderer Nutzer akzeptierte, bestellte die Pizzen und lieferte sie aus. Dieser Tausch wurde später als "Bitcoin Pizza Day" bekannt. Laszlo bewies, dass Bitcoin als Tauschmittel verwendet werden kann. **Begleite uns zum Pizza-Abend bei De Pizzabakkers! (ab 18:00)** Bitte antworte so schnell wie möglich; wir müssen bei De Pizzabakkers reservieren und es gibt nur begrenzten Platz. Nimm unbedingt deine geladene Lightning-Wallet mit!

We'll start into the weekend with some Sport and what is better than having a bike tour on Friday 22nd May? If you'd like to bike along, sign up here! We expect this to take about 4 to 5 hours. On the route, we will see at least two beautiful castles, and we’ll have a pause in Breukelen where we will get a snack! **This tour is for everyone. You don't have to prepare anything, it's enough to be at the bike rental at the time.** The following information is for the curious: You can see the [tour](https://www.komoot.com/de-de/tour/2884792439?share_token=aCVbZHeYrkmmS52GP5uwrR7Q3EweCrOv65hA2MpYgtf4nSaL8V&ref=wtd) on the app [Komoot](https://www.komoot.com/). It's approx. 46km, **we may adapt it as a group on the day. As last year we’re very flexible and adaptive!** The bike rental is payed by Stichting Rust Nederland. Many thanks to Erik Jonkers for the sponsoring and to Jana Dönszelman for helping with the meetup page and organization. **Agenda** 1. We'll meet at the bike [rental place](https://willemstraatbike.nl/contact/) it is near to the conference venue. (5 Minutes by bike) 2. Everyone receives their bike. 3. We’ll go over “Hogeweidebrücke” 4. We’ll see Kasteel Nijenrode and get a snack at the marketplace of Breukelen 5. We’ll see Schloss Zuylen 6. We ride back to Utrecht and return the bikes! Looking for more fun things to do during RustWeek? Take a look at our activities page: [https://2026.rustweek.org/events/social-activities/](https://2026.rustweek.org/events/social-activities/)

Discover Utrecht on foot with our friendly tour guides! This tour will take place at 10:00 AM on Friday, the 22nd of May, and will take one and a half hours (until 11:30 AM). There are 35 spots available. The tour is free of charge for RustWeek attendees. The tour starts at Kinepolis (the conference venue). Feel free to join our Discord at https://discord.gg/FSwaWZdk6k if you have questions! Our Discord and the RustWeek website, https://2026.rustweek.org/events/social-activities/, offer more activities.

*Since the guided meditations for this event are in Dutch, this description is too.* Wil je je drukke week afsluiten en ontspannen aan het weekend beginnen? Dan ben je geheel vrijblijvend welkom bij de vrijdagavond meditatie van [Jewel Heart](https://www.jewelheart.nl/). Deze meditatieavond heeft een licht en open karakter. De meditaties bestaan uit drie delen. We beginnen met het gewaarworden van je lichamelijke sensaties. In een korter deel twee doen we een loopmeditatie en in deel drie is er een eenvoudige, geleide visualisatie meditatie. Het geheel wordt afgesloten met een gesprek onder het genot van een kop thee, voor wie daar zin in heeft. 📍[Jewel Heart, Hatertseveldweg 284, Nijmegen](https://maps.app.goo.gl/D4FzqLbkaqs2JNDG8). Loop de oprit op en dan is de ingang aan je rechterzijde 🕒Zaal open vanaf 19.30 uur, meditatie van 20.00 tot 21.00 Je bent van harte welkom! Aan deze activiteit kun je per keer meedoen. Er zijn geen verplichtingen. Op vrijwillige basis kun je op de avond zelf een donatie doen. Kijk ook naar onze -[Open activiteiten](https://www.jewelheart.nl/nl/open-activiteiten/) -[Cursussen](https://www.jewelheart.nl/nl/cursussen-overzicht/)

**Please note: the new name of the bar is GOTO. On Google Maps it's still Bloemerbar.** **Join us for Maytime Drinks for Expats & Locals!** The days are getting longer, the weather is warming up, and it’s the perfect time to meet new people! ☀️ Join us for Maytime Drinks for Expats & Locals and enjoy a laid-back evening of great conversations, cultural exchange, and new friendships. **What to expect** * A lively and inclusive atmosphere to enjoy good company. * Conversations with a diverse mix of locals and internationals. * A laid-back evening of cultural exchange, friendships, and fun. **Who should join** * **Expats** looking to expand their social circle and make new friends. * **Locals** eager to share their culture and connect with an international crowd. * **Anyone** looking for a relaxed, social evening filled with great energy and good vibes. Don't miss out - **RSVP now** and join us for an unforgettable evening! Join the WhatsApp group: brand.page/expatslocalswhatsapp Follow us on Instagram: instagram.com/expats.locals Become a Welcomer: https://www.expatslocals.com/become-a-welcomer

[Get your tickets here!](https://ccu.stager.co/shop/default/events/111653443?utm_campaign=more-than-human-meetup&utm_source=meetup) Creative Coding Utrecht invites you to an evening of presentations and discussion on artistic and research projects at the intersection of AI, bioacoustics, and symbiotic relations. This meet-up explores more-than-human intelligences: how algorithms, birds, and other beings interact, communicate, and co-create. The event foregrounds the act of listening as a relational practice, one that spans species and technologies. **Presentations:** **BioacousticAI** This project develops deep learning methods for wildlife sound monitoring, enabling more precise and scalable assessments of animal populations. By analysing acoustic data, BioacousticAI contributes to biodiversity research and conservation efforts, offering new ways to “hear” ecosystems and their inhabitants. *Presented by Céline Angonin, a researcher and musician whose work bridges machine learning and bioacoustics, with a focus on the sonic dimensions of ecological systems.* **Chorusing Symbionts** An investigation into interspecies music, this project bridges humans, robots, and animals through ecoacoustics and embodied interaction. Inspired by AI and bioacoustic research, it proposes a form of “sensorial science-fiction,” where artificial creatures evolve in symbiotic relationship with their natural counterparts, blurring boundaries between organic and synthetic life. *Presented by Matteo Holyoke Marangoni, an artist whose practice integrates music, visual art, robotics, and new technologies to create immersive, multisensory environments.* **Vogelluisterstation** A sensor station that records, analyses and visualises bird sounds, making them accessible to both citizen scientists and professionals. The project aims to democratise ecological data, offering insights into local bird activity while lowering technical barriers to engagement with non-human worlds. *Presented by Niels Jansen, an artist, creative coder, and educator whose work explores digital improvisation in music, dance, and interactive installations.* **Program:** 19:30 - doors open 20:00 - presentations 20:45 - break 21:00 - Q&A 21:30 - informal drinks 22:00 - end event [Get your tickets here!](https://ccu.stager.co/shop/default/events/111653443?utm_campaign=more-than-human-meetup&utm_source=meetup)

Join us for a fun Friday night of improv theatre in English. Play, laugh, and meet new people in Utrecht during this welcoming drop-in workshop led by Burgert Kirsten, one of Improv Utrecht’s professional trainers. Everyone is welcome. You do not need any acting experience, and you do not need to be fluent in English. Many participants are not native speakers. Each week, several people join for the very first time, alongside regulars who come back again and again. Expect a group of around 12 to 22 people in total. What to expect Meet a mix of international and Dutch players Learn the basics of improvisation, a valuable modern skill Play fun and accessible theatre games Laugh a lot and surprise yourself along the way Practical information Doors open between 19:50 and 20:00. Please enter together with the group. Workshop time is from 20:00 to 22:00. Full details and route description can be found at www.improvutrecht.nl/drop-in-workshops. After the workshop, people usually head together to the pub De Hondekop for a drink and a chat. How to sign up Please mark yourself as attending via our website at at [www.improvutrecht.nl/drop-in-workshops.](http://www.improvutrecht.nl/drop-in-workshops.) If you can no longer attend, remember to remove your signup so someone else can take your spot. Price Suggested donation €10 to €20, payable in cash or via Tikkie. If you are not able to pay much, you are still very welcome. Pay what you can or what you felt the workshop was worth. Your contribution helps cover the room rental and the professional trainers. Curious about more? Check out our improv courses at [https://www.improvutrecht.nl](https://l.facebook.com/l.php?u=https%3A%2F%2Fwww.improvutrecht.nl%2F%3Ffbclid%3DIwZXh0bgNhZW0CMTAAYnJpZBExYzVUWUpNcUx3Qmxyc0tCNnNydGMGYXBwX2lkEDIyMjAzOTE3ODgyMDA4OTIAAR4aOuBKx2VBkJDoGyYCRHQXSTHuVoJHy0WS1bZAftQYuSLPcNgmTQeaBv4hpw_aem_5jJND0IPMoJD8mXqM4l2SA&h=AT0HQGS9N7lDDerT4Jh2s7yQZ3yqXcU3N7DHXcnh_ArhUbPBNnFc1Vs5ILLXJTm8W6M0qWOaOlvHeCdiG9IvYCgONK3G7Mx7YP3_ERn_wSRix-AtI5wPA8WvGq1ijPS5zLOaIIFzJ3kK6yajLPE&__tn__=q&c%5B0%5D=AT0toyw-m6q1Kl9A4pude9T05YHtdW_ajvYBWe_MixS8-d0JBdNz089yFCaZxIjsj41oPDYTZr-pLoVp3Nbw6oS2l-b59hWsbjVnOl__PH25Cx3iZDHpMxmtl8_kxDTepak27ZG-3b10bx8fSuh2QAJtRaEuxCrWtVE) Tickets for courses via [https://improv-utrecht.weticket.io](https://improv-utrecht.weticket.com/?fbclid=IwZXh0bgNhZW0CMTAAYnJpZBExYzVUWUpNcUx3Qmxyc0tCNnNydGMGYXBwX2lkEDIyMjAzOTE3ODgyMDA4OTIAAR7kmRsV6LQrIsZqtZLBNbCbr9_NHgu23lRTafAiyzXQMBjXirebJNUXyW7-Jg_aem_Ps3bRMMWxOjgfL78fqIL8w) Follow Improv Utrecht Meetup [https://www.meetup.com/utrecht-improv-theater](https://www.meetup.com/utrecht-improv-theater?fbclid=IwZXh0bgNhZW0CMTAAYnJpZBExYzVUWUpNcUx3Qmxyc0tCNnNydGMGYXBwX2lkEDIyMjAzOTE3ODgyMDA4OTIAAR4aOuBKx2VBkJDoGyYCRHQXSTHuVoJHy0WS1bZAftQYuSLPcNgmTQeaBv4hpw_aem_5jJND0IPMoJD8mXqM4l2SA) Instagram @improvutrecht Facebook https://facebook.com/ImprovUtrecht

We are continuing our discussion of Ludwig Wittgenstein’s *Philosophical Investigations*. Ludwig Wittgenstein was a 20th century philosopher who aimed to demonstrate that philosophical problems arrise from misunderstandings in language. The solution to these problems is found through insight into the workings of language - effectively dissolving them, rather than solving them. Before we get to these contemplations, we need to first have a proper look at language and how it is learned and taught. In our first discussion we alternated between feeling confused and thinking: this is just... common sense? Maybe that's what Wittgenstein intended, maybe not - let's keep going! The plan for the next discussion is: * Finish the remaining remarks from last time: **27–64** * Discuss new remarks: **65–77** Please prepare by (re)reading the aforementioned remarks! Have fun!

Come along, lovely queer hikers! 🌿✨ This time we’re serving an easy-going queer nature moment with a short loop through **Landgoed Heidestein** near Zeist. Think dreamy forest paths, shimmering fens, a peaceful forest pond, and heather fields - a lot of diversity for such a short walk :) We’re teaming up with **Cocktail (COC’s group for LGBTQIA+ refugees & asylum seekers)** for this event, so besides soaking up nature, we’re creating space for connection, sharing stories, and learning from each other’s journeys and experiences. Expect a vibe that’s part hike, part picknick, part wholesome community exchange. 🌈 Bring your snacks and blankets, as we’ll pause along the way for a relaxed picnic moment together. Because queer joy isn’t just about where we go, but who we walk with. 💖 **Practical info** 📏 **Distance:** 5 or 7 km (loop walk) 📍 **Start:** Bus stop Prinses Margrietlaan, Zeist (5km option) Driebergen-Zeist station (7km option) 🏁 **End:** Back at the starting point 🥾 **Level:** easy - chill pace 🤝 **Meeting point:** outside the train station **Driebergen-Zeist at 13:45** or bus stop **Prinses Margrietlaan (Zeist) at 14:20** ❗You’re welcome to join from another direction. If you come by car you can park at P+R Driebergen-Zeist. Please note: we published this hike with Cocktail simultaneously, which is also why we lowered the participant number from Hiking Queer NL's side. Pack your: 🍱 snacks 🚰 water 🧥 rain coat/umbrella ☀️ sun screen 🏳️‍🌈 anything else you might need ❌ If you signed up and cannot make it in the end, please cancel your RSVP attendance so we know how many people will show up and someone else can take your place instead. 💗 A voluntary donation helps us to keep the Meetup group up and running :) you can either pay via a Tikkie or in cash after we finish the hike. *Hiking Queers Netherlands & Cocktail (COC)*

Join us for a relaxed and friendly matcha tasting meetup. I’ll bring matcha for everyone to try, and you’re welcome to bring your own snacks and drinks, including alcohol if you like. This is a casual event for meeting new people, enjoying Japanese tea culture, and spending a cozy afternoon together. Beginners are very welcome. Free to join.

**Modern and Authentic kintsugi workshop in Utrecht.** Choose from three options: * 1-Day Modern Kintsugi workshop-€60 * 2-Day Modern Kintsugi workshop-€96 * 4-Day Authentic Kintsugi workshop -€180 For all details, please visit my website. [https://japanworkshopnet.com/upcoming-workshops/](https://japanworkshopnet.com/upcoming-workshops/) Location: **CLAY TO PLATE** [Biltstraat 55, 3572 AG, Utrecht](https://www.claytoplate.com/) **Booking is essential**. Please contact me if you would like to participate in the workshop. Email: info@japanworkshopnet.com Mobile:0616059840

Come and join us for an evening of Buddhist meditation with like-minded people. The doors open at 7:00 PM, and meditation begins promptly at 7:15 PM. The meditation will last between 30 to 40 minutes, followed by tea and biscuits for anyone who would like to stay and chat. On some evenings, there will also be a short Dharma talk to provide some Buddhist context. The meditation space is down at the canal. To get there, you can take the stairs down. The meditation is offered on a donation basis. See our [website](https://utrechtbuddhistcentre.nl/) for more information.

*Since this day will be in Dutch, this description is too.* **Ontdek de kracht van stilte** *“De innerlijke kracht van stilte, verkregen vanuit een diepe gronding van lichaam en geest, schept de basis voor ware vrede en harmonie.”* – Gelek Rimpoche Een paar keer per jaar organiseren we op zondag een bijzondere dag van meditatie en verstilling. Even weg van de drukte, om tot rust te komen en opnieuw contact te maken met je eigen adem, je lichaam, je innerlijke stilte. We doen dit door middel van bodyscans, mindful bewegen, zit- en loopmeditatie, inspirerende teksten en uitwisseling met elkaar. Ook de lunch (zelf meenemen) gebruiken we als oefening in bewust aanwezig zijn - in stilte. Of je nu veel mediteert of helemaal aan het begin staat - je bent welkom zoals je bent. *Misschien is dit zo’n dag waar jij aan toe bent? Je bent van harte uitgenodigd.* **Datum:** Zondag 21 september 2025 **Plaats:** Jewel Heart, Hatertseveldweg 284, Nijmegen. **Tijd**: 10.30u-16.00u (inloop vanaf 10.00 uur) **Bijdrage**: Jewel Heart-leden kunnen gratis deelnemen. Niet-leden betalen € 30,- Aanmelden graag vóór vrijdag 22 mei 16.00 uur via info@jewelheart.nl Kijk ook naar onze andere [open activiteiten](https://www.jewelheart.nl/nl/open-activiteiten/) en [cursussen](https://www.jewelheart.nl/nl/cursussen-overzicht/)

**Welcome to Drunken Philosophy** a casual, curious social discussion **Optional topic for this meetup: What's up with all the AI hate?** A recent survey found that 74% of Americans have a negative view of AI, and I want to know why. Come out and debate whether AI is good or bad. My hot take: a labor-saving tool that could potentially help cure cancer gets called dangerous because it might raise unemployment or cause a speculative investment bubble, that tells you a lot more about capitalism and the economic system we live under than it does about the tool itself. As a computer programmer, I think AI is a wonderful tool that has increased my productivity by at least an order of magnitude. I'd go so far as to say Claude Code is the best tool I have ever used. Debate me and name a better one. Is AI potentially dangerous? Yes, but so are a lot of tools. Chainsaws. Steam engines (early ones would occasionally explode and kill everyone in the room). Do you think cavemen sat around debating whether fire could be used as a weapon or for self-harm, and decided not to discover it? I have two friends who hate AI for opposite reasons: one thinks it's a fad and not useful, and the other thinks it's going to take over everything and cause human extinction. Come out tonight, have a friendly debate, and make some friends. No lectures. Friendly crowd. Drop in for one drink and stay if it's fun.

Main Library, Meeting Room 2B Join us for a welcoming evening of reflection, gentle music, and meaningful conversation. We’ll begin with a short grounding moment, followed by a brief reading from spiritual or philosophical traditions, and an open reflection circle where participants can share (or simply listen). Libera Animae is an interfaith community focused on inner growth, creativity, and authentic connection. All backgrounds are welcome.

NOTICE CHANGE OF LOCATION. WE WILL BE MEETING AT THE SHARON WOODS METRO PARK - THIS MONTH ONLY. Sharon Woods Metro Park, 6911 Cleveland Ave, Westerville, OH 43081 Enter the park from Cleveland Avenue and stay on the main park drive until it dead-ends into a turn around parking lot. We will meet at the Schrock Lake Shelter just off this parking area to the right. We will be taking a Guided Walk with access very near the shelter, on the Edward S Thomas trail, an ADA flat, hard-packed gravel surface trail. This walk will be led by Carrie Keller, Outdoor Naturalist at the park, and Megan Richley, Inclusion Coordinator for the Metro Parks. Wear sneakers or other shoes covering the entire foot. Sandals or flip-flops are ill advised. Sighted guides will be available. Target audience for this group is persons who are visually impaired, especially those who have experienced recent loss, however, all are welcome, including family members and supports. Light refreshments will be served. There will not be a Conference Call option for this meeting.

ASH is Atheists, Skeptics and Humanists of First Unitarian Universalists of Columbus Ohio TBD Snacks are usually available, and you are welcome to bringing something to share!

By popular demand, the group wanted to read and discuss the semi-autobiographical novel by Henri-Pierre Roche, that inspired the Truffaut movie we watched last year. The book is available through the Columbus Library's interlibrary loan system. They reported there are twenty-eight copies available in the state of Ohio. If you have a library card, you can file an interlibrary loan request here: https://www.columbuslibrary.org/library-services/ . There are also used copies available on Amazon and eBay for under twenty dollars. You may want to rewatch the movie after reading the book, so we can compare and contrast in our discussion. The Columbus Library has four copies on DVD, and it's streaming on HBOMax.