Roller Coasters

Mark your calendars: the next Haskell Utrecht Meetup will be on February 2nd. We will be back in the University Library - room 0.21 - in the City Center. Note that you can park your bicycle under the library if you enter through the central courtyard. We hope to see you there! We have two speakers confirmed, Jaro Reinders and Niek Mulleners. Agenda: * 19:15 Doors open * 19:30 Welcome * 19:35 **Jaro Reinders - Algebraic Effects for Verified Compilers** * Break * 20:30 **Niek Mulleners - Programming with Holes, Types, and Tests** * 21:00-ish Finish * Drinks @ Florin **Algebraic Effects for Verified Compilers - Jaro Reijnders** Algebraic effects are a promising approach to reason about programs with side effects. Recent work on interaction trees has shown that algebraic effects can be used to verify compilers extrinsically. In the hope of avoiding overhead of extrinsic verification, I have researched how to use algebraic effects more directly as the intermediate representation in a verified compiler. I will present this approach and its complications. **Programming with Holes, Types, and Tests - Niek Mulleners** The duty of the compiler is to turn programs into executable code. When a program is incomplete or incorrect, it should tell the programmer exactly why their program cannot be executed and, ideally, how this can be fixed. To do so, the compiler has to understand the programmer's intentions. In this talk, I will explore how programmers can express their intentions through types, tests, and sketches (programs containing holes), and how the compiler might use this information to assist them in writing programs.

Kom naar het HaHaHo Makers Lab Utrecht voor een avond vol kennis & ervaringsdelen en maken, met de focus op elektronica met microprocessoren zoals Arduino & Raspberry Pi, LED’s en meetapparatuur. 19:00 Inloop + opzetten apparatuur 19:45 Standup: wat wil iedereen doen en/of leren deze avond? 20:00 Parallelle activiteiten: – startactiviteiten voor nieuwe deelnemers (Arduino, soldering, meetapparatuur, etc.) – onderlinge kennisuitwisseling adhv de wensen uit de standup – werken aan het gezamenlijke [PraatPaal-project](https://github.com/hadoopmarc/hahaho-interactive-pole) – werken aan je eigen project – ordenen/markeren van de ladenkasten met elektronisch componenten 21:30 Start met opruimen 21:45 Einde en verlaten van de Bibliotheek Een laptop is niet noodzakelijk maar komt vaak van pas! We vragen een vrijwillige donatie van €5 per avond om de inventaris met apparatuur en elektronische componenten op peil te kunnen houden. English 19:00 Room available for setting up equipment 19:45 Standup: what are the participant’s plans and wishes for the evening? 20:00 Parallel activities: – starter activities for new participants (Arduino, soldering, measuring equipment, etc.) – sharing knowledge as follow-up on the plans and wishes expressed during the standup – working on the community [Interactive Pole project](https://github.com/hadoopmarc/hahaho-interactive-pole) – working on your individual project – sorting the chest of drawers with electrical components 21:30 Start decluttering the room 21:45 End: leave the Public Library Bring your laptop if you want to program microcontrollers! We ask for a voluntary donation of €5 per evening to maintain the inventory with equipment and electrical components.

Craft night done right at the Krachtcentrale! Looking to activate your imagination? Join us for a night of abstract watercolor painting. Grab a drink at the bar, then head upstairs to the entresol for a playful evening of painting. Bring your own watercolors or use what we have on-hand. No experience needed, just your curiosity and creativity. This is a fun, social evening of painting and chatting while making our own little messy masterpieces. Come solo or with friends. About your host: Michelle is a Huizen based creative, originally from Portland, Oregon. Often crafting with paints, pens, fabric, woodblock, ceramics and more, she has loved playing with color since she was a kid.

**Ursula Blythe - The Philosophy of Grief: Love, loss, and the so-called human condition** ATTEND IN PERSON OR ON ZOOM Can Philosophy Inform Grief? Death is part of the human condition, yet we tend to avoid the subject in everyday conversations and philosophical discourse. Engaging with Grief reminds people of their own inevitable losses and demise during their life-cycle. However, death remains a curious mystery where our sense of loss and confusion is somehow out of our control. This phenomena generates the concept and real-life experience of Grief itself. As a starting point, it is important to understand or appreciate: Why we avoid the topic of Grief, particularly across Western cultures? Indeed, there are many social, psychological, and philosophical reasons for avoiding the discussion of Grief. As a prelude to my talk, I have signposted some significant examples of why we may avert discussions of Grief, as follows: Emotional Discomfort: Grief is an intensely painful and overwhelming emotion. Discussing it openly can make both the grieving person and others feel uncomfortable, as it forces an acknowledgment of vulnerability and mortality. Fear of Saying the Wrong Thing: Many folks are unsure of what to say or how to support someone who is grieving. They fear causing further pain or appearing insensitive which often leads them to avoid the elephant in the room! Social Norms and Stigma: Western culture often emphasises resilience and “moving on” quickly. So, open displays of intense emotions, especially prolonged sadness can be seen as a sign of weakness or an inability to cope, leading to avoidance of the subject. Lack of Personal Experience: If an individual has not experienced a significant loss themselves, they may struggle to empathise or appreciate the depth of another’s pain. Pace of Modern Life: Everyday life moves quickly, and there is often little time or space for the extended period of mourning that Grief requires. People may feel pressure to maintain normalcy and avoid “bringing down the mood” in social interactions. In Philosophical Terms: Traditional philosophy, particularly from the Stoics onward, has often focused on how to overcome or control emotions like ‘Grief’ through reason, rather than exploring its inherent value or meaning. The goal was often ataraxia (a state of freedom from emotional disturbance) which positions Grief as something to be managed, rather than discussed openly. Solomon (2007) states that the avoidance of Grief stems from a human disposition to: Shield ourselves and others from intense pain and the profound existential challenges that Grief presents. On reflection, normative definitions explain Loss as the event of losing something or someone. However, death remains a curious mystery here a sense of loss and bewilderment is out of our control known as the ‘process’ or ‘stages’ of Grief, which I will strongly argue against. For me, Grief is nether inherently rational or irrational, as it a natural emotional, mental, and physical response to the loss of a loved one. However, everyone’s experience of Grief is different, both culturally and individually. When endeavouring to “draw out meaning” from Grief. Perhaps it is very subjective in the early stages, and more objective in the later stages, which may generate a new understanding of Grief as a philosophical concept. In this talk, I will be drawing on the work of C.S. Lewis (1963), Robert C. Solomon (2007) and Michael Cholbi (2022), in order to assess if philosophy can actually inform our understanding and meaning of Grief. **Ursula Mary Blythe** is a public philosopher, essayist, researcher, and someone who has experienced profound loss and grief in recent years. This event is sponsored by the Royal institute of Philosophy. Lecture and discussion! See you there? For the full programme of events pls see [pfalondon.org](http://pfalondon.org)

ATTEND IN PERSON OR ONLINE This event is sponsored by the Royal institute of Philosophy. Lecture and discussion! See you there? For the full programme of events pls see pfalondon.org

If you are living in The Netherlands, by now, you may well have noticed the amount of open water. If you enjoy cycling in the city, you may wish to feel safer as you navigate the bridges and canals. And you may also want to get ready for visiting the beach, pools or the many lakes this summer. Learning how to swim takes approx 1 year and it all starts with the very first lesson. New comers enroll via our website and pay € 30,50, this is the first lesson and a goody bag. After the class you agree with the personal swim coach how to continue to obtain your final objectives. Enrolling is only possible via [www.your-personal-swim-coach.nl ](https://www.your-personal-swim-coach.nl/)hence a rvsp via meetup is not enough.

Samen sporten, gewoon voor de fun, elke week een divers programma, met allerlei verschillende sporten. Je hoeft niet de beste te zijn, maar wel zin hebben om samen te spelen en te leren. Tijdens een training doen we verschillende spelletjes, basketbal, voetbal. volleybal, spikebal, honkbal. Kom je ook, de bal ligt bij jou!! Eerste keer meedoen is altijd gratis, daarna kan je beslissen of dit voor jou is, of niet!! Dus kom een keer proberen. Kan je niet op deze dag, we sporten ook op andere dagen nl Zondag om 9:30 of Maandag om 20:30 Stuur mij een berichtje als je op die dagen een keer wil proberen! The amount of people rsvp'd to this game doesn't match the real number of people at the event, as Meetup is only used for promotion purposes.

**NEW DATE: Friday February 6th** Let's kick off 2026 together! 🎉 For the first time, **Dutch AUG** and **Flutter Netherlands** are teaming up for a New Year's drinks meetup 🥂 Join us at **Quignon in Utrecht** on **Friday, February 6th, from 17:00 to 20:00** — perfect for dropping by after work. This won't be your typical talks-and-pizza night, just good company, a few drinks, and a chance to start the new year with others from the community. Both groups share a lot of common ground — we're all building mobile apps, often with the same tools, and powered by Google technologies. So a joint event mixing the communities felt like a fun way to start the year! Everyone gets a few drinks on us to start the evening, plus some snacks to share. After that, it's pay-as-you-drink at the bar 🍻. Space is 80 people in total, shared across both meetup groups. So with 40 per group, be quick! If this event fills up here, check the other group's Meetup page to sign up there instead: * [Dutch AUG](https://www.meetup.com/nl-nl/dutch-aug/) * [Flutter Netherlands](https://www.meetup.com/flutter-holland/) (using Flutter Holland meetup page) Please note: You only have to register **once**! We're excited to toast the new year, catch up with familiar faces, and welcome new ones. See you at [Quignon](%5Bhttps://quignon.nl/%5D(https://quignon.nl/))! **NOTE:** Please drink responsibly. If you come by car, think of the limit, try some alcohol free versions or arrange a taxi or carpool. Best is of course public transport. For people by car in general: there are several Q-parks in Utrecht, but ParkBee is also a good option.

It's time for a new Dutch PowerShell User Group in-person edition. This continues our community events, bringing people together around DevOps, PowerShell scripting, and automation in the Netherlands. Hosted at Info Support in Veenendaal, the evening will be a chance not only to learn but also to reconnect with fellow community members. **Speakers** As part of this restart, we have opened a [Call for Papers](https://sessionize.com/dupsug/) to give both new and experienced speakers the opportunity to contribute. The full program will be announced soon. **Agenda** The event will take place on the 4th of February, 2026. All times are listed in CET. * 17:30 – 18:00 Arrival * 18:00 – 18:45 Dinner * 18:45 – 19:00 Welcome from Info Support / Organizers * 19:00 – 19:45 Keep secrets away from AI Assistants: Secure Secrets Management with PowerShell by Jev Suchoi * 19:45 – 20:15 Break * 20:15 – 21:00 Show and tell: Show, in a short 5-10 minute session, PowerShell things that you are proud of. This could be something you made or improved, or a cool VSCode extension that everybody should start using immediately! Or a way of working with scripts that makes things easier and more efficient, etc. Sharing is caring! * 21:00 – 21:30 Networking **Speaker Information** With the restart of DuPSUG, we are opening the stage for both familiar names and new voices. The [CFP](https://sessionize.com/dupsug/) is currently live, and speakers will be announced shortly. **Sessions** As we restart our events, sessions will continue to focus on advanced topics in automation, scripting, and DevOps. **Location** We are in-person at: Info Support Kruisboog 42 3905 TG Veenendaal Participation is free, and you are encouraged to attend in person. **Tickets** We kindly ask you to register your attendance through Meetup. Our events are made possible through sponsorship, and accurate attendance numbers help us secure continued support. Please register if you plan to attend, and update your RSVP if your plans change.

'THE THURSDAY MURDER CLUB' by Richard Osman 'Smart, compassionate, warm, moving and so VERY funny' Marian Keyes 'So smart and funny. Deplorably good' Ian Rankin 'Thrilling, moving, laugh-out-loud funny' - Mark Billingham In a peaceful retirement village, four unlikely friends meet up once a week to investigate unsolved murders. But when a brutal killing takes place on their very doorstep, the Thursday Murder Club find themselves in the middle of their first live case. Elizabeth, Joyce, Ibrahim and Ron might be pushing eighty but they still have a few tricks up their sleeves. Can our unorthodox but brilliant gang catch the killer before it's too late? The Times Crime Book of the Month Guardian Best Crime and Thrillers. ***Please read the book and join us for a lively discussion (in English) about the contents during our afternoon book club meeting.*** \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\- **PLEASE NOTE:** This is an IN-PERSON event in Amersfoort, The Netherlands. Please cancel your attendance in advance if you are unable to join, so that those on the waitlist can participate. Looking forward to seeing you all IN REAL LIFE then! Best regards, Sandra

Is public speaking something you’ve always wanted to learn? Then you’ve come to the right place! Experience a safe and playful environment at U-Speak Toastmasters where you can develop your public speaking, communication, and leadership skills! ## **Welcome to U-Speak! Toastmasters** Join our vibrant community at U-Speak!, where internationals and Dutch locals from Utrecht and its surroundings come together. U-speak! Toastmasters is a welcoming, safe, supportive and playful environment where you can work on your public speaking, communication and leadership skills! Guest visits are much appreciated. See below for more info 👇 ## **Discover our meeting experience** Curious about what happens during our meetings? Here’s a glimpse into a typical evening at U-Speak! Our gatherings feature a lineup of three prepared speeches, engaging evaluations and impromptu speaking sessions. At U-Speak!, every member gets their chance to shine. Whether you’re delivering a speech, providing feedback, or stepping up for impromptu speaking, our supportive environment ensures that everyone’s voice is heard and valued. * ⏰ Time: 19:15 - 21:30 (7.15pm to 9.30pm) Walkin at 19:15; Start of the meeting at 19:30 * 🌐 Venue: Room 8, Top Floor, Pub Florin, Utrecht * 🙋🙋‍♂️🙋‍♀️Attendance: Typically, 15-20 people attend each meeting Many of our club members are not on Meetup, so the number of people attending as indicated here is not reflective of the actual number of people attending on a night. * 🙋🙋‍♂️🙋‍♀️ Guests are welcome; rsvp is encouraged

We begin our journey at Arnhem Central Station and will be rolling into the landscapes of the Veluwezoom, combining historic estates, peaceful forests, and one of the most beautiful viewpoints in the Netherlands. We start at Arnhem Central Station, from where we quickly leave the city behind and enter the green oasis of Sonsbeekpark. Here we walk through the beautiful parkland and stop at the Belvedere Toren to enjoy views over the park and surrounding area. From Sonsbeekpark, the route continues to 18th-century Huis Zypendaal, a historic country estate set in a quiet, wooded environment. The hike then leads us deeper into nature as we enter the Waterberg national forest, where forest trails and natural surroundings provide a calm and refreshing atmosphere. We’ll take a short break here (8-9km). We will leave Arnhem behind and make our way to Rozendaal and will visit at Kasteel en Park Rosendael, a beautiful castle estate known for its gardens and water features. This will be our lunch break, with time to relax and enjoy the surroundings. After lunch, the hike continues toward Veluwezoom National Park and pass Rozendaalse Veld and will have a break at the Posbank Paviljoen, one of the highlights of the route. From here, we enjoy a panoramic view over the heathlands and hills of the Veluwezoom—an unforgettable moment and a perfect photo opportunity. The final stretch leads us downhill to Rheden Central Station, where the hike ends and public transport is available for the return journey. Or you can treat yourself to tasty pancake before you leave. This hike offers a varied experience of city parks, historic estates, forests, and open landscapes, making it a rewarding and memorable day outdoors. **📍When and where to meet?** We’ll meet at 11:00 at Arnhem Centraal train station. https://maps.app.goo.gl/W5tuBVNqbJ4zQw9B6 ⏰ We **start walking a few minutes after meeting up** — we don’t wait for latecomers, as the forest calls and daylight is short this time of year. **🚗 Coming by car?** There is a big parking next to the train station **⏸️ Planned Breaks** After 8 km: short break at Waterberg park After 13 km: Lunch break at Kasteel and Park Rosendael https://maps.app.goo.gl/skttJQdakUHrjLAS9 After 19km: break at the Posbank Paviljoen https://maps.app.goo.gl/wowuqj3sRY5hcid37 **💸 Payment** Please pay as soon as you sign up: To keep things fair for everyone, if we don’t receive your payment within 48 hours, we will need to remove you from the participant list. If there’s a waiting list, this will happen sooner (in less than 48 hours). If that happens, no worries — you’re always welcome to sign up again if there’s space. 🌟 Early Bird Deal! Join now for just €4 — available for 3 days (72h). After that, the price will be €5. https://tikkie.me/pay/7flhf3f6erltb3cv5635 **👟 Good to know** * Refund policy: Cancellations are fully refundable up to 1 week before the event (This is Friday 31 January at 23h59). After this period, the fee becomes non-refundable. * Hike difficulty: Our hikes are moderately challenging. Please only join if you’re confident you can keep up with the group’s pace (5 km/ h)— it’s more fun for everyone when we can walk together without long waits. * If the pace is too challenging: We may kindly suggest you continue at your own pace. We’ll give you clear directions to the nearest bus or train so you can return comfortably. * At your own risk: You participate at your own risk, so please make sure you have appropriate insurance coverage for outdoor activities. * Payment note: With Tikkie we only see initials (e.g., J. Doe instead of John Doe). Please include your Meetup name in the payment note so we can match it easily. * Friends joining: If you bring a friend, make sure they also register and pay. * What to bring: Snacks, lunch, and water/ or hot thee/ coffee (depending on the hike distance). * Stay connected: Join our WhatsApp group to be the first to hear about future hikes — ask for the QR code during the hike. * T-shirts: Fairwear-certified organic cotton, eco-friendly inks — €25. Sustainable, odor-resistant, and perfect for hiking. Let us know your size and we’ll bring one for you.

## Details **What is Toastmasters?** Toastmasters International is a nonprofit educational organization that’s been empowering people to become confident communicators and leaders since 1924. Worldwide, there are more than 266,000 members in over 14,200 clubs in 150 countries. In the Netherlands, there are over **40 clubs** across the country, including those in major cities such as Amsterdam, Utrecht, and Rotterdam. This network of clubs and their learn-by-doing program is sure to help you improve. You can visit Toastmasters clubs as a guest or become a member. **What does a meeting look like?** Some of the members give short, prepared speeches, which other club members later evaluate. A typical meeting also includes short impromptu speeches. In this improvisation part of the meeting, everybody gets a chance to speak, including guests, if they wish. We usually end the evening with a drink at the bar. **How do I become a guest at a meeting?** It’s easy! Simply RSVP for one of our upcoming meetings here on Meetup to let us know you’re coming. If you have any questions, contact us at [utrechttoastmasters@gmail.com.](http://utrechttoastmasters@gmail.com./) If you visit and like us, we can talk about membership! **Additional information** Our cozy venue has a maximum capacity of 30 people - perfect for an engaging. Please be on time to grab a seat and mingle before the speeches begin!

Join us for some focused writing time. All writers and all experience levels are welcome and don’t worry, no one will see what you've written. This session is about getting your writing done and meeting other writers in your area. When you show up, say hello to everyone, grab a drink, and get your writing tools ready. Once you’re all settled, take some time to chat with your fellow writers. Once everyone’s arrived, I will lead quick introductions and then set the timer for our quiet and focused writing session. Afterward, we’ll have time to chat and get to know each other. We often talk about our successes and challenges as writers. If you don’t have time to stick around, no worries! **A note about the format** We don’t host critiques or readings. These events are a safe space for writers of all skill levels and genres to work on their craft, so no one will read or critique your writing. For our full event schedule, visit [https://shutupwrite.com](https://www.shutupwrite.com). **Other Important Details:** WiFi name/password: [PLEASE INCLUDE DETAILS] Travel / Parking info: [PLEASE INCLUDE DETAILS]

Do you sometimes feel like you do well in life then something happens and you slide back, never quite getting ahead. At this Meetup you'll find out how to identify what actually causes the lows, the highs and everything in between. More importantly you’ll get the secret of how to gain control over your life so the highs are higher and the lows go away. Wouldn’t it be nice to stop the wild roller coaster ride for good? Or at least make it a fun roller coaster ride, with more ups and downs. There is a hidden factor that will be going over and you’re going to be quite surprised what it is and how much it affects your life. Be sure to click on the red "Attend" button below to come to the event. We look forward to seeing you there. This group is hosted at the Dianetics and Scientology Life Improvement Center.

WQC has weekly Thursday night social nights at the Westerville Java Central. Come and grab a coffee and connect with the community: low stakes, chill environment, and tasty drinks. No registration is required; come as you are.

COLUMBUS RECREATION CENTERS require membership fee to play. Register & Pay at the desk when you arrive. $5 day pass is available. I have some extra pickle ball paddles and balls if you don’t have one. Definitely bring your own paddle if you have one and bring some balls if you have them. Legal Stuff: The event hosts/Organizers are just fellow member volunteers. By participating in any event, you assume all risks of liability and injury inherent in these activities. You are responsible for your own safety and for determining if you are in condition fit to participate. You are also responsible for knowing and abiding by all laws and rules during your participation in any event.
 Photos & or Video: by attending these events you acknowledge photos and or video may be taken and used on this and other platforms.

A quiet writing and sharing space, Queer Quills features some prompts, supplies and friendly faces to help get some inspiration or feedback for your writing. Hope to see you there!

Dale Gnidovec, Curator of the Orton Hall Museum of Geology at The Ohio State University, will be presenting a program he has wanted to share with us for a long time: Plate Tectonics. His description of his program: Continents on the move - Nothing in Earth history makes sense without moving continents - it tells us why mountains, volcanoes, minerals, and fossils are where they are. This talk examines the evidence for continental drift, why it was disbelieved, and explains how the more-encompassing theory of plate tectonics was developed and eventually proven. Dale is an energetic, incredibly knowledgeable, and very entertaining speaker and this will be another wonderful program by Dale. Hope to see you there! Food and drinks will be provided at the event. Feel free to show up a little bit early to hang out and talk. Going forward our meetings will be hybrid. You can meet us in-person or attend online Join Zoom Meeting [https://us02web.zoom.us/j/87836564953?pwd=4Mi57ElZkDIFlb1fnlNwOJ0NiOK4tP.1](https://us02web.zoom.us/j/87836564953?pwd=4Mi57ElZkDIFlb1fnlNwOJ0NiOK4tP.1) Meeting ID: 878 3656 4953 Passcode: 760812 One tap mobile +19292056099,,87836564953#,,,,\*760812# US (New York) +13017158592,,87836564953#,,,,\*760812# US (Washington DC) The formal presentation will start at noon