Cycling

**Carlos Ortega** **“La ecuación de Gray-Scott y una historia de Codex-coding”** Se presentará una solución en **R** del modelo Gray-Scott, construida con **Shiny** y desarrollada de forma interactiva con un **LLM mediante Codex**. El proyecto combina simulación, visualización y experimentación en una demo muy vistosa y fácil de explorar. Una propuesta ideal para descubrir una forma distinta de crear y prototipar con R. **Francisco J. Rodríguez** **“Movimiento LunaR y eclipses con R”** En esta charla se hace una **introducción a los eclipses y qué algoritmos están implementados en RMoon** para que nos ayude a entender un poco mejor este fenómeno que tendrá su momento álgido este año en **España el día 12 de Agosto** con el eclipse total de Sol que se verá en varias zonas de la península ibérica en todo su esplendor al atardecer. Se explicará cómo se **puede estudiar un movimiento tan sumamente complejo** como es el de la Luna y como a partir de las predicciones que se nos puede ofrecer en distintas bases de datos, se consigue ubicar, con un alto grado de exactitud nuestro satélite en el cielo haciendo uso de mínimos conceptos matemáticos que nos permitirán entender por un lado la complejidad, pero por otro la mecánica del movimiento lunar.

**After a long winter hibernation, we're baaack!** Let's start off the kayaking season on the Rio Zêzere, departing from a meeting point just south of the Castelo do Bode dam. We will paddle 9 kms down the lush river landscapes and through a few “mini rapids” on our way to the river beach in Constância. Whether you're an experienced kayaker or a sporty beginner looking to try something new, this event is perfect for outdoor enthusiasts. **Duration**: approx. 4-5 hours in total * 2.5 hours on the water (incl. breaks) * 2 hours for a picnic lunch and swim at the river beach **Price**: €20 per person. This includes: * Kayak rental, including life jacket and paddle * Certified monitors to ensure the safety of all participants To reserve your spot and facilitate organization with the kayak company, please send your **payment** via Revolut (@maaadison) or MBWay (+491624520214) **by the end of the day Thursday, May 28th**. First come, first served! **What to bring:** * Swimsuit, neoprene, and/or clothes that can get wet * Shoes/sandals that can get wet * Sunscreen and hat * Change of clothes, second pair of shoes, and a towel * Waterproof case for your phone to take pictures along the way * Picnic lunch and blanket **Level:** Suitable for beginners and children (8+). Well-behaved dogs welcome. Basic instructions will be given by the guides before we begin. The kayak rental company covers personal accident and civil liability insurance at no extra cost. Safety is taken very seriously and there will be certified monitors guiding us along the descent. **How to get there**: 🚙 : Arrive by **09:30** by car(pool) to the **[drop-off point](google.com/maps/place/39%C2%B032'50.5%22N+8%C2%B020'48.1%22W/@39.5473611,-8.3466944,17z/data=!3m1!4b1!4m4!3m3!8m2!3d39.5473611!4d-8.3466944?entry=tts&g_ep=EgoyMDI1MDUxMi4wIPu8ASoASAFQAw%3D%3D&skid=4b837780-0960-4c40-a9e4-08a1e9f19e21)** 🚂 : Arrive by **09:15** to the train station in **Entroncamento**. From there, the rental company will shuttle you to the starting point. There are several train options from e.g. Oriente at different price points - be aware that your Navegante pass is NOT valid on these trains. *\*\* Please inform me 24hrs in advance if you are planning to arrive by train* After you have pre-paid, you will be invited to the WhatsApp community to organize carpooling as well as share pictures and other event-related information. There is no public transport in the area, so make sure to join the group chat! **Important notes:** * This event will take place even with a chance of light rain - consider a rain jacket for your own comfort See you on the water! *Lisbon Kayak Crew is not liable for any damages or injuries incurred during this activity. Please evaluate your own health and physical state and participate at your own risk.*

**Carlos Ortega** **“La ecuación de Gray-Scott y una historia de Codex-coding”** Se presentará una solución en **R** del modelo Gray-Scott, construida con **Shiny** y desarrollada de forma interactiva con un **LLM mediante Codex**. El proyecto combina simulación, visualización y experimentación en una demo muy vistosa y fácil de explorar. Una propuesta ideal para descubrir una forma distinta de crear y prototipar con R. **Francisco J. Rodríguez** **“Movimiento LunaR y eclipses con R”** En esta charla se hace una **introducción a los eclipses y qué algoritmos están implementados en RMoon** para que nos ayude a entender un poco mejor este fenómeno que tendrá su momento álgido este año en **España el día 12 de Agosto** con el eclipse total de Sol que se verá en varias zonas de la península ibérica en todo su esplendor al atardecer. Se explicará cómo se **puede estudiar un movimiento tan sumamente complejo** como es el de la Luna y como a partir de las predicciones que se nos puede ofrecer en distintas bases de datos, se consigue ubicar, con un alto grado de exactitud nuestro satélite en el cielo haciendo uso de mínimos conceptos matemáticos que nos permitirán entender por un lado la complejidad, pero por otro la mecánica del movimiento lunar.

**Weather permitting**, we’ll take a casual ride from Pickerington Ponds (Glacier Knoll) to Three Creeks and back. Distance is **18–25 miles**, depending on where we turn around and whether we add a side loop. Pace is around **12 mph**, but this is a fun, no‑drop ride — we can slow down as needed. Here’s the **map** showing Glacier Knoll (bike), Confluence Park (flag), and BrewDog: [https://www.google.com/maps/d/edit..](https://www.google.com/maps/d/edit..). Text or call Scott at **614‑975‑4458** if you’re coming. Columbus ski club membership not required for this event. CSC assumes no responsibility for the event or any injuries as this is organized by a third party.

BIKE RIDE TO SUNBURY Dust off your bikes, pump up your tires, and get out and ride. • When: Saturday, May 30, 10AM • Where: Leaving from the Westerville Library, 126 S. State Street, 43081 ◦ Meet at East side of parking lot by the playground. Trip Itentiary • 20 miles round trip • Ride to Sunbury, stop for lunch (Location TBD), then ride back to the Westerville Library • All skill levels welcome Contact: Therese Butz (614-561-1976), Art Kahn (614-370-5246) Columbus Ski Club membership not required for this event. CSC assumes no responsibility for the event or any injuries as this is organized by a third party.

**Weather permitting**, we’ll take a casual ride from Pickerington Ponds (Glacier Knoll) to Three Creeks and back. Distance is **18–25 miles**, depending on where we turn around and whether we add a side loop. Pace is around **12 mph**, but this is a fun, no‑drop ride — we can slow down as needed. Here’s the **map** showing Glacier Knoll (bike), Confluence Park (flag), and BrewDog: [https://www.google.com/maps/d/edit..](https://www.google.com/maps/d/edit..). Text or call Scott at **614‑975‑4458** if you’re coming. Columbus ski club membership not required for this event. CSC assumes no responsibility for the event or any injuries as this is organized by a third party.

Discover practical ways homeowners can expand tree canopy on their own properties and advocate for stronger tree coverage in their communities. Come learn how important trees are, even in our own yards, for helping with climate change by absorbing carbon and reducing heat, providing habitat for wildlife, and improving the health and wellbeing of our communities through cleaner air, shade, and more comfortable places to live. **Presenter** Todd Fleishans is a local consulting arborist with more than twenty years of experience. His credentials include ISA Board Certified Master Arborist, Certified Urban Forestry Arborist, Certified Tree Safety Professional, and Registered Consulting Arborist. He works with residential, commercial, and municipal clients, providing expertise in tree identification, health, risk assessment, and valuation. **Evening's Agenda** This meeting has the option to either attend in-person at the Bloomfield Township Library at 1099 Lone Pine Rd, Bloomfield Township, MI 48302 in Meeting Room 2 or online via Zoom. For those attending in-person, there will be a meet-n-greet before the presentation - see the agenda below for details. * 6:30 pm – Doors open for a meet and greet with members, supporters, and the local Sierra Club Executive Committee * 7:00 pm – Introductions and presentation begin (remote participants should join at this time) * 8:00 pm – Question-and-answer session begins **About SEMG Monthly Meetings & Presentations:** The Sierra Club Southeast Michigan Group (SEMG) offers free presentations during its monthly first-Thursday meetings at 7 pm. Meetings are held via Zoom or in person, begin with brief announcements, and feature an hour-long presentation with Q&A. All are welcome.

Short North Street Skates return Saturday, April 4 and we’re excited to get back rolling together. These weekly rollouts are a chance to move through the city as a group, build community, and create more visibility for skating and small-wheeled movement in Columbus. Details: Meet: 1160 N High St 9:30 AM meet 10:00 AM rollout All wheels welcome We’ll be skating through the Short North and surrounding areas at a steady, social pace. Routes will use a mix of streets and bike lanes, so comfort navigating the city is helpful, but you don’t need to be an expert. If you’ve been meaning to come out, this is a great place to start. Come solo or bring a friend!