COSine Convention

01/26/2026

O Wonderful Fandom!

We hope everyone had a wonderful convention and made it home safely!

Thank you all for coming! We hope to see you next year.

What was your favorite part of the convention? 🥰

01/20/2026

We also have a Dealers Den, Author Alley, and Fan Tables!
NOTE: Dealers Den = Dealers Room
As with the artists, please reply with perhaps your website, a photo, etc. to get folks excited to buy from you!

Send a message to learn more

01/17/2026

COSine 2026 is coming up January 23-25, 2026 at the Embassy Suites by Hilton Colorado Springs.

Just wanted to send out one last reminder about COSine, which is just one week away!

The team just took up the airship to do some advanced weather checks, which is a bit odd, because I thought they just checked the weather app on their phones. This is the message they sent:

“Weather’s looking good for the con, with the happy sun symbol for Friday and Sunday, and only a bit of cloud for Saturday. Also, does anyone know how to fly an airship—the purple mountains majesty are getting awfully close…”

Online registration is now closed, but you can register at the door for the entire weekend, or for day passes.

And just a reminder of our guests—Cory Doctorow, Dr. Josiah Seaman, Michael Carroll, Connie Willis, and Courtney Willis. And more hoopy froods, writers, artists, and techies than you can shake a stick at. If you are the sort of person who likes to shake sticks at people.

And if you want even more Cory, he will be at the Tattered Cover on the Thursday before the con!
Contacting Us
Feel free to ping us if you have any questions or issues, airship driving manuals, pyranometers, working weather control devices, or really pretty seashells.
General: info @ cosinecon.org
Programming: programming @ cosinecon.org
Art Show: artshow @ cosinecon.org
Dealers/Authors Row: dealers @ cosinecon.org
Gaming: info @ cosinecon.org
Volunteering: info @ cosinecon.org
Hope to see you next week...

Arlen, Eli, Karen, Morland
The COSine Con Com

Send a message to learn more

01/07/2026

˚　　　　✦　　　.　　. 　 ˚　.　　　　　 . ✦　　　 　˚　　　　 . ★⋆.
　　　. 　　˚　✭　 　　*　　 　　✦　　　.　　.　　　✦　˚ 　　　　 ˚　.˚　　　　　✭　.　　. 　 ˚　.　　　　 　　 　　　　 ✦
ART SHOW!
˚　　　　✦　　　.　　. 　 ˚　.　　　　　 . ✦　　　 　˚　　　　 . ★⋆.
　　　. 　　˚　✭　 　　*　　 　　✦　　　.　　.　　　✦　˚ 　　　　 ˚　.˚　　　　　✭　.　　. 　 ˚　.　　　　 　　 　　　　 ✦
COSine has a wonderful art show with new artists and artists that have been with us since our convention started.

As usual, we'll have:
* Silent Auction (High bid picks up on Sunday at 2 pm)
* Quick Sales (No bids? Pay quick sale and take it immediately)
* Print Shop (Buy art for a set price and take it immediately).

Come by and come buy! Bid high! Bid often!

Heather Carr
Michael Carroll ~ Artist Guest of Honor
Peri Charlifu
Jessica Coyle
Kyle Crutcher
Brenna Deutchman
Steve Evans ~ New
Kyra Ferguson
Kevie Frost
Thrifty Gryphon
Amy Griswold
Craig Griswold
Robert Hay
Jim Humble
Reynold Mackey
Theresa Mather
Reed Mingault ~ New
Don Pelton
Beverly Pfeifer
Bob Pfeifer
Shroom
Peachtastic ~ New
Fire Thieves Studio
Daniel Tomlinson ~ New
Beverly Warner
Gary Weston
Ben Yakura

Artists, you can add a preview of your art, link to your website, etc. to this thread to help people get excited about what we can buy!

12/30/2025

COSine 2026 will be January 23-25, 2026 at the Embassy Suites by Hilton Colorado Springs.

A Happy Merry to you all!

COSine is now only a few weeks away! The schedule is done (you can see it here https://cosinecon.org/currentschedule/, and also the list of participants https://cosinecon.org/participants/), and we have fired up the fusion reactor to get ready to start printing the program books—and to top off the charges on the staff and volunteers (once we find the right cables).

If you want to get the best rates before they go up, now would be a great time to preregister https://cosinecon.org/registration/. Aside from saving money, it also guarantees that you get a spiffy laminated badge with your name preprinted on it!

Spam Spam Spam Spam Spam
Before moving on, I did want to address something. Many of you have contacted us to let us know about messages offering to sell you the COSine mailing list. Just to be clear, we do not, have not, will not ever sell our mailing list or your contact info!

The messages are definitely spam, and while we are sure that the senders—Tabitha/Wendy/Priah/Layla/Kelly/et al—are lovely people, we suspect that responding to these messages would not end well. They’ve tried to sell us our own list multiple times as well, which is at least a bit tempting, since their version has a lot more names on it than ours!

Hotel
You can book a room at the Hilton site here https://www.hilton.com/en/attend-my-event/coscces-xco-205684a8-fb33-4ff4-b4e8-a735d3f63574/. You can also call them at 719-599-9100. Be sure to mention COSine to get the con rate (and so the con gets credit for your room nights :-).

The deadline for getting the reduced rate has been extended to January 7th. However, the hotel is filling up fast. If you’d like a room (particularly if you’d like a double-queen room vs. a king room) you should probably book as soon as possible.

If you have any problems with booking a room, please let us know (just send a message to [email protected]) and we’ll help get it sorted.

Guests of Honor
One more quick rundown of our main guests:
Cory Doctorow – Our Guest of Honor, the amazing writer, journalist and activist. He’s best known for his Little Brother series, and also for coining the term Ensh*ttification (and writing a book with that title. He'll also be doing a panel about it at COSine). It explains why almost every interaction with technology these days has turned into a rage-inducing nightmare. Or is that just me?
Dr. Josiah Seaman – Our Science Guest of Honor, a Geneticist and Bioinformatician who also knows a lot about a lot of different subjects. He and Courtney have a really cool hands-on science panel planned.
Michael Carroll – Our artist guest of honor, Michael is best known as an award-winning space artist who literally has some of his art on Mars (in digital form) and is also an author and international teacher and lecturer.
Connie Willis – Special guest and Sci-Fi Grand Master. Everyone always looks forward to her panels at COSine, but I definitely want to hear what she has to say on the other of our rudely-named panels this year!
Courtney Willis – Special guest, the inimitable Dr. Science. As well as a big hands-on science demo with Josiah, he’s also bringing some 150+-year-old sewing machines from his (large) collection, and is going to do a make-and-take panel where you can try them out!

Contacting Us
Feel free to ping us if you have any questions or issues, prehistoric computing devices, Minas Tirith LEGO sets, house-trained llamas, or portable black holes.
General: info @ cosinecon.org
Programming: programming @ cosinecon.org
Art Show: artshow @ cosinecon.org
Dealers/Authors Row: dealers @ cosinecon.org
Gaming: info @ cosinecon.org
Volunteering: info @ cosinecon.org

Arlen, Eli, Karen, Morland
The COSine Con Com

12/08/2025

COSine 2026 Status Report #3

COSine 2026 will be January 23-25, 2026 at the Embassy Suites by Hilton Colorado Springs.

Only a bit more than a month and a half to go before COSine! Amazingly, things are starting to come together. You can see the (preliminary) schedule here (https://cosinecon.org/currentschedule/), and also the list of our talented and charming participants, not to mention our main guests (https://cosinecon.org/participants/):
Cory Doctorow – Our Guest of Honor, the amazing writer, journalist and activist. He’s best known for his Little Brother series, and also for coining the term Ensh*ttification (and writing a book with that title. He'll also be doing a panel about it at COSine). It explains why almost every interaction with technology these days has turned into a rage-inducing nightmare. Or is that just me?
Dr. Josiah Seaman – Our Science Guest of Honor, a Geneticist and Bioinformatician who also knows a lot about a lot of different subjects. He and Courtney have a really cool hands-on science panel planned.
Michael Carroll – Our artist guest of honor, Michael is best known as an award-winning space artist who literally has some of his art on Mars (in digital form) and is also an author and international teacher and lecturer.
Connie Willis – Special guest and Sci-Fi Grand Master. Everyone always looks forward to her panels at COSine, but I definitely want to hear what she has to say on the other of our rudely-named panels this year!
Courtney Willis – Special guest, the inimitable Dr. Science. As well as a big hands-on science demo with Josiah, he’s also bringing down some 150+-year-old sewing machines from his (large) collection, and is going to do a make-and-take panel where you can try them out!

Registering
Haven’t signed up yet? Register now (https://cosinecon.org/registration/), register often. Also, what better x-mas gift could there be than a membership to COSine? (Note: I’m just being told there are 197 better gifts. But still, top 200. Not bad.) Not sure if you’ve already registered? You can check using our online registration lookup tool (https://reglookup.cosinecon.org/).

It is also cheaper to buy a membership ahead of time than at the door!

Hotel
You can find details on registering for a room at our hotel, the Embassy Suites by Hilton Colorado Springs. You can also call them at 719-599-9100. Be sure to mention COSine to get the con rate (and so the con gets credit for your room nights :-).

If you have any problems with booking a room, please let us know (just send a message to [email protected]) and we’ll help get it sorted. Also, be aware—the con rate is only available until January 2nd, 2026.

Note: Due to the joys of the Hilton registration system (see discussion of Ensh*ttification above), some people, at some times, have seen better rates than the con rate. If you see one, you should definitely take it. However, if you could also let us know, we can tell the hotel and get credit for your stay!

Contacting Us
Feel free to ping us if you have any questions or issues, sequenced dinosaur DNA, alien tech, cool seashells, or any pieces of the Key to Time (willing to trade).

General: info @ cosinecon.org
Programming: programming @ cosinecon.org
Art Show: artshow @ cosinecon.org
Dealers/Authors Row: dealers @ cosinecon.org
Gaming: info @ cosinecon.org
Volunteering: info @ cosinecon.org

Arlen, Eli, Karen, Morland
The COSine Con Com

Send a message to learn more

11/05/2025

COSine 2026 will be January 23-25, 2026 at the Embassy Suites by Hilton Colorado Springs.

I hope you all enjoyed an extra hour of sleep on Sunday? The clocks going back also gave you an extra hour to register for COSine before the prices go up after Friday! You can register here https://cosinecon.org/registration/. Not sure if you’ve already registered? You can check using our online registration lookup tool https://reglookup.cosinecon.org/

We just got the program book/badge art from our artist guest of honor, Michael Carroll, and it is amazing! We’ve also been talking to our other guests of honor about programming.

Josiah Seaman, our science guest of honor, is planning some live demos (with assistance from Courtney “Doctor Science” Willis) as well as some very interesting talks. Courtney is also planning on doing a make-and-take where you make something on a genuine 19th century sewing machine (and, yes, he is bringing several).

The schedule is well underway, with dozens of writers, techies, and other interesting people coming, not to mention our guest of honor, author and activist, the amazing Cory Doctorow, and Sci-Fi Grand Master, the incredible Connie Willis!

Hotel and a fraud warning

You can find details on registering for a room at our hotel, the Embassy Suites by Hilton Colorado Springs. You can also call them at 719-599-9100. Be sure to mention COSine to get the con rate (and so the con gets credit for your room nights :-).

Warning: Several people have reported getting an email that is supposed to be from us, but is actually a scam! It may come from an address that looks like it comes from "member-hotels," but it takes you to a form on a site called zohopublic (just a generic forms service) where you have to choose a hotel, then asks for credit card details in plain text.

It also asks for the same amount of money, no matter which hotel you pick, or how many nights, which, as frauds go, just seems sloppy. Jeez--put in a little effort.

We have reached out to Hilton about this, and they are going to see if they can get zohopublic to take down the form, but it will likely pop up again in a different manner, so please be careful.

Contacting Us
Feel free to ping us if you have any questions or issues, bits of re-entered satellites, working time machines, or manuals for how to repair non-working time machines. Preferably with pictures.
General: [email protected]
Programming: programming @ cosinecon.org
Art Show: artshow @ cosinecon.org
Dealers/Authors Row: dealers @ cosinecon.org
Gaming: info @ cosinecon.org
Volunteering: info @ cosinecon.org
Arlen, Eli, Karen, Morland
The COSine Con Com

Registration Lookup You can use this to see if you are registered for COSine 2026. Just enter your e-mail address and you will receive an e-mail listing all registrations associated with that e-mail. Note: It may take a few minutes for the e-mail to arrive (if you don't see it, then check your spam....

02/04/2025

UPDATE: All folks have contacted our Art Show Director.
Plans are being made for payment and pickup! Thank you all!

Hi Con Attendees!
In followup, we have a bumper crop of unpicked up art at the art show. Thank you very much to 3 of the folks who left their contact information and have met with The Cheryl.

The remaining folks we are trying to track down are badges and initials: (Information removed, because we've heard from the folks.)

These items total 223 (+ tax).

Send a message to learn more

01/03/2025

We have a Dealers Room (Dealers Den next year, because alliteration is funzies) and Author Alley!

Dealers:
Who Else Books
Theresa Mather
Ad Astra Where Worlds Collide
Dad's Dork Den
K.J.'s Jerky
Knight Writing Press
Periapt Press
Primordial Pals
Rockhound Studio
Beauty and the Beads
Star bleau
Tycho Dorian Art and Writing
Vipi Ink
Biostration
Gathering Splinters
Chaotic Dreamers
Geek Way Homes
4 A Custom Keepsake
Your Wizard Masaage

Authors:
A.L. Kessler
Alastair Mayer
Blue Fyre Press
BMW the Author
Caitrín Casey
Carly Stevens
Henderson Infinity Press
Horizon View Press LLC
Peter Sartucci
Robert G. Williscroft
Sam Ledel's books
Tales & Legends
Theropod Publishing, LLC
Tiffany Passmore
Lena Johnson
J.Nathanial Corres

Send a message to learn more

01/01/2025

We hope that you are excited about COSine!

We have an Art Show!
Here is a list of our artists!

Mitzi Bartlett
Peri Charlifu
Heather Carr
Jessica Coyle
Kyle Crutcher
Douglas Davis
Brenna Deutchman
Kevie Frost
Jessica Garramone
Kat Hall
Robert Hay
Jim Humble
Atlas / Shroom
Reynold Mackey
Q Magnus
Theresa Mather
Don Pelton
Beverly Pfeifer
Bob Pfeifer
Charles Redding
Beverly Warner
Gary Weston

DISCLAIMER: The art show picture is from our last hotel, but it shows a nice variety of table / panel art with some of our artists, staff, and attendees.

12/19/2024

COSine 2025 will be January 24-26, 2025 at the Embassy Suites by Hilton Colorado Springs.

A Happy Merry to you all!

COSine is a little over a month away! There are a few deadlines coming up:
Registration rates go up soon after the start of the new year. Register at the lower rate here (https://cosinecon.org/events/cosine/). Think how much better you'll feel to get at least one thing done and out of the way!
Not sure if you’ve already registered? Check using our registration lookup tool (https://reglookup.cosinecon.org/).
The reduced hotel con room rate is only available until January 3rd. Details here (https://cosinecon.org/cosine/hotel/).
We are reviving the last of the staff from suspended animation in preparation for the con. Many of them still have their memories.
The programming schedule is now done* and you can see it online (https://cosinecon.org/currentschedule/), along with a list of all of the participants (https://cosinecon.org/participants/). We are pretty excited about this year’s programming! Note: If you think you should be on the schedule, but haven't seen an email about it, please check the list and/or contact us. The email spam gremlins seem especially pernicious right now!

[*For some definition of “done.” There will likely be a few last minute tweaks and changes.]

Scam warning
A lot of people have reported an email offer to get our mailing/contact list. In fact, they also tried to sell us our own list. It generally has a very specific number of contacts (ex: 6,381 which is, um, high). We get these all the time for other cons, but it seems to be going to attendees now.
Just to be clear, we have not and will not ever sell our contact list.
We do sell advertising space in our program book at very reasonable rates, which will be seen by our very many millions of attendees each year. Ping us (programming at cosinecon.org) if you are interested (but the deadline is coming up).

And here’s the list of our guests for this year:

Lawrence Watt-Evans (Guest of Honor). He is a Hugo Award-winning author, best known for his Ethshar series, starting with The Misenchanted Sword, now up to 15 novels! He is also a sci-fi and horror author, and has been the president of the Horror Writers Association and the Eastern Regional Director of the Science Fiction and Fantasy Writers Association.
Dr. Kachun Yu (Science Guest of Honor). Kachun is the curator of space science at the Denver Museum of Nature & Science, where he focuses on visualizations of astronomical datasets in immersive and non-immersive settings.
Theresa Mather (Artist GoH). She is an incredible artist who paints on canvas, feathers, and stone. She describes herself as a cryptopictographer – a painter of things that don't exist.
And Connie Willis (SFWA Grand Master) and Courtney "Dr. Science" Willis have agreed to come back as special guests!
They will be joined by dozens of other authors, techies, artists, experts, and masses of lifeless tissues assembled into cultured, sophisticated people-about-town.

Contacting Us
Feel free to ping us if you have any questions, suggestions for future panels, interesting pocket lint, a captured New Jersey UFO, etc.
General: info at cosinecon.org
Programming: programming at cosinecon.org
Art Show: artshow at cosinecon.org (Both full, wait-listed)
Dealers/Authors Row: dealers at cosinecon.org (Both full, wait-listed)
Gaming: [email protected]
Volunteering: [email protected]
Hope to see you next month!

Arlen, Morland, Karen, Eli, Richard
The COSine Con Com

Send a message to learn more

11/01/2024

COSine 2025 Spooky Status Report #3
(AKA Rates increase TONIGHT ~ October 31, 2024)

COSine 2025 will be January 24-26, 2025 at the Embassy Suites by Hilton Colorado Springs.

It's now only two days until Halloween, when small children will come to your door and demand tribute to avoid their terrible retribution. We don’t quite have the staff to send someone to everyone’s door, but you will face a terrible fate if you don’t sign up by the end of the month by, uh, having to pay slightly more for your COSine membership.

Okay, maybe mild inconvenience?

Anyway, the rates go up after October 31st, so now is a great time to buy your membership (https://cosinecon.org/registration/)! Not sure if you already have a membership? Check with our online registration lookup tool (https://reglookup.cosinecon.org/).

And thank you to all of the COSiners who stopped by to say hello to us at MileHiCon this last weekend. We hope you enjoy your ducks!

If you missed it, here’s the lineup for COSine 2025:
Lawrence Watt-Evans (Guest of Honor). He is a Hugo-winning author, best known for his Ethshar series, starting with The Misenchanted Sword, now up to 15 novels! He is also a sci-fi and horror author, and has been the president of the Horror Writers Association and the Eastern Regional Director of the Science Fiction and Fantasy Writers Association.
Dr. Ka Chun Yu (Science Guest of Honor). Ka Chun is the curator of space science at the Denver Museum of Nature & Science, where he focuses on visualizations of astronomical datasets in immersive and non-immersive settings.
Theresa Mather (Artist GoH). She is an incredible artist who paints on canvas, feathers, and stone. She describes herself as a cryptopictographer – a painter of things that don't exist.
And Connie Willis (SFWA Grand Master) and Courtney "Dr. Science" Willis have agreed to come back as special guests!
Along with dozens of other authors, techies, artists, bon vivants, and hoopy froods.

A few bits of news…

Hotel
Our friends at the Embassy Suites have managed to (at least partially) wrestle the registration system into some form of submission. It is now possible (gasp) to register for a king, two queens, or an accessible room directly on their website! Details here (https://cosinecon.org/hotel/). With capabilities like that, it’s possible this whole world-wide-web thing might actually catch on…

BTW--Please make sure you are not selecting an accessible room unless you actually need one. They are a limited resource (and it's easy to choose one by accident).

Charity Raffle/Silent Auction
We are very pleased to announce that our charity this year will be the Denver Museum of Nature & Science (https://www.dmns.org/), home of our science guest of honor, Dr. Ka Chun Yu. Well, not his actual home…

Contacting Us
Feel free to ping us if you have any questions, suggestions for panels, interest in the dealer room/art show/offers of large amounts of cash (properly laundered only)/etc.
General: info @ cosinecon.org
Programming: programming @ cosinecon.org
Art Show: artshow @ cosinecon.org
Dealers/Authors Row: dealers @ cosinecon.org
Gaming: info @ cosinecon.org
Volunteering: info @ cosinecon.org
And to end as scarily as we began... boo!

Arlen, Morland, Karen, Eli, Richard
The COSine Con Com

Send a message to learn more