The Graveyard Of Schrödinger

Well done Simon! This proved a little tougher for you than I anticipated, but I thought you did very well, even if doing a few things in a different order would have made a few steps a little easier. In particular, you made your life a little difficult at the end as you didn't use the 16/06/24 grave in C9. That said, I'm really glad that you found several of my favourite steps, including the sudden parity deductions and the strange way that difficulties summing to 7 in the 07/08/16 grave magically resolves it! One of the things I was happiest about when constructing the puzzle, is that I managed to make every single total possible in isolation, which means, at the start, it is impossible to eliminate any totals without thinking about the path logic. I was desperate to find a final grid which allowed the path to finish the way it does as I agree it is a bit ridiculous. I know other solvers have been convinced they've broken the puzzle when they find they can't draw the path straight from box 8 to box 9. A couple of comments I see have correctly spotted that there was a small logical leap when placing the digit in R6C7, but that doesn't matter much. You'd identified the totals correctly after all and even without using the 16/06/24 grave I think you could have found your way through using the deductions you made in box 9. Hopefully I can come up with a new twist for another graveyard next year. After all, you did give me this idea in the last graveyard feature!

I love two things about this video: 1) that half a year ago, you said "and cells cannot be Schrödinger cells - don't get any ideas, setters!". And then a setter took you up on the challenge and 2) instead of exasperation, you ended up enjoying every minute of schrödingerfied cells. :)

Got lucky at 1:24:00? Simon plonks a 2 in C7R6 even though it it could have been a 0 with the 27 in C8R6.

1:24:09 Simon assumes here that R6C7 must be a 2, which does turn out to be correct, but he skips some lovely logic around proving where the final Schrödinger cells are and how the path must move, which would ultimately end up proving that R6C2 must be a 2. All Simon should have concluded at this point is that R6C8 is definitely a 7, and similarly that R6C9 is a 4, regardless of which cell is Schrödinger. And since the possibility R6C9 being a 0/4 Schrödinger cell doesn’t change the sum for the cage it’s a part of, you can continue from that point into the logic for the cages in box 9, which then rather beautifully forces the completion of the path and the disambiguation of the Schrödinger cells and remaining digits. I honestly don’t blame Simon — by this point in a long solve with lots of complicated steps, it’s so easy to make a little mistake, not to mention the added strain of doing it on camera, and he was clearly a bit tired at this point. And the rest of the solve up to this point was wonderful to watch, and his delight at finding the end of the path mirrored my own. But just in case anyone else was wondering about how to get the 2 logically, I thought I’d share the path I found from this point: So, R6C4 = 4 regardless of whether it’s Schrödinger. Therefore the other two cells in its 16/06/24 cage must add up to either 2, 12, or 20. 20 is impossible with 7,8,9 already used in the box (3456 only add to 18), and 2 is impossible because R7/8C9 would have to be a 0/2 pair, and 2 is already used in the column. Therefore they must be adding to 12, using only 0,1,3,5,6 as options. The only way the math works is to use 1/5/6, requiring that R8C9 is the Schrödinger cell in the box. This makes the 14/11/19 grave 0/2/3/9 summing to 14. (You can also work these cages out in the opposite order as Simon did, but I found it a bit more complicated than starting with the 16/06/24 cage because of the possible totals and the geometry of the cage.) From here, you know the 6 must in the Schrödinger cell in R8C9, with either 1 or 5, which sorts out the 1/3 pair in box 6, and the 0/6 pair in box 3. To disambiguate what goes in the Schrödinger cells in boxes 6&9 with the 7 and 6 respectively, you now have to look back at the path, and how it can now possibly get into R9C9. Since R9C8 is now Schrödinger, and definitely includes a 6 in the 1/4/5/6 cage, it includes the highest digits and can’t be on the path, so the path must go through the 4 in R9C8. It then cannot take the 8 in R9C7, which is the highest in its cage, so it must turn up and get out through the 14 cage. Since it only take at most 2 cells to avoid taking the highest/lowest digits, and and can’t take the 9 in R8C7, it must take R7/8C8, but not R7C7. This disambiguates the order of the 0/2/3 in that cage, as the 0 can’t be on the path and therefore must be in R7C7, proving that R6C7 is a 2. From there everything is resolved, and the path is forced as Simon shows. It’s honestly such a fabulous puzzle, and I thoroughly enjoyed solving it! Congrats to fjam for yet another fabulous puzzle in this series!

i almost panicked until i remembered the uk daylight savings time 😂 glad to have this channel as an indispensable part of my daily routine!! ❤

At 1:24:40, did Simon make a presumption that R6C7 was a 2? Couldn't it have been a 0, and then R6C8 might've been a 2/7 Schrodinger cell?

Hello Simon. I have been following your channel religiously for about a month now and it has been one hell of a journey. I had never solved a Sudoku in the 26 years of my life and now I'm solving zipper lines, palindromes, German whispers, and whatnot. Thank you so much for making these videos and helping me find a new hobby. Of all the puzzles I have watched, I had the most fun trying to solve this one. Needed a bit of help from you but I did most of it on my own and it made me feel very proud. @fjam deserves a shoutout for this fantastic puzzle. I don't think I've ever seen anything like it in my life. Absolutely magnificent.

Well this one was really a humdinger. Those gravestones were really a scare bringer. With terror I froze On that path colored rose At the ghost (or the non-ghost) of Schrodinger! (Leaves a virtual cupcake with figurines of Puss in Boots and Dulcinea on top, Fnaire's and my Halloween costumes)

57:13 finish. This puzzle was such fun! I loved how you think the path is going one way, and all of a sudden you are in a completely different area. Masterful!

That’s one of the best puzzles this year on the channel, difficult but so much fun!

At roughly 1:24:30 Simon made a lucky mistake stating that it has to be 2. It could be a 0, and the next cell is a 07. I can't disprove it at that point.

1:24:32 . It was too early to assume that the 2 was in r6c7, as it could still have been part of the schrodinger pair at the time. It will get disambiguated based on the path a bit later, knowing that the 0 and 7 would block the path forces them both into the schrodinger cell.

Love that the path is how you start and gives so much at the start but by the end you’ve been kind of been forced to abandon it for a while and when you finally get back to path logic your sure you’ve made some kind of error but then it turns out that you haven’t at all. Brilliantly done.

Definitely one of the best puzzles I've solved in a while.

Rules: 04:41 Let's Get Cracking: 06:46 What about this video's Top Tier Simarkisms?! The Secret: 5x (11:16, 11:18, 11:29, 16:47, 44:04) Bobbins: 2x (10:50, 10:54) Three In the Corner: 2x (15:05, 17:00) Phistomefel: 1x (58:47) And how about this video's Simarkisms?! Ah: 28x (07:07, 07:42, 07:50, 07:50, 10:37, 16:01, 17:17, 17:17, 18:18, 20:55, 21:49, 23:13, 30:47, 32:34, 35:34, 38:47, 43:28, 48:46, 1:06:03, 1:07:46, 1:07:59, 1:10:49, 1:17:32, 1:19:43, 1:21:14, 1:23:25, 1:30:03, 1:35:43) Hang On: 16x (20:04, 30:47, 31:18, 42:42, 50:17, 55:03, 56:11, 56:11, 1:01:26, 1:09:29, 1:10:16, 1:12:46, 1:14:57, 1:15:28, 1:15:59, 1:30:49) Sorry: 10x (11:04, 25:51, 27:35, 1:06:39, 1:11:31, 1:16:03, 1:19:00, 1:27:17, 1:29:58, 1:35:01) Beautiful: 7x (08:01, 19:05, 19:09, 57:31, 57:52, 1:03:05, 1:20:06) Good Grief: 6x (16:29, 25:09, 54:06, 57:49, 1:02:58, 1:15:03) Clever: 6x (18:38, 18:38, 23:18, 24:46, 27:29, 1:33:00) Goodness: 5x (01:58, 07:14, 27:19, 1:09:01, 1:18:20) Bother: 5x (22:39, 44:22, 55:03, 1:05:05, 1:18:34) Ridiculous: 5x (23:18, 48:21, 1:33:00, 1:33:26, 1:34:13) By Sudoku: 5x (28:08, 46:48, 54:47, 1:05:27, 1:25:27) In Fact: 5x (08:43, 19:22, 1:07:00, 1:24:02) Wow: 5x (30:07, 40:17, 46:52, 48:51, 52:47) Pencil Mark/mark: 5x (35:28, 39:28, 1:09:15, 1:12:49, 1:28:36) What on Earth: 4x (22:54, 41:58, 1:23:45, 1:25:02) Brilliant: 4x (50:17, 50:21, 1:11:52, 1:35:21) Obviously: 4x (23:52, 44:39, 1:11:00, 1:13:57) I've Got It!: 3x (04:25, 1:35:26, 1:35:29) What Does This Mean?: 3x (13:39, 52:53, 1:06:47) Stuck: 2x (1:11:42, 1:12:00) Barbaric: 2x (1:23:38, 1:23:41) Apologies: 1x (10:02) The Answer is: 1x (33:51) In the Spotlight: 1x (17:02) I Have no Clue: 1x (1:31:35) Lovely: 1x (07:57) Incredible: 1x (1:34:39) Extraordinary: 1x (1:34:25) First Digit: 1x (16:54) Gorgeous: 1x (1:17:16) Surely: 1x (46:07) Whoopsie: 1x (18:19) We Can Do Better Than That: 1x (29:51) Phone is Buzzing: 1x (1:10:49) Fabulous: 1x (00:36) That's Huge: 1x (1:05:11) Have a Think: 1x (44:36) Cake!: 1x (04:21) Middly Digit: 1x (28:51) Most popular number(>9), digit and colour this video: Twelve (26 mentions) One (95 mentions) Purple (3 mentions) Antithesis Battles: Low (13) - High (10) Even (16) - Odd (5) Lowest (21) - Highest (17) Row (9) - Column (7) FAQ: Q1: You missed something! A1: That could very well be the case! Human speech can be hard to understand for computers like me! Point out the ones that I missed and maybe I'll learn! Q2: Can you do this for another channel? A2: I've been thinking about that and wrote some code to make that possible. Let me know which channel you think would be a good fit!

Wow that was great. Loved watching this solve and especially the finish. I was as amazed as Simon was with the final path.

Fantastic puzzle. A little bit high on the work-to-cleverness ratio, but had plenty of cleverness nonetheless. This ruleset clearly gave the constructor a lot of creative leeway while setting, and the effort they put into making each step interesting was very apparent.

57:51 Very nice deduction, finding the Schrödinger cell due to parity in the cages!

this puzzle took me over 5 hours of just having it open trying to take it in. at times i couldn’t see any way to break it down but i made it. it was exhausting!!

I'm also trying to distract myself from the horrible weather. Thanks, Simon, for the company!