I’m not singing, but somewhere, out there, beneath the pale moonlight, there are arrows and thermometers to fill the grid. Try to place all of the digits without flipping your lid. Somewhere, out there, there’s no 6 nor 7. Out where dreams come true.
I’ll save the punchline for those who solve the puzzle. It’s the end of another month, and so time for another Gattai! This will also bring this run of Renban puzzles to close. For now. I do like Renban as a constraint, but I’ll try to mix things up for a while.
Slow Thermometers are often used to make thermometers very, very long, much longer than nine cells. But they don’t have to be! The average length of these thermometers is 2.7 cells, and they’re very, very slow.
Sometimes different constraints are identical, at least under some conditions. For example, these are all two-cell thermometers, which could be replaced by greater-than or lesser-than symbols. So I don’t create puzzles with greater-than or less-than symbols. I use two-cell thermometers instead!
That thermometer in the center, it is 23 cells long, and yet still contains only digits between 1 and 9 inclusive. 23 cells is one of the longest slow thermometers possible within a standard 9x9 Sudoku grid, although I’ve heard rumors of even longer. I think to be longer, the thermo has to cross itself, which can lead to some confusion. There are a few different ways to arrange such long thermometers, and this is one.
I looked up a few temperature scales to use for puzzles involving “slow” thermometers like these, and there are some odd ones. It’s nice to live in a world in which such things are settled, in which we have two settled temperature scales oriented around humans, and easy math to convert between them. Team Fahrenheit and Team Celsius don’t apply here, though. Here, temperatures rise very, very slowly, or sometimes not at all.
It’s a big one, and it’s anchored by Gravity Cages at the bottom. While these cages don’t directly affect anything else in the puzzle, I like to imagine they’ll combine to form a black hole, pulling everything in all four grids into a single cell.
The world is full of things to measure, and scales for reporting those measurements. Some are more rational than others, some are more human-oriented than others, and some are older than others, but none of them involve thermometers that sometimes rise and sometimes don’t. This puzzle does, though!
It’s an XV Thermo puzzle, except you can’t see it all at once. You can see just enough to fill in one cell, after which you’ll be able to see more. This is the second of four puzzles exploring a guided solve path using Fog of War.
Modern integrated circuits are mass-produced and extremely tiny, but I remember when even products shipped by manufacturers like Sony had internal circuits soldered together, and chips glued glued in place.