The Moving Sofa Constant

July 21, 2006 9:01 AM

The Moving Sofa Constant. We have noticed you have a small personal problem with sofas. You move them and get them stuck in hallways. But it's nothing a little math won't fix.
posted by storybored (29 comments total)

Richard MacDuff?
posted by keswick at 9:05 AM on July 21, 2006

There are ALOT of tables on that page.
posted by ChasFile at 9:05 AM on July 21, 2006

And if you're having trouble parking the moving van, you must of necessity learn about Rényi's Parking Constant. For those of you who are constantly fascinated, there's the book.
posted by storybored at 9:07 AM on July 21, 2006

Is Hammersley's Sofa bigger than Shephard's Piano?

Either way, I'm not helping either of them move.
posted by justkevin at 9:11 AM on July 21, 2006

I have never seen a sofa shaped like a phone, but I guess if I ever do, I know where I can move it to.
posted by poppo at 9:15 AM on July 21, 2006

Dirk Gently would be so proud.
posted by soyjoy at 9:18 AM on July 21, 2006

I had the same thought, soyjoy.

Neat link, thanks.
posted by brain_drain at 9:26 AM on July 21, 2006

What's the formula that equates the cost required to get your 'friends' to help? I know it includes pizza.
posted by NationalKato at 9:29 AM on July 21, 2006

NationalKato: and beer!

The link: not a particularly useful constant, unless you have a couch shaped like that. Was this constant derived in the 70's? They had lots of weird furniture then.
posted by antifuse at 9:34 AM on July 21, 2006

Yes, this definitely triggers a long, dark teatime in my soul.
posted by GuyZero at 9:49 AM on July 21, 2006

The next time I have to move my phone receiver I am going to refer to these diagrams. Thank you.
posted by iconomy at 9:51 AM on July 21, 2006

I wish I had this formula (and a muscular mathemetician) with me when I was trying to move a piano up a flight of curving stairs back in the Seventies...
posted by kozad at 9:52 AM on July 21, 2006

A math geek will sit there and calculate all of that cruft to see if the sofa will possibly fit down that hallway.

In the meantime, I've already picked the sofa up on my back and carried it to its new location. Without damaging the walls.

I wonder what the calculation for "Lower it off the balcony with a rope so you avoid the hallways entirely" is. :)
posted by drstein at 9:54 AM on July 21, 2006

Would the shape significantly change if it were in 3 dimensions?
posted by empath at 10:02 AM on July 21, 2006

My hand to god, it's the emess, I was saying this:

just this morning, to my parakeet, over coffee.
posted by OmieWise at 10:08 AM on July 21, 2006

Would the shape significantly change if it were in 3 dimensions?

Yes. I leave the proof as an exercise for the reader.
posted by Plutor at 10:10 AM on July 21, 2006

keswick with the win.
posted by dvdgee at 10:11 AM on July 21, 2006

Dirk Gently would not, indeed, be pleased. In fact, he had a full simulation with a working 3d model a long time before this inferior work surfaced. It's obvious such a simple formula could not account for Detective Gently's particular sofa. But a tip of the hat to them, nonetheless.
posted by splice at 10:22 AM on July 21, 2006

Would the shape significantly change if it were in 3 dimensions?

I don't understand this question. How would you even phrase this particular problem such that it made sense in 3 dimensions?
posted by UrineSoakedRube at 10:59 AM on July 21, 2006

I have never seen a sofa shaped like a phone, but I guess if I ever do, I know where I can move it to.

not a particularly useful constant, unless you have a couch shaped like that.

The next time I have to move my phone receiver I am going to refer to these diagrams. Thank you.

Not sure if everybody is kidding or not, but isn't the practical application of this simply that you need to pick a couch that fits inside the phone in order to guaranteee that it can make the turn?
posted by misterbrandt at 12:27 PM on July 21, 2006

Not sure if everybody is kidding or not, but isn't the practical application of this simply that you need to pick a couch that fits inside the phone in order to guaranteee that it can make the turn?

No. Imagine a sofa that's 1 unit by 1 unit. This sofa would not fit inside Hammersley's Sofa, but would make it around the corner with no difficulty.
posted by UrineSoakedRube at 12:31 PM on July 21, 2006

Nerdpr0n.
posted by ZenMasterThis at 12:40 PM on July 21, 2006

This will no doubt come in handy the next time I need to move my 2-dimensional sofa.
posted by graventy at 1:47 PM on July 21, 2006

UrineSoakedRube: "Imagine a sofa that's 1 unit by 1 unit. This sofa would not fit inside Hammersley's Sofa, but would make it around the corner with no difficulty."

Also a semicircular sofa with a radius of one unit.
posted by Plutor at 1:55 PM on July 21, 2006

justkevin: "Is Hammersley's Sofa bigger than Shephard's Piano?"

Usenet post about the sofa problem, Shephard's Piano, and another called the "Conway car: what is the maximum area rigid 2-D shape that can reverse in a T-junction, all roads having unit width?"
posted by Plutor at 2:00 PM on July 21, 2006

Well, i tried to be subtle with a tip of the hat to keswick, but "splice" has me ready to go into full-on flamewar mode. Mr. Gently never had any bloody problems with any bloody couch, and to say any different is tantamount to slander. Nor did he work on any 3d simulations relating to couches - none at all. I fail to see why you people are so intent upon besmirching the good man's reputation vis-a-vis couch ownership, when the first bloody comment in the thread already identified the true perpetrator of such couch shenanigans. Shame on you, all of you.

Fridges are an entirely different subject altogether, and beyond the scope of any paltry mathematical formulae.
posted by dvdgee at 4:21 PM on July 21, 2006

I guess he lives in Flatland, then? The solution to moving any long piece of furniture around a corner frequently involves standing it on end, or nearly enough.

Also, rotating the sofa about its long axis often yields a profile that goes around the corner better than keeping it level.
posted by George_Spiggott at 7:13 PM on July 21, 2006

When I was a mover I would be amazed at the moving wizardry of the better movers who, I'm sure, would not have any clue what a differential looked like. Contrarially, I know what it looks like but I can neither make use of it, or any intuative version. (Just in case any of y'all want me to help you move).
My nickname as a mover was "Gorilla" in small part because of my great strength (and matching simian intellect), and in small part because I'm a Robin Williams/Yeti hirsute type, but mostly because of those Samsonite luggage commercials.
posted by Smedleyman at 8:04 PM on July 21, 2006

I guess he lives in Flatland, then? The solution to moving any long piece of furniture around a corner frequently involves standing it on end, or nearly enough.

No, but he is a mathematician. And the most helpful tool in a mathematician's bag is simplifying the problem beyond usefulness. See also:

"A dairy in a college town was having trouble staying competitive and keeping their costs down. The board met and decided to hire the smartest person they could find to help them make their operation more efficient. It was suggested that they find somebody at the university, for they must be very intelligent. They contacted a Nobel Laureate physicist, who agreed to help them out.

The physicist visited their operation and took copious notes on herd management, milking operations, packaging, etc. After six months, he called them and announced that he had a solution. The board met with high expectations.

The physicist began his presentation, "First, assume a spherical cow."

posted by Plutor at 5:33 AM on July 24, 2006