Your favorite (afforadable) math trinkets?

[EternusVia]

Hi all,

I want to buy my mathematics professor (who is also my adviser) a gift as a token of my gratitude for his hard work. Do you have a favorite math trinket/toy that you would recommend?

Note: He loves abstract math. His dissertation was in topology.

Thank you!

 

[Greg Bernhardt]

More of an engineering toy, but I always loved the metal links or parts put together and you needed to get a certain link off or the pieces separated. That can be entertaining for hours.

 

[Danger]

Same caveat as Greg's answer: I've always loved Newton's cradle. A waitress that I worked with in the bar gave me a small one as a gift once and I played with it like a besotted idiot for hours and hours. She was the only person at work who had any idea of how a scientific mind works, even though she wasn't precisely of that nature herself.

 

[collinsmark]

I might suggest perhaps a Rubik's Cube, but he probably already has one.

Maybe something alone these lines instead?


[Source: http://www.numberphile.com/videos/shapes_constant.html]

(If you go that route, you might want to get several of them for practical reasons.)

Some of these could work, but might be a little over the top:


[Source: http://www.numberphile.com/videos/mobius_bridge.html]

[Edit: See the end of that last video for a link to a video on Klein bottles and similar sorts of shapes. Those are some other ideas.]

 

[Danger]

Maybe something alone these lines instead?

Thanks for those links! I've bookmarked them to my "Amusements" folder.
There are two things that I've always wanted to make since I was about 10, and I think that I will pretty soon now that I can afford it and have time. One is a strip of crimson/orange electroluminescent panel about 6—8 cm wide and maybe 80 cm long twisted into a Mobius band and mounted vertically on a chrome or black base, with little round (blue, maybe?) LED's spaced 1—2 cm apart along the centreline on a "chase" sequencer. Its purpose would be for decoration rather than any useful lighting, and I'd love to see people's faces as they try to figure out where the lights are going. The other is a chrome wire-frame track (like a roller coaster) arranged as a Mobius band with a big steel ball (like from a pinball machine) perpetually rolling along it through some sort of magnetic adhesion/propulsion that I haven't figured out yet.

 

[BobG]

My favorite is a tie clip that's a fully working (albeit very small) slide rule.

My second favorite is my Otis King cylindrical slide rule. The scale is 10 feet long (but still fits in my pocket, as the scale is wrapped around a cylinder).

My third favorite is my Post 1460 Versalog slide rule.

My fourth favorite is my Picket N4-ES Hyperbolic dual base speed rule.

My fifth favorite is my Faber Castell 2/83N slide rule with mint green racing stripes.

My sixth favorite is my 4lb sledge hammer, ruler, and string.

My seventh favorite is a bicycle tire and a rope (plus whatever rotating chair is available).

My eighth favorite would have to be my pocket Pickett slide rule (which my avatar partially pictures).

 

[Bandersnatch]

Maybe these:

You could ask him if he could show you how to bisect an angle with your gift, because you coulod never figure it out yourself.

 

[Danger]

If he has a good sense of humour and you don't care that it isn't expensive, I just thought of something that he could use as a desk display to weird out other students. I guarantee that nobody else will have one, since I just invented it. (If you do it, post a picture on PF.)
Get a slip-on-cover cardboard box such as a jigsaw puzzle would come in. Print false labels to cover the 5 sides of the lid indicating that it's a plastic 500-piece 3D puzzle, along with a photorealistic rendering of a Penrose triangle. Fill the box with a bunch of hard plastic scraps, shrink-wrap the whole thing, and tell him to never open it because it will wreck the joke.

 

[Danger]

Maybe a 3D chess set? A copy of Godel Escher Bach? (I've never read it, but the math fanatics in my SF club 30 years ago loved it)

 

[EternusVia]

Thank you for all the recommendations!