Whoa, 4 Colors Not So Sufficient...

 Things never seem to be as simple as they appear... "Computational Complexity" notes that, subtly, 4 colors are not so sufficient in the Four Color Map Theorem as most assume...:

https://blog.computationalcomplexity.org/2021/08/do-four-colors-suffice.html

Hahh!

 A little end-of-week humor... I don't see a lot of new math humor these days that really makes me chuckle any more, but this bumper sticker recently seen on Twitter (H/T Simon Pampena) did (...though perhaps it's quite old and I've just missed it or forgotten it):

Strip Tease...

The Möbius strip of course...

I suspect we all think we've read enough about Möbius strips in the last many years (decades?)... but I'd encourage folks to make time for Evelyn Lamb's current read on the topic (one of her "favorite spaces"):

http://blogs.scientificamerican.com/roots-of-unity/a-few-of-my-favorite-spaces-the-moebius-strip/

She relates it back to the four-color-theorem, which is not often done (or six-color-theorem in this case). And these days, if you're expounding on Möbius strips, it's almost obligatory to include Vi Hart's story based on the same. I'm happy to report that Dr. Lamb does so at the end.

The Topology of DNA

New from Numberphile; amazing stuff (of life):

M&Ms in a Klein Bottle

From 10 yrs. ago, but recently tweeted by Clifford Pickover, this yummy topology puzzle:

http://www.kleinbottle.com/m%26ms_in_a_klein_bottle.htm

and the interesting, winning answer here:

http://www.kleinbottle.com/Bernie_Tao.htm

(next question: how many Snicker Bars will fit in a tesseract?... just kidding)