hi-res

Here’s a physically intuitive reason that rotations ↺

(which seem circular) are in fact linear maps.

If you have two independent wheels that can only roll straight forward and straight back, it is possible to turn the luggage. By doing both linear maps at once (which is what a matrix
$\large \dpi{300} \bg_white \begin{pmatrix} a \rightsquigarrow a & | & a \rightsquigarrow b & | & a \rightsquigarrow c \\ \hline b \rightsquigarrow a & | & b \rightsquigarrow b & | & b \rightsquigarrow c \\ \hline c \rightsquigarrow a & | & c \rightsquigarrow b & | & c \rightsquigarrow c \end{pmatrix}$

or Lie action does) and opposite each other, two straights ↓↑ make a twist ↺.

Or if you could get a car | luggage | segway with split (= independent = disconnected) axles

to roll the right wheel(s) independently and opposite to the left wheel(s)

, then you would spin around in place.

Still Life with Cat

(I don’t know the title or the artist of this image. If you know/are the artist, please isomorphismes.tumblr.com/ask with the correct attributions!)

hi-res

108 Plays

This morning I had another talk with the German Chancellor, Herr Hitler, and here is the paper which bears his name upon it as well as mine. (cheers) Some of you, perhaps, have already heard what it contains but I would just like to read it to you: “We, the German Fuhrer and Chancellor, and the British Prime Minister, have had a further meeting today, and are agreed in recognising that the question of Anglo-German relations is of the first importance for the two countries, and for Europe. (mutters of approval) We regard the agreement signed last night and the Anglo-German Naval Agreement as symbolic of the desire of our two peoples never to go to war with one another again.

(wild cheering)

—Neville Chamberlain, 30th September 1938

I wish I could meet a super-smart lawyer from the early Middle Ages who would persuasively argue me the divine right of kings, primogeniture, appanage, the distinction between movable and immovable property.

(Source: Wikipedia)

hi-res

317 Plays

(That’s Just) The Way My Dick Is by My Dick

“Quality Time”

Words that seem innocuous to me can set other people into anger mode. (I too, of course, have my own buttons that can be pushed—mostly economics-related.)

One woman who has raised more children than I can even fathom doing (9) will launch off if she hears the phrase “quality time”.

She says “Quality time” is short for “I don’t really know my kids—but I’ll make up for it by going to their sports games and dance recitals.”

To her, ∄ such thing as “quality time”—time spent with your kids that’s significantly better than, or can make up for, other, less important, time. For her you really get to know your kids during all the unimportant, mundane, pedestrian moments of life.