If you have a Computer

• Protect Your Eyes, You Can’t Replace Them
  • Check out an app like f.lux to adjust the temperature of your display with day-night, reducing eye strain and affect on sleep cycles.
  • Check out an app like “Awareness” or “Time Out” (Mac only) that reminds you to take a break every 10-20 minutes to exercise your eyes and body. (There’s the 20-20-20 rule: every 20 minutes take 20 seconds to look at something 20 feet away.)
• Mouse If your mouse has a lot of friction, check out PTFE tape to put on the underside.
• Backing Up What would you loose if the drive on your computer (or phone) failed (or was lost)? Aim to follow the 3-2-1 backup rule: 3 copies of your data on 2 media types with 1 copy offsite.

If you have a Mac

• In Finder:
  • Use the combination command and the up arrow key (⌘↑) to go up (left) a column (especially if you are in a Save As… dialog and it won’t let you go further to the left without going to the dropdown menu).
  • Double click on column dividers to right-size them or right click on them for more options.
• Try out a window manager, I recommend Spectacle, you can easily put two windows side-by-side etc with some keyboard shortcuts.

Visualizing 4D Regular Polytopes: Hypernom

There are five convex regular polytopes in three dimensions: the Platonic Solids: tetrahedron, cube, octahedron, dodecahedron, and icosahedron. In four dimensions, there are six. All higher dimensions only have three. (In two dimensions, there are infinitely many: all the regular polygons). A full list of regular polytopes (including those that are not convex and those that are not finite) is here

https://en.wikipedia.org/wiki/List_of_regular_polytopes_and_compounds

http://hypernom.com/ is a wonderful visualization/game (created by Vi Hart et al) taking place on the (three dimensional) boundaries of the six convex regular polytopes in four dimensions.

How do you Build and Pilot Rockets?

Play this game: Kerbal Space Program

(and maybe read this https://what-if.xkcd.com/85/)

How to Estimate Large Quantities?

Fermi Estimation! Use orders of magnitude. A nice example: https://what-if.xkcd.com/84/

What is the correct month-day order?

by ISO 8601: YYYY-MM-DD

This makes it totally unambiguous and has the advantage of being big-endian, so it sorts easily (good for filenames).

Geometric Series

Disclaimer: The argument below is not rigorous. It happens to give the right answer, and is a useful way of thinking of/remembering this fact, but manipulating infinite series without the proper care can easily lead you astray.

Visualizing Infinite Ordinals

http://www.madore.org/~david/math/drawordinals.html

Anamorphic Illusions

These are spectacular: http://www.varini.org/varini/02indc/indgen.html

This, as with all OK GO, is inspiring: https://www.youtube.com/watch?v=m86ae_e_ptU

pro-pre-ante-pen-ultimate

ultimate : last

penultimate : second to last

antepenultimate : third to last

preantepenultimate : fourth to last

propreantepenultimate : fifth to last

Mnemonics

RED LEFT PORT

we require a mnemonic to remember e whenever we scribble math
2.    7    1    8     2     8     1    8     2     8      4   ...