Once in a while you stumble in a good book, and for me recently that was Applied Analysis by Cornelius Lanczos, published by Dover Books. This is a little gem of numerical analysis, and although it is a bit outdated, it is a book full of interesting tidbits of knowledge.
I recently decided that I ought to have a canonical set of colors to use in my publications and so I came up with the following seven colors:
Here are gnuplot definitions of lines using these colors. Feel free to use this set, and if you have suggestion on how to improve it, let me know!
# Canonical colors - full line
set style line 1 lc rgb '#000000' lt 1 lw 3.0 ps 0.5 pt 7 # black
set style line 2 lc rgb '#16469D' lt 1 lw 3.0 ps 0.5 pt 7 # dark blue
set style line 3 lc rgb '#BD202D' lt 1 lw 3.0 ps 0.5 pt 7 # red
set style line 4 lc rgb '#00A14B' lt 1 lw 3.0 ps 0.5 pt 7 # green
set style line 5 lc rgb '#4B96D1' lt 1 lw 3.0 ps 0.5 pt 7 # light blue
set style line 6 lc rgb '#F16521' lt 1 lw 3.0 ps 0.5 pt 7 # orange
set style line 7 lc rgb '#9F6EAF' lt 1 lw 3.0 ps 0.5 pt 7 # light purple
# Canonical colors - dashed line
set style line 11 lc rgb '#000000' lt 2 lw 3.0 ps 0.5 pt 7 # black
set style line 12 lc rgb '#16469D' lt 2 lw 3.0 ps 0.5 pt 7 # dark blue
set style line 13 lc rgb '#BD202D' lt 2 lw 3.0 ps 0.5 pt 7 # red
set style line 14 lc rgb '#00A14B' lt 2 lw 3.0 ps 0.5 pt 7 # green
set style line 15 lc rgb '#4B96D1' lt 2 lw 3.0 ps 0.5 pt 7 # light blue
set style line 16 lc rgb '#F16521' lt 2 lw 3.0 ps 0.5 pt 7 # orange
set style line 17 lc rgb '#9F6EAF' lt 2 lw 3.0 ps 0.5 pt 7 # light purple
Leonard Susskind has a great set of introductory lectures on string theory and M-theory.
I have been watching the first six lectures and I really enjoyed them. All the material is interesting and requires only some knowledge of quantum mechanics and special relativity. I really liked the explanation (in Lecture 4 or 5) of why some string theories need 26 dimension to work.
- – hyphen, used to join words and to separate syllables of a single word
Correct: “second-order PT”, “Lennard-Jones potential”
- − minus, used to indicated negative numbers and the subtraction sign
Correct: “1−2 = −1”
Wrong: “second−order PT”
- – en dash, used in ranges, used to contrast values, or illustrate a relationship between two things
Correct: “pp. 38–55”, “Fermi–Dirac statistics”, “Hartree–Fock”
Wrong: “–1”, “Lennard–Jones potential”
- — em dash, demarcates a parenthetical thought
Correct: “However, one might anticipate that in certain cases—in particular, when determining potential energy surfaces—the elimination of redundancies could pose a serious problem.”
In latex you can get this in the following way using the standard keyboard dash (-)
Minus sign: $0$, $1$ and $-1$
En dash: Hartree
Em dash: in certain cases
For more info check out the wikipedia article on dash.