Style for important dates, PIC code simplification.

master
Karchnu 2022-01-23 23:25:34 +01:00
parent 90ab23350c
commit f65e71cf75
4 changed files with 106 additions and 100 deletions

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@ -1,4 +1,12 @@
.so macros.ms
.de IMPORTANT_DATE
.gcolor darkblue
.I "\\$1"
\h'7p'
.gcolor black
.shift
\\$*
..
.so universe-from-nothing/header.ms
.TWO_COLUMNS
.so universe-from-nothing/preface.ms

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@ -121,67 +121,43 @@ TODO: explain how we measure stuff with telescopes (resolution, focal, arcsecond
Diffraction: behavior of waves when reaching an aperture.
.PS
reset
rad_large_circle = 0.6 # Size of circles.
rad_empty_space = 0.5 # Size of circles.
rad_light_source = 0.3 # Size of circles.
rad_aperture = 0.1 # Size of circles.
fill_large_circle = 0.1 # Represents light intensity.
fill_empty_space = 0.6 # Represents light intensity.
fill_light_source = 0 # Represents light intensity.
.\" Radius for different circles.
rad_large_circle = 0.6
rad_empty_space = 0.5
rad_light_source = 0.3
rad_aperture = 0.1
txt_x_shift = 0.05 # Shift from arrow start.
txt_y_shift = 0.05 # Shift from arrow start.
space_between_arrows_y = -0.25 # Allow space for text.
.\" Light intensity.
fill_large_circle = 0.1 # Very bright.
fill_empty_space = 0.6 # Little bright.
fill_light_source = 0 # Completely bright.
CIRCULAR_DIFFRACTION_FIGURE: [
circlerad = rad_large_circle
circle fill fill_large_circle
arrow_x_shift = 0.05
txt_y_shift = 0.25 # Allow space for text.
circlerad = rad_empty_space
move to last circle + (-circlerad, 0)
circle fill fill_empty_space
.\" Circles.
HALO: circle rad rad_large_circle fill fill_large_circle
EMPTY: circle with .c at HALO.c rad rad_empty_space fill fill_empty_space
SOURCE: circle with .c at HALO.c rad rad_light_source fill fill_light_source
APERTURE: circle with .c at HALO.c rad rad_aperture fill fill_light_source dashed
circlerad = rad_light_source
move to last circle + (-circlerad, 0)
circle fill fill_light_source
.\" Legend.
TAPERTURE: "Aperture, where light can pass through" ljust at HALO.e + (0.3, 0)
TSOURCE: "Main visible light source, very bright" ljust at Here + (0, -txt_y_shift)
TEMPTY: "Empty space, very little light" ljust at Here + (0, -txt_y_shift)
THALO: "Halo, thin light" ljust at Here + (0, -txt_y_shift)
circlerad = rad_light_source
move to last circle + (-circlerad, 0)
LIGHT_SOURCE: circle fill fill_light_source
.\" Arrows.
arrow from TAPERTURE + (-arrow_x_shift,0) to APERTURE chop 0 chop rad_aperture
arrow from TSOURCE + (-arrow_x_shift,0) to SOURCE chop 0 chop rad_light_source
arrow from TEMPTY + (-arrow_x_shift,0) to EMPTY chop 0 chop rad_empty_space
arrow from THALO + (-arrow_x_shift,0) to HALO chop 0 chop rad_large_circle
circlerad = rad_aperture
move to last circle + (-circlerad, 0)
APERTURE: circle fill fill_light_source dashed
# LEGEND.
move 0.6
arrow to APERTURE chop 0 chop rad_aperture
move to last arrow.s + (txt_x_shift,txt_y_shift)
"Aperture, where light can pass through" ljust
move to last arrow.s + (0,space_between_arrows_y)
arrow to LIGHT_SOURCE chop 0 chop rad_light_source
move to last arrow.s + (txt_x_shift,txt_y_shift)
"Main visible light source, very bright" ljust
move to last arrow.s + (0,space_between_arrows_y)
arrow to LIGHT_SOURCE chop 0 chop rad_empty_space
move to last arrow.s + (txt_x_shift,txt_y_shift)
"Empty space, very little light" ljust
move to last arrow.s + (0,space_between_arrows_y)
arrow to LIGHT_SOURCE chop 0 chop rad_large_circle
move to last arrow.s + (txt_x_shift,txt_y_shift)
"Halo, thin light" ljust
# let's cheat a little
# Center the figure.
.\" Let's cheat a little: centering the figure.
false_line_x = 2.7
line from LIGHT_SOURCE + (false_line_x,0) to LIGHT_SOURCE + (false_line_x,0)
]
line from SOURCE + (false_line_x,0) to SOURCE + (false_line_x,0)
move to CIRCULAR_DIFFRACTION_FIGURE + (0, -1)
"Circular diffraction"
.ps 14
"Circular diffraction" at HALO.s + (1, -1)
.PE

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@ -5,13 +5,13 @@ Contrary to the book, I describe things chronogically in the summary.
Some pieces of information (such as dates, explanations, events), absent from the book, are added for the sake of completeness.
.METAINFO2
1514: Nicolaus Copernicus suggests an heliocentric model.
.IMPORTANT_DATE 1514 Nicolaus Copernicus suggests an heliocentric model.
.EXPLANATION1
Planets move around the sun.
.EXPLANATION2
Between 1609 and 1619: Johannes Kepler publishes his
.IMPORTANT_DATE "Between 1609 and 1619" Johannes Kepler publishes his
.I "laws of planetary motions" ,
which fixes a few problems with the view of Copernicus on the matter:
@ -44,8 +44,7 @@ of a planet is directly proportional to the
of its orbit (or, in other words, of the "semi-major axis" of the ellipse, half of the distance across the widest part of the ellipse).
.ENDBULLET
1665: Isaac Newton uses a prism to see the sunlight disperse into the colors of a rainbow.
.IMPORTANT_DATE 1665 Isaac Newton uses a prism to see the sunlight disperse into the colors of a rainbow.
He manages to obtain this result by only letting the light of the sun enter a room by a small hole in the window shutter.
His conclusion: the white light contains all these colors.
@ -53,9 +52,9 @@ His conclusion: the white light contains all these colors.
Sunlight contains a spectrum of colors.
.EXPLANATION2
1784: first observation of Cepheid variable star, which are stars whose brightness varies over some regular period.
.IMPORTANT_DATE 1784 first observation of Cepheid variable star, which are stars whose brightness varies over some regular period.
(around) 1815: a scientist\*[*]
.IMPORTANT_DATE "(around) 1815" a scientist\*[*]
.FOOTNOTE1
His name is not given in the book.
.FOOTNOTE2
@ -72,13 +71,13 @@ some part of the solar spectrum.
Different materials, different parts of the spectrum.
.EXPLANATION2
1842: Christian Doppler discovers the Doppler Effect.
.IMPORTANT_DATE 1842 Christian Doppler discovers the Doppler Effect.
.EXPLANATION1
Doppler Effect: a wave coming at you will be stretched if the source is moving away from you, or compressed if the source is coming toward you.
.EXPLANATION2
1868: a scientist\*[*]
.IMPORTANT_DATE 1868 a scientist\*[*]
.FOOTNOTE1
Again, not named in the book.
.FOOTNOTE2
@ -101,7 +100,7 @@ is isolated on Earth.
The spectrum of radiation of stars provides their composition, temperature and evolution.
.EXPLANATION2
1908-1912: Henrietta Swan Leavitt discovers a relation between the brightness of Cepheid variable stars and their pulsation period.
.IMPORTANT_DATE 1908-1912 Henrietta Swan Leavitt discovers a relation between the brightness of Cepheid variable stars and their pulsation period.
.EXPLANATION1
The light spreads out uniformly over a sphere whose area increases as the square of the distance (this is called the inverse-square law).
@ -120,7 +119,7 @@ Therefore, comparing its known luminosity to its observed brightness gives us th
.\".CITATION2
.\".NAMECITATION "Lawrence Krauss"
.
Starting in 1912, Slipher observes the spectra of light coming from nearby stars and distant spiral nebulae\*[*]
.IMPORTANT_DATE "Starting in 1912" Slipher observes the spectra of light coming from nearby stars and distant spiral nebulae\*[*]
.FOOTNOTE1
.I Nebulae
that we will soon find out they are actually entire galaxies.
@ -130,7 +129,7 @@ The difference is a shift of the same wavelength in the
.I absorbed
lines.
1916, A. Einstein publishes his work on the
.IMPORTANT_DATE 1916 A. Einstein publishes his work on the
.I "general theory of relativity" .
This work is about gravity, space and time, and explains not only how objects move in the universe, but also how the universe itself might evolve.
Amongst many uses of this theory, the orbit of Mercury can be predicted more accurately than before with Newton's theory of gravity.
@ -147,7 +146,7 @@ Gravitation is thought to be an attractive force: objects should then always col
Also, the scientific community still thinks the universe as static, eternal and composed of a single galaxy (our Milky Way) surrounded by a vast, dark, infinite empty space.
And without accurate knowledge of the distances with observed stars, nor better images, this idea seems consistent with the observations.
1917: Mount Wilson 100-inch (2.5 m) Hooker telescope, the world's largest at the time (from 1917 to 1949).
.IMPORTANT_DATE 1917 Mount Wilson 100-inch (2.5 m) Hooker telescope, the world's largest at the time (from 1917 to 1949).
It will soon help to discover many things.
For example,
to prove the Andromeda nebula is external to our galaxy (1923, Edwin Hubble),
@ -159,7 +158,7 @@ etc\*[*].
We now make ten times bigger telescopes and hundred times bigger in area.
.FOOTNOTE2
1923-1924, with the period-luminosity relation and the measurement of Cepheid variable stars, Hubble determines that the distance with some Cepheids are too great to be inside our Milky Way\*[*].
.IMPORTANT_DATE 1923-1924 with the period-luminosity relation and the measurement of Cepheid variable stars, Hubble determines that the distance with some Cepheids are too great to be inside our Milky Way\*[*].
.FOOTNOTE1
Hubble identifies a first galaxy (NGC 6822) in 1925, then the Triangulum galaxy (M33) in 1926, and Andromeda (M31) in 1929.
.FOOTNOTE2
@ -168,16 +167,16 @@ Hubble identifies a first galaxy (NGC 6822) in 1925, then the Triangulum galaxy
The universe contains other galaxies.
.EXPLANATION2
1925: Hubble publishes his study on spiral
.IMPORTANT_DATE 1925 Hubble publishes his study on spiral
.I nebulae ,
where he identified Cepheid variable stars in them (including the
.I nebulae
we currently know as Andromeda).
1927: Georges Lemaître is the first person to suggest the universe is expanding.
.IMPORTANT_DATE 1927 Georges Lemaître is the first person to suggest the universe is expanding.
This is his conclusion after solving the Einstein's equations for general relativity.
1929: Hubble remarks that galaxies are moving away from each other.
.IMPORTANT_DATE 1929 Hubble remarks that galaxies are moving away from each other.
More importantly, the more distant, the faster the velocity.
The relation is linear: a galaxy twice more distant is moving away twice as fast.
@ -185,7 +184,7 @@ The relation is linear: a galaxy twice more distant is moving away twice as fast
The universe is expanding.
.EXPLANATION2
1930: Georges Lemaître proposes that the universe began in a very small point, which he called
.IMPORTANT_DATE 1930 Georges Lemaître proposes that the universe began in a very small point, which he called
.I "Primeval Atom" \*[*].
.FOOTNOTE1
This isn't accepted by the scientific community right away: actual observations were provided by Edwin Hubble beforehand.

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@ -185,43 +185,66 @@ Stay tuned, kids!
.PARAGRAPH_UNINDENTED
.ft H
.PS
.ps 7
.vs 9p
.ps 7
reset
scale = 1.4
mag_massive_obj_x = 1.4
mag_massive_obj_y = -1
.
rad_obs = 0.3
rad_massive_obj = 0.5
rad_mag = 0.4
rad_dist = 0.27
.
.defcolor lightgreen rgb 0.9 1.0 0.9
.defcolor lightblue rgb 0.9 0.9 1.0
.defcolor bloatcode rgb 1.0 0.1 0.1
.\" Drawing direction.
down
OBSERVER: circle rad rad_obs "Observer"
scale = 1.4
.\""""""""""""""""""""""""""""""
.\" Variables to ajust elements.
.\" Distances x and y between the massive object and magnified ones.
mag_obj_x = 1.4
mag_obj_y = -1
.\" Radius of the different celestial objects.
rad_obs = 0.3
rad_massive_obj = 0.5
rad_mag = 0.4
rad_dist = 0.27
.\" Distance between the light beam of the distant object
.\" reaching the observer and the massive object's center.
dist_beam_massive_obj = 0.32
.\"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
.\" Drawing of the celestial corpses (planets, galaxies, etc.).
.\" Observer, massive object and the distant object.
OBSERVER: circle radius rad_obs "Observer"
move
MASSIVE_OBJECT: circle rad rad_massive_obj "Massive" "object"
move 1
TARGET: circle rad rad_dist "Distant" "object"
move to MASSIVE_OBJECT + ( mag_massive_obj_x, mag_massive_obj_y)
MAGNIFIED1: circle rad rad_mag "Magnified" "distant" "object"
move to MASSIVE_OBJECT + (-mag_massive_obj_x, mag_massive_obj_y)
MAGNIFIED2: circle rad rad_mag "Magnified" "distant" "object"
.
MASSIVE_OBJ: circle radius rad_massive_obj "Massive" "object"
move
TARGET: circle radius rad_dist "Distant" "object"
.\" "radius" can be abreviated in "rad".
.\" Magnified objects.
MAGNIFIED1: circle rad rad_mag "Magnified" "distant" "object" at MASSIVE_OBJ + ( mag_obj_x, mag_obj_y)
MAGNIFIED2: circle rad rad_mag "Magnified" "distant" "object" at MASSIVE_OBJ + (-mag_obj_x, mag_obj_y)
.\" Lines from the magnified objects to the observer.
.\" chop = do not draw within the circles (a radius is given).
line from MAGNIFIED1 to OBSERVER chop rad_mag chop rad_obs dashed
line from MAGNIFIED2 to OBSERVER chop rad_mag chop rad_obs dashed
.
rad_correction = 0.32
spline -> from TARGET to MASSIVE_OBJECT.e + (rad_massive_obj-rad_correction,0) to OBSERVER chop rad_dist chop rad_obs
spline -> from TARGET to MASSIVE_OBJECT.w + (-rad_massive_obj+rad_correction,0) to OBSERVER chop rad_dist chop rad_obs
.
move to TARGET + (0,-0.7)
.\" Arrows, from distant object to the observer.
spline -> from TARGET to MASSIVE_OBJ.e + (dist_beam_massive_obj,0) to OBSERVER chop rad_dist chop rad_obs
spline -> from TARGET to MASSIVE_OBJ.w + (-dist_beam_massive_obj,0) to OBSERVER chop rad_dist chop rad_obs
.vs
.ps 14
"Gravitational lensing"
"Gravitational lensing" at TARGET + (0,-0.7)
.PE
.PS
reset
.PE
.ft R