#!/usr/bin/env python3
"""Generate the claims table on docs/globe-claims/index.html from one data set.
The book's closing chapter assigns the heliocentrists a hundred and three claims of its own
choosing. This is the list the globe model actually rests on: fourteen structural claims,
each with its number, the observation that tests it, what would falsify it, how far a reader
can check it without an agency, and a reference with enough detail to act on. Edit the data
here, re-run, and the page and tests/test_globe_claims.py follow.
python3 build_globe_claims.py -> rewrites the page table in place
python3 build_globe_claims.py --check -> prints the tally and exits
"""
import os
import re
import sys
ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
PAGE = os.path.join(ROOT, "docs", "globe-claims", "index.html")
SITE = "https://funwithscience.net/globe-deconstruction/"
# check level: "ground" = modest kit from a garden; "tools" = amateur astronomy tools, not agencies
GROUND, TOOLS = "ground", "tools"
# (id, title, claim with the number, the test, what would falsify it, check level, reader-check line, reference html, site pages)
CLAIMS = [
("shape", "Shape",
"The Earth is an oblate spheroid: mean radius 6,371 km, equatorial 6,378 km, polar 6,357 km, flattening 1/298.",
"Horizon dip grows as √h and hidden height as D²/2R; Polaris’s altitude equals latitude; a degree of latitude is about 111 km everywhere.",
"A horizon that never hides objects bottom-up; Polaris not tracking latitude; a degree of latitude that changes length with position.",
GROUND, "A camera at two known heights over calm water, or a sextant on Polaris and a road atlas.",
"Moritz, “Geodetic Reference System 1980,” Journal of Geodesy 74 (2000) 128 for the ellipsoid constants; the hiding arithmetic on the Reverse Refraction Solver.",
["bottom-up-observations", "long-path-cases", "celestial-globes"]),
("spin", "Spin",
"The Earth turns once on its axis in 23 h 56 m 4 s (one solar day of 24 h), west to east.",
"Star trails at 15.04° per hour about the celestial pole; the Foucault pendulum precessing at 15° × sin(latitude) per hour; Coriolis on drifting buoys and in every weather model.",
"Stars and planets turning at different rates; a pendulum that does not precess; no Coriolis.",
GROUND, "A fixed camera on the night sky for an hour, or a long pendulum watched for one.",
"IERS Conventions (2010), Technical Note 36, ch. 1, for the rotation rate; the Coriolis drifter data on this site.",
["sky-rate-and-shadows", "earth-rotation", "coriolis-drifters"]),
("atmosphere", "An atmosphere held by gravity",
"Air pressure falls with height by the hydrostatic (barometric) law: about 12 hPa per 100 m at sea level, halving by 5.5 km.",
"Any radiosonde sounding; a phone barometer carried up a hill; the same law predicting the altimeter setting every aircraft uses.",
"A pressure profile that is not hydrostatic; pressure not falling with height.",
GROUND, "A phone barometer and a 100 m hill.",
"U.S. Standard Atmosphere 1976, Table 1; the University of Wyoming sounding archive for any station and date.",
["hydrostatics"]),
("refraction", "Refraction, computable from the weather",
"Light through air bends toward denser air. The bend follows the temperature gradient, k = 503·(P/T²)·(0.0342 + dT/dh), is greatest along the horizon, lifts the setting Sun by about 34′ in standard air (k ≈ 0.13–0.17), and cannot exceed what a gradient the air can hold allows: past −34.2 °C/km a layer overturns.",
"Sunset and moonrise times against the almanac; hidden heights across water against the day’s sounding; the mirage classes matching the measured inversion.",
"Refraction that does not follow the measured gradient; the gradients a flat plane needs for the same pictures actually occurring in the air.",
GROUND, "A timed sunset against the almanac, or a photograph across water with the nearest sounding.",
"Bomford, Geodesy (4th ed., OUP 1980), §3.19 on the refraction coefficient; the Reverse Refraction Solver, which prices any photograph on both surfaces; Ives (1968) on instrumented looming, cited on the Rampion page.",
["long-path-cases", "rampion", "mirrored-reflections", "sunlight-and-shadows"]),
("orbit", "Orbit",
"The Earth orbits the Sun in 365.256 days at a mean distance of 149.6 million km.",
"Stellar aberration of 20.5″, the same for every star, in phase with the orbit; annual parallax of the nearest stars (Proxima 0.77″, 61 Cygni 0.29″); the night sky shifting by 1° a day.",
"Zero aberration; zero parallax; a sky that does not advance through the year.",
TOOLS, "Bessel’s 1838 parallax of 61 Cygni has been repeated by amateurs with a CCD over a season; aberration needs a year of careful astrometry. Tools, not agencies.",
"Bessel’s letter to Herschel on the parallax of 61 Cygni, MNRAS 4 (1838) 152; Bradley, “An account of a new discovered motion of the fix’d stars,” Phil. Trans. 35 (1728) 637; the astronomical unit from Venus radar, Muhleman, AJ 67 (1962) 277.",
["sun-does-not-shrink", "sunlight-and-shadows"]),
("kepler", "Everything orbits the Sun; moons orbit planets",
"Kepler’s laws hold with one mass at the centre: T² ∝ a³ for every planet about the Sun and for every moon about its planet, with the constant fixed by the central mass.",
"A fortnight of Galilean-moon timings in a small telescope gives Jupiter’s GM to a few per cent; Venus runs a full crescent-to-gibbous phase cycle; retrograde loops fall at opposition.",
"A body whose period breaks T² ∝ a³; Venus without a full phase cycle; retrograde motion at the wrong time.",
GROUND, "A 100-mm telescope, a clock, and two weeks on Jupiter’s moons.",
"Kepler, Astronomia Nova (1609) and Harmonices Mundi (1619); the CLEA “Revolution of the Moons of Jupiter” exercise for the amateur measurement.",
["jupiter-shadows", "eight-planets", "planetary-imaging"]),
("stars", "Stars are distant, not infinitely so",
"The stars are suns at light-years, with small but measured motions: Barnard’s star moves 10.4″ a year; parallaxes are measured to microarcseconds by Gaia; the Plough’s shape changes over tens of thousands of years.",
"Two photographs of Barnard’s star a year apart in a 100-mm telescope show the shift; the same spectral lines in starlight as in sunlight.",
"Any star at a dome-scale distance (kilometres to thousands of kilometres) measured by parallax; stars with no proper motion at all.",
TOOLS, "A small telescope and a camera, two nights a year apart, on Barnard’s star; a grating for the spectrum.",
"Barnard, “A small star with large proper-motion,” AJ 29 (1916) 181; Gaia Collaboration, “Gaia Data Release 3,” A&A 674 (2023) A1.",
["sky-rate-and-shadows"]),
("gas", "Gas obeys Newton’s third law",
"Exhaust is mass; momentum is conserved whatever the phase. A rocket’s thrust is the mass rate times the exhaust speed and does not need anything outside to push on.",
"Thrust measured in a vacuum chamber, and in flight above the atmosphere where ambient pressure is zero; thrust that rises as the ambient pressure falls, as the nozzle equation says.",
"Thrust that falls to zero as the chamber pressure does; a measured engine that pushes only when there is air behind it.",
GROUND, "A balloon cart in a bell jar under a pump, with the question the run must answer set out on the rockets page.",
"Sutton & Biblarz, Rocket Propulsion Elements (9th ed., Wiley 2017), ch. 2–3, the thrust equation and its pressure term; the in-flight measurements on Thrust, Measured in Flight.",
["rockets-in-vacuum", "thrust-in-flight", "action-lab-footage"]),
("gravity", "Gravity: proportional to mass, and universal",
"Weight is proportional to mass everywhere (g = 9.81 m/s² at the surface); the same inverse-square law, with one constant, gives the Moon’s month, every satellite’s period, and two tides a day with springs and neaps on the lunar cycle. g is 9.780 m/s² at the equator and 9.832 at the poles.",
"A spring scale against a balance shows weight tracking mass. A seconds pendulum runs about 2 ms per swing slower at the equator than at 60° N, 2.7 ms against the pole — 1,000 swings against a stopwatch shows it — and the 0.53 % pole-to-equator difference decomposes into 0.35 % from the spin and 0.18 % from the bulge, so one pendulum carried north tests claims 1, 2 and 9 together. The fall-off with distance is the part that needs a friend at altitude or the satellite periods.",
"Weight not proportional to mass; the same g at every latitude; a satellite or moon whose period does not match GM/r³; tides not on the lunar cycle.",
GROUND, "A pendulum, a stopwatch and a trip north; a tide table and a lunar calendar.",
"Moritz (2000), as above, for the normal-gravity formula; Kater’s pendulum, Phil. Trans. 108 (1818) 33; NOAA Tides & Currents for the springs and neaps.",
["hydrostatics", "equator-flight"]),
("tilt", "Axial tilt, and the seasons",
"The axis is tilted 23.44° to the orbit. The Sun’s noon altitude swings ±23.44° through the year; the midnight sun runs poleward of 66.56° in both hemispheres; day and night are equal everywhere at the equinox.",
"A noon shadow measured on the solstices and equinoxes; the sunrise azimuth swinging 47° along the horizon through the year at mid-latitudes; sunrise and sunset tables.",
"A southern midnight sun that does not occur; unequal days at the equinox; a noon-Sun swing of other than 46.9°.",
GROUND, "A stick and its noon shadow on four days of the year.",
"The Astronomical Almanac (USNO/HMNAO), section C, for obliquity and the Sun’s declination; the USNO rise/set tables for the azimuth swing.",
["sunlight-and-shadows", "antarctica-magnetic"]),
("sunmoon", "The Sun and the Moon",
"The Sun is 149.6 million km away and 1.39 million km across, a constant 0.53° wide from sunrise to sunset; the Moon is 384,400 km away and 3,474 km across, a sphere lit by the Sun, its phase set by the Sun–Moon–Earth angle and its terminator a curve only a lit sphere shows.",
"The Sun’s angular size measured through the day with a filter; the Moon’s phase against the Sun’s direction; the lunar distance from a timed occultation seen from two places.",
"A Sun that visibly shrinks toward the horizon; a phase inconsistent with the Sun’s position; a terminator that is not the edge of a lit sphere.",
GROUND, "A solar filter and a camera at two times of day; a month of Moon photographs with the Sun’s position noted.",
"The Astronomical Almanac, sections C and D; the angular-size measurement on The Sun Does Not Shrink and the terminator geometry on Is the Moon a Ball?.",
["sun-does-not-shrink", "moon-sphericity", "full-moon-lighting", "luminaries"]),
("eclipses", "Eclipse geometry",
"A lunar eclipse shows a circular Earth shadow about 2.7 Moon-diameters wide whatever the Moon’s altitude; a solar eclipse’s track of totality is 100–270 km wide and is predicted to the kilometre and the second centuries ahead.",
"The next lunar eclipse, photographed; the next solar eclipse, met at the predicted place and time.",
"A non-circular umbra; a shadow edge whose curvature changes with the Moon’s altitude; a predicted eclipse that fails to occur where and when stated.",
GROUND, "A camera at the next lunar eclipse; a map and a clock at the next solar one.",
"Espenak & Meeus, Five Millennium Canon of Lunar Eclipses (NASA TP-2009-214172); the eclipse pages on this site.",
["selenelion", "eclipse-trajectory", "luminaries"]),
("hemispheres", "Two hemispheres, symmetric",
"The southern sky turns clockwise about a southern pole with its own circumpolar stars; Coriolis reverses sign; the Sun crosses the northern sky right to left; both hemispheres see a midnight sun at the same latitude band.",
"A star-trail photograph from the southern hemisphere; a southern sunrise-to-sunset time-lapse; the drifter data by hemisphere.",
"A southern sky that behaves like a stretched northern one: no southern pole of rotation, or the same sense of rotation at both poles.",
GROUND, "A camera on the night sky from anywhere south of the equator, or a friend there with one.",
"The Coriolis drifter analysis on this site, split by hemisphere; any southern-hemisphere star-trail photograph with its location.",
["coriolis-drifters", "celestial-globes"]),
("surface", "Surface geometry is spherical",
"Distances and directions on the surface follow spherical, not planar, geometry: great circles are the shortest routes, a triangle’s angles sum to more than 180°, and Sydney–Santiago is 11,300 km, flown non-stop in 12–14 hours.",
"Published flight times against great-circle distances on many routes at once, southern routes included; surveyed triangulation networks that close only with spherical excess.",
"A flight time inconsistent with the spherical distance; a large surveyed triangle whose angles sum to exactly 180°.",
GROUND, "A timetable and the haversine formula, for as many routes as patience allows.",
"Any airline timetable against the great-circle distance (the haversine calculator at Movable Type computes it); Torge & Müller, Geodesy (4th ed., de Gruyter 2012), ch. 2, on spherical excess in triangulation.",
["equator-flight", "antarctica-magnetic"]),
]
PAGES = {
"bottom-up-observations": "Bottom Up Observations", "long-path-cases": "Chicago & Pontchartrain", "celestial-globes": "Celestial Globes Exposed",
"sky-rate-and-shadows": "The Sky Turns at One Rate", "earth-rotation": "Does the Earth Spin?", "coriolis-drifters": "Coriolis Drifters",
"hydrostatics": "Hydrostatics", "rampion": "The Black Swan (Rampion)", "mirrored-reflections": "Mirrored Reflections",
"sunlight-and-shadows": "Sunlight & Shadows", "sun-does-not-shrink": "The Sun Does Not Shrink", "jupiter-shadows": "Jupiter's Shadows",
"eight-planets": "The Eight-Planet Photograph", "planetary-imaging": "Stacked & Sharpened", "rockets-in-vacuum": "Rockets Don't Push Against Air",
"thrust-in-flight": "Thrust, Measured in Flight", "action-lab-footage": "Action Lab Footage", "equator-flight": "Equator Flight Data",
"antarctica-magnetic": "The Compass in Antarctica", "moon-sphericity": "Is the Moon a Ball?", "full-moon-lighting": "Full-Moon Lighting",
"luminaries": "Where's the Moon's Silhouette?", "selenelion": "The Selenelion", "eclipse-trajectory": "The Eclipse Trajectory",
}
def validate():
assert len(CLAIMS) == 14
ids = [c[0] for c in CLAIMS]; assert len(set(ids)) == 14
for c in CLAIMS:
assert c[5] in (GROUND, TOOLS), c[0]
assert "href=" in c[7], c[0]
for p in c[8]:
assert p in PAGES and os.path.isdir(os.path.join(ROOT, "docs", p)), (c[0], p)
def tally():
return {GROUND: sum(1 for c in CLAIMS if c[5] == GROUND), TOOLS: sum(1 for c in CLAIMS if c[5] == TOOLS)}
def table_html():
o = ['
#
The claim, with its number
The test
What would falsify it
Reader-check
']
for i, (cid, title, claim, test, falsify, level, reader, ref, pages) in enumerate(CLAIMS, 1):
chip = 'from the ground' if level == GROUND else 'tools, not agencies'
links = ", ".join(f'{PAGES[p]}' for p in pages)
o.append(f'
{i}
{title}. {claim} {ref}
'
f'
{test} On this site: {links}
{falsify}
{chip} {reader}
')
o.append("
")
return "\n".join(o)
def inject(html, key, body):
pat = re.compile(rf"().*?()", re.S)
assert pat.search(html), key
return pat.sub(lambda m: m.group(1) + "\n" + body + "\n" + m.group(2), html)
def main():
validate()
if "--check" in sys.argv:
print(len(CLAIMS), "claims", tally()); return
html = open(PAGE, encoding="utf-8").read()
html = inject(html, "TABLE", table_html())
open(PAGE, "w", encoding="utf-8").write(html)
print("wrote", os.path.relpath(PAGE, ROOT), tally())
if __name__ == "__main__":
main()