321540ed91e193ce555f1a706111f7cd1af6dacc
7
Commits
| Author | SHA1 | Message | Date | |
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  SenrokaiandClaude Opus 5.5
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20c34f9662 |
Test the 1972 hand-over to the leap seconds where it happens, and give the ΔT comment its measured joins
The continuity test sampled 1972 at 2451544.5 + (1972 - 2000) x 365.2425 +/- 0.01 d, which is JD
2441317.70 and .72; the switch is at the calendar's 1 January 1972, JD 2441317.5, so both samples
read the leap-second table (42.184 and 42.184) and the join was never compared. Moving the switch
two years early (a 1.99 s step in 1970) passed all 836 tests. The hand-over now has its own test:
the step across midnight must be under 0.1 s (it is 0.067: 42.2514 to 42.184), and the last day of
1971 must still read the polynomial's 42.2485 s. Control: the switch at JD_1972 - 730 fails that
test only (1 failed, 836 passed).
The polynomials' own joins, measured 1e-6 d either side: 0.251 s at 1600, 0.162 at 1700, 0.087 at
500, 0.088 at 1900, and under 0.06 elsewhere.
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SenrokaiandClaude Opus 5.5
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cbe4908219 |
Turn Earth by the Earth Rotation Angle, so its lit face stays Horizons' at AD 1 as it is today
Earth was turned by its IAU W, taken at the clock's UT plus today's 69.184 s. That W is a straight
line fitted to the present: 360.9856235 degrees a day, which, once its pole's -0.641 degrees a
century in right ascension is counted, runs 6.3e-6 degrees a day slow of Earth's real turning. The
followsUt comment said the clock's date "already says how far it has turned"; it did not. Against
Horizons (observer quantity 14 from the Sun, TIME_TYPE=UT, Earth one light-time back) the drawn
sub-solar point was 2.3 degrees off at AD 1000 and 4.5 at AD 1.
Earth is now turned by the IERS Earth Rotation Angle (IERS Conventions 2010, eq. 5.15) at the
clock's date, counted from the node the IAU's W starts at, 90 degrees past the pole's right
ascension. The pole is unchanged. Drawn minus Horizons, in degrees:
date before after
2025-06-01 12:00 (unit) +0.06 -0.003
AD 1000, JD 2086455 (unit) -2.3 -0.001
AD 1, JD 1721600 (unit) -4.5 +0.051
live app, :4301, same probe as the review's
JD 2460900.25 +0.089 +0.005
JD 2086300.5 -2.281 +0.010
JD 1800000 -4.049 +0.056
JD 1721450.75 -4.530 +0.072
At noon UTC on 1 June 2025 the Sun now stands over 0.52 W on the drawn sphere, where the equation
of time puts it at 0.53 W (0.43 W before).
TT_MINUS_UTC_DAYS had no other use and is removed; its comment also counted 37 leap seconds where
UTC has taken 27 on top of the 10 s it started from in 1972.
Tests: body-orientation.spec 'lights Earth's face where Horizons does at the far end of the clock
too: AD 1000 and AD 1' (within 0.15 degrees), and the renderer's AD 1000 Earth test now checks the
drawn face against Horizons instead of against the IAU W the old code used. Control: turning Earth
by its IAU W at UT + 69.184 s again fails both named tests (2 failed, 834 passed). The README says
which model turns Earth.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
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SenrokaiandClaude Opus 5.5
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34ae803c06 |
Take TT - UT from the historical record before 1972, so the far dates the clock reaches turn every body by the right amount
The clock reaches AD 1, but TT - UT was held at today's 69.184 s. At AD 1000 it was 1 574 s and at AD 1 about 10 570 (Espenak and Meeus, NASA's Five Millennium Canon; Horizons' TDB - UT gives 1 658 and 10 466 on JD 2086455 and 1721600). So every spin but Earth's was (ΔT - 69 s) times its rate out, Jupiter 15.2 degrees at AD 1000 and 106 at AD 1, Mars 6 and 43, and every orbit that much behind: the Moon about 0.2 and 1.4 degrees. ttMinusUtSeconds gives TT - UT for a date on the clock: the Espenak-Meeus polynomials before 1972, 32.184 s plus UTC's leap seconds from 1972 to the last one, at the start of 2017, and 69.184 s held after it, as Horizons holds it. Its pieces join within 0.1 s. tdbFromUtc, which positions and spins already share, now adds it. Within 0.2 s of Horizons in 1950, 105 s at AD 1 and 86 s at AD 1000, where the historical record itself is that uncertain. Earth is the exception: its turning is what UT counts, so the clock's date already says how far it has turned, and ΔT would turn it again, 44 degrees at AD 1. Its W, fitted to today, keeps today's 69.184 s (bodyOrientation's followsUt, set for Earth in the system view and on its page). In the running app at 1000-01-01 00:00 UT, Jupiter's drawn prime meridian sits 0.000 degrees from its IAU W at TT and 15.164 from where the held offset put it; Earth's sits on its W at UT + 69.184 s, 6.288 degrees short of what TT would have turned it to. The renderer spec now hands its frozen Horizons vectors over as the UT dates that name them through the same TT - UT, and checks Jupiter's and Earth's prime meridians at AD 1000. Controls: the leap-second rule used before 1972 fails "follows the historical record before 1972"; TT - UT held at 69 s fails "turns Jupiter at AD 1000 by its W"; Earth turned at TDB, or the renderer or the page not keeping it on UT, fails the Earth tests. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> |
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SenrokaiandClaude Opus 5.5
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d4808788ec |
Take the orbits at TDB as the spins already were, so a locked moon faces the planet it is drawn round
Every element set here runs on TDB: Standish's T_eph, the SSD satellite and SBDB epochs, the IAU's d and T. bodyOrientation already took the clock's UTC to TDB, but SystemOrbitsRenderer.update and the body page's heliocentricPosition fed the UTC date straight to meanElementsAt, so in one frame each body's place was 69.184 s behind its spin. That is n x 69 s of orbit: Phobos 0.90 degrees, Mimas 0.31, Deimos 0.23, Enceladus 0.21, Miranda 0.20, Io 0.16, Tethys 0.15, Europa 0.08, the Moon 0.011. 48319c3's table measured the app at a UTC date against Horizons at the same number read as TDB, which hid it, and its "nothing for anything else" was wrong: Io's 0.16 is four to five times Io's worst model error there (0.035). tdbFromUtc, in constants.ts, is now the one conversion, and positions and spins both go through it. In the running app, clock pinned to 2025-06-01 12:00 UTC, Io's face towards Jupiter is at 0.024 E, latitude -0.009, where Horizons (observer quantity 14 from Jupiter's centre) has 0.036 E and -0.003: 0.012 degrees apart, where it was 0.175. The renderer spec checks that point, and now hands its frozen Horizons vectors, which are TDB, to update() as the UTC dates that name them, 69.184 s earlier; the same frozen rows fed at the UTC date fail for Io and Europa. A body-page test checks that the Sun lights the point it stands over at the same TDB instant the body is turned for. Controls: taking the renderer's orbits at the clock's UTC fails "faces jupiter and the Sun with the points Horizons gives on io"; taking the page's Sun there fails "takes the Sun where it stands at the same TDB instant". Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> |
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SenrokaiandClaude Opus 5.5
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cdf474bcd5 |
Turn every body in the system view by its IAU pole and prime meridian, so the lit face is the real one
Until now each body's axis was its orbit normal, tipped by the obliquity about the orbit's node, an azimuth the data never gave. Its phase started at an arbitrary point at the elements' epoch. The rate and the sense were real; the face towards the Sun was not. Now each of the 33 bodies with IAU elements is set, every tick, from its pole and its W at the clock's date. Eris, Haumea and Makemake keep the old fallback: their published period, about their orbit normal. None of them has an obliquity, so the tilt code that only served bodies now turned by the IAU is gone. Exoplanets have no rotation published and stay still, as before. The texture convention is settled once, in src/app/shared/rendering/body-orientation.ts (MAP_TO_BODY): - SphereGeometry runs u eastward about +Y from a seam on -X, so u = 0.5 faces +X. - Every photograph in the catalogue is centred on longitude 0 with east to the right. Checked on the maps: Greenwich; Olympus Mons 134 degrees left of centre; Mare Crisium right and Mare Orientale left; Kuiper just left. - A map labelled in west longitude is still drawn east-right, so where longitude 0 sits is the only question, and for all of them it is the centre. - So a quarter turn about X puts the map on the IAU body frame: pole +Z, prime meridian +X. The scene is already ICRF equatorial (the ecliptic is turned into it by the J2000 obliquity), so the pole goes in as it is. The equator frame is built through laplacePlaneToEquatorial, the same conversion the moons' Laplace planes use; moonFrame now calls it too. The clock is UTC and the elements TDB, so TT - UTC (69.184 s) is added: Earth turns 0.29 degrees in that time, Jupiter 0.70 and Phobos 0.90. Measured on the live app (port 4311), clock pinned to 2025-06-01 12:00 UTC: - The Sun stands over 0.433 W, 22.125 N on Earth's drawn sphere. The equation of time puts it at 0.53 W. - Each body was drawn one light-time earlier and compared with Horizons' observer quantities 14 and 15: - Earth (from the Sun): longitude 0.095 off. - Mars: sub-Earth 0.001, sub-solar 0.004. - Jupiter: sub-Earth 0.005, sub-solar 0.002. - The Moon: sub-solar 0.004; sub-Earth 0.699, which is the error of its mean orbit. - Horizons' latitudes are planetodetic. Raw, they differ by the flattening: Earth 0.14, Mars 0.23-0.27, Jupiter 0.33, the Moon (a sphere) 0.000. The unit tests put the same comparison through real raycasts on the drawn spheres' texture coordinates, with the latitudes put on each body's flattened figure. Every residual is within 0.09 degrees, but for the Moon's sub-Earth point (0.70 and 0.09). The retrograde tests of #33 are rewritten for the IAU's convention: a planet's named pole is the one on the north side, so W runs backwards for Venus and Uranus, while Pluto follows the right-hand rule. The spin read off the drawn sphere, against the drawn orbit's normal, is 177.36 for Venus, 97.77 for Uranus and 119.61 for Pluto, all past 90, and 23.44 for Earth. Each is within 0.5 of Horizons. Six mutants, each failing its named test: the map upside down; UTC taken for TDB (Jupiter's test); W turned the wrong way (the retrograde test, and again Earth's noon test); moons, or planets, not turned by the IAU; and the fallback ignoring a negative period. Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com> |
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SenrokaiandClaude Opus 5.5
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48319c3fe2 |
Move the solar system on JPL's mean elements, so it stays right as the clock runs
Every body carried one set of osculating elements from Horizons at 2025-01-01, run forward by
Kepler with a GM from a table of mass ratios. That set is exact at its instant and drifts from
then on, and the clock now runs a month a second: the Moon, with Earth's mass ratio lacking its
own and the osculating axis, went round in 27.70 days instead of 27.32, 66 degrees out after a
year, and its locked face was spun at the same wrong rate.
Planets and Pluto now take Standish's Table 2a/2b ("Keplerian Elements for Approximate
Positions of the Major Planets"): elements against the J2000 ecliptic, their rates per century,
and the b, c, s, f terms of Jupiter to Pluto, fit for 3000 BC to AD 3000. Table 1 is closer near
the present (Saturn 0.23 degrees at worst 1950-2100, against 0.32 here) but is only fit for
1800-2050, and by AD 3000 has Saturn 4.3 degrees out where Table 2 holds every planet within 0.3.
The moons take JPL SSD's satellite mean elements: sidereal mean motion n to ten figures, the
periods of their node and periapsis, and each one's local Laplace plane by its pole. They
propagate with n itself, never a GM: gmForParent and its mass table are gone. Horizons still
gives size, spin and obliquity.
Both tables are read from the Internet Archive's copy of JPL's pages, pinned to one capture: the
live approx_pos page has dropped Pluto, and the live sats/elem page has dropped n and rounds the
period to four or five figures (Phobos 0.3187 d, a revolution out within a decade).
What the tables leave implicit, measured against Horizons before it was accepted:
- The precession periods are magnitudes. A node regresses on a prograde orbit and advances on a
retrograde one; a periapsis advances except where a resonance forces the eccentricity. Io's
and Europa's follow their conjunction line backwards at 2 n(Europa) - n(Io) = 0.74 degrees a
day, which is exactly the 1.625- and 1.394-year periods in the table. Read as advancing, Io
was 0.9 degrees out and Europa 2.1.
- On a retrograde orbit the node's turning is added back to the mean anomaly. Taken off, Triton
drifted a degree a year, 105 degrees by 2100.
- The Laplace frame's x axis is where the plane rises through the ICRF equator, RA of the pole
plus 90. Read against the ecliptic, Io was 2.8 degrees out, Phobos 54 and Titan 127.
Orbit lines are now drawn in their own plane and turned by a quaternion each tick, so a turning
node carries the line with the body: fixed at one date, the Moon's line would be up to 69 000 km
off it nine years on. The Earth row is the Earth-Moon barycentre, 4 700 km from Earth, 0.002
degrees from the Sun. A tidally locked moon's day is now 360 / n, its sidereal period (the Moon
27.321662 d), so it stays locked to the orbit it is drawn on.
Angular error against Horizons VECTORS (ICRF, TDB; heliocentric for planets, planet-centred for
moons), degrees, read from the live renderer's markers in the running app:
body 1950-01-01 1975-01-01 1987-07-23 2000-01-01 2025-01-01 2037-03-06 2050-01-01 2075-01-01 2100-01-01 max
mercury 0.004 0.002 0.003 0.002 0.002 0.001 0.000 0.002 0.000 0.004
venus 0.003 0.007 0.003 0.004 0.004 0.004 0.003 0.004 0.004 0.007
earth 0.003 0.008 0.002 0.005 0.004 0.009 0.003 0.002 0.003 0.009
mars 0.009 0.010 0.008 0.024 0.009 0.012 0.009 0.011 0.028 0.028
jupiter 0.063 0.030 0.171 0.135 0.013 0.020 0.056 0.041 0.075 0.171
saturn 0.080 0.064 0.018 0.320 0.066 0.114 0.044 0.164 0.177 0.320
uranus 0.018 0.169 0.068 0.050 0.101 0.015 0.141 0.017 0.114 0.169
neptune 0.070 0.028 0.004 0.021 0.036 0.037 0.013 0.029 0.072 0.072
pluto 0.045 0.054 0.041 0.033 0.019 0.020 0.023 0.027 0.026 0.054
moon 0.486 1.928 0.127 0.631 1.407 1.086 0.720 0.339 1.180 1.928
phobos 2.068 0.294 0.881 1.113 0.313 0.636 2.089 5.862 11.099 11.099
deimos 0.077 0.043 0.310 0.066 0.164 0.068 0.034 0.468 0.044 0.468
io 0.021 0.015 0.010 0.019 0.009 0.035 0.006 0.011 0.022 0.035
europa 0.036 0.039 0.053 0.064 0.078 0.032 0.006 0.034 0.044 0.078
ganymede 0.132 0.103 0.018 0.007 0.023 0.054 0.091 0.118 0.044 0.132
callisto 0.040 0.019 0.023 0.019 0.038 0.008 0.060 0.119 0.056 0.119
titan 0.003 0.019 0.023 0.023 0.027 0.028 0.048 0.008 0.014 0.048
triton 0.051 0.029 0.009 0.021 0.052 0.048 0.063 0.089 0.137 0.137
Three miss what was hoped for, and why:
- Jupiter 0.17, Saturn 0.32, Uranus 0.17 against the 0.1 hoped for: short-period perturbations
of the giants by one another, which no Keplerian fit carries. Standish states his own Table 2
errors as 600, 1 000 and 2 000 arcseconds (0.17, 0.28, 0.56 degrees). Out to AD 3000, measured
at 1800, 2200, 2400, 2600 and 3000, every planet stays within 0.3.
- The Moon, 1.9: evection (1.27) and variation (0.66), which a mean ellipse leaves out.
- Phobos, 2.1 until 2050, then 5.9 in 2075 and 11.1 in 2100, growing as the square of the time:
its tidal acceleration, which the table has no column for. Its elements are MAR080's, epoch
1950. The map's dates are also UTC where the elements are TDB, 69 s today,
which is 0.9 degrees of Phobos and nothing for anything else.
Held in place by:
- build.ts: each body's mean elements against Horizons' own osculating elements on the ETL's
2025-01-01, at most 0.25 degrees for a planet and 2.5 for a moon (measured: Uranus 0.101, the
Moon 1.407; a regressing Triton node reads 10.24 and fails), and every moon's day equal to its
sidereal period (a 1% error fails).
- Unit tests freezing nine Horizons vectors (Earth 2100, Jupiter 1950, Saturn 2075, Pluto 1975,
the Moon 2050, Io and Europa 1950, Titan and Triton 2100) through SystemOrbitsRenderer, the
Moon kept on its own turning line, the retrograde rule, the Standish terms, the Laplace frame,
and both table parsers. Nine mutants each fail the test named for them, and the two
validators each refuse a mutated build of the real catalogue.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
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Senrokai
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d7e8ea1d4d |
@
Add star-map Angular app, ETL pipeline, and caveman plugin Angular 3D star map (galaxy/system/body views, Three.js rendering, navigation store) plus the NASA ETL tooling that builds the star, exoplanet and solar-system datasets, Playwright e2e suite, and the cs:caveman Claude Code plugin (command, agent, skill). Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> @ |