The project was started 1997-10-20. The first draft was finished approximately 1998-08-21. Final draft finished 1999-08-12.
Abbreviations used throughout: ly = light year; eyr = Earth year; e Eri = epsilon Eridani. ``Terra'' is generally used for Earth, the homeword of the humans, and ``Sol'' is its primary star. By contrast, ``the Sun'' is the primary star of whatever world you are on: epsilon Eridani for most of the story.
``E'' format numbers: you have a number (with or without a decimal point) followed by ``e'' and a (signed) integer. The number is multiplied by ten to the integer power. For example, 1e3 is one thousand while 1e-3 is one thousandth. ``E'' format is much easier to use than alternatives: for example, the luminosity of e Eri is 1.09e26 W, not ``one point zero nine times ten to the twenty-sixth power, watts''. Or even worse: ``one hundred and nine heptillion watts''; who can interpret that? In heptal radix, ``h'' is used instead of ``e''.
e Eri | Sol | e Eri/Sol | |
Distance | 10.8 ly | ||
Spectral class | K2 | G2 | |
Absolute magnitude | 6.1 | 4.72 | 1.38 |
Apparent magnitude | 3.7 | 2.32 (from other star) | |
Luminosity | 1.09e26 W | 3.90e26 W | 0.281 |
Color temperature | 5040 K | 6420 K | |
Wavelength peak | 574 nm (yel-grn) | 451 nm (blue) |
Likely the color of e Eri would appear similar to Sol but the sky would be much darker. For Sol the experimental peak is 450 to 480 nm due to absorbtion lines. For Sol spectral density 50% points are 330 to 800 nm.
Orbit radius, same power | 8.6e10 m | 1.50e11 m | 0.575 AU |
Length of year | 1.810e7 sec | 3.156e7 sec | 0.573 eyr |
Apparent radius of star | 0.75 deg | 0.53 deg | 1.41 |
(from equal power orbit) | |||
Absolute radius of star | 1.13e9 m | 1.39e9 m | 0.81 |
Mass | 1.51e30 Kg | 1.991e30 Kg | 0.76 |
Age (but see below) | 2.69e9 eyr | 4.63e9 eyr | 0.581 |
Geocentric coordinates | 3h30m-9d38m | 15h30m+9d38m | |
In constellation | Eridanus | Serpens (caput) |
The apparent magnitude of Sol (as seen from epsilon Eridani) is very similar to alpha Serpentis, which is 2.5 to 3. In the story the Serpent is said to have two eyes; the stars are close, 2.5 degrees apart (neglecting parallax effects on constellation shapes, which really can't be neglected). For comparison, Luna is 0.5 degree across and Lyra is 7 x 4 degrees.
Note, in earlier calculations the absolute magnitude of Sol was taken as 2.5. Since the orbital period of Wotan is woven into the story in many places I have not adjusted the radius of the ``equal power'' orbit, which in fact gets 0.85 times the insolation of Terra.
The age of e Eri was picked somewhat arbitrarily; a younger but plausible age improves the ability of the heptapi to use nuclear power. After chapter 6 was written I found a hard statement of the age of e Eri: 0.1 x Sol rather than 0.58 x Sol (2.69e9 eyr) as the story says. 5e8 years is far too young to produce any life, much less to produce heptapi. Reference: Govert Schilling, News of the Week: ``Hints of a Nearby Solar System?'', Science, v281 p 152 (1998-07-10), quoting Jane Greaves (Joint Astronomy Center, Hawaii) speaking at the Protostars and Planets Conference, Santa Barbara, approx same date.
Reference for star data: Norton, Arthur P, Norton's Star Atlas 17th ed, Longman (Wiley in USA), 1986, ISBN 0-582-98898-5 in UK, 0-470-20678-0 in USA. Chapter 4, p. 94.
The Kuiper cloud of e Eri has been observed, but resolution is not good enough to detect planets if they were present. All this information, except for Terra, is fictional.
Orbital | Length of | Illumin- | Mass | Surface | Name | |
Radius | Year | ation | Radius | |||
(meters) | (sec) | (x Terra) | (Kg) | (meters) | ||
I | 6.02e10 | 1.06e7 | 2.04 | 5.38e24 | 6.64e6 | Njord |
II | 8.60e10 | 1.810e7 | 1.0 | 2.99e27 | 1.55e8 | Wotan |
IIa | 4.60e8 | 1.38634e5 | 1.0 | 8.395e24 | 7.373e6 | Thor |
III | 1.38e11 | 3,66e7 | 0.39 | 4.28e26 | 1.05e8 | Freyja |
IV | 2.41e11 | 8.48e7 | 0.13 | 5.62e23 | 3.22e6 | Loki |
( | 1.50e11 | 3.156e7 | 1.0 | 5.983e24 | 6.37e6 | Terra) |
Kuiper cloud of comets: radius 2.5e12 m to 4.5e12 m. Oort cloud: not sure; farther out. Estimated mass of Kuiper cloud material for Sol: 6e25 Kg (10 x Terra). The story says that the comet abundance at e Eri is about 1/10 Sol, which would be 1 earth mass. An update: William R. Ward and Joseph M. Hahn, ``Neptune's Eccentricity and the Nature of the Kuiper Belt'', Science, v280 (1998-06-26) p2104. Direct observations of Kuiper cloud objects are rare. In the article the mass in Sol's Kuiper cloud is estimated to be 1 x Terra in the radius range of 48 AU (Neptune's radius) to 75 AU = 1.13e13 m. The story remains with 1 Terran mass in e Eri's Kuiper cloud.
More on Kuiper cloud: The measured radius of e Eri's Kuiper cloud is about the same as for Sol (story says it's less), and the ``number of comets'' is around 1000 x Sol. Also the age of e Eri is given as 0.1 x Sol rather than 0.58 x Sol (2.69e9 eyr) as the story says. Reference: Govert Schilling, News of the Week: ``Hints of a Nearby Solar System?'', Science, v281 p 152 (1998-07-10), quoting Jane Greaves (Joint Astronomy Center, Hawaii) speaking at the Protostars and Planets Conference, Santa Barbara, approx same date.
Njord: Having a similar size and insolation as Venus, it has an Earthlike oxygen atmosphere. A large ocean was recently present but has mostly evaporated due to warming of the stratospheric cold trap, due to chlorofluorocarbon production. Sea-dwelling inhabitants, the heptapi (heptapus-es), will soon be extinct. In reality the effect of greenhouse gases on the stratospheric cold trap is very complex, depending on details of the absorbtion and emission spectra. The effect of CO2 in Terra's stratosphere is to cool it, not warm it as hypothesized for Njord. Frozen particles of nitric and sulfuric acid provide a site where chlorine oxides from the decomposition of chlorofluorocarbons can catalytically react with ozone.
Wotan: It's a gas giant, a little larger than Jupiter, but at a radius so the insolation is similar to Terra.
Thor: Moon of Wotan. It's rocky and generally Earthlike, though a little larger, but it lacks most volatiles. It has a very limited atmosphere and no surface water. Spin-orbit locked, like Luna.
Freyja: Gas giant, analogous to Saturn. No significant moons.
Loki: Cold, dimly illuminated rockball, like Mars in size.
Thor | Terra | ||
Rotation period | 1.38634e5 sec | 8.6400e4 sec | (38.48 hours) |
Mean density | 5.0 g/cc | 5.5 g/cc | |
Surface gravity | 10.3 m/s2 | 9.8 m/s2 | |
Mass | 8.395e24 Kg | 5.983e24 Kg | |
Radius | 7.373e6 m | 6.37e6 m | |
Surface area | 6.83e14 m2 | 5.10e14 m2 | |
Orbiter's velocity | 8627 m/s | 7823 m/s | (at 150 Km) |
Primary power from star | 1.395e3 W/m2 | (same) | |
Blackbody surface temp | 280 K | (same) | P/4 = s T4 |
Neighboring object | Wotan | Terra | Luna |
Radius of neighbor | 1.55e8 m | 6.37e6 m | 1.74e6 m |
Distance from neighbor | 4.60e8 m | 3.84e8 m | 3.84e8 m |
Neighbor subtends angle | 39 degrees | 1.90 deg | 0.52 deg |
Thor's velocity vs. Wotan | 2.082e4 m/s | ||
Orbiter's velocity over Wotan | 3.585e4 m/s | (at 150 Km) | |
Gravity over Wotan | 8.30 m/s2 | (at 150 Km) |
See below under ``CQMT Pusher Design'' for the equations from which much of this material was obtained.
Distance | 10.8 ly = 1.022e17 m |
Average speed desired | 0.666 c |
Maximum velocity | 0.85 c |
Average time dilation | 0.713 |
Travel time | 16.2 eyr = 5.11e8 sec |
Onboard duration | 11.6 eyr = 3.66e8 sec |
Spacecraft mass (total) | 6680 Kg |
Peak power | 2.12e12 W |
Proton energy at this speed | 842 MeV |
But see below; the shield mass was underestimated by about a factor of 3.5. Also, the power per kilogram was underestimated. However, 2.12e12 W is a very convenient number for the plot, so it wasn't corrected.
Time to manufacture a set of eggs: | 2 eyr |
Time to sexual maturity: | 16 eyr |
Generation time (minimum): | 18 eyr |
Human lifetime: | 80 eyr |
Lion lifetime: | Unknown, longer |
(Note: as actually written the story deviates from this outline. See the timeline for times of various events as actually appearing.)
Each Novanima is identified by a letter representing the species, a unique serial number in decimal, hyphen, and an octal encoding of the recognition scent. The latter has fourteen odor components which can be present or absent. Two indicate the species (and are both absent in lions). Females smell of allspice while males smell of cinnamon, and the 2000 bit encodes both scents, being one for females and zero for males.
Name | Code | Species | Sex | Mate | Job | Name means |
Tiger | L6-3512 | Lion | F | Simba | Mission Commander | |
Simba | L7-1340 | Lion | M | Tiger | Biotech, Medic | |
Willie | -- | Human | M | Wilma | Mechanical Engr | |
Wilma | -- | Human | F | Willie | Geology, Astronomy |
Kittens (born in chapter 11 and 12):
Iris | L1001-1212 | Lion | M | Lucent | Student Leader | Rainbow (Greek) |
Iris is Tiger's favorite because she feels guilty about aborting Iris-3. Iris has a problem with short attention span. This retards his lesson progress, and he feels unworthy because of it. He thinks before acting, but is decisive and determined. He's willing to break rules and suffer the consequences if he sees a benefit to it. He loves to explore.
Jacinth | L1002-3027 | Lion | F | Ken | Gem zircon |
Jacinth is impulsive and aggressive. In chapter 18 she takes the lead in piloting spacecraft. She ends up taking the lead in cooking.
Ken | L1003-0522 | Lion | M | Jacinth | Economics | Japanese sword |
Ken is the smartest of the kittens. He is reserved, timid and tends toward introspection. Nonetheless he can be courageous when really needed. He has a problem with passive-resistive behavior and depression. One of his major contributions is the money system (economics).
Lucent | L1004-3565 | Lion | F | Iris | Shining |
Lucent is intelligent and prudent. She thinks before acting. She can be forceful if needed but prefers to avoid confrontation. (A major Terran corporation has this name.)
Mica | O1005-0275 | Otter | M | Night | Papermaker | Sparkly rock |
Tiger and Simba remember the sparkly black mica crystals in a rock they sat on, on their wedding day.
Night | O1006-3431 | Otter | F | Mica | Ball bearings | Black fur |
Like other otters, Night is prudent and thoughtful and social, but is courageous when it's needed. She decides on a career manufacturing rotating machinery.
Oso | U1009-1530 | 'Uomi | M | Petra | Agriculture | Bear (Spanish) |
Named in honor of El Oso, padre of Mariposa and Coyote, who was killed in Simba Leones. Stonecutter and farmer.
Petra | U1010-3037 | 'Uomi | F | Oso | Stone (Latin) |
Several incidents of brat behavior and overreaction.
Quin | U1011-1624 | 'Uomi | M | Valeria | Biotech | Quinone |
Interested in genetic engineering. Plastic producer for the colony. His name refers to the quinones in the Chang bushes.
Rose | J1013-3400 | Jaguar | F | Orion | Medic | Has thorns |
Rose is smart. She is Iris' close friend because of a match in lesson progress. Medical training.
Selen | O1007-0160 | Otter | M | Titania | Psychologist | Moon |
Selen is always happy and is highly social. Unbalanced about sex. His work is craft manufacturing: pottery and textiles. He becomes the colony's psychologist. (At least one Swede has the family name of Selen. Original origin unknown.)
Titania | O1008-3026 | Otter | F | Selen | Artist, Medic | The metal |
Titania is fierce defending her position. She is an excellent artist and consumes Mica's paper. Medical training. Works in genetic engineering.
Orion | J1014-1210 | Jaguar | M | Rose | Mighty hunter |
Name should start with U but none suitable. Orion is strong and aggressive and boisterous. He's a little behind the others in lesson progress.
Valeria | U1012-2423 | 'Uomi | F | Quin | Metalworker | Roman legion |
Valeria has the nickname Vulcan because of her manufacturing and metalworking specialty. In Chapter 13 she is greatly disturbed because she's a fake human, not real, but gets this worked out. The last Roman legion to stand against chaos in Britain was Valeria Victrix.
Wolf | J1015-1725 | Jaguar | M | Xena | Willie's son |
Wolf is less aggressive and more introspective than Orion, and not as muscular.
Xena | J1016-3062 | Jaguar | F | Wolf | Warrior | Stranger |
Xena takes her Warrior Princess role seriously, being the colony's military expert. (Name is normally spelled Xenia, from the Greek. In a currently popular TV series Xena is a warrior princess.)
The crew's kittens on Terra:
Nbr | Shoulder | Crotch |
1 | Sweat | Extend genitalia |
2 | Wake up (reset 3 and 4) | Urinate |
3 | Blood pressure down | Sex |
4 | Sleep | Defecate |
Through the Tiger hole (name changed to Alembic d'Alimentation Trans-Spatiale or AATS), null-mass (photonic) signals take a very small amount of time longer than they would have taken on a normal space geodesic path between the endpoints. Non-null effects are best analyzed in a non-accelerating reference frame such as Terra's.
To operate a CQMT pusher (beside overhead and losses) requires power as if a mechanical connection existed, i.e. Force*Velocity. Power is in fact transferred through the hole to the spacecraft and is subject to the Doppler shift, but it's easier to analyses as if the active end were on Terra and acted on mass inflated by the Lorentz-Fitzgerald contraction. Excess power cannot be dissipated safely on the spacecraft and is returned through the hole to Terra.
m | Spacecraft rest mass |
V | Velocity of spacecraft (relative to Terra) |
v | abs(V) |
a | Acceleration of spacecraft |
F | Force exerted by pusher |
p | Power supplied to spacecraft (excluding overhead and losses). |
c | Speed of light |
Evaluation for power fixed on Terra by sundipper output. We're referring to longitudinal acceleration. At zero velocity the acceleration at finite power is technically infinite; the initial transient is ignored during which the force on the pusher is the limiting factor.
F dt = m/(1-(v/c)2)0.5 dv | If transverse |
F dt = m/(1-(v/c)2)1.5 dv | If longitudinal |
(Reference: Eddington, sir Arthur, The Mathematical Theory of Relativity, Cambridge University Press, 1922, p. 31)
a = v' = (1-(v/c)2)1.5 (p/mv) | F = ma, solve for a |
Let b = v/c | |
db/dt = b' = (p/mc2) (1-b2)1.5/b | The same, dimensionless |
Let T = mc2/p | |
dt = T b/(1-b2)1.5 db | Separate variables |
t = T / (1-b2)0.5 | Integrate both sides |
(T/t)2 = 1-b2 | Solve for b |
b = (1 - (T/t)2)0.5 | Finish solving for b |
x = c intg (b dt) | Integrate to get position |
w = T/t, dw = -T dt/t2, dt = -T dw/w2 | Change of variables |
x = -cT intg (1-w2)0.5/w2 dw | Finish the integral |
= -(cT) ((1-(T/t)2)0.5t/T + arcsin(T/t)) from t = T to infinity. | |
= -(cT) (bt/T + arcsin(T/t)) | |
a = c db/dt = c/T (1-b2)1.5/b |
The following table contains a numerical integration of the starship's motion. All quantities except arc length are evaluated in the reference frame of the start point (Terra). Quantities are "dimensionless", that is, velocities are normalized by the speed of light, and times (equivalently distances) are normalized by how long it would take for the power fed to the ship (assumed constant in the start point reference frame) to equal its rest mass. The trajectory shown is accelerating only. For the actual journey the ship would accelerate for half the time, then do a symmetrical deceleration.
These are the columns in the table:
Time | Arclen | Distance | Speed | Accel | Avg Speed |
T | s | X | v | a | v(avg) |
1.00 | 0.000 | 0.000 | 0.0000 | 0.000 | 0.000 |
1.10 | 0.095 | 0.029 | 0.4166 | 1.803 | 0.286 |
1.20 | 0.182 | 0.078 | 0.5528 | 1.047 | 0.388 |
1.30 | 0.262 | 0.138 | 0.6390 | 0.712 | 0.458 |
1.40 | 0.336 | 0.205 | 0.6999 | 0.521 | 0.512 |
1.50 | 0.405 | 0.277 | 0.7454 | 0.398 | 0.554 |
1.60 | 0.470 | 0.353 | 0.7806 | 0.313 | 0.589 |
1.70 | 0.531 | 0.433 | 0.8087 | 0.252 | 0.618 |
1.80 | 0.588 | 0.515 | 0.8315 | 0.206 | 0.644 |
1.90 | 0.642 | 0.599 | 0.8503 | 0.171 | 0.666 <- |
2.00 | 0.693 | 0.685 | 0.8660 | 0.144 | 0.685 |
2.10 | 0.742 | 0.772 | 0.8793 | 0.123 | 0.702 |
2.20 | 0.788 | 0.861 | 0.8907 | 0.105 | 0.717 |
2.30 | 0.833 | 0.950 | 0.9005 | 0.091 | 0.731 |
2.40 | 0.875 | 1.041 | 0.9091 | 0.080 | 0.743 |
2.50 | 0.916 | 1.132 | 0.9165 | 0.070 | 0.755 |
2.60 | 0.956 | 1.224 | 0.9231 | 0.062 | 0.765 |
2.70 | 0.993 | 1.317 | 0.9289 | 0.055 | 0.774 |
2.80 | 1.030 | 1.410 | 0.9340 | 0.049 | 0.783 |
2.90 | 1.065 | 1.503 | 0.9387 | 0.044 | 0.791 |
3.00 | 1.099 | 1.597 | 0.9428 | 0.039 | 0.799 |
When the spacecraft slows down, the decrease in kinetic energy relative to the power nexus is sent back through the hole (minus losses and overhead). It is assumed that the equipment is sized to accommodate the same power coming out as coming in, but no more. Thus the relevant journey is halfway to the target, at which point the spacecraft reverses thrust for an equal time. It is desired to make the trip of 10.8 ly at an average speed of 2/3 c, or a travel time of 16.2 yr. From the table above, this means t/T has to run from 1.0 to 1.90, v(max) = 0.85 c, x = 0.599 cT = 5.4 ly (half way then turn around), so T = 9.0 yr. At maximum velocity, acceleration is 0.154 M/s2 (i.e. very small).
Protons at 0.85 c have an energy of 842 MeV vs. rest. Shielding cross section is 2e-2 barn/electron (asymptotic over 100 MeV) = 2e-30 m2/el. Water has a density of 3.3e29 el/m3 so the e-folding depth is 1.5 m. In space the dose from (non-solar) cosmic rays is 5e-4 gray/day. For the planned journey the nondirectional dose is 2.96 gray. Reference for cosmic rays and shielding: Gregory, A. and R.W. Clay, ``Cosmic Radiation'', in: Weast, R.C. (ed.), Handbook of Chemistry and Physics, 63rd ed. (1982), CRC, page F-175.
Density of interstellar matter: 1e-24 g/cc = 1e-21 Kg/m3 (average over patches) = 6e5 protons/m3. Radiation power: 1.9e4 W/m2 = 12.6 gray/sec. (over 1.5 m e-folding distance). Times journey duration this gives 4.8e12 gray. To reduce this dose to equal the nondirectional dose requires e-folding of 28, or 42 m of water. Suppose we can squeeze everything into 0.5 m2 shadow area.
Hydrogen intercepted | 8.02e-5 Kg |
Energy at 0.85c | 7.22e12 J |
Radiation dose (1.5 m e-folding) | 4.81e12 gray |
Assumed metallicity | 2% |
Dust intercepted | 1.61e-6 Kg |
Dust grain mass | 3.16e-16 Kg |
Kinetic energy at 0.85c | 25.5 J (mc2(1/(1-(v/c)2)0.5-1)) |
Density of grains (approx) | 4.8e-8 #/m3 |
Quantity of grains hit | 6.12 #/sec (0.5 m2 area) |
2.45e9 grains | |
7.75e-7 Kg |
Reference: M. Baguhl et al, Space Sci Rev #72 p471 (1995), quoted in: Colwell, J.E., Horanyi, M, Grun, E., ``Capture of Interplanetary and Interstellar Dust by the Jovian Magnetosphere'', Science, v280 #5360 (1998-04-03). Measurement of dust impacts by Galileo and Ulysses show that beyond 3 AU the dust flux is dominated by interstellar grains with a flux of 1e-8 #/cm2 sec parallel to the local interstellar wind. Their mean mass is 10(-12.5±1.5) gram. The velocity of the grains is approximately equal to Jupiter's orbital velocity, 2.079e3 m/sec.
If the spacecraft loses power when traveling at maximum speed, the radiation power (if independent of velocity, which is not accurate but isn't too bad of an approximation) would bring it to rest in about 6e9 eyr. The radius of the universe is approximately 1.6e10 eyr, so in reality the spacecraft would continue moving at considerable speed, though not 0.85c, ``to the utter end of the universe''.
4 people | 280 Kg |
Supplies and stuff | 1000 Kg |
Pusher, power conversion | 500 Kg |
Structure | 500 Kg |
Radiation shield | 21000 Kg |
Total | 23080 Kg |
For T = 9.0 yr, m = 6680 Kg, then p = 7.32e12 w (formerly 2.12e12 watts). Conversion: p = mc2/T = 3.17e8 m (mass in Kg, power in watts). Note that the plot was established for a prior underestimate of the shield mass (total 6680 Kg vs. 23080 Kg). The 3.5x increase in needed power would be inconvenient, though, and so the story was not corrected.
Mass of telescope | 10 tons |
Cross sectional area | 10 m2 |
Nominal orbital altitude | 400 Km (250 U.S. miles) |
Scale height of exosphere | 6500 m |
The disaster is assumed to have been an impulsive discharge of maneuvering fuel which lowered the perigee. For the plot, the telescope's orbit will decay in about 8 days = 7e5 sec. Preliminary calculation show a perigee around 100 Km. The major effect of atmospheric drag would be to gradually lower the apogee, circularizing the orbit, upon which the telescope spirals in rapidly. It should be noted that after the story was written, AXAF (renamed the Chandra X-ray Observatory) was not placed in low Earth orbit but instead well outside the van Allen belts. This orbital placement, however, would necessitate quite a bit of changes to the plot.
Energy in nominal orbit | -5.8937e11 J |
Energy in 100-400 orbit | -6.0273e11 J. delta = 1.33e10 J |
Energy in 100 Km orbit | -6.1670e11 J, delta = 2.73e10 J |
Power to take down satellite | 2.00e4 W |
Let's assume that atmospheric drag is concentrated over 1/4 of the orbit (actually an overestimate given the scale height). Drag = RAv2 (R = density). The drag is inferred from the loss power, and the perigee altitude is inferred from the air density necessary to give this drag.
Orbital velocity | 7850 m/s |
Drag force (average) | 2.5 Nt |
Drag force (peak) | 10.2 Nt |
Air density | 1.65e-8 Kg/m3 |
Perigee altitude | 125 Km |
To rescue the satellite we'll need to apply twice the drag power. The pusher chip efficiency is assumed to be 85% but half of that is dissipated on the ground.
Heat sink power | 3e3 W |
Heat sink temperature | 70 C = 343 K |
Radiance at that temp. | 785 W/m2 |
Radiator area | 3.8 m2 |
Square flat sheet, 2 sides | 1.38 m edge length |
Power per chip | 30 W |
Size of case | 2 cm approximately square |
Number of chips | 100 (plus 100 partners) |
Radiator area per chip | .038 m2 |
Radius of circular patch | 11 cm |
Pitch of square grid | 19 cm |
To calculate the thickness of the sheet: the temperature drop is
intg (r1,r2) P dr/(2pi rtC) = P/(2pi tC) ln(r2/r1)
where P = power, C = thermal conductivity, t = thickness, r1-r2 = patch radii.
Target conductive drop | 15 K |
Conductivity of copper | 394 W/mK |
Thickness (for 30 W) | 1.9 mm |
Mass of copper | 57 Kg |
Reference for atmospheric data: U.S. Standard Atmosphere (1976), NOAA-NASA-USAF, in: Weast, R.C. (ed.), Handbook of Chemistry and Physics, 63rd edition (1982), CRC, page F-164.
Alaungpaya ``The Coming Buddha'' reigned 1752-1760, reuniting (or re-conquering) all of Burma plus at least some of Thailand. He was killed in battle during the Thailand campaign. In 1886 the King was deposed and Burma was annexed by Britain. Independence was gained in 1948, after which there was a sequence of various parliamentary, socialist and outright brutal regimes.
Skill | Main person | Backup |
Biology | Simba* | Willie* |
Biotechnology | Simba* | Willie* |
Geology | Wilma | Tiger* |
Plasma Physics | Willie* | Simba* |
Astronomy | Wilma* | Tiger* |
Mechanical Engineering | Willie | Wilma* |
Quantum Computer Design | Tiger | Simba* |
Programming | Simba, Tiger | Everyone |
Medical | Simba | Wilma* |
* = needs to be learned.
The varieties of grain grown on Terra, in order of importance (quantity?), are wheat, maize, rice, oats, barley, rye, millet, sorghum. Chang bushes are bioengineered to produce simulations of all these grains. In addition the Chang bushes are said to produce soybean and azuki bean flavors. Additional starch crops (not Chang varieties) are yams, sweet potato, Inca potato, and cassava (taro).
The Chang bushes economize on water by using sunlight energy to isomerize quinones, and then at night opening the stomata, taking in CO2 and releasing O2. The bushes also actively transport water from the air. In Simba Leones a net positive water balance was alleged during summer in the Panamint valley. Cacti also use the strategy of storing energy during the day and opening the stomata at night, although they don't use quinones and don't actively take up water.
Chang bushes are host to symbiotic acacia ants. These defend their plants fiercely against herbivores. If a pheromone is sprayed in a box set near a plant, the ants will bring seeds (ripe ones only) to the box. The plants have hollow spaces in their stems for the ants to live in, and secrete food for the ants. Some acacia species actually have this arrangement with specialized ant species (not including seed collection).
Data is used for Terra's crust. It's kind of fudged up with added volatiles; quantities are guessed. It's well known that there are substantial segregation effects, so the abundance in comet dust will be different. Carbon is assumed about equal to oxygen. Fractions are by mass. Fractions add up to about 1.043, sorry.
CH4 | 0.25 |
H2O | 0.25 |
CO2 | 0.10 |
CO | 0.10 |
NH3 | 0.20 |
O (Total) | 0.35 (Sum of O content of above items) |
Al | 0.061 |
Fe | 0.038 |
Na | 0.021 |
K | 0.020 |
Ti | 0.0033 |
Cu | 5.3e-5 |
More authoritative cosmic abundances (by count of atoms):
H | 1 - Y - Z (0.95?) |
He | 5e-2 |
O | 6.7e-4 |
C | 3.5e-4 |
N | 1.1e-4 |
Si | 3.5e-5 |
Mg | 3.4e-5 |
Ne | 2.8e-5 |
S | 6.0e-6 |
Ca | 2.0e-6 |
Fe | ? |
Mass of seed (dry) | 0.025 g |
Mass of seedling | 10 g |
Doubling time | 30 days |
Time to harvest 1st seeds | 90 days / 80 g |
Full size plant | 10 Kg |
Production (immature plant) | 1e-3 of plant mass per day = |
10% of plant mass every 100 days | |
Production (mature plant) | 2e-3 per day = 20 gram/day |
Seed cycle | 30 days (seeds develop asynchronously). |
Initially the story was written with 1 gram seeds, but that's the size of a small Lima bean, not realistic for rice, wheat and oat simulations. The time between planting and the 10 gram stage would actually be at least a month, but too much already depends on the schedule below, so it's assumed to be instantaneous.
Days | Kg per | Total | Seeds | |
+arriv | plant | Kg | Kg/day | |
Most of planting done | 30 | 0.01 | 500 | 0 (planted 50 Kg) |
Start thinning weak plants | 90 | 0.04 | 2000 | 0 (immature seeds start) |
First harvest | 120 | 0.08 | 2000 | 2.0 |
Mature plants | 330 | 10.0 | 2000 | 4.0 |
Days | Kg per | Total | Seeds | |
+arriv | plant | Kg | Kg/day | |
Initial test sprouts | 5 | 0.01 | 0.08 | 0 |
Most of planting done | 30 | 0.01 | 40 | 0 (planted 4 Kg) |
First harvest | 120 | 0.08 | 320 | 0.32 |
Full production | 200 | 0.5 | 2000 | 2.0 |
Mature plants | 330 | 10.0 | 2000 | 4.0 |
Lions are assumed to have the same need for calories as a human. However, they are autotrophic: they can make all needed vitamins (not minerals) and can manufacture protein in their livers.
Infants | Protein | 2g/Kg.day |
Adult male | Protein | 56 g/day = 0.8 g/Kg.day (70 Kg male) |
Adult female | Protein | 46 g/day |
Lumberjack | Energy | 3700 kcal/day = 1.55e7 J/day |
Household Worker | Energy | 2100 kcal/day = 8.78e6 J/day |
Geneva Convention | Energy | 1500 kcal/day = 6.27e6 J/day |
Florence on Diet | Energy | 1000 kcal/day = 4.18e6 J/day |
Killer Whale | Energy | 55 kcal/Kg.day = 2.3e5 J/Kg.day |
Protein | Fat | CH2O | Calories | Joules | |
Kg/Kg | Kg/Kg | Kg/Kg | Mcal/Kg | J/Kg x1e6 | |
Millet (dry) | .103 | .029 | .655 | 3.28 | 13.7 |
Rice (dry) | .075 | .020 | .780 | 3.60 | 15.0 |
Wheat (seeds, dry) | .137 | .028 | .629 | 3.30 | 13.8 |
Soybean flour, no fat | .470 | .010 | .032 | 3.26 | 13.6 |
Soybean flour, full fat | .371 | .200 | .229 | 4.66 | 19.5 |
Chicken, meat only | .233 | -- | -- | 1.35 | 5.7 |
Sea otter, homogenized | -- | -- | -- | 1.81 | 7.6 |
Pork lard | -- | 1.0 | -- | 8.85 | 37.0 |
Fat (on the hoof) | -- | .925 | -- | 8.19 | 34.0 |
The last item refers to fat on a living body, for diet calculations. Reference for killer whale (Orcinus orca) and sea otter (Enhydra lutris): J.A. Estes et al, "Killer Whale Predation on Sea Otters Linking Oceanic and Nearshore Ecosystems", Science, vol. 282 nbr 5388 (1998-10-16), page 473.
Rice in CIMMYT experimental plots under ideal conditions of fertilization, pesticide application, water and weather can produce 2 tons (edible portion) per hectare 3 times a year. This corresponds to 1.67 grams per m2 per day or 6 Kcal/m2.day or 2.5e4 J/m2.day. This data is from around 1970. In 1999 yields up to 22 tons/ha.yr are occasionally obtained, but 12 to 15 tons/ha.yr is more typical of what real farmers get with the best new varieties of wheat.
In Simba Leones, Simba tells the Stanford board plan people that he properly eats 7 MJ/day, and can handle 5 MJ/day uncomfortably without losing mass. Assuming Chang bush production is equal to the CIMMYT performance, this corresponds to:
Joules/day | 7e6 | 5e6 |
Percent full power | 100% | 71% |
Kcal/day | 1700 | 1200 (rounded) |
Kg/day Chang seeds | 0.507 (500g) | 0.362 (360g) |
Nbr of mature Chang plants | 25 | 18 |
Floor area (mature plants) | 279 m2 | 199 m2 |
Floor area (immature plants) | 558 m2 | 398 m2 |
The proportions of C,N,P average 106 C / 16 N / 1 P with little variation, in worldwide samples of marine particulate matter (microscopic plants). The proportions in the soft tissue (not? counting bones) of humans is nearly the same. Reference: {C. and G.} Copin-Montegut, Deep-Sea Research v30 p31 (1983). Quoted in: Paul G. Falkowski, Richard T. Barber, Victor Smetacek, ``Biogeochemical Controls and Feedbacks on Ocean Primary Productivity'', Science, v281 p200 (1998-07-10).
Symbols: | |
a | acceleration = 3 m/s2, |
d | distance, |
t | travel time. |
Basic formula: d = .5at2, t = (2d/a)0.5
Plan: constant acceleration half way, then turn over and constant deceleration. Thus d -> d/2, t -> t/2.
Formula: t = 2 (2(d/2)/a)0.5 = 2 (d/a)0.5
From | To | Distance (m) | Time (eday) | |
Kuiper Cloud | Njord | 4.5e12 | 28.3 | |
Njord | Wotan | 8.60e10 | 3.9 | Quadrature |
Wotan | Thor | 4.60e8 | 0.29 | |
Thor | Freyja | 2.24e11 | 6.3 | Opposition |
Freyja | Loki | 1.03e11 | 4.3 | Conjunction |
Loki | Njord | 1.38e11 | 5.0 | Quadrature |
Kuiper Cloud | Wotan | 4.5e12 | 15.5 |
All assuming acceleration at 3 m/s2 except the last, in which the miner accelerates at 10 m/s2.
B = Tiger's age in eyr; N = newsfeed date. See the main timeline for details on these units.
Event | Day | B | N | Correlations |
Arrival | 0 | 50.4 | 50.5 | Start chapter 4 |
Get oriented, arrive comet | 10 | 50.4 | 50.5 | |
Finish comet activities | 30 | 50.5 | 50.8 | |
Arrive at Njord | 60 | 50.6 | 51.2 | Start chapter 5 |
Finish Njord | 90 | 50.6 | 51.6 | |
Arrive at Wotan | 94 | 50.7 | 51.7 | |
Finish Wotan and Thor | 125 | 50.7 | 52.1 | harvest starts,160 g/day |
Arrive at Freyja | 130 | 50.8 | 52.2 | |
Finish Freyja | 140 | 50.8 | 52.3 | |
Arrive at Loki | 145 | 50.8 | 52.4 | harvest 320 g/day at 150 days |
Finish Loki | 165 | 50.9 | 52.7 | |
Arrive at Njord again | 170 | 50.9 | 52.7 | end of chapter 5 |
180 | (harvest 640 g/day) | |||
200 | (1000 g/day, full production) |
l | wavelength (lambda) = 500 nm |
d | diameter of mirror = 30 cm |
r | distance to target = 150 Km |
e | diffraction limit |
l/d | 1.6e-6 rad |
e | rl/d = 0.25 m |
However, Spot Image sells pictures with 25 m resolution. A spy satellite (with better mirrors than Tiger has) can show a U-2 on the ground, probably with 1 to 2 meter feature size. Let's assume 25 m resolution. An image of 2k x 2k pixels would cover (50 Km)2. Complete tiled coverage would take 273200 images or 1.09e12 pixels. Let's assume 8 multispectral channels of 8 bits each; gives 8 terabytes. Note, figures are for Thor. Njord is ``a bit smaller than Earth'' whereas Thor is a bit larger.
Orbital velocity: 7823 m/s, which means 6 seconds per frame. How long to cover the whole planet? Over-coverage due to orbital convergence (on a polar orbit) increases the time by pi /2. 2 orbiters but half the planet is in night. Thus: 28.5 days.
How does the coverage time vary with planetary parameters? Assume a fixed patch size of p2. Other than through the patch size we'll neglect the height above the surface.
v = (ra)0.5 = (Gm/r)0.5 | (orbital velocity) |
v = ((4pi /3)Gqr2)0.5 | (q = density) |
A = 4pi r2 | (surface area) |
t = (pi /4) (A/p2) (p/v) | (time to cover the whole surface) |
t = (pi /4) (12pi /Gq)0.5 (r/p) |
A comet that's rich in dust, for easy mining, will be very hard to see in visible light because the dust is black. However, it will radiate in thermal infrared.
Radius of Kuiper cloud (avg.) | 3.5e12 m |
Power from e Eri | 1.09e26 W |
Power density at Kuiper cloud | 0.708 W/m2 |
Stefan-Boltzmann const. | 5.67e-8 W/m2K4 |
Blackbody temperature | 42 K (P/4 = s T4) |
Peak of normalized Planck distr. | hf/kT = 2.821 |
Wavelength of maximum power | 1.21e-4 m (hc/(2.821)kT) |
The power density is divided by 4 because the comet is spherical, not flat (integral of sin2) and it faces away from the star half the time. Thanks to Dr. Peter Wang, president of Fermionics, Inc., for suggesting the detector design: photoconductive silicon doped with low-lying impurity states. It would need to be cooled to 4K.
Original sea level | 6260830 geopotential meters. |
Sea level (truncated 2 digits) | 60830 |
Lower limit of erosion | 60000 |
Plate surface; atmosphere base | 57000, varies a lot. |
Chapter 5 (40% through): He's nominated to the SEC but the committee won't approve it, and a supporter has them adjourn sine die rather than have an embarrassing rejection. (Which committee handles the SEC, and is that proper Senate procedure?)
Chapter 9 (90%): He's nominated to the SEC and confirmed.
Chapter 12 (73%): He's nominated as Chairman the FRB and confirmed. (Handled by the Committee on Banking, Housing, and Urban Affairs, per Senate rules.)
On 1998-08-17 I sent a message to senator@feinstein.senate.gov asking for help on the above questions. 1998-11-20 I got a form letter reply saying the message had been received.
A prof in the political science department suggested that I read committee transcripts, which are on a web site. I decided that for a relatively minor subplot that degree of research was anally retentive. The sections in chapters 5 and 9 have been rewritten so the parliamentary maneuvers are handled informally by the chairman, which is plausible. If the Senator comes through, the sections can be revised again.
References indicate that the Chairman is appointed by the President, saying nothing about advice and consent of the Senate. However, recently a FRB member was promoted to Vice-Chairman and Senate confirmation was obtained. The story was rewritten accordingly.
Ch | Day | Activity |
6 | 1 | Collect air and water samples, attacked by heptapus, find truck |
6 | 2 | Water radioactivity. Imaging program. |
6 | 3 | Observe heptapi by sonar. Decode their sonar output. |
7 | 4 | Meet bravo heptapus. Meet commander. |
7 | 5 | More water samples. Look for mines. Language progress. |
7 | 6 | Visit by the Nagus. Survey Eastern ocean. |
8 | 7 | Armageddon. (Day 0 on chapter 9 timeline.) |
8 | 8 | Debate replanting. |
8 | 9 | Continue debate. Gaia plan. Tentative decision to replant. |
9 | 10 | Final decision to replant. Design colonists. |
9 | 11 | Begin execution phase, no longer day by day. |
9 | 31 | End of chapter: arrive at Thor. |
Ch | Length | Activity |
10 | ? | Smelting ore |
10 | 40 | Heptapus archaeology |
Symbolize U-238 by ``U'' and U-235 by ``X''. Let [U] and [X] = concentration of the species in the ore. Let u and x represent the e-folding times for decay (1.44 times the half life = half life over ln(2)). t = elapsed time; [U0] = initial concentration. It is assumed that the nuclear processes in a supernova (R process) that synthesize the uranium isotopes produce [X0]/[U0] which is similar everywhere, i.e. Terra and Njord.
[U] = [U0] exp(-t/u) and similarly for X.
[X]/[U] = ([X0]/[U0]) exp(-t(1/x - 1/u))
Terra was assembled 4.63e9 years ago. It is not known how long elapsed between Terra's supernova and assembly of Terra, but almost certainly it was well under 1e9 years, probably no more than 1e8 years. Thus I neglect that time.
Presently, [X]/[U] = 7.11e-3
u.5 = 4.51e9 yr; x.5 = 7.1e8 yr (half lives)
1/(1/x - 1/u) = 1.216e9 yr (= 1 / 8.23e-10) (e-folding)
exp(-t(1/x - 1/u)) = exp(-3.81) = 0.0222 with t = age of Terra.
[X0]/[U0] = 0.321
[X]/[U] = 0.035 would occur at a time of 2.69e9 years
Common Name | Freon-11 |
Formula | CFCl3 |
Boiling point | 23.82 C |
Average molecular mass | 137.37 amu |
Assuming most common isotopes: | |
C-12 | 12.00000 |
F-19 | 18.99840 |
Cl-35 | 34.96885 |
Total molecular mass | 135.90495 |
Numbers are in heptal (base 7). In Heptapus language the numeric format is unit, exponent, separator (H), integer part, point, fractional part. In English we use the opposite order (1.23H4 Unit) using H as the marker for a heptal exponent.
Length unit: tentacle lengths (about 2 meters).
Time unit: swim strokes (about 1.5 seconds).
Conversion procedure on calculator:
(All energies in KeV)
Cobalt-60 | ||
Halflife | 5.26 eyr | |
Decay energy | 2819 | |
Beta rays | 315 (99.87%), a few at 663 and 1488 | |
Gamma rays | 1173 (99.88%) | |
1332 (100%) | ||
2158 (0.001%) | ||
Strontium-90 | ||
Halflife | 28.1 eyr | |
Decay energy | 546 | |
Beta rays | 546 (100%) | |
Gamma rays | None | |
Cesium-137 | ||
Halflife | 30.23 eyr | |
Decay energy | 1176 | |
Beta rays | 511 (94%) | |
1176 (6%) | ||
Gamma rays | 662 (85%) |
Reference: Handbook of Chemistry and Physics, Table of the Isotopes, B-264; ibid, Gamma energies and intensities of radionuclides, B-340
This data is in fact for Terra. Thor will be terraformed similarly.
Area of ocean | 3.61e14 m2 (71% of surface) (For Terra) |
Mean depth of ocean | 3794 m |
Maximum depth | 10430 m |
Volume of ocean | 1.37e18 m3 (area * mean depth) |
1.66e18 m3 (mass of hydrosphere) | |
Water buried in lithosphere | 2e18 ton approx. |
Water in mantle as OH | 2e20 ton approx. |
Mass of atmosphere | 5.14e18 Kg |
Mass of Njord oceans (puddles) | 2.5e14 ton (fiction) |
Some geologists also believe that there is a substantial amount of hydrogen dissolved in the Earth's core, like several percent by mass, and if the redox state of the mantle were to change, that could become available as surface water.
Reference for Terran data: ``The Earth: its Mass, Dimensions and Other Related Quantities'' from NASA TT-F-533, translation of Russian sources or data table with references dated mostly 1950-1959. In: Weast, R.C. (ed.), Handbook of Chemistry and Physics, 63rd ed (1982), CRC, page F-154.
This is Willie's assignment. Value is the potential energy to go from place A to place B, in units of (m/s)2.
From/To | Infinity | Njord | Wotan | Thor | Freyja |
Loki | 4.296e+08 | -1.306e+09 | -2.028e+09 | -1.251e+09 | -5.722e+08 |
Freyja | 1.002e+09 | -7.339e+08 | -1.456e+09 | -6.789e+08 | |
Thor | 1.681e+09 | -5.503e+07 | -7.772e+08 | ||
Wotan | 2.458e+09 | 7.221e+08 | |||
Njord | 1.736e+09 |
Potential energy to refill Njord puddle from Wotan: 1.79e23 J. This is equal to ship's power for 2683 eyr.
This is Wilma's assignment. Comet infall time (Kepler's law):
R = semimajor axis of comet's orbit (radius of circular orbit)
G = gravitational constant
M = mass of primary (e Eri)
t = period of orbit
For circular orbit (orbital period for comet will be the same):
w = 2pi /t (angular frequency)
a = R w2 = GM/R2 (Acceleration)
w = (GM/R3)0.5
t = 2pi (GM)-1/2 R3/2 = 6.261e-10 R3/2(for e Eri)
If the comet of mass m needs to be moved laterally a distance dx within
(arbitrary) time T, the force F needed to do it is:
dx = 1/2 F/m T2
m = 1/2 F/dx T2
F = 2m dx/T2
We're approximating that all comets have the same semimajor axis and all have a very high eccentricity (so periapsis is well within Wotan's orbit). Each comet has a particular location in phase space, which is the direct product of position space (3D) and momentum space (3D). In the story there's a maximum force F which can be used to move comets laterally so they hit Thor, and a (fixed) time T during which the force can act. It's evident that the product (m dX) is fixed; thus it's irrelevant whether a few large comets or many small ones are chosen. The set of points (hypothetical comets) that will hit Thor by themselves within a time T is topologically equivalent to a 4D ball. Given the upper bound on impulse, a 5D tubular region of phase space can be pushed to hit Thor. The problem is thus equivalent to arraying the comets on a 2D sphere of radius 2R and saying that one point on that sphere will drop on Thor, and comets within dX of that point can be pushed into Thor. Of course comets in the outbound portion of the orbit can be pushed for a longer time, or shorter inbound, so the available impulse will average out.
The available impulse can be used to move many little comets or fewer bigger ones, or all the comets in a small tube vs. some of the comets in a big tube. But for optimum performance one should clean out all the comets in the smaller tube. For a radius dX the average displacement dx = 2/3 dX.
Also a comet could hit Thor on the inbound or outbound portion of its orbit, and could also be steered via Freyja and Wotan (in the latter case hitting Thor after a turn around e Eri), so there are six independent regions of the cloud that can be made to collide. Thus the density of the cloud should be inflated by a factor of six. So if the total mass of the Kuiper cloud is K (and doubling R since it's a radius):
m | = 6K pi dX2 / (16pi R2) = K/16 (dX/R)2 (mass in radius dX) |
dX | = R (8/3 m/K)0.5 |
F | = 2m (2/3 dX) / T2 = 8/3 (2/3)0.5 R m1.5/(K0.5 T2) |
2R | Average rad. of Kuiper cloud | 3.5e12 m (must divide by 2) |
1/2 Period (infall time) | 7.25e8 sec = 22.96 eyr | |
Velocity at Wotan's orbit | 4.84e4 m/s (from potential energy) | |
T | Push time demanded by plot | 3.15e8 sec = 10 eyr |
m | Required comet mass | 9.25e17 Kg (neglecting composition) |
K | Mass of Kuiper cloud | 5.983e24 Kg (1 x Terra) |
F | Force required | 1.40e10 Nt |
Number of large chips (3000 Nt) | 4.66e6 chips | |
Radius of equivalent sphere | 9.03e4 m (density 0.3 g/cc) | |
Number of comets, 1 Km radius | 3.08e6 comets |
The above is to put an atmosphere on Thor so people could breathe pure oxygen with helmets, not suits, on the plate surface, not just in the subduction trench, which means a density at the plate surface of 18% Terran normal. To refill the Njord puddle would require 2.5e17 Kg H2O, 1e18 Kg total, which takes about the same resources to do. Using the assumptions on production rate in snowball.pl, the B factories would put out 4.247e+06 chips in 12 years. Of course the chips are also being used to bring in water. Details, details. The story assumes a favorable orbit for the big comet that provides most of the atmosphere, so the indicated number of chips is an overestimate, plotwise.
Atomic composition of incoming comet material, from cosmic abundances (count of atoms):
Element | Rel. to H | Relative |
O | 6.7e-4 | 12 |
C | 3.5e-4 | 6 |
N | 1.1e-4 | 2 |
H | 30 (combined only) |
Estimated composition and proportion of molecules. ``Rel'' gives the proportion by molecules (unnormalized) and the mass percent. It's assumed (without objective evidence) that half the carbon is in CH4 and half is in CO2.
Compound | Rel. | By Mass | Kcal/Mole | J/Mole | |
NH3 | 2 | 11% | -3.9 | -1.63e4 | |
CH4 | 3 | 15% | -12.1 | -5.06e4 | (half the carbon) |
CO2 | 3 | 41% | -94.3 | -3.95e5 | |
H2O | 6 | 34% | -56.7 | -2.37e5 | (liquid) |
CO | (small) | -32.8 | -1.37e5 | ||
CH2O | -- | -38.6 | -1.62e5 | (biomass, eth glycol) | |
C2H6 | -20.2 | -8.38e4 | |||
C3H8 | -24.8 | -1.03e5 | |||
CH2 | -4.93 | -2.04e4 | (per additional unit) | ||
C6H6 | +19.8 | +8.29e4 |
Desired composition of atmosphere plus ocean, imitating the Terran atmosphere and ocean but not subterranean water. An approximately equal amount of water is buried in the lithosphere and 100 times more is dissolved in the mantle as OH.
Compound | Qty Kg | Qty Moles |
H2O | 1.66e24 | 9.22e25 |
O2 | 1.08e18 | 3.37e19 |
N2 | 4.06e18 | 1.45e19 |
CO2 | A lot |
H2 is not gravitationally bound and if produced in large quantities will exit the planet before reacting with atmospheric oxygen. In the story water is deposited in orbit around the planet and is photolysed by solar ultraviolet.
Reaction: CH4 + 2 H2O -> CO2 + 4 H2 (1.30e5 J/M endothermic) gives:
Reaction: CH4 + CO2 -> 2 CH2O (biomass) -> 2 H2O + 2 C (coal): Perfect!
Reaction: n CH4 + m CO2 -> C(n+m)H(4n-4m) + 2m H2O
Reaction: 2 NH3 + 3 CH4 + 3 CO2 -> N2 + 6 H2O + C6H6
Reaction: C + 2 H2O -> CO2 + 2 H2
If we assume CH4 + CO2 -> 2C + 2 H2O, creating an Earth-type ocean (1.66e24 Kg H2O) requires the following inputs with 2:3:3:6 mix.
Compound | Kg | Moles |
NH3 | 2.61e23 | 1.54e25 |
CH4 | 3.69e23 | 2.30e25 |
CO2 | 1.02e24 | 2.30e25 |
H2O | 8.30e23 | 4.61e25 |
An equal amount of water is produced in the reaction, plus an equal number of moles of carbon.
We'll build an Earth-density atmosphere from comet impacts and later bring in the rest of the H2O and CO2 after fractionation on Freyja, leaving behind the NH3 and CH4. Mass of Terra's atmosphere: 5.14e18 Kg, 79% N2.
Compound | Kg | Moles | |
N2 + O2 | 5.14e18 | 1.78e20 | Total atmosphere when finished |
N2 | 3.94e18 | 1.41e20 | |
O2 | 1.20e18 | 3.74e19 | |
NH3 | 4.79e18 | 2.82e20 | Composition of comet material |
CH4 | 6.77e18 | 4.23e20 | |
CO2 | 1.86e19 | 4.23e20 | |
H2O | 1.52e19 | 8.46e20 |
Oxygen will be derived from CO2 + H2O -> CH2O + O2, endothermic 4.70e5 J/M or 113.31 Kcal/M. This plan is changed later to ultraviolet dissociation of H2O and NH3 whereupon the H2 escapes to Wotan.
Total energy to produce oxygen | 1.76e25 J |
Solar power | 6.37e18 W (incl 50% atmos loss only) |
Time to produce oxygen (50% eff) | 2.76e6 sec = 31.9 days :-) |
Mass of oxygen per area | 2.36e3 Kg/m2 |
Biomass per area | 2.21e3 Kg/m2 |
Tree production rate | 10 ton/hectare-eyr = 1 Kg/m2.eyr |
Time to produce oxygen (biomass) | 2.21e3 eyr |
Disposing of reduced species: | |
CH4 + H2O -> CH2O + 2 H2 | 30.2 Kcal/M, 1.26e5 J/M endothermic |
Total energy to dispose of CH4 | 5.33e25 J |
Mass of CH4 per area | 1.33e4 Kg/m2 |
Biomass per area | 2.50e4 Kg/m2 |
Time to dispose (biomass) | 2.50e4 eyr |
2 NH3 -> N2 + 3 H2, per N: | 3.9 Kcal/M, 1.63e4 J/M endothermic |
Total energy to produce N2: | 4.60e24 J |
The coding regions of all human genes extend over about 120 Mb. Reference: David G. Wang et al (27 authors), ``Large-Scale Identification, Mapping and Genotyping of Single-Nucleotide Polymorphisms in the Human Genome'', Science, v280 (1998-05-15) p. 1077; in the article a reference is given which may be the original source of this number.
The total size of the human genome is about 3 Gb. Essential areas in addition to coding regions include upstream regulatory domains, introns, transfer and ribosomal RNA genes, centromeres and telomeres. Introns tend to be larger than really necessary for their regulatory and evolutionary functions. In addition there are numerous classes of repeated sequences, pseudogenes, retrotransposons, integrated viral genome fragments and so on, collectively termed ``junk DNA''.
The cystic fibrosis gene is about 30 Kb long but is strung out over 1.5 Mb with many large introns. Some genes have 40 to 50 introns. Most genes are present in a single copy, but gene duplication events are common too, and the pairs tend to diverge in sequence and function. (In some cases one copy becomes inoperative; this is a "pseudogene".) Some plants such as maize and rice have clearly duplicated their entire genomes in nature, being quadruploid or even octuploid (doubled twice), though the copies aren't exact.
The figure of ``about 300 Mb'' for the lion genome is probably reasonable. If the issue comes up, we'll use 312 Mb as the exact size.
The initial site for the colony is in a subduction trench 1e4 meters deep. The atmosphere is a mixture of argon (mass 40, monatomic) and nitrogen (mass 28, diatomic). What is the pressure at the bottom of the trench as additional material is added at the top, uniformly diluting the argon, assuming the trench holds a negligible fraction of the total atmosphere?
Pv = RT | Equation of state |
Cv = (n[j]+1/2)R | Ideal gas specific heat, const volume |
Cp = (n[j]+3/2)R | Same at constant pressure |
y = Cp/Cv = (n[j]+3)/(n[j]+1) | Normal symbol: gamma. |
The dependence of Cv and Cp on the number of atoms per molecule is almost exact for n=1 and 2, less exact for n=3, and poor for more atoms.
In an atmosphere heated from below, the temperature and pressure as a function of altitude z will be such that when a unit of gas moves from point A to point B, the change of gravitational potential energy will exactly balance the change of thermal energy (and a corresponding statement about derivatives). Less temperature gradient and there's no energy to drive convection; more gradient and the convection will accelerate until the gradient is smoothed out. (Reference: Reif, Fundamentals of Statistical and Thermal Physics, McGraw-Hill (NY), 1965, p. 159.)
Pvy = K | Constant in adiabatic convection. |
v = K(1/y) P(-1/y) | |
dP/dz = -gr = -gm/v = -mgK(-1/y)P(1/y) | |
P(-1/y)dP = -mgK(-1/y)dz | |
P(1-1/y) = -mgK(-1/y)(1-1/y)z | Valid for negative z; z = 0 when T = 0 |
K = P(RT/P)y = Ry Ty P(1-y) | evaluated at one point, P0 and T0. |
K(-1/y) = P0((y-1)/y) / (R T0) | |
P = P0 (((y-1)/y)mg/(R T0) (-z))(y/(y-1)) | |
z0 = -(y/(y-1)) R T0 / mg | |
P = P0 (z/z0)(y/(y-1)) | with both z, z0 negative. |
T0 = 280 K (blackbody temperature). | |
v = RT/P | |
P(1-y)Ty = const. | |
T = T0 (P/P0)((y-1)/y) = T0 z/z0 | (!) |
In the following table, the pressure and temperature are given at the bottom of the trench assuming adiabatic conditions, and the ``pressure ratio'' has the plate surface pressure in the denominator. In reality, radiative cooling will produce a superadiabatic lapse rate, decreasing the temperature and increasing the pressure, but this effect is not referred to explicitly in the story.
Cv | gamma | Mol wt | Scale | Press | Press | Temp | Composition |
J/MK | Kg/M | ht, M | ratio | Nt/m2 | K | percent Earth normal | |
16.62 | 1.50 | 34.00 | -1.99e+4 | 3.38 | 1.03e+4 | 420 | Ar 1.5 N2 1.5 |
15.25 | 1.55 | 36.00 | -1.78e+4 | 3.54 | 1.61e+4 | 437 | Ar 3.0 N2 1.5 |
16.62 | 1.50 | 34.00 | -1.99e+4 | 3.38 | 2.06e+4 | 420 | Ar 3.0 N2 3.0 |
18.00 | 1.46 | 32.00 | -2.24e+4 | 3.22 | 2.94e+4 | 405 | Ar 3.0 N2 6.0 |
25.35 | 1.33 | 28.99 | -3.16e+4 | 3.05 | 5.53e+4 | 369 | Ar 3.0 NH3 3.7 CH4,CO2 5.6 |
20.74 | 1.40 | 28.95 | -2.73e+4 | 2.98 | 3.01e+5 | 383 | O2 21 N2 78 Ar 0.96 |
The first row is the initially chosen atmosphere at 3% Earth normal. The resulting pressure at Gondolin is too low to be practical. So let's fiddle with the composition by adding more argon: the second row. This is what's used in the story. Rows 3 and 4 show the effect of gradual addition of nitrogen. Row 5 is the atmosphere after some major comet bombardment; P0 (on plate surface) is 18% Earth normal = 1.81e4 Nt/m2; better than the original trench bottom. The last row is Earth normal.
Terra's surface oxygen partial pressure is 2.12e4 Pa. Andean people handle 1.0e4 Pa after major adaptation. Pure O2 at 1.64e4 Pa is equivalent to an altitude on Terra of about 2100 M (6900 ft); 1600 M is handled by ``ordinary'' people after modest adaptation.
The atmosphere mass after the comet (row 5) is about 9.44e17 Kg.
Day Event | |
0 | Heptapi blow themselves up (in ch. 8; day 7 on ch. 6 timeline) |
1 | Planning about replanting (chapter 8) |
2 | Continue debate. Gaia plan. Tentative decision (chapter 8). |
3 | Final decision to replant (chapter 9) |
3 | Production schedule and Novanima design (chapter 9) |
Begin search for heptapus cities. Start comet miner returning. | |
9 | Find heptapus village. Inspect heptapus city. |
19 | Comet miner arrives. |
20 | Depart for Thor. |
24 | Arrive at Thor. |
These items are made in the Japanese chip prototyper (proto) and the B factory, which is about 4 times faster. Times in Earth days.
Proto | Bfact | Description |
2 | .5 | Small pusher chip, 100 Nt (includes partner) |
10 | 2.5 | Large pusher chip, 3000 Nt (includes partner) |
2 | .5 | Video camera |
2 | .5 | W32 CPU chip |
2 | .5 | Memory 64 Mb total |
15 | APX detector | |
15 | X-ray detector | |
15 | Interplanetary bee prototype (4 sections) (not including partner) | |
15 | 0.45 | Production bee (chiller, or pusher 10000 Nt) |
15 | 0.45 | Power nexus for set of four full-size bees |
From Encyclopedia Brittanica, ``Concrete'', the proportions to make it are:
Aggregate (rocks and sand) | 9 units (by mass) |
Cement | 2 units |
Water | 1 unit |
Total | 12 units |
Plus carbon dioxide | 2.5 units (releasing the 1 unit of water) |
The carbon dioxide is absorbed during about thirty days after pouring. The amount was computed by assuming that all the water hydrates oxides, and the hydroxide is entirely replaced by carbonate (probably an overestimate):
Thor's rotation period (also orbital period) is 1.385e5 sec = 38.48 Earth hours. The crew decide on a 3:2 day cycle with the activity cycle 9.235e4 secs long (25.7 Earth hours). Pro forma, a Thor Hour is day/36 = 3848 secs.
Eclipses: Wotan subtends 39 degrees, so the longest eclipse would last 3.90 (Thor) hours = 1.50e4 seconds. Most or all days have eclipses; the inclination of Thor's orbit hasn't been specified but it's nonzero. The timings given below are for longitude 0 (sub-Wotan point) where the eclipse is centered in the day.
Under a variety of scoring variations, where waking in daylight and sleeping in night are preferred, it's optimal to wake at sunrise on one of the days and pessimal to wake six hours later, or at sunset two days later. The scores are periodic over 12 hours. Phase 6 has about 3/4 the ``correctly lighted'' hours of phase 0.
Day | Wake | Events | Sleep | Events |
1 | Sunrise | Eclipse: wake+8 | Sunrise+16 | Sunset: sleep+2 |
2 | Sunset+6 | Sunrise: wake+12 | Sunrise+4 | Eclipse: sleep+4 |
3 | Sunrise+12 | Sunset: wake+6 | Sunset+10 | (none) |
At Gondolin Wotan hangs in the west (ch. 10) so it's at maybe +45 to 50 degrees (East). In chapter 21-23 the day phase is critical and the plot is designed for 0 degrees (sub-Wotan point). Gondor doesn't have timezones; hour zero is sunrise at the sub-Wotan point.
Mithrim | Gondolin | |
Longitude | 0 deg | +50 deg (East) |
Sunrise (type 1) | 0 hrs | 19 hrs (= -5 hrs) |
Eclipse (center) | 9 hrs | 9 hrs |
(Range) | 7 - 11 hrs | 7 - 11 hrs |
Eclipse (after sunrise) | 9 hrs | 14 hrs |
(Range) | 7 - 11 hrs | 12 - 16 hrs |
Unless specified, time units refer to Thor, except Earth seconds are always used (there is no special second adapted to Thor's rotation).
Seconds per day | 92423 approx. |
Hours (Thor) per day | 24 |
Hours (Earth) per day | 25.673 |
Thor rotations per day | 2/3 |
Seconds per (Wotan) year | 1.810e7 |
Days per year | 195.83 |
Days per month | 28 (1.016 x average Earth month) |
Months per year | 7 (minus 1 day on unleap years). |
Seconds per Earth year | 3.156e7 |
Earth years per Wotan year | 0.574 = 1 / 1.743 |
The year starts on the day containing the vernal equinox. Most years are 196 days long; about 1/6 have an anti-leap day and are 195 days long.
Len | Day | Activity |
5 | 0 | Smelting ore at Thor |
4 | 5 | Travel back to Njord |
42 | 9 | Heptapus archaeology at Njord |
4 | 51 | Travel to Thor |
1 | 55 | Test dig at the Gondolin site |
Gondolin is in a subduction trench about 1e4 meters below the surrounding plate surface (ocean floor, on Terra). On Terra there would be 3000 to 4000 meters of ocean (mean 3794 m) above the plate surface but the trench would also be partially filled with copious sediment. The trench axis runs southeast to northwest, or, convergence is northeast to southwest. The northeast plate is going down. It has about a twenty degree slope, though the land is cracked and irregular, meaning that there's a horizontal distance of about 2.7e4 meters to the plate surface, or 3e4 meters path length not counting going around or through the numerous deep canyons. The southwest side is a continental block. Its edge has about a 40 degree slope and is dominated by landslides into the trench. Gondolin is established somewhat to the southeast of the trench center on the descending (northeast) plate, and Sirion flows northwest.
One way Thor to Freyja | 1.81e4 sec | (5 hours, at 10 G) |
Thor to Wotan | 7.52e2 sec | (at 10 G) |
Freeze a snowball | 5e4 sec | |
One way Freyja to Thor | 9.07e4 sec | (with snowball, at 2 G) |
Wotan to Thor | 3.75e3 sec | (at 2 G) |
Total (Thor <-> Freyja) | 1.59e5 sec | |
Total (Thor <-> Wotan) | 5.45e4 sec | |
Potential energy, Freyja/Wotan | 0.874 | (vs. Thor, ratio) |
Ratio (PE/trip time) | 0.300 | |
Division of chips | 0.231 Wotan, 0.718 Freyja | |
Mass of snowball | 0.5 Kg | |
Number of butterflies | 7100 | (at start of chapter 11) |
Mass flow (Freyja + Wotan) | 3.22e-2 Kg/sec | = 1.72e-2 + 1.50e-2 |
Power (Freyja -> Thor only) | 1.17e7 watts | (Wotan -> Thor is equal) |
Time per snowball arrival | 15.5 sec | |
Time per chip | 1.10e5 sec | (avg round trip time) |
Partway through chapter 12 the integrated implanter gun lets Willie make implanter factories in 2.5e5 secs each. This timeline is replicated in an analysis for chapter 16.
Ages are in Earth months, for Novanima species and Homo sapiens.
Nova. | H.sap | Event |
0 | -9 | Implantation |
7 | 0 | Birth |
9 | 3 | Ready to implant next set of kittens |
16 | -- | First handsigns |
19 | 15-20 | Toilet training (goes as needed, and presses own buttons) |
20 | 13 | First words (voice) |
30 | 24 | Useful conversation |
40 | ? | Can pay attention to stories |
50 | 42 | Reading on their own |
Age of | Event | |||
Lions | Otters | 'Uomi | Jaguars | |
0 | Lions implanted (start of chapter 11) | |||
7 | Lions born (end of ch 11) | |||
8 | Finish dome 2 | |||
9 | 0 | Otters implanted | ||
14 | 5 | Iris finds a jacinth crystal (ch 12) | ||
15 | 6 | Lions ejected from pockets | ||
16 | 7 | Otters born | ||
16 | 7 | Selen plays pattycake with Lucent (ch 12) | ||
19 | 10 | 1 | Finish dome 3 | |
25 | 16 | 7 | 'Uomi born | |
25 | 16 | 7 | Swimming lessons (ch 12) | |
27 | 18 | 9 | 0 | Jaguars implanted; work on other life |
29 | 20 | 11 | 2 | Finish dome 4 |
34 | 25 | 16 | 7 | Jaguars born |
39 | 30 | 21 | 13 | Simba finishes air plant; finish dome 5 |
42 | 33 | 24 | 15 | Jaguars ejected from pockets |
43 | 34 | 25 | 16 | Reading lesson (ch 12) |
49 | 40 | 31 | 22 | Finish dome 6 |
Domes are 24 m diameter, floor area 452 m2, except 1/3 is occupied by mats, tables, tunnel ports, emergency cans, foundations, etc. Effectively 300 m2. With practice it takes 0.8 eyr to build one residential dome, with tunnels. An agricultural dome takes 0.3 eyr (it's less elaborate, less digging.) It takes 1000 m2 of floor area to feed four adult lions and humans (260 Kg biomass). Kittens count double due to higher metabolism. This table assumes all 16 kittens were born at the same time, ignoring the actual 27 month skew. (See ``Human Nutrition'', chapter 4.)
Age | Mass | Total | Food | Area | Domes | Kitten |
eyr | Kg/ktn | Kg | Kg/day | m2 | Multiplier | |
0 | 0 | 260 | 1.88 | 1036 | 3.5 | |
1 | 6 | 452 | 3.27 | 1800 | 6 | 2x |
5 | 20 | 900 | 6.52 | 3600 | 12 | 2x |
10 | 35 | 1380 | 10.0 | 5500 | 18 | 2x |
15 | 55 | 1580 | 11.4 | 6300 | 21 | 1.5x |
20 | 70 | 1380 | 10.0 | 5500 | 18 | 1x |
Each dome has at least a small amount of each plant species, for disaster recovery, but the major occupants go like this (in chapter 12):
1A | Chang bushes |
2A | Chang bushes |
3A | Vegetables |
4A | Nonfoods: trees, sagebrush and feather grass |
Kittens are segregated by sex but, as much as possible, not by species. This table indicates what combinations of species and sexes don't have a dome in which all can legally meet. In the failed list, sets with fewer species are listed first.
Theorem: If there are M species there are 2M combinations of sexes. To accommodate every one requires 2M domes. In N domes the number of M-species combinations that can't be realized is 2M - N. Empirically it's possible to get sex assignments, for 4 species in 5 domes, such that this relation holds for every subset of species, i.e. 4x(8-5) 3-species combinations plus (16-5) 4-species combinations are illegal. Similarly for 4 species in 6 domes. All combinations of two species are legal in 4 or more domes. In 4 to 6 domes a relatively few combinations of three species are illegal.
(For reference: 6 domes 4 species took 1.5 days to compute, in PERL, hiss, boo.)
This is the assignment finally adopted. (H) indicates the home dome.
Dome | Lions | Otters | 'Uomi | Jaguars |
1 | (Adults) | |||
2 | Male | Male | Female | Female |
3 | Female | Female | Male(H) | Female(H) |
4 | Female | Female | Female(H) | Male(H) |
5 | Male(H) | Female(H) | Male | Male |
6 | Female(H) | Male(H) | Male | Male |
Given two Novanima of specified species and sex, which dome(s) can they meet in?
Species | mm | mf | fm | ff | |
Lion | Otter | 2 | 5 | 6 | 3,4 |
Lion | 'Uomi | 5 | 2 | 3,6 | 4 |
Lion | Jaguar | 5 | 2 | 4,6 | 3 |
Otter | 'Uomi | 6 | 2 | 3,5 | 4 |
Otter | Jaguar | 6 | 2 | 4,5 | 3 |
'Uomi | Jaguar | 5,6 | 3 | 4 | 2 |
Dome assignments during emergency (chapter 14):
Dome | Lions | Otters | 'Uomi | Jaguars | |
1 | Male(H) | Male(H) | Female | Female | Adults(H) |
2 | Male | Male | Female(H) | Female(H) | |
3 | Female(H) | Female(H) | Male | Male | |
4 | Female | Female | Male(H) | Male(H) | |
5 | Burned | ||||
6 | No Cover |
Dome assignments after mate selection (chapter 17 and 18): * indicates moved.
Dome | Occupants |
1 | Adults |
2 | Open space |
3 | Quin and Valeria* |
Wolf* and Xena | |
4 | Oso* and Petra |
Orion and Rose* | |
5 | Iris and Lucent* |
Selen* and Titania | |
6 | Ken* and Jacinth |
Mica and Night* |
Day | Event |
0 | Chapter 13 starts, quoted age 19.7 tyr (11.3 eyr). Tail docked. |
5 | Valeria is angry with Tiger. |
40 | Chapter 14. Iris insists on being ready to do damage control. |
47 | Comet impact. Iris is hit by a meteor. |
48 | Rain and flooding. |
Numbers are age when the skill is learned, in eyr from assembly or begetting (subtract 0.75 eyr for human age from birth). Grade and Homo sapiens progress rates refers to public schools with ``ordinary'' kids.
Grade | H.sapiens | N.leo | Skill |
K-1 | 6 | 4-5 | Reading |
1 | 7 | 6 | 1 or 2 digit add |
2 | 8 | 7 | Simple multiply |
3 | 9 | 6 | Writing (unstructured) |
5 | 11 | 7-8 | Formal grammar |
5 | 11 | 9 | Fractions |
6 | 12 | 9 | Decimals |
6 | 12 | 10 | Long division |
7 | 13 | 11 | Syntactic analysis |
7 | 13 | 11 | Writing paragraphs |
8 | 14 | 12 | Writing essays |
9 | 15 | 13 | Algebra |
10 | 16 | 14 | Geometry |
The colony's coinage is patterned after the European Union. The 1 and 2 Euro coins are bimetallic, with brass on the outside and inside, respectively, and German silver for the other half. This brass has the composition Cu(75%) Zn(20%) Ni(5%) and the German silver is Cu(75%) Ni(25%).
The 0.1, 0.2 and 0.5 Euro coins are in Nordic Gold, which is a brass consisting of Cu(89%) Al(5%) Zn(5%) Sn(1%). It is said to be very resistant to tarnish, probably due to the aluminum.
The 0.01, 0.02 and 0.05 Euro coins are steel jacketed with (pure?) copper.
Let g = e-folding time for population growth, and p(t) = population as a function of time. Suppose the population is known at two times:
Let r = age of lions at the begetting of the first kitten and k = number of kittens per couple, assumed one per eyr. In the story they rush it: r = 18 eyr, k = 8. Two parents are needed. Taking a linear average,
Total population as a function of time (Tiger's ``B'' age), assuming all the kittens were assembled at once and reproduction in each generation is simultaneous.
Date | Population |
54.7 | 16 (kittens) |
77 | 80 |
99 | 326 |
121 | 1350 |
157 | 1.3e4 |
194 | 1.3e5 |
230 | 1.3e6 |
266 | 1.3e7 |
303 | 1.3e8 |
Later (chapter 21) it's assumed that kittens are produced once every 2 Thor years (14 months), whereas on Terra it's once every eyr (12 months). The above model goes by 1 per eyr.
Adult | Kitten | Time | Making | Technological Advance |
age | age | secs | each | |
52.2 | 5e5 | B fac | Willie makes B factories 50% of 2000 hr/eyr | |
3.89e4 | chip | Time for B factory to make a butterfly chip | ||
56.0 | 1 | 2.5e5 | B fac | Integrated implanter gun |
58.7 | 4 | 1e5 | B fac | Automated assembly of most of B factory |
60.7 | 6 | 8e3 | B fac | Automated assembly of most of smelter |
65.0 | 10 | 2.5e5 | A fac | Manual assembly of A factory |
5.0e5 | B fac | Time for A factory to make B factory | ||
70.0 | 15 | 2.0e5 | A fac | Simplification of A factory |
75.0 | 20 | 8.0e3 | A fac | E factory prototype, A factory finished by hand |
100 | 45 | 5.0e5 | E fac | Time for E factory to make itself |
2.5e5 | A fac | Time for E factory to make A factory |
Ages are in eyr.
Results (program snowball.pl):
The digit after each word is the tone (in the Mandarin or guo2 yue3 "national language" dialect):
1 | High even |
2 | Rising |
3 | Down-Up |
4 | Falling |
Date | 72.7 |
Ship power (SS David Franck) | 2.12e12 W |
Ship power (Chinese ship) | 2.5e12 (with same chip area) |
Solar power (at Terra) | 1e4 W/m2 |
Solar power at sundipper orbit | 100 x Terra |
Efficiency of sundippers | 39% |
Total area of sundippers | 5.43e6 m2 |
Number of B factories: | 7.409e+04 |
Time per chip: | 38880 sec |
Area per chip: | 10 x 10 cm |
Time to make chips: | 2.852e8 sec = 9.06 eyr = 15.8 tyr |
Water rate: | 1.913e+10 Kg/eyr = 1.096e10 Kg/tyr |
Potential energy, Freyja -> Thor | 6.789e8 J/Kg |
Power | 4.123e11 W |
Fraction of starship power | 0.194 |
(This analysis is oversimplified since some water comes from Wotan and the chips would be redeployed to the longer Freyja -> Thor run, reducing the water flow. This is mentioned in the story.)
Suppose a fraction W of the land is designated for large contiguous wilderness patches, P is a similar fraction for people patches, and the remainder (1-W-P) is to be split up in the same proportions recursively at smaller scales. In the remainder, all the land will eventually be in one or the other category, just in larger or smaller patches. Thus the ratio of wilderness to people area is just W/P.
For the purpose of the story, W = 0.25 and P = 0.25.
The story originally described ``about 50 villages, a few isolated homesteads, and our permanent capital''. Assume 20 families (an average of 6 people each counting kittens) per village, 100 families in isolated homesteads, and 300 families in the capital. Population:
Unit | Quantity | Fam/vil | People |
Villages | 50 | 20 | 6000 |
Homesteads | 100 | 1 | 600 |
Capital | 1 | 300 | 1800 |
Total | 8400 |
Using the population growth model developed for chapter 16, it would take 100 years, until 154.1, to achieve this population. This won't do. Lan Ying would be 112 eyr old. We need her to be about 70 eyr old which makes the date 111.7. At that point the population would be 580 people. This corresponds to about 2.6 generations at 8 kittens per 2 parents.
Unit | Quantity | Fam/vil | People |
Villages | 8 | 10 | 480 |
Homesteads | 5 | 1 | 30 |
Capital | 1 | 12 | 70 |
Total | 580 |
Name | Serno | Age eyr | Sex | Role |
Talisman | J1282-0440 | 24 | Male | Parent, crazy |
Joy | J1297-2003 | 24 | Female | Parent, driven mad |
Ardent | J1548-1441 | 6.7 | Male | Senior kitten |
Blaze | J1555-3577 | 5.5 | Female | Murdered |
Cinder | J1580-0422 | 4.3 | Male | Turned back, fell in hole |
Diablo | J1581-3234 | 3.2 | Female | Renamed Dragon |
Ember | J1582-1116 | 2.0 | Male | |
Flame | J1583-1153 | 10mo | Male | Pocket kitten |
See ``Day Phase'' for chapter 10, above. The listed eclipses are for latitude 0 (sub-Wotan point). Ardent mentions that the eclipse occurs after they started running away, helping them evade Talisman. ``Hr'' = hour of day. ``Lt'' = lighting phase: day vs. night.
Day | Type | Sunrise | Eclipse | Sunset | Hr | Lt | Events |
1 | 1 | 0 | 8 | 18 | 1 | d | Kittens run away from home |
0? | d | Tiger starts hiking | |||||
2 | 2 | 12 | 20 | -- | 6 | n | Tiger meets kittens |
7 | n | Rescue Cinder from hole | |||||
8 | n | Back to Mithrim | |||||
10 | n | Pick up Simba from trail | |||||
11 | n | Confront Talisman; he runs | |||||
19 | d | Talisman collects supplies | |||||
3 | 3 | -- | None | 6 | 0 | d | Talisman at Mithrim, hides |
1 | d | Talisman tries to rape Tiger | |||||
4 | d | Death ceremony for Talisman |
Each mature Chang bush produces (10 Kg bush mass)*(2e-3 per day) = 20 grams of seeds per day. A 70 Kg person consumes 507 grams of seeds per day, the output from 25.4 plants. 360 grams per day is the lower bound for starvation. (See Chang plant growth schedule, chapter 4.) Kittens count double by mass, due to higher metabolism. The Fire Kittens are undersized due to insufficient food. (See Food and Oxygen Production, chapter 12.)
Name | Age eyr | Mass Kg | |
Talisman | 24 | 70 | |
Joy | 24 | 70 | |
Ardent | 6.7 | 20 | (Kittens count double mass) |
Blaze | 5.5 | 18 | (Deceased, not counted) |
Cinder | 4.3 | 15 | |
Diablo | 3.2 | 10 | |
Ember | 2.0 | 6 | |
Flame | 10mo | 3 | (Age after begetting, not birth) |
Total mass | 248 Kg | ||
Food needed | 1.80 Kg/day | ||
Starvation | 1.28 Kg/day | ||
Plants | 90 | mature healthy plants (minimum) | |
Floor area | 1000 m2 | for 90 plants |
We'll say they have 100 plants, but not healthy ones, due to ant flu and inadequate fertilization. Talisman believes fertilizer is a government plot to pollute his precious bodily fluids.
Two times are given for each event: B = Tiger's biological age (where the journey counts as zero elapsed, since Tiger is frozen); N = what would have been Tiger's age had she stayed on Terra, minus speed of light delay. The latter is the age of Tiger's friends when they sent reports in the news feed then being received by Tiger. The term "friend" means someone, like the other original lions, assembled at the same time Tiger was. Units are eyr (Earth years). Decimal numbers are eyrs and decimals.
Months: Tiger was assembled in March so that's age 0.0.
.0 | Mar | .5 | Sep |
.1 | Apr | .6 | Oct |
.2 | May | .7 | Nov |
.3 | Jun | .8 | Jan |
.4 | Aug | .9 | Feb |
Upon arrival, newsfeed is read at 5x speedup for one year until they catch up. N dates are corrected for this and are marked *. If A = arrival date, N = (B-A)/5 + A.
B | N | Event |
0 | 0 | Tiger assembled (in March). (Birth 195 Earth days later.) |
16.0 | 16.0 | Tiger and Simba marry. (Simba is 1 month younger.) |
17.5 | 17.5 | Tiger starts college |
21.3 | 21.3 | Attila begotten (other kittens 1 year apart). Finish college. |
28.3 | 28.3 | Surya begotten (zero age for him). |
42.3 | 42.3 | Anansi begotten (grandkitten: Alex x Attila) |
44.6 | 44.6 | Begin ch 1: discover CQMT. Surya and Holly get into MIT. |
45.0 | 45.0 | Ch 2: A Rescue in Space. Stock market collapse. |
45.5 | 45.5 | Surya starts college (MIT) (his age 17.2 eyr) |
47.8 | 47.8 | Ch 3: UNESCO Conference, starship announced. |
49.3 | 49.3 | Ch 3: Test flight; test freezing process. |
49.5 | 49.5 | Ch 3: Wolf starts college (Wooly 1 year later). |
50.4 | 50.4 | End of Ch 3: Launch. 16.2 years pass frozen. |
50.4 | 50.4* | Ch 4: Arrive at epsilon Eridani. |
50.46 | 50.7* | Election results (not a presidential election) (ref. in ch 8) |
50.6 | 51.2* | End ch 4: grow plants, find comet, mine it, go to Njord, ch 5. |
50.6 | 51.3* | Wolf finishes college |
50.7 | 51.4* | Chinese launch starship. |
50.7 | 52.0* | Charlie nominated for SEC, not confirmed. |
50.8 | 52.3* | Wooly finishes college |
50.8 | 52.4* | Chinese lose contact with ship. |
50.86 | 52.7* | Election results (presidential). Faraldo out, Martin in. |
50.9 | 52.9* | Ch 6, 7, 8, 9. Heptapi discovered, destroyed. |
51.0 | 53.3* | Surya finishes grad school (4+4 eyr), thesis published |
51.0 | 53.4* | Charlie appointed to SEC, confirmed. |
51.0 | 53.4* | Revolution in China, Maoists in power. |
51.0 | 53.4* | End of ch 9. |
51.2 | 54.4* | End of ch 10: start work on Gondolin. |
54.7 | 60.1 | Ch 11: implant lion kittens. |
55.1 | 60.5 | Anansi starts college. (Not mentioned in story.) |
55.2 | 60.6 | Lion kittens born (end of ch 11, start ch 12). Dome 2 done. |
55.4 | 60.8 | Implant otters. |
56.2 | 61.6 | Implant uomi. |
56.3 | 61.7 | Dome 3 done (takes 1.1 yr due to kitten care). |
57.0 | 62.4 | Implant jaguars. |
57.1 | 62.5 | Dome 4 done. (Not mentioned in story.) |
57.6 | 63.0 | Jaguars born. |
57.9 | 63.3 | Dome 5 done. (Not mentioned in story.) |
58.4 | 63.8 | Jaguars out of pockets. Kittens learn to read. |
58.4 | 63.8 | Last date for return to Terra. |
58.6 | 64.0 | Charlie appointed chairman of the FRB, confirmed. |
58.7 | 64.1 | Dome 6 done. Food crisis, begin building greenhouse domes. |
59.7 | 65.1 | Four ag domes built. Iris asks for reading lesson. End ch. 12. |
62.0 | 67.4 | First comet impact. |
66.0 | 71.4 | Big comet impact. Chapter 13, 14, 15. (Lions 11.3 eyr) |
66.7 | 72.1 | Night suggests putting snowballs in orbit. Chapter 16. |
67.3 | 72.7 | Chinese launch second starship. |
71.2 | 76.6 | Iris sexually mature. Ken delayed until 71.9. |
71.9 | 77.3 | Lions and otters get married. Chapter 17. |
71.9 | 77.3 | Revolution in China, Maoists out of power. |
72.0 | 77.4 | Tiger sees Terran reaction to arrival at e Eri. (Not in story.) |
72.5 | 77.9 | Terran reaction to Heptapus debacle. Obliquely mentioned in 17. |
72.7 | 78.1 | Chinese starship arrives. Chapter 18. Lan Ying's age 31 eyr. |
72.7 | 78.1 | Uomi and jaguars get married. Chapter 19. |
76.3 | 81.7 | Terran reaction to colony formation orders. (Not in story.) |
77.5 | 82.9 | Wilma dies. Described (flashback) in chapter 21. |
77.8 | 83.2 | Willie dies. |
100.0 | 105.4 | E factory capable of making A factory and smelter. |
106.0 | 111.4 | Full atmosphere mass of 5.14e18 Kg. Chip production restrained. |
111.7 | 117.1 | Chapter 21, 22, 23. |
126.0 | 131.4 | Full ocean mass of 1.66e21 Kg. |