Parameter |
Probability that feature will fall in the required range for physical life |
local abundance and distribution of dark matter |
0.1 |
relative abundances of different exotic mass particles |
0.01 |
decay rates of different exotic mass particles |
0.05 |
density of quasars |
0.1 |
density of giant galaxies in the early universe |
0.1 |
galaxy cluster size |
0.1 |
galaxy cluster density |
0.1 |
galaxy cluster location |
0.1 |
galaxy size |
0.1 |
galaxy type |
0.1 |
galaxy mass distribution |
0.2 |
size of galactic central bulge |
0.2 |
galaxy location |
0.1 |
variability of local dwarf galaxy absorption rate |
0.1 |
quantity of galactic dust |
0.1 |
giant star density in galaxy |
0.1 |
frequency of gamma ray bursts in galaxy |
0.05 |
star location relative to galactic center |
0.2 |
star distance from corotation circle of galaxy |
0.005 |
ratio of inner dark halo mass to stellar mass for galaxy |
0.1 |
star distance from closest spiral arm |
0.1 |
z-axis extremes of star’s orbit |
0.02 |
proximity of solar nebula to a normal type I supernova eruption |
0.01 |
timing of solar nebula formation relative to a normal type I supernova eruption |
0.01 |
proximity of solar nebula to a type II supernova eruption |
0.01 |
timing of solar nebula formation relative to type II supernova eruption |
0.01 |
timing of hypernovae eruptions |
0.2 |
number of hypernovae eruptions |
0.1 |
masses of stars that become hypernovae |
0.1 |
flux of cosmic ray protons |
0.1 |
variability of cosmic ray proton flux |
0.1 |
gas dispersal rate by companion stars, shock waves, and molecular cloud expansion in the Sun’s birthing star cluster |
0.1 |
number of stars in birthing cluster |
0.01 |
star formation rate in parent star vicinity during history of that star |
0.1 |
variation in star formation rate in parent star vicinity during history of that star |
0.1 |
birth date of the star-planetary system |
0.01 |
number of stars in system |
0.7 |
number and timing of close encounters by nearby stars |
0.01 |
proximity of close stellar encounters |
0.1 |
masses of close stellar encounters |
0.1 |
density of brown dwarfs |
0.1 |
distance from nearest black hole |
0.2 |
absorption rate of planets and planetismals by parent star |
0.1 |
star age |
0.4 |
star metallicity |
0.05 |
ratio of 40K, 235,238U, 232Th to iron in star-planetary system |
0.02 |
star orbital eccentricity |
0.1 |
star mass |
0.001 |
star luminosity change relative to speciation types & rates |
0.00001 |
star color |
0.4 |
star rotation rate |
0.3 |
rate of change in star rotation rate |
0.3 |
star magnetic field |
0.1 |
star magnetic field variability |
0.1 |
stellar wind strength and variability |
0.1 |
short period variation in parent star diameter |
0.1 |
star’s carbon to oxygen ratio |
0.01 |
star’s space velocity relative to Local Standard of Rest |
0.05 |
star’s short term luminosity variability |
0.05 |
star’s long term luminosity variability |
0.05 |
amplitude and duration of star spot cycle |
0.1 |
number & timing of solar system encounters with interstellar gas clouds and cloudlets |
0.1 |
galactic tidal forces on planetary system |
0.2 |
H3+ production |
0.1 |
supernovae rates & locations |
0.01 |
white dwarf binary types, rates, & locations |
0.01 |
structure of comet cloud surrounding planetary system |
0.3 |
planetary distance from star |
0.001 |
inclination of planetary orbit |
0.5 |
axis tilt of planet |
0.3 |
rate of change of axial tilt |
0.01 |
period and size of axis tilt variation |
0.1 |
planetary rotation period |
0.1 |
rate of change in planetary rotation period |
0.05 |
planetary revolution period |
0.2 |
planetary orbit eccentricity |
0.3 |
rate of change of planetary orbital eccentricity |
0.1 |
rate of change of planetary inclination |
0.5 |
period and size of eccentricity variation |
0.1 |
period and size of inclination variation |
0.1 |
precession in planet’s rotation |
0.3 |
rate of change in planet’s precession |
0.3 |
polycyclic aromatic hydrocarbon abundance in solar nebula |
0.1 |
number of moons |
0.2 |
mass and distance of moon |
0.01 |
surface gravity (escape velocity) |
0.001 |
tidal force from sun and moon |
0.1 |
magnetic field |
0.01 |
rate of change & character of change in magnetic field |
0.1 |
albedo (planet reflectivity) |
0.1 |
density |
0.1 |
density of interstellar and interplanetary dust particles in vicinity of life-support planet |
0.3 |
reducing strength of planet’s primordial mantle |
0.3 |
thickness of crust |
0.01 |
timing of birth of continent formation |
0.1 |
oceans-to-continents ratio |
0.2 |
rate of change in oceans to continents ratio |
0.1 |
global distribution of continents |
0.3 |
frequency, timing, & extent of ice ages |
0.1 |
frequency, timing, & extent of global snowball events |
0.1 |
silicate dust annealing by nebular shocks |
0.02 |
asteroidal & cometary collision rate |
0.1 |
change in asteroidal & cometary collision rates |
0.1 |
rate of change in asteroidal & cometary collision rates |
0.1 |
mass of body colliding with primordial Earth |
0.002 |
timing of body colliding with primordial Earth |
0.05 |
location of body’s collision with primordial Earth |
0.05 |
position & mass of Jupiter relative to Earth |
0.01 |
major planet eccentricities |
0.05 |
major planet orbital instabilities |
0.05 |
drift and rate of drift in major planet distances |
0.05 |
number & distribution of planets |
0.001 |
distance of gas giant planets from mean motion resonances |
0.02 |
orbital separation distances among inner planets |
0.01 |
mass of Neptune |
0.1 |
total mass of Kuiper Belt asteroids |
0.1 |
mass distribution of Kuiper Belt asteroids |
0.2 |
average rainfall precipitation |
0.01 |
variation and timing of average rainfall precipitation |
0.01 |
atmospheric transparency |
0.01 |
atmospheric pressure |
0.01 |
atmospheric viscosity |
0.1 |
atmospheric electric discharge rate |
0.01 |
atmospheric temperature gradient |
0.01 |
carbon dioxide level in atmosphere |
0.01 |
rates of change in carbon dioxide levels in atmosphere throughout the planet’s history |
0.001 |
rates of change in water vapor levels in atmosphere throughout the planet’s history |
0.01 |
rate of change in methane level in early atmosphere |
0.01 |
oxygen quantity in atmosphere |
0.01 |
nitrogen quantity in atmosphere |
0.01 |
carbon monoxide quantity in atmosphere |
0.1 |
chlorine quantity in atmosphere |
0.1 |
aerosol particle density emitted from forests |
0.05 |
cobalt quantity in crust |
0.1 |
arsenic quantity in crust |
0.1 |
copper quantity in crust |
0.1 |
boron quantity in crust |
0.1 |
cadmium quantity in crust |
0.1 |
calcium quantity in crust |
0.4 |
fluorine quantity in crust |
0.1 |
iodine quantity in crust |
0.1 |
magnesium in crust |
0.4 |
manganese quantity in crust |
0.1 |
nickel quantity in crust |
0.1 |
phosphorus quantity in crust |
0.1 |
potassium quantity in crust |
0.4 |
tin quantity in crust |
0.1 |
zinc quantity in crust |
0.1 |
molybdenum quantity in crust |
0.05 |
vanadium quantity in crust |
0.1 |
chromium quantity in crust |
0.1 |
selenium quantity in crust |
0.1 |
iron quantity in oceans |
0.1 |
tropospheric ozone quantity |
0.01 |
stratospheric ozone quantity |
0.01 |
mesospheric ozone quantity |
0.01 |
water vapor level in atmosphere |
0.01 |
oxygen to nitrogen ratio in atmosphere |
0.1 |
quantity of greenhouse gases in atmosphere |
0.01 |
rate of change in greenhouse gases in atmosphere |
0.01 |
poleward heat transport in atmosphere by mid-latitude storms |
0.2 |
quantity of forest & grass fires |
0.01 |
quantity of sea salt aerosols in troposphere |
0.1 |
soil mineralization |
0.1 |
quantity of anaeorbic bacteria in the oceans |
0.01 |
quantity of aerobic bacteria in the oceans |
0.01 |
quantity of anaerobic nitrogen-fixing bacteria in the early oceans |
0.01 |
quantity, variety, and timing of sulfate-reducing bacteria |
0.00001 |
quantity of geobacteraceae |
0.01 |
quantity of aerobic photoheterotrophic bacteria |
0.01 |
quantity of decomposer bacteria in soil |
0.01 |
quantity of mycorrhizal fungi in soil |
0.01 |
quantity of nitrifying microbes in soil |
0.01 |
quantity & timing of vascular plant introductions |
0.001 |
quantity, timing, & placement of carbonate-producing animals |
0.00001 |
quantity, timing, & placement of methanogens |
0.00001 |
phosphorus and iron absorption by banded iron formations |
0.01 |
quantity of soil sulfur |
0.1 |
ratio of electrically conducting inner core radius to radius of the adjacent turbulent fluid shell |
0.2 |
ratio of core to shell (see above) magnetic diffusivity |
0.2 |
magnetic Reynold’s number of the shell (see above) |
0.2 |
elasticity of iron in the inner core |
0.2 |
electromagnetic Maxwell shear stresses in the inner core |
0.2 |
core precession frequency for planet |
0.1 |
rate of interior heat loss for planet |
0.1 |
quantity of sulfur in the planet’s core |
0.1 |
quantity of silicon in the planet’s core |
0.1 |
quantity of water at subduction zones in the crust |
0.01 |
quantity of high pressure ice in subducting crustal slabs |
0.1 |
hydration rate of subducted minerals |
0.1 |
water absorption capacity of planet’s lower mantle |
0.1 |
tectonic activity |
0.05 |
rate of decline in tectonic activity |
0.1 |
volcanic activity |
0.1 |
rate of decline in volcanic activity |
0.1 |
location of volcanic eruptions |
0.1 |
continental relief |
0.1 |
viscosity at Earth core boundaries |
0.01 |
viscosity of lithosphere |
0.2 |
thickness of mid-mantle boundary |
0.1 |
rate of sedimentary loading at crustal subduction zones |
0.1 |
biomass to comet infall ratio |
0.01 |
regularity of cometary infall |
0.1 |
number, intensity, and location of hurricanes |
0.02 |
intensity of primordial cosmic superwinds |
0.05 |
number of smoking quasars |
0.05 |
formation of large terrestrial planet in the presence of two or more gas giant planets |
0.1 |
orbital stability of large terrestrial planet in the presence of two or more gas giant planets |
0.01 |
total mass of Oort Cloud objects |
0.2 |
mass distribution of Oort Cloud objects |
0.2 |
air turbulence in troposphere |
0.1 |
quantity of sulfate aerosols in troposphere |
0.1 |
quantity of actinide bioreducing bacteria |
0.01 |
quantity of phytoplankton |
0.001 |
hydrothermal alteration of ancient oceanic basalts |
0.01 |
quantity of iodocarbon-emitting marine organisms |
0.01 |
location of dislocation creep relative to diffusion creep in and near the crust-mantle boundary (determines mantle convection dynamics) |
0.1 |
size of oxygen sinks in the planet’s crust |
0.2 |
size of oxygen sinks in the planet’s mantle |
0.2 |
mantle plume production |
0.1 |
number and mass of planets in system suffering significant drift |
0.2 |
mass of the galaxy’s central black hole |
0.3 |
timing of the growth of the galaxy’s central black hole |
0.5 |
rate of in-spiraling gas into galaxy’s central black hole during life epoch |
0.05 |
distance from nearest giant galaxy |
0.5 |
distance from nearest Seyfert galaxy |
0.9 |
amount of mass loss by star in its youth |
0.1 |
rate of mass loss of star in its youth |
0.3 |
rate of mass loss by star during its middle age |
0.3 |
quantity of magnetars (proto-neutron stars with very strong magnetic fields) produced during galaxy’s history |
0.05 |
variation in coverage of star’s surface by faculae |
0.5 |
ratio of galaxy’s dark halo mass to its baryonic mass |
0.2 |
ratio of galaxy’s dark halo mass to its dark halo core mass |
0.2 |
galaxy cluster formation rate |
0.1 |
proximity of supernovae and hypernovae throughout history of planet and planetary system |
0.1 |
tidal heating from neighboring galaxies |
0.5 |
tidal heating from dark galactic and galaxy cluster halos |
0.5 |
intensity and duration of galactic winds |
0.3 |
density of dwarf galaxies in vicinity of home galaxy |
0.1 |
amount of photoevaporation during planetary formation from parent star and other nearby stars |
0.2 |
orbital inclinations of companion planets in system |
0.1 |
variation of orbital inclinations of companion planets |
0.2 |
inclinations and eccentricities of nearby terrestrial planets |
0.3 |
in-spiral rate of stars into black holes within parent galaxy |
0.7 |
strength of magnetocentrifugally launched wind of parent star during its protostar era |
0.2 |
degree to which the atmospheric composition of the planet departs from thermodynamic equilibrium |
0.01 |
delivery rate of volatiles to planet from asteroid-comet belts during epoch of planet formation |
0.1 |
amount of outward migration of Neptune |
0.1 |
amount of outward migration of Uranus |
0.1 |
Q-value (rigidity) of planet during its early history |
0.2 |
variation in Q-value of planet during its early history |
0.3 |
injection efficiency of shock wave material from nearby supernovae into collapsing molecular cloud that forms star and planetary system |
0.1 |
number of giant galaxies in galaxy cluster |
0.2 |
number of large galaxies in galaxy cluster |
0.2 |
number of dwarf galaxies in galaxy cluster |
0.2 |
number and sizes of planets and planetesimals consumed by star |
0.3 |
distance of galaxy’s corotation circle from center of galaxy |
0.1 |
rate of diffusion of heavy elements from galactic center out to the galaxy’s corotation circle |
0.2 |
outward migration of star relative to galactic center |
0.3 |
degree to which exotic matter self interacts |
0.01 |
migration of planet during its formation in the protoplanetary disk |
0.1 |
viscosity gradient in protoplanetary disk |
0.1 |
variations in star’s diameter |
0.1 |
average quantity of gas infused into the universe’s first star clusters |
0.1 |
frequency of late impacts by large asteroids and comets |
0.1 |
level of supersonic turbulence in the infant universe |
0.05 |
number and sizes of intergalactic hydrogen gas clouds in galaxy’s vicinity |
0.1 |
average longevity of intergalactic hydrogen gas clouds in galaxy’s vicinity |
0.2 |
minimization of chloromethane production by rotting plants and fungi that are exposed to the atmosphere (life’s survival demands very efficient burial mechanisms and relatively low temperatures) |
..01 |
avoidance of apsidal phase locking in the orbits of planets in the planetary system |
0.03 |
number density of the first metal-free stars to form in the universe |
0.02 |
epoch during which the first metal-free stars form in cosmic history |
0.1 |
level of spot production on star’s surface |
0.2 |
variability of spot production on star’s surface |
0.2 |
size of the carbon sink in the deep mantle of the planet |
0.05 |
average circumstellar medium density for white dwarf red giant pairs |
0.2 |
number densities of metal-poor and extremely metal-poor galaxies |
0.1 |
rate of growth of central spheroid for the galaxy |
0.05 |
amount of gas infalling into the central core of the galaxy |
0.1 |
level of cooling of gas infalling into the central core of the galaxy |
0.1 |
ratio of dual water molecules, (H2O)2, to single water molecules, H 2O, in the troposphere |
0.03 |
heavy element abundance in the intracluster medium for the early universe |
0.1 |
quantity of volatiles on and in Earth-sized planet in the habitable zone |
0.001 |
rate of infall of intergalactic gas into emerging and growing galaxies during first five billion years of cosmic history |
0.1 |
pressure of the intra-galaxy-cluster medium |
0.1 |
proximity of solar nebula to a type I supernova whose core underwent significant gravitational collapse before carbon deflagration |
0.01 |
timing of solar nebula formation relative to a type I supernova whose core underwent significant gravitational collapse before carbon deflagrataion |
0.01 |
sizes of largest cosmic structures in the universe |
0.01 |
level of spiral substructure in spiral galaxy |
0.2 |
mass of outer gas giant planet relative to inner gas giant planet |
0.05 |
Kozai oscillation level in planetary system |
0.7 |
triggering of El Nino events by explosive volcanic eruptions |
0.1 |
time window between the peak of kerogen production and the appearance of intelligent life |
0.1 |
time window between the production of cisterns in the planet’s crust that can effectively collect and store petroleum and natural gas and the appearance of intelligent life |
0.1 |
reduction of Kuiper Belt mass during planetary system’s early history |
0.1 |
efficiency of stellar mass loss during final stages of stellar burning |
0.3 |
efficiency of flows of silicate melt, hypersaline hydrothermal fluids, and hydrothermal vapors in the upper crust |
0.2 |
supernova eruption rate when galaxy is young |
0.2 |
range of rotation rates for stars are on the verge of becoming supernovae |
0.2 |
quantity of dust formed in the ejecta of Population III supernovae |
0.1 |
chemical composition of dust ejected by Population III stars |
0.3 |
time in cosmic history when the merging of galaxies peaks |
0.2 |
efficiency of ocean pumps that return nutrients to ocean surfaces |
0.1 |
sulfur and sulfate content of oceans |
0.3 |
density of extragalactic intruder stars in solar neighborhood |
0.4 |
density of dust-exporting stars in solar neighborhood |
0.3 |
average rate of increase in galaxy sizes |
0.1 |
change in average rate of increase in galaxy sizes throughout cosmic history |
0.1 |
proximity of solar nebula to asymptotic giant branch stars |
0.05 |
timing of solar nebula formation relative to its close approach to asymptotic giant branch stars |
0.05 |
orientation of continents relative to prevailing winds |
0.3 |
quantity and proximity of gamma-ray burst events relative to emerging solar nebula |
0.01 |
proximity of superbubbles to planetary system during life epoch of life-support planet |
0.03 |
proximity of strong ultraviolet emitting stars to planetary system during life epoch of life-support planet |
0.02 |
number, mass, and distance from star of gas giant planets in addition to planets of the mass and distance of Jupiter and Saturn |
0.01 |
quantity and proximity of galactic gamma-ray burst events relative to time window for intelligent life |
0.1 |
infall of buckminsterfullerenes from interplanetary and interstellar space upon surface of planet |
0.3 |
quantity of silicic acid in the oceans |
0.1 |
heat flow through the planet’s mantle from radiometric decay in planet’s core |
0.002 |
water absorption by planet’s mantle |
0.01 |
timing of star formation peak for the universe |
0.2 |
timing of star formation peak for the galaxy |
0.2 |