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This is a copy of the scales of measurement list that I have been making. Thanks to the many people who gave me suggestions about earlier versions.
I would be grateful for factual and grammar corrections. I would also like to know if people have specific objects that they think should be included in these scales. I am interested in objects which do the following things:
A. Illustrate a physical principle (for example, the Compton length as
a basic quantum "fuzziness" length)
B. Are particularly fantastic (for example, the LIGO project wants to
look for length fluctuations smaller than a nuclear diameter)
C. Fill in holes in my order-of-magnitude scale
D. Are especially interesting for some other reason
I would be grateful for suggestions as to how to better word specific entries so as to make them maximally illuminating in the available space. Please send any comments/suggestions/corrections to me via email.
An XMOSAIC page has been created for my timelines and scales of measurement list. The URL is the following:
http://www.astro.psu.edu/users/niel/scales/scales.html
If you are not able to obtain one of my lists via XMOSAIC or usenet, please send me an email request and I will email you the list you want. Please specify desired format (ASCII or TEX).
Thank you,This document is copyright Niel Brandt 1994. You are allowed to copy, distribute, and edit this document at will without any obligation as long as you do not remove the above header. Reproduction and distribution for personal profit is not permitted.
3 x 10-6 | arcseconds | Angular size of a 108 solar mass Schwarzschild black hole in M31 |
0.0002 | arcseconds | Typical VLBA resolution at 43 GHz |
0.0005 | arcseconds | Person on the Moon |
0.001 | arcseconds | Typical VLBI resolution |
0.0015 | arcseconds | Hipparcos satellite astrometric positional accuracy |
0.04 | arcseconds | Hubble Space Telescope FOC optical angular resolution |
0.1 | arcseconds | VLA largest configuration resolution at 23 GHz |
0.1 | arcseconds | Hubble Space Telescope WFC optical angular resolution |
0.15 | arcseconds | 1 meter optical reflector yellow light diffraction limit |
0.5 | arcseconds | WHT MARTINI guide star system resolution |
0.6 | arcseconds | Rough optical telescope atmospheric seeing limit |
0.8 | arcseconds | Angular diameter of Europa |
1 | arcseconds | AXAF X-ray satellite angular resolution goal |
1.32 | arcseconds | Yearly proper motion of Sirius |
1.75 | arcseconds | Gravitational deflection of a light ray which grazes the Sun |
2.9 | arcseconds | Angular diameter of a M31 sized galaxy at z=0.5 in optical light |
5 | arcseconds | ROSAT X-ray satellite HRI angular resolution |
8 | arcseconds | Angular separation of the gravitationally lensed quasar 0957+561 |
25 | arcseconds | ROSAT X-ray satellite PSPC angular resolution |
36 | arcseconds | Angular diameter of Jupiter |
120 | arcseconds | Human eye resolution |
120 | arcseconds | Typical optical telescope field of view |
150 | arcseconds | Rough Crab Nebula radius |
210 | arcseconds | Rough Cir X-1 radio nebula radius |
400 | arcseconds | Cluster imprint on the cosmic microwave background radiation |
480 | arcseconds | OVRO 5.5 meter 32 GHz telescope resolution |
700 | arcseconds | Jodrell bank 250 foot 1420.4 MHz telescope resolution |
1200 | arcseconds | ROSAT X-ray satellite HRI field of view radius |
1500 | arcseconds | ASCA X-ray satellite GIS field of view radius |
1865 | arcseconds | Angular diameter of the Moon at its mean distance |
1800 | arcseconds | 100 Mpc structure imprint on the cosmic microwave background radiation |
1922 | arcseconds | Angular diameter of the Sun at its mean distance |
3100 | arcseconds | Maximum angular scale of causal connection on the cosmic microwave background radiation |
3600 | arcseconds | ROSAT X-ray satellite PSPC field of view radius |
7500 | arcseconds | Angular diameter of W50 |
10800 | arcseconds | Angular diameter of the LMC |
14400 | arcseconds | Angular diameter of M31 in optical light |
19800 | arcseconds | Palomar Optical Sky Survey plate field of view |
25200 | arcseconds | COBE DMR resolution limit |
5 x 10-44 | seconds | Planck-Wheeler time |
4 x 10-24 | seconds | Typical lifetime of strong interaction resonance |
8 x 10-21 | seconds | Electron light crossing time |
1 x 10-13 | seconds | Typical period of vibration of an atom in a solid |
1 x 10-13 | seconds | Typical X-ray line electric dipole radiative transition time |
1.6 x 10-9 | seconds | Typical hydrogen 2p ---> 1s radiative transition time (electric dipole one photon process) |
8 x 10-4 | seconds | Mass shedding minimum spin period for a neutron star |
1.6 x 10-3 | seconds | Spin period of PSR 1957+20 |
0.12 | seconds | Typical hydrogen 2s ---> 1s radiative transition time (strictly forbidden two photon process) |
10 | seconds | Median duration of a classical gamma-ray burst |
2 000 | seconds | Sun dynamic time scale |
8.6 x 104 | seconds | Earth rotation time |
3.2 x 107 | seconds | Earth orbit time around the Sun |
1.6 x 109 | seconds | Typical time between Milky Way supernovae |
1.9 x 1011 | seconds | Carbon-14 half-life |
3 x 1012 | seconds | Rough lifetime of a supernova remnant |
1.5 x 1013 | seconds | Typical HMXB evolution time |
3 x 1013 | seconds | Rough time for evolution of a biological species |
1.6 x 1014 | seconds | Main sequence lifetime for a 30 solar mass star |
3 x 1014 | seconds | Hydrogen 21 cm spin flip time |
3 x 1014 | seconds | Rough Lyapunov time of the solar system |
6.3 x 1014 | seconds | Sun thermal time scale |
1.3 x 1015 | seconds | E-folding time for a black hole accreting at the Eddington rate with an efficiency of 0.1 |
1.9 x 1015 | seconds | Main sequence lifetime for a 5 solar mass star |
2 x 1015 | seconds | Timescale for Los Angeles to pass San Francisco via continental drift |
2.4 x 1015 | seconds | Typical LMXB evolution time |
7.3 x 1015 | seconds | Orbit time for sun around galaxy center |
1.1 x 1016 | seconds | PSR 1913+16 orbital gravitational radiation coalescence timescale |
2 x 1016 | seconds | Rough supernova biological extinction time |
6 x 1016 | seconds | Minimum age of PSR J0437-4715 |
6 x 1016 | seconds | Time for galaxy to cross a cluster |
1.1 x 1017 | seconds | Primeval slime to man time |
1.5 x 1017 | seconds | Age of Earth and Sun |
1.5 x 1017 | seconds | Uranium-238 half-life |
2.7 x 1017 | seconds | Look back time to z=1 |
3 x 1017 | seconds | Main sequence lifetime for a 1 solar mass star |
3.3 x 1017 | seconds | Look back time to z=2 |
3.3 x 1017 | seconds | Sun nuclear time scale |
3.7 x 1017 | seconds | Look back time to z=4 |
3.8 x 1017 | seconds | Rough age of the Milky Way |
3.8 x 1017 | seconds | Look back time to the z=4.897 quasar PC 1247+3406 |
4 x 1017 | seconds | Rough age of 47 Tucanae (an old globular cluster) |
4.1 x 1017 | seconds | Age of the universe |
2.5 x 1018 | seconds | Globular cluster evaporation time |
3 x 1025 | seconds | Galaxy dynamical relaxation timescale |
3 x 1027 | seconds | Earth/Sun orbital gravitational radiation coalescence timescale |
1 x 1039 | seconds | Lower limit on the proton lifetime |
4.7 x 1073 | seconds | 1 solar mass black hole Hawking evaporation time |
1.6 x 10-35 | meters | Planck-Wheeler length |
2 x 10-35 | meters | Rough postulated superstring size |
1 x 10-24 | meters | Effective 1 MeV neutrino radius |
1.6 x 10-22 | meters | Radius of a 10 solar mass star squeezed down to the Planck-Wheeler density |
1.5 x 10-18 | meters | Classical proton radius |
1.6 x 10-17 | meters | W +/- Compton wavelength = rough weak force length |
4 x 10-17 | meters | LIGO 4 km gravity-wave detector needed sensitivity |
1.3 x 10-15 | meters | Proton Compton wavelength = rough proton fuzziness length |
1.44 x 10-15 | meters | Rough nuclear radius |
2.8 x 10-15 | meters | Classical electron radius |
8.8 x 10-15 | meters | Pi-meson Compton wavelength = attractive strong force length |
1.2 x 10-12 | meters | 1 MeV gamma-ray wavelength |
2.4 x 10-12 | meters | Electron Compton wavelength = rough electron fuzziness length |
5.3 x 10-11 | meters | Bohr radius |
2.6 x 10-10 | meters | Copper atom spacing in solid copper |
3.5 x 10-10 | meters | H2O molecular diameter |
4 x 10-10 | meters | ROSAT X-ray satellite mirror rms surface error |
1.2 x 10-9 | meters | 1 keV X-ray wavelength |
3 x 10-9 | meters | Typical mean nucleon spacing during primordial nucleosynthesis |
3.4 x 10-9 | meters | DNA double helix turn length |
6 x 10-8 | meters | Typical rms surface error of a Keck telescope mirror |
7.0 x 10-8 | meters | Molecular mean free path in the atmosphere |
1 x 10-7 | meters | Typical size of a virus |
3 x 10-7 | meters | Interstellar dust grain size |
5 x 10-7 | meters | Optical photon wavelength |
4 x 10-6 | meters | Typical size of a cell |
2 x 10-4 | meters | Small dust particle size |
0.03 | meters | Lunar laser ranging accuracy (Science 265, 482) |
0.068 | meters | Unraveled human DNA strand length |
1.8 | meters | Man |
30 | meters | Blue Whale |
3700 | meters | Mean ocean depth |
4000 | meters | Error in our knowledge of the distance to Jupiter |
5500 | meters | Rough radius of Halley's comet |
8847 | meters | Height of Mount Everest |
10000 | meters | Neutron star radius |
10000 | meters | Typical asteroid radius |
10000 | meters | Typical comet radius |
11032 | meters | Depth of the Mariana Trench |
12000 | meters | Height of troposphere |
12000 | meters | Typical airliner cruising altitute |
30000 | meters | Typical thickness of the Earth's crust |
5.5 x 105 | meters | Height of the ASCA X-ray satellite orbit |
9 x 105 | meters | Height of the COBE satellite orbit |
3.2 x 106 | meters | Length of the Great Wall of China |
6.3 x 106 | meters | Radius of the Earth |
4.2 x 107 | meters | Geostationary satellite orbit height |
7.1 x 107 | meters | Radius of Jupiter |
9 x 107 | meters | Distance to the Earth's solar wind bow shock |
3.8 x 108 | meters | Distance to the Moon |
7.0 x 108 | meters | Radius of the Sun |
1 x 109 | meters | Typical X-ray binary accretion disk circularization radius |
1.7 x 109 | meters | 5 solar mass star main sequence radius |
7 x 109 | meters | Typical standoff radius of Jupiter's solar wind bow shock |
1.47 x 1011 | meters | Event horizon radius for a 108 solar mass maximally rotating Kerr black hole |
1.50 x 1011 | meters | Earth/Sun mean distance |
1.5 x 1011 | meters | Radius of the red giant Mira at minimum light |
3 x 1011 | meters | Radius of the red giant Mira at maximum light |
5 x 1011 | meters | Radius of the 20 solar mass red supergiant Betelgeuse at maximum light |
5.91 x 1012 | meters | Pluto/Sun mean distance |
1.5 x 1013 | meters | Expected distance to the solar wind termination shock |
2 x 1014 | meters | Rough stellar separation in the central parsec of the Milky Way |
4 x 1014 | meters | Rough stellar separation in a globular cluster |
2 x 1015 | meters | Rough Oort Cloud/Sun distance |
3 x 1015 | meters | Seyfert galaxy characteristic broad line region radius |
9.46 x 1015 | meters | 1 light-year |
3.08 x 1016 | meters | 1 parsec |
4 x 1016 | meters | Nearest nonsolar star to Earth |
4.5 x 1016 | meters | Rough Crab Nebula radius |
3 x 1017 | meters | Rough Cir X-1 radio nebula radius |
3 x 1017 | meters | Rough supernova biological extinction distance |
5 x 1017 | meters | Typical interstellar medium cloud size |
1.4 x 1018 | meters | Hyades open cluster distance |
1.5 x 1018 | meters | Trigonometric parallax distance determination limit |
1.5 x 1018 | meters | Typical globular cluster radius |
2 x 1018 | meters | Rough radius of the local interstellar hot gas bubble |
5 x 1018 | meters | Seyfert galaxy characteristic narrow line region radius |
5 x 1018 | meters | Diameter of W50 |
5.2 x 1018 | meters | Distance to the 20 solar mass red supergiant Betelgeuse (will go supernova within 10000 years) |
6 x 1019 | meters | Typical dwarf galaxy radius |
6.6 x 1019 | meters | Distance to the Crab Nebula |
1.2 x 1020 | meters | Milky Way characteristic thickness |
2 x 1020 | meters | Estimated distance to Cir X-1 |
2.4 x 1020 | meters | Distance from Sun to galactic center |
3.9 x 1020 | meters | Milky Way disk radius |
1.5 x 1021 | meters | Distance to the LMC |
2 x 1021 | meters | Rough Milky Way dark matter halo radius |
1 x 1022 | meters | Typical active galaxy jet length |
1 x 1022 | meters | Length of the "superantennae" of IRAS 19254-7245 |
1.9 x 1022 | meters | Distance to M31 |
3 x 1022 | meters | Radius of the core of the Virgo cluster of galaxies |
4 x 1022 | meters | Rough Local Group radius |
9.2 x 1022 | meters | Cepheid variable distance determination limit (via ground observations) |
1.2 x 1023 | meters | Distance to the Circinus galaxy |
5 x 1023 | meters | Rough boundary between the nonlinear and linear gravitational collapse regimes |
7 x 1023 | meters | Distance to NGC 1068 |
7 x 1023 | meters | Distance to the center of the Virgo cluster of galaxies |
2.3 x 1024 | meters | Shapley supercluster radius |
3 x 1024 | meters | Typical length scale probed by the Harvard/Smithsonian CfA redshift survey |
4.1 x 1024 | meters | Luminosity distance to the z=0.022 Coma cluster of galaxies |
1.5 x 1025 | meters | Typical length scale probed by the Lick survey |
3.0 x 1025 | meters | Luminosity distance to the z=0.158 quasar 3C273 |
3 x 1025 | meters | Typical length scale probed by the 4C radio galaxy survey |
3 x 1025 | meters | Schwarzschild radius of a singularity with the mass of a critical density universe |
5.5 x 1026 | meters | Luminosity distance to the z=2.286 ultraluminous IRAS galaxy IRAS F10214+4724 |
1.3 x 1027 | meters | Luminosity distance to the z=4.897 quasar PC 1247+3406 |
1 x 10-9 | m s-1 | Sea floor spreading rate |
1.6 x 10-9 | m s-1 | Average slip rate of the San Andreas fault |
1 x 10-8 | m s-1 | Typical rainfall rate in a semi-arid climate |
2 x 10-8 | m s-1 | Grass growth rate |
3 x 10-6 | m s-1 | Typical glacial advance rate |
1 x 10-3 | m s-1 | Equivalent radial velocity resolution of pulsar pulse arrival time analysis |
1.3 | m s-1 | Human walking speed |
10 | m s-1 | Speed of the motion induced on the Sun by Jupiter |
10 | m s-1 | Radial velocity resolution of high precision Doppler spectroscopy |
25 | m s-1 | Car speed |
100 | m s-1 | Typical speed of an electric pulse in the nervous system |
330 | m s-1 | Sound speed in air |
480 | m s-1 | Earth's atmosphere molecular rms velocity |
600 | m s-1 | Fighter jet speed |
2380 | m s-1 | Escape velocity from Moon's surface |
10000 | m s-1 | Typical longitudinal seismic wave velocity in the Earth's mantle |
11000 | m s-1 | Escape velocity from the Earth's surface |
20000 | m s-1 | Globular cluster stellar velocity dispersion |
29000 | m s-1 | Earth's motion around the Sun |
40000 | m s-1 | Globular cluster stellar escape velocity |
1 x 105 | m s-1 | Typical Galactic pulsar vertical velocity component |
1 x 105 | m s-1 | Average speed of the initial stroke of a lightning flash |
2.2 x 105 | m s-1 | Rotational velocity of the Sun around the Milky Way's center |
3 x 105 | m s-1 | Orbital speed of PSR 1913+16 |
3 x 105 | m s-1 | Rough velocity of Geminga's proper motion |
3.1 x 105 | m s-1 | Escape velocity from the Milky Way for objects in the solar neighborhood |
3.65 x 105 | m s-1 | Motion of the solar system barycenter relative to the cosmic microwave background |
4.1 x 105 | m s-1 | Orbital speed of Cen X-3 |
6.2 x 105 | m s-1 | Escape velocity from the Sun's surface |
6.22 x 105 | m s-1 | Motion of the Local Group relative to the cosmic microwave background |
8 x 105 | m s-1 | Typical galaxy cluster galaxy velocity dispersion |
2 x 106 | m s-1 | Speed of n=1 hydrogen electron |
5 x 106 | m s-1 | Young (months old) supernova ejecta |
1.2 x 107 | m s-1 | Velocity of the wind streaming out from H1413+117 "Cloverleaf" (Nature 371, 559) |
7.8 x 107 | m s-1 | SS433 jet speed |
1.4 x 108 | m s-1 | Keplerian orbital velocity at the surface of a neutron star |
2 x 108 | m s-1 | Escape velocity from neutron star surface |
2.998 x 108 | m s-1 | Light in a vacuum |
4.2 x 10-36 | kilograms | Mass equivalent of a green light photon |
1.4 x 10-35 | kilograms | Electron antineutrino upper mass limit |
4.4 x 10-31 | kilograms | Muon neutrino upper mass limit |
9.11 x 10-31 | kilograms | Electron mass |
6.2 x 10-29 | kilograms | Tauon neutrino upper mass limit |
1.67 x 10-27 | kilograms | Proton mass |
9 x 10-27 | kilograms | Bottom quark mass |
4.8 x 10-26 | kilograms | Mean mass of atmosphere molecule |
1.4 x 10-25 | kilograms | W +/- mass (82 GeV) |
1.6 x 10-25 | kilograms | Z0 mass (93 GeV) |
2 x 10-25 | kilograms | Favored Higgs boson mass |
3 x 10-25 | kilograms | Most probable top quark mass |
4 x 10-25 | kilograms | DNA nucleotide |
1 x 10-22 | kilograms | Typical protein molecule mass |
5 x 10-21 | kilograms | E. Coli ribosome |
1 x 10-16 | kilograms | Interstellar dust grain mass |
8 x 10-15 | kilograms | Rough mass of a human DNA molecule |
7 x 10-13 | kilograms | Typical mass of a cell |
2.2 x 10-8 | kilograms | Planck-Wheeler mass |
1 x 10-5 | kilograms | Typical mosquito mass |
0.02 | kilograms | Typical goldfish mass |
70 | kilograms | Typical human mass |
70 | kilograms | Lower limit to the allowed mass for a Sumo wrestler |
100 | kilograms | Meteorite mass before entry into Earth's atmosphere |
420 | kilograms | ASCA X-ray satellite mass |
900 | kilograms | Compton Gamma-Ray Observatory satellite mass |
1000 | kilograms | Car |
2200 | kilograms | ISO infrared satellite mass at launch |
10000 | kilograms | Tyrannosaurus Rex |
5 x 1011 | kilograms | Initial mass of a primordial black hole with evaporation time equal to the universe's age |
1 x 1013 | kilograms | Typical comet mass |
3 x 1014 | kilograms | Typical mountain mass |
1.1 x 1016 | kilograms | Superterranean biomass of Earth (ocean organisms are included) |
5.3 x 1018 | kilograms | Total mass of Earth's atmosphere |
3 x 1019 | kilograms | Typical asteroid mass |
1.4 x 1021 | kilograms | Total mass of Earth's oceans |
4.8 x 1022 | kilograms | Mass of Europa |
7.3 x 1022 | kilograms | Mass of the Moon |
2 x 1024 | kilograms | Rough Oort cloud mass |
5.98 x 1024 | kilograms | Mass of the Earth |
1.9 x 1027 | kilograms | Mass of Jupiter |
1.6 x 1029 | kilograms | Minimum mass to fusion burn hydrogen |
4 x 1029 | kilograms | Rough mass of MACHO and EROS microlensing objects |
1.99 x 1030 | kilograms | Mass of the Sun |
2.8 x 1030 | kilograms | Chandrasekhar mass (maximum mass for a white dwarf) |
6.0 x 1030 | kilograms | Oppenheimer-Volkoff mass (maximum mass for a neutron star) |
1.2 x 1031 | kilograms | Minimum mass of the unseen object in GS2023+338/V404 Cygni |
4 x 1031 | kilograms | Rough stellar mass above which the evolutionary endpoint is a black hole |
1.0 x 1032 | kilograms | Mass of the most massive member of Plaskett's star |
1.2 x 1032 | kilograms | Rough mass at which a star becomes unstable to pulsations |
2 x 1033 | kilograms | Typical interstellar cloud mass |
1 x 1036 | kilograms | Typical mass of a globular cluster |
6 x 1036 | kilograms | Best guess for the mass of a possible Milky Way central black hole |
1 x 1037 | kilograms | Rough baryonic Jeans mass immediately after decoupling |
4 x 1039 | kilograms | Rough mass of the SMC |
2 x 1040 | kilograms | Rough mass of the LMC |
7 x 1041 | kilograms | Rough mass of the Milky Way (visible and dark matter) |
1.3 x 1044 | kilograms | Rough mass of the stars in the Coma galaxy cluster |
6.4 x 1044 | kilograms | Rough mass of the X-ray gas in the Coma galaxy cluster |
2.7 x 1045 | kilograms | Rough virial mass of the Coma galaxy cluster |
6 x 1045 | kilograms | Rough virial mass of the Abell 2163 galaxy cluster |
2 x 1048 | kilograms | Rough baryonic Jeans mass immediately before decoupling |
1.4 x 1049 | kilograms | Rough total mass in spiral galaxies |
2 x 1049 | kilograms | Rough total (baryonic and nonbaryonic) mass in galaxy clusters |
3 x 1049 | kilograms | Rough total mass in elliptical and spheroidal galaxies |
8 x 1049 | kilograms | Rough total mass of visible matter in the universe |
1 x 1051 | kilograms | Rough total baryon mass predicted by primordial nucleosynthesis |
2 x 1052 | kilograms | Rough total mass of a critical density universe |
2 x 10-38 | kg m-3 | Effective density of the 100-300 MHz radio background |
1 x 10-35 | kg m-3 | Effective density of the 1--10 MeV gamma-ray background |
8 x 10-35 | kg m-3 | Effective density of the 2--100 keV X-ray background |
1.1 x 10-33 | kg m-3 | Upper limit to the effective density of the gravitational wave background |
1 x 10-32 | kg m-3 | Effective density of the starlight released in a Hubble time |
4.6 x 10-31 | kg m-3 | Effective density of the cosmic microwave background radiation |
2 x 10-29 | kg m-3 | Smoothed density of visible galactic material throughout universe |
2 x 10-28 | kg m-3 | Smoothed baryon density predicted by primordial nucleosynthesis |
4.7 x 10-27 | kg m-3 | Critical density of the universe |
2 x 10-24 | kg m-3 | Typical gas in a cluster of galaxies |
3 x 10-21 | kg m-3 | Typical gas in the interstellar medium of the Milky Way |
7 x 10-21 | kg m-3 | Dynamically inferred Milky Way disk density |
5 x 10-20 | kg m-3 | Typical density of the gas in the central kiloparsec of an interacting or starburst galaxy |
1 x 10-9 | kg m-3 | Best room temperature vacuum achieved on Earth |
1.7 x 10-4 | kg m-3 | Mean density of Antares (19 solar masses) |
1.3 | kg m-3 | Density of air |
700 | kg m-3 | Mean density of Saturn |
1000 | kg m-3 | Density of water |
1300 | kg m-3 | Mean density of Jupiter |
1400 | kg m-3 | Mean density of the Sun |
3300 | kg m-3 | Mean density of the Moon |
5500 | kg m-3 | Mean density of the Earth |
7860 | kg m-3 | Density of iron |
19300 | kg m-3 | Density of gold |
5 x 107 | kg m-3 | Typical white dwarf mean density |
3 x 1010 | kg m-3 | Typical white dwarf central density |
1.1 x 1012 | kg m-3 | Inverse beta decay threshold |
4.3 x 1014 | kg m-3 | Neutron drip density |
6 x 1017 | kg m-3 | Nuclear density |
1 x 1018 | kg m-3 | Typical neutron star central density |
5 x 1096 | kg m-3 | Planck-Wheeler density, at which quantum gravitational effects become important |
6 x 10-25 | joules | Lamb-Retherford shift |
9.5 x 10-25 | joules | 21.049 cm photon---hyperfine shift |
4 x 10-22 | joules | Molecular rotation transition |
4 x 10-21 | joules | kTroom = translational kinetic energy of atmosphere gas molecule |
7 x 10-21 | joules | Donor level/conduction band gap in a doped semiconductor |
3 x 10-20 | joules | Molecular vibration transition |
1.6 x 10-19 | joules | Valence band/conduction band gap in a semiconductor |
2.2 x 10-19 | joules | Bond energy of an organic substance with half-life 30000 years |
3.8 x 10-19 | joules | Green light photon |
9 x 10-19 | joules | Valence band/conduction band gap in an insulator |
1.1 x 10-18 | joules | Fermi energy in copper = depth of Fermi sea |
1.1 x 10-18 | joules | Positronium ionization energy |
2.2 x 10-18 | joules | Hydrogen n=1 binding energy |
1.6 x 10-16 | joules | 1 keV X-ray |
1.5 x 10-15 | joules | Hydrogenic iron n=1 binding energy |
8.18 x 10-14 | joules | Electron rest mass |
1.6 x 10-13 | joules | 1 MeV gamma-ray |
1.6 x 10-13 (Z1 x Z2) joules | Coulomb barrier height | 1.3 x 10-12 joules Nucleon binding energy |
4.3 x 10-12 | joules | Energy from 4 x 1 H ---> 4 He |
1.50 x 10-10 | joules | Proton rest mass |
1.6 x 10-7 | joules | Particle kinetic energy in a 1 TeV accelerator |
10 | joules | Well hit tennis ball |
51 | joules | Fly's Eye most energetic cosmic ray event |
2 x 105 | joules | Energy from a light bulb burning for 1 hour |
4.2 x 109 | joules | Explosion energy of 1 ton of TNT |
2 x 1010 | joules | Rough energy of a lightning flash |
2 x 1011 | joules | Rough human total energy output in a lifetime |
1.5 x 1014 | joules | Typical atomic bomb explosion energy |
6 x 1016 | joules | Tunguska 50 m diameter meteorite impact energy |
1 x 1017 | joules | Powerful H-bomb explosion energy |
3 x 1017 | joules | Elastic wave energy release from a large (M=8.5) earthquake |
5 x 1017 | joules | Explosion energy of Krakatoa |
3 x 1018 | joules | Superman flying at 70 per cent of light speed |
9 x 1018 | joules | USA electricity usage in 1986 |
5 x 1019 | joules | Rough explosion energy of the Lake Toba eruption in Sumatra |
4 x 1023 | joules | K-T 10 km diameter meteorite impact energy |
2.5 x 1022 | joules | Energy from the comet Shoemaker-Levy 9 fragment G impact on Jupiter |
1 x 1024 | joules | Power released by an evaporating black hole during the last second of its life |
2.1 x 1029 | joules | The Earth's rotational energy |
3 x 1031 | joules | The Earth's total heat content |
7 x 1034 | joules | Total rotational energy of the planets |
2.5 x 1035 | joules | Rotational energy of the Sun |
3 x 1036 | joules | Gravitational internal binding energy of Jupiter |
6 x 1037 | joules | Nova Persei outburst |
3 x 1041 | joules | A 450 km s-1 neutron star kick |
3 x 1043 | joules | Energy needed to make the local superbubble |
1.3 x 1044 | joules | Total radiant energy from the Sun |
3 x 1044 | joules | Energy in photons from a type II supernova explosion |
3 x 1046 | joules | Energy in neutrinos from a type II supernova explosion |
2 x 1053 | joules | Typical gravitational binding energy of a galaxy |
2 x 1054 | joules | Typical magnetic and kinetic energy in a large radio lobe (Shu 311) |
5.2 x 1054 | joules | Rotational energy of a 108 solar mass maximal Kerr black hole |
5 x 1057 | joules | Typical gravitational binding energy of a cluster of galaxies |
2 x 107 | joules kg-1 | Efficiency of the metabolism of food |
1.3 x 1013 | joules kg-1 | Efficiency of dropping matter onto a white dwarf |
6.3 x 1014 | joules kg-1 | Efficiency of fusion burning hydrogen |
5.1 x 1015 | joules kg-1 | Slowly spiraling accretion onto a Schwarzschild black hole |
7.5 x 1015 | joules kg-1 | Shakura-Sunyaev efficiency for accretion onto a Newtonian "black hole" |
8 x 1015 | joules kg-1 | Efficiency of dropping matter onto a neutron star |
2.6 x 1016 | joules kg-1 | Slowly spiraling prograde accretion onto a realistically maximally rotating Kerr black hole |
3.8 x 1016 | joules kg-1 | Slowly spiraling prograde accretion onto a theoretically maximally rotating Kerr black hole |
8.99 x 1016 | joules kg-1 | Efficiency of matter-antimatter annihilation |
4 x 10-6 | watts | Average energy output from 1 kilogram of the Milky Way |
1 x 10-3 | watts | Optical disc player laser |
6 | watts | Amateur short wave radio transmitter |
60 | watts | Light bulb |
100 | watts | Gravitational wave power from the Earth-Sun system |
150 | watts | Human being under normal conditions |
750 | watts | Maximum long duration horse output |
1500 | watts | Typical fireplace fire |
20000 | watts | Car |
1 x 105 | watts | Running Tyrannosaurus Rex |
3 x 108 | watts | Nuclear power reactor |
3 x 108 | watts | Moderate thunderstorm electrical power generation rate |
1.3 x 109 | watts | Hoover dam |
3 x 1011 | watts | USA average electricity usage rate in 1986 |
1 x 1013 | watts | Solar radio luminosity |
8 x 1013 | watts | Powerful nanosecond pulse laser |
1.7 x 1017 | watts | Insolation of Earth |
1 x 1023 | watts | Typical white dwarf luminosity |
8 x 1024 | watts | Gravitational wave radiation from PSR 1913+16 |
3.9 x 1026 | watts | Solar luminosity |
5 x 1026 | watts | The 2--10 keV flux of the cataclysmic variable FO Aquarii |
1 x 1028 | watts | Typical X-ray luminosity of an X-ray pulsar |
1 x 1028 | watts | X-ray luminosity associated with Sgr A* |
3.5 x 1028 | watts | Rotational energy loss rate from the Geminga pulsar |
2.4 x 1029 | watts | 5 solar mass star on main sequence |
4 x 1030 | watts | Cygnus X-1 X-ray luminosity |
5.5 x 1030 | watts | Luminosity of the 20 solar mass red supergiant Betelgeuse at maximum light |
1 x 1031 | watts | Crab Nebula energy output |
2 x 1031 | watts | Eddington limit for a 1.4 solar mass neutron star |
3 x 1031 | watts | Typical luminosity of Cir X-1 in zero phase |
1 x 1033 | watts | Rough luminosity of Eta Carinae in April 1843 |
5 x 1035 | watts | Type II supernova peak photon luminosity |
3 x 1036 | watts | Milky Way |
1.5 x 1038 | watts | Coma cluster X-ray gas luminosity |
1 x 1039 | watts | 108 solar mass black hole accreting at 1/10 of the Eddington limit |
1 x 1039 | watts | Typical quasar luminosity |
1 x 1040 | watts | Rough luminosity of the quasar 3C273 |
2 x 1041 | watts | Rough luminosity of the z=2.286 ultraluminous IRAS galaxy IRAS F10214+4724 |
1 x 1042 | watts | Rough luminosity of a cosmological gamma-ray burst |
7 x 10-7 | kelvins | Laser cooling of cesium atoms |
1.3 x 10-5 | kelvins | Cosmic microwave background quadrupole anisotropy |
5 x 10-4 | kelvins | Typical Sunyaev-Zel'dovich cosmic microwave background decrement |
3.3 x 10-3 | kelvins | Cosmic microwave background dipole anisotropy |
0.01 | kelvins | Typical limit of liquid helium dilution cooling |
0.3 | kelvins | Typical limit of liquid helium evaporation cooling |
2.17 | kelvins | Liquid 4 He superfluid transition temperature |
2.726 | kelvins | Cosmic microwave background temperature today |
3.20 | kelvins | Liquid 3 He boiling point |
4 | kelvins | Typical limit of Joule-Thomson effect cooling |
4.18 | kelvins | Liquid 4 He boiling point |
6 | kelvins | Typical noise temperature of a HEMT receiver at 30 GHz |
12 | kelvins | Lanthanum (under pressure) superconductivity critical temperature (highest for a pure element) |
20 | kelvins | Liquid H2 boiling temperature |
77 | kelvins | Liquid N2 boiling temperature |
133 | kelvins | Mercury-barium-calcium-copper oxide compound superconductivity critical temperature |
273 | kelvins | Water freezing temperature |
311 | kelvins | Human surface temperature |
373 | kelvins | Water boiling temperature |
388 | kelvins | Brimstone melting temperature---upper limit to the temperature of Hell |
506 | kelvins | Paper burning temperature |
740 | kelvins | Typical surface temperature of Venus |
1811 | kelvins | Melting temperature of iron |
3000 | kelvins | Cosmic microwave background temperature at decoupling |
5770 | kelvins | Solar effective temperature |
5 x 105 | kelvins | Surface temperature of the Geminga pulsar |
3 x 106 | kelvins | Polar cap temperature of the Geminga pulsar |
3 x 106 | kelvins | Typical fusion experiment |
1.4 x 107 | kelvins | Center of the Sun |
1.5 x 107 | kelvins | Changeover temperature from the proton-proton chain to the CNO cycle |
2.7 x 107 | kelvins | Center of a 5 solar mass star |
5 x 107 | kelvins | Typical gas temperature in a cluster of galaxies |
1 x 108 | kelvins | Typical cataclysmic variable accretion column shock temperature |
3 x 108 | kelvins | Center of a supernova |
4 x 108 | kelvins | Characteristic temperature for electron-positron pair production |
4 x 108 | kelvins | Minimum primordial nucleosynthesis temperature |
5 x 108 | kelvins | Inner accretion disc temperature of Cyg X-1 |
7 x 108 | kelvins | Thermal electrons become relativistic |
1 x 109 | kelvins | Maximum primordial nucleosynthesis temperature |
1 x 109 | kelvins | Rough superconductivity critical temperature in a neutron star |
1 x 1010 | kelvins | Rough plasma pair catastrophe temperature |
3 x 1015 | kelvins | Rough electroweak unification temperature |
7 x 10-13 | N m-2 | Typical gas pressure in a cluster of galaxies |
5 x 10-12 | N m-2 | Pressure in the best vacuum achieved on Earth |
5 x 10-6 | N m-2 | Solar radiation pressure at the Earth |
1 x 10-5 | N m-2 | Pressure of a sound wave at the human threshold of hearing |
0.2 | N m-2 | Solar radiation pressure at the surface of the Sun |
30 | N m-2 | Pressure of a sound wave at the human threshold of pain |
1 x 104 | N m-2 | Mean human arterial blood overpressure |
1.5 x 104 | N m-2 | Standing person |
1 x 105 | N m-2 | Typical atmospheric pressure |
1.5 x 106 | N m-2 | High pressure bicycle tire |
2 x 107 | N m-2 | Typical scuba tank pressure |
9 x 107 | N m-2 | Peak pressure of a fist on concrete during a karate strike |
1.1 x 108 | N m-2 | Pressure at the bottom of the Marianas trench |
6 x 109 | N m-2 | Pressure needed for the natural crystalization of diamonds |
1 x 1010 | N m-2 | Conventional high pressure laboratory press |
2 x 1011 | N m-2 | Peak pressure from a diamond anvil pressure cell |
5 x 1011 | N m-2 | Central pressure of the Earth |
4 x 1012 | N m-2 | Central pressure of Jupiter |
2 x 1013 | N m-2 | Radiation pressure at the center of the Sun |
2.7 x 1016 | N m-2 | Central pressure of the Sun |
1 x 1023 | N m-2 | Typical central pressure of a white dwarf |
1 x 1034 | N m-2 | Typical central pressure of a neutron star |
1 x 10-12 | W m-2 | Threshold of hearing (0 dB) |
1 x 10-11 | W m-2 | Rustle of leaves (10 dB) |
1 x 10-10 | W m-2 | Quiet whisper (20 dB) |
1 x 10-9 | W m-2 | Soft music (30 dB) |
3 x 10-8 | W m-2 | Average residence (45 dB) |
1 x 10-6 | W m-2 | Background music (60 dB) |
3 x 10-6 | W m-2 | Ordinary conversation at 0.5 meters (65 dB) |
1 x 10-5 | W m-2 | Busy street traffic (70 dB) |
3 x 10-5 | W m-2 | Typical factory (75 dB) |
1 x 10-3 | W m-2 | Rough boundary of unsafe sound levels (90 dB) |
1 x 10-2 | W m-2 | Lawn mower (100 dB) |
1 | W m-2 | Loud rock music concert (120 dB) |
10 | W m-2 | Threshold of pain (130 dB) |
100 | W m-2 | Jet plane at 30 meters (140 dB) |
9.128 x 10-35 | kg m2 s-1 | Magnitude of the electron spin angular momentum |
1.054 x 10-34 | kg m2 s-1 | Planck angular momentum |
3 x 1012 | kg m2 s-1 | Rough angular momentum of an artificial satellite |
5.9 x 1033 | kg m2 s-1 | Earth rotational angular momentum |
1.7 x 1041 | kg m2 s-1 | Sun rotational angular momentum |
3.1 x 1043 | kg m2 s-1 | Total angular momentum of our solar system |
2 x 1055 | kg m2 s-1 | Angular momentum of the Sun around the center of the Milky Way |
4 x 1066 | kg m2 s-1 | Rough total angular momentum of the Milky Way |
1 x 10-12 | tesla | Typical magnetic field needed for good radio reception |
5 x 10-10 | tesla | Typical magnetic field strength in the local interstellar medium |
1 x 10-9 | tesla | Typical magnetic field strength in a radio lobe |
1 x 10-8 | tesla | Typical magnetic field strength in the central 300 parsecs of the Milky Way |
5 x 10-8 | tesla | Magnetic field in the Crab Nebula |
1 x 10-7 | tesla | Magnetic field in The Arc at the Milky Way center |
1 x 10-6 | tesla | Typical magnetic field from a hand held cordless phone |
3 x 10-5 | tesla | Magnetic field at Earth's surface |
1 x 10-4 | tesla | Magnetic field near Sun's pole |
4 x 10-4 | tesla | Magnetic field at Jupiter's cloud tops |
0.1 | tesla | Ap star magnetic field |
0.2 | tesla | Sunspot magnetic field |
1 | tesla | Typical medical NMR magnetic field |
2 | tesla | Magnetic field felt by the electron in a n=1 hydrogen atom |
12 | tesla | Typical magnetic field used in high resolution NMR spectroscopy |
25 | tesla | Powerful superconducting/normal hybrid magnet |
1 x 108 | tesla | Typical single pulsar dipole magnetic field strength |
1 x 104 | amperes | Peak lightning bolt current |
5 x 106 | amperes | Current along Io's flux tube |
3 x 108 | volts | Typical potential difference across a lightning bolt |
3 x 106 | volts m-1 | Electrical discharge field in air with ions |
1 x 1012 | volts m-1 | Typical electric field at the surface of a pulsar |
1 x 1019 | volts m-1 | QED pair production electric field limit |
440 | bits | Spiegelman monster genome |
18000 | bits | Qbeta virus genome |
32000 | bits | Single spaced typed page |
6.6 x 105 | bits | Uncompressed ASCII version of Lysistrata |
4.36 x 106 | bits | C. elegans nematode chromosome III --- longest contiguous piece of DNA sequenced |
6 x 106 | bits | E. Coli genome |
6.3 x 106 | bits | Uncompressed ASCII version of A Tale of Two Cities |
1 x 109 | bits | Microcomputer hard drive |
2.5 x 109 | bits | Twenty volume edition of the Oxford English Dictionary on CD-ROM |
7 x 109 | bits | MACHO project data intake per night |
9 x 109 | bits | Human genome |
8 x 1010 | bits | Sloan Digital Sky Survey spectral database |
2 x 1011 | bits | International Halley watch database |
5 x 1011 | bits | VCR tape |
1 x 1012 | bits | Speed reading for 80 years with perfect memory |
8.8 x 1012 | bits | HST archive size in mid-1994 |
9 x 1012 | bits | VLA FIRST Survey data set |
2 x 1013 | bits | Digitized new Palomar sky survey |
5 x 1013 | bits | Sloan Digital Sky Survey 0.4 arcsecond pixel map |
8 x 1013 | bits | NSF backbone traffic in March 1994 |
3 x 1016 | bits | HDTV for 80 years with perfect memory |
200 | bits s-1 | Typical reading and talking rate |
500 | bits s-1 | Fast speed reading rate |
24 000 | bits s-1 | Hipparcos satellite data acquisition rate |
56 000 | bits s-1 | Typical Internet link |
1 x 105 | bits s-1 | High quality audio |
1.4 x 105 | bits s-1 | HST archive mean growth rate |
1 x 107 | bits s-1 | Xerox Ethernet |
1 x 107 | bits s-1 | HDTV bit rate after compression |
4.5 x 107 | bits s-1 | Internet backbone T3 link |
6 x 107 | bits s-1 | Sloan Digital Sky Survey data acquisition rate |
3 x 1010 | bits s-1 | Soliton optical fiber information transmission rate |
2 x 1015 | bits s-1 | Sexual reproduction genetic information transmission rate |
2 x 105 | 1994 USA dollars | Vancouver liquid mercury mirror telescope |
1.5 x 107 | 1994 USA dollars | Development and construction cost of the Giant Meterwave Radio Telescope near Pune, India |
2.9 x 107 | 1994 USA dollars | Total predicted cost of the Sloan Digital Sky Survey |
5.5 x 107 | 1994 USA dollars | Development, construction, and launch cost of the Clementine I spacecraft |
8.5 x 107 | 1994 USA dollars | VLBA development and construction cost |
9 x 107 | 1994 USA dollars | Development and construction cost of the Keck telescope |
1 x 108 | 1994 USA dollars | Development and construction cost of the ASCA X-ray satellite |
1.5 x 108 | 1994 USA dollars | Rough cost of a European Ariane rocket launch |
2 x 108 | 1994 USA dollars | Development and construction cost of the VLA |
9 x 108 | 1994 USA dollars | Development, construction, and launch cost of the Magellan probe |
9.8 x 108 | 1994 USA dollars | Development, construction, and launch cost of the Mars Observer spacecraft |
1.5 x 109 | 1994 USA dollars | Planned total cost of the AXAF X-ray mission |
1.8 x 109 | 1994 USA dollars | Amount of food stamp fraud in the USA in 1993 |
3.5 x 109 | 1994 USA dollars | Planned total cost of the Cassini spacecraft |
3.8 x 109 | 1994 USA dollars | Microsoft revenue in 1993 |
1.3 x 1010 | 1994 USA dollars | Lockheed revenue in 1993 |
1.4 x 1010 | 1994 USA dollars | NASA planned 1995 budget |
2.8 x 1010 | 1994 USA dollars | Planned cost for the space station |
2.6 x 1011 | 1994 USA dollars | United States 1994 military spending |
2.6 x 1011 | 1994 USA dollars | United States 1994 predicted defecit |
1.3 x 1012 | 1994 USA dollars | United States 1994 tax receipts |
1.5 x 1012 | 1994 USA dollars | United States 1994 federal government spending |
4.4 x 1012 | 1994 USA dollars | United States 1994 national debt |
0.004 | Black velvet optical light albedo | 0.012 Black cloth optical light albedo |
0.04 | Halley's comet optical light albedo | 0.068 Moon optical light albedo |
0.14 | Mars optical light albedo | 0.40 Earth optical light albedo |
0.80 | White paper optical light albedo | 0.85 Venus optical light albedo |
1 x 10-10 | pc-3 | Space density of X-ray binaries in the Milky Way |
5 x 10-7 | pc-3 | Space density of pulsars in the solar neighborhood |
3 x 10-6 | pc-3 | Space density of cataclysmic variables in the solar neighborhood |
0.1 | pc-3 | Space density of main sequence stars in the solar neighborhood |
1 x 10-9 | Mpc-3 | Ultraluminous IRAS galaxies |
1 x 10-9 | Mpc-3 | Quasars |
1 x 10-7 | Mpc-3 | QSOs |
1 x 10-7 | Mpc-3 | FR II radio galaxies (edge-brightened) |
5 x 10-6 | Mpc-3 | FR I radio galaxies (not edge-brightened) |
1 x 10-4 | Mpc-3 | Seyfert galaxies |
0.1 | Mpc-3 | Field galaxies |
0.6 | Mpc-3 | Group galaxies |
-26.8 | V | apparent magnitude of the Sun |
-12.5 | V | apparent magnitude of the full Moon |
-1.5 | V | apparent magnitude of Sirius |
0.1 | V | apparent magnitude of the LMC |
0.5 | V | apparent magnitude of Betelgeuse |
3.4 | V | apparent magnitude of M31 |
10.5 | V | apparent magnitude of the z=0.00363 Seyfert 2 NGC 1068 |
11.6 | V | apparent magnitude of the z=0.00170 H II region galaxy NGC 5408 |
12.8 | V | apparent magnitude of the z=0.158 quasar 3C273 |
13.6 | V | apparent magnitude of the z=0.0167 Seyfert 1 NGC 7469 |
15.3 | V | apparent magnitude of the z=0.239 quasar PG 0953+414 (ApJ 435, L12) |
19.55 | V | apparent magnitude of the z=3.67 quasar DHM 0054-284 |
25.5 | V | apparent magnitude of a typical Cepheid in M100 (ApJ 435, L33) |
-27.5 | MV of the z=0.158 quasar 3C273 |
-24.1 | MV of the z=0.239 quasar PG 0953+414 (ApJ 435, L12) |
-21.1 | MV of M31 |
-21.0 | MV of a typical Seyfert host galaxy |
-19.5 | MV limit on the host galaxy of the z=0.239 quasar PG 0953+414 (ApJ 435, L12) |
-18.5 | MV of the LMC |
-6.0 | MV of Betelgeuse |
4.4 | MV of the most luminous star in Alpha Centauri |
4.79 | MV of the Sun |
Note: I assume an inflationary Omega_0=1.0 dust-filled Friedmann-Robertson-Walker universe with H_0=50 km s-1 Mpc-1 = 1.62 x 10-18 s-1 for all calculations. Space densities are given for "here and now."