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 Mass volume-density  kg/m3
How much mass per cubic meter?
How many nucleons per cubic meter?

How much mass per  .

 kg/m3 nucleons/m3 ... 100 10-27 10-26 10-25 103 10-24 10-23 10-22 106 10-21 ~ interstellar gas 10-20 Milky Way's disk 10-19 109 10-18 10-17 10-16 1012 10-15 10-14 10-13 1015 10-12 10-11 10-10 1018 10-9 10-8 10-7 1021 10-6 10-5 10-4 1024 10-3 g/cm3 10-2 0.0001 10-1 helium & hydrogen (stp) 1027 0.001 100 1 kg/m3 | air | oxygen & nitrogen (stp) 0.01 101 Kapoc | lb/ft3 0.1 102 styrofoam | snow | balsa wood 1030 1 103 1000 kg/m3 | water | wood | rock | most stuff | gassy planets | Sun 10 104 most metals | iron | lead | gold | rocky planets | Earth | lb/in3 100 105 Sun's core 1033 106 107 108 White dwarf 1036 109 1010 White dwarf's core 1011 1039 1012 1013 1014 1042 1015 1016 1017 1045 1018 nucleus | neutron star's core ...

## Conversions

 A View from the Back of the Envelope Comments encouraged. - Mitchell N Charity
```Doables:
explain mass=nucleon count approximation
interstellar too narrow??
what could be added at low density?
partials- pollen
air at altitude
Klien
region around one
landmarks- styrofoam? 100(Sizesaurus,p132), "all is one",
reference objects
comments on compressibility (or leave for its own page...?)
avoid including /ft^3 /in^3 in scale...?  Remove or reexamine.

Notes:
interstellar (10-18 to -21 in Sizesaurus) (3x10-21 in Brandt)
MilkyWay's disk - from Brandt's
7 x 10^{-21}     kg m^{-3}  Dynamically inferred Milky Way disk density
In 10^n g/cm^3: 0 h2o, macroscopic on earth basically lt (20g/cm^3),
^2  to ^7  physical properties determined by e- exclusion fluid,
^7  to ^12 by nuclei stuff
^12 to ^15 nuclei, ceasing to bind excess n,
are immersed in neutron exclusion fluid
^15 to ... weird
^14 avg atomic nuclei
From nice Dense Matter Physics  I. BACKGROUND AND SCOPE

History:
1998.Apr.14   Rewrote, rediscovered first draft (sigh), merged, placed online.
1997.Jun.27   First draft.

Old notes:

Do:  sun  1H/m3  atoms  nucleus (=neutronium?)  flag bhole
mean galactic  visib universe
Landmarks: g/cm3  1kkg/m3  h2o gas air rock he/hy(blimp) iron coins?
specific volume
specific density
include g/cm3?

Solar mass/cubic parsec 6.770 × 10-20 kg/m3
STP gas density for molecular weight M = 0.044615M kg/m3
of mercury (0C) 13595, water (4C) 999.97 kg/m3 [Lindeburg fcov]
surface water sea (15C) 1026 [Cow 236] 1025 [Vade 46/Lind]
1 ton long/short / yd3 1329/1187 kg/m3
lb/in3 27680
lb/ft3 16.018
lb/gal(USlq) 119.83
oz/in3 1730.0
earth (mean) 5520 kg/m3 [Lindeburg fcov] 5500 [Cow 236]
air STP 1.293 [Cow 236/Lind], SP20C 1.20 [Lindeburg fcov]
From [Cow 238]:
water 0C 999.87, 4C 1k, 15C 999.13, 25C 997.07
From [Cow 244]:
ox 1.14 n 0.81 he 0.12 h 0.07
cork 0.22-0.26
glass 2.4-2.8
ice 0C 0.917
paraffin wax 0.9
woods (oven dry) balsa .12-.20, oak .67-.98, others .5-.7
lube oil .90-.92, olive .92
glycerine 1.26, alcohol 0.8
steel 7.8 bronze 8.8-8.9 brass 8.4-8.7
zn 7.1, u 18.7, tungsten 19.3 ti 4.5 Tin 7.3 na 0.97 nickle 8.9 magnesium 1.74
iron pure 7.88 wrought 7.85 cast 7.6 steel 7.83
cu 9, graphite 2.25, diamond 3.514, ca 1.55, al 2.70
stuff is the density of water
intersteller gas 3 × 10-24 g/cm3 [Vade 80]
center of the Sun is about 150 grams per cubic centimeter [http://www.hao.ucar.edu/...

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