A View from the Back of the Envelope top
 
Mass volume-density 
kg/m3
Scale of some things 
Mass Volume
 
 
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
...

Landmarks

Conversions

A View from the Back of the Envelope
Comments encouraged. - Mitchell N Charity <mcharity@lcs.mit.edu
Doables:
  a <air,mumble,styrofoam,waterrock,lead> scheme
  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.
  water column loaded with sediments

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
Nmolec/xm^3 solid/gasspread
Landmarks: g/cm3  1kkg/m3  h2o gas air rock he/hy(blimp) iron coins?
specific volume
specific density
include g/cm3?

From [Vade p7]:
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
From [Vade 46]: g/cm3
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/...