A View from the Back of the Envelope top

Length
m (meter)
Scale of some things
Landmarks
Scaling the universe to your desktop
Length Area Volume
[ Scale | Landmarks | Other ]
Rough Draft

100 m you (3 ft)
10-1 m apple, baseball (softball best)
10-2 m marble, pinky-tip
10-3 m grain of sugar
10-4 m (?) width of a fine hair (?)

Earth radius - "Six ee Six meters" (6 × 106 m, aka 6E6, -6%, ±<1% )
Earth to Moon distance - 4 × 108 m, "Four ee Eight" (+4% "up by four percent", ±<1%)
Earth to Sun distance - 150 billion meters (1.5 × 1011 m) (+<1%, ±<1%)
93 million miles (+<1%, ±<1%)
Sirius (distance to) - 8 × 1016 m ("eight ee sixteen") (-2%, ±~1%?)

x 3x 1x 0.3
100 m you (3 ft) soccer ball
10-1 m apple, baseball (softball best) soccer ballsoftballgolf ball
10-2 m marble, pinky-tip golf ballmarbledrop
10-3 m grain of sugar dropgrain of sugardust
10-4 m (?) width of a fine hair (?)

A grain of sugar - 1 mm, 10-3 m

Earth radius - "Six ee Six meters" (6 × 106 m, aka 6E6, -6%, ±<1% )
106 × 6.38 | 6.36 m±<1%equitorial | polar radius [Cow]
106 × 6.37 m±<1%
106 × 6.4 m+0.3% | +1%, ±<1%
106 × 6 m-6%, ±<1%"six ee six is down by six percent"
107 m+58%, ±<1%
106 m-84%, ±<1%

Earth to Moon distance - 4 × 108 m, "Four ee Eight" (+4% "up by four percent", ±<1%)
108 × 3.84 m±<1%mean distance [Cow,p236]
108 × 3.8 m-1%
108 × 4 m+4%
109 × 1/2 m+30%
108 m-74%

Earth to Sun distance - 150 billion meters (1.5 × 1011 m) (+<1%, ±<1%)
93 million miles (+<1%, ±<1%)

1011 × 1.496 m±<1%[VadeMecum,p75]
93 million miles+<1%(1.50 × 1011 m)
1011 × 1.5 m+<1%
1011 m-33%
150 billion m+<1%
150 million km+<1%

No wonder the "93 million miles" expression is soo popular.
Lets switch to "150 million kilometers" or "150 billion meters".
[Hmm... perhaps non-US (aka metric) intro books are a source of similar?]

Sirius (distance to) - 8 × 1016 m ("eight ee sixteen") (-2%, ±~1%?)
8.6 ltyr±~1%?[VadeMecum,p80]
9 ltyr+5%
10 ltyr+16%
1017 × 0.81 m±~1%?
1016 × 8 m-2%
1017 m+23%

Sirius is a nice, easily seen northern hemisphere star.

inch (in) - 2.5 cm (±<2%)
10-2 × 2.540±<1%exact?
10-2 × 2.54
2.54 cm		±<1%
10-2 × 2.5
2.5 cm		-<2%, ±<1%
10-2 × 3
3 cm		+18%, ±<1%
10-2 × 2
2 cm		+21%, ±<1%

A View from the Back of the Envelope
Comments encouraged. - Mitchell N Charity <mcharity@lcs.mit.edu>