In a bubble

A la izquierda toda el agua del mundo, 1.4 mil millones de kilómetros cúbicos, incluyendo el mar, lagos, rios, nubes, etcétera. A la derecha toda la masa de aire en una burbuja, 5.140.000.000.000.000 toneladas, las dos en una burbuja a nivel del mar, las dos a la misma escala del tamaño de la tierra.
Un poco de números:

1. Image Measurements
   The image was imported into Adobe Photoshop Elements, enhanced to better reveal spherical outlines, and measured using the Info tool. Measurements from several trials were averaged.
   Earth diameter = 185 pixels Water diameter = 22 pixels Air diameter = 30 pixels
   Relevant physical constants and relationships:
   Spherical volume = (1/6) x Pi x diameter^3 Earth diameter = 12,732 km Mean molar mass of air = 28.94 g / mol Atmospheric pressure (sea level) = 101,325 Pa Temperature (sea level) = 20 C = 293 K Universal gas law constant = R = 8.3145 m^3 Pa / (mol K)
2. Water Calculations
   Ocean mass = 1.35 x 10^18 tonnes (Andrew Nowicki) = 1.35 x 10^21 kg
   Ocean volume = 1.35 x 10^21 L = 1.35 x 10^24 cm^3 = 1.35 x 10^9 km^3
   Solving for diameter, Sphere diameter = 1.371 x 10^3 km
   Normalizing to pixels, Sphere diameter = 1.371 x 10^3 km x (185 pixels / 12,732 km) = 20 pixels
   This value compare favorably with the measured diameter of 22 pixels. Note that the preceding calculations are based on ocean mass, while the image also included ice, water vapor, fresh water, etc.
3. Air Calculations
   Air mass = 5.1480 x 10^18 kg (Andrew Nowicki) = 5.1480 x 10^21 g
   Air molecules = 5.1480 x 10^21 g / (28.94 g / mol) = 1.777 x 10^20 mol
   Using the Ideal Gas Law, PV = nRT (101,325 Pa) x (Air volume) = (1.777 x 10^20 mol) x (8.3145 m^3 Pa / (mol K)) x 293 K
   Air volume = 4.273 x 10^18 m^3 = 4.273 x 10^9 km^3
   Solving for diameter, Sphere diameter = 2.013 x 10^3 km
   Normalizing to pixels, Sphere diameter = 2.013 x 10^3 km x (185 pixels / 12,732 km) = 29 pixels
   This value compare very favorably with the measured diameter of 30 pixels.
   Conclusion: The posted image is correct.

Fuente: http://blog.phiffer.org/post/27344630/left-all-the-water-in-the-world-1-4087-billion