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1 cm3 of water weighs a lot more than 1 gram ?? From a quick skim through, many of his calcs seem to be based on this i.e. major error.



1ml = 1cm^3 of water weighs almost exactly 1 gram. A liter of water (1000ml = 1000 cm^3) weighs almost exactly a kilogram. http://www.wolframalpha.com/input/?i=weight%20of%201cm^3%20o...


Article's author also confuses units:

    "The entire planet’s electrical consumption is right around 5 terawatt-hours."
...consumption is of course power, i.e. watts, not energy, i.e. watt-hours. That is not to mention that 5TW is a wrong estimate:

http://www.wolframalpha.com/input/?i=world+electricity+consu...


Uh, maybe if you're talking about heavy water. The density of liquid H2O at standard temperature and pressure is almost exactly 1g/cm^3.


Even heavy water would only weigh 1.112 grams per cc (at 4 degrees Celsius).

The molar mass of heavy water is 20.0276 versus 18.01528 for regular water.


The density of water is 1000 kg/m^3 at 4 degrees C. [1]

1000 kg/m^3 * (1000 g / kg) * (1m / 100cm)^3 = 1 g/cm^3.

1 cc of water weighs one gram.

[1] https://www.google.com/search?q=density+of+water+at+4+c


The weight of one cubic centimeter of water is in fact one gram. By definition.


Not by definition: a kilogram is defined as the exact mass of a lump of iridium-platinum alloy sitting in a vault in Paris (well, Sèvres). But the kilogram was designed to be the weight of a liter of water at its melting point, and then later 4°C (where water achieves maximum density).


One cubic centimetre of water at 4 degrees Celsius used to define one gram (or more precisely one litre -> one kilogram, which comes out to be the exact same thing) [1], [2].

Although 1 cm^3 of water is still pretty damn close to 1g.

[1] https://en.wikipedia.org/wiki/Grave_%28unit%29

[2] https://www.youtube.com/watch?v=ZMByI4s-D-Y (around 1:50, and actually the whole video is excellent)


Yes it is sorry and thanks, I knew that 1 ml = 1 but I did not check out my incorrect instinct re volume. I was thinking of 5 grams to a teaspoon, intuitively 5 cc seems to me, much bigger than 1 small teaspoon. Still surprising to me though, how 5 grapes can fit on a teaspoon ?


Only at one specific temperature (4 degrees C).




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