a kilogram is a kilogram, right?
What weighs more, a kilogram of feathers or a kilogram of lead? You might think they weigh the same, but just how certain can you be?
Since 1889, the exact weight of a kilogram has been defined by a platinum-based ingot called “Le Grand K”, jealously guarded in a safe in Paris. It is the only unit of measure defined by an artificial sample. Several close replicas exist around the world, but over time, like the master kilogram, they have changed by about the weight of an eyelash as they deteriorate, forcing scientists to rethink the definition.
Weights and measures varied on a local and regional level for millennia. They even varied among social classes, whether they were employed within a city or outside its walls, or on land or on sea. A general rule in Europe was that measures increased in size or distance once land was no longer in sight.
carob and wheat
The Chinese picul was the weight a man could carry on a shoulder pole. Early Babylon and Egypt, length was measured with the forearm, hand, or finger, and time by the sun, moon and other heavenly bodies. Containers were filled with plant seeds to measure volumes; seeds and stones served as standards for weights, giving rise to gems being measured in carats, deriving from the carob seed. For thousands of years, Mediterranean civilizations used weight standards based on grains of wheat. Some poor blighter had to sit there and count out the grains to find the weight.
a heavy heart
Though mostly useful, weights also have a sinister past. The ancient Egyptians judged people on their behavior during their lifetime by the weight of their heart when they died. The heart was weighed on large scales against the principle of truth and justice, represented by a feather. If it balanced, the deceased would be granted a place in the Afterlife. If it was heavy with the weight of wrongdoings, the balance would sink and the heart would be grabbed and devoured by a terrifying beast.
In the Netherlands, authorities reasoned that witches needed to be light enough to fly on brooms, so people suspected of witchcraft were dragged to the weigh house for judgement, resulting in thousands of innocent people being sent to death.
a modern weight
Great scientific advances in physics, astronomy, chemistry, and indeed beliefs, made consensus a must, so France created the metric system in 1793, England the imperial system in 1824. The kilogram is the base unit of mass in the metric system. It equals 1000 grams and is very nearly equal to the mass of 1,000 cubic cm of water.
The new definition of a kilogram decided upon recently in Versailles uses a Kibble Balance, which in very basic terms involves an electric current passing through an electromagnet. For a more technical description, try these links to BBC and The Statesman.
The world record for clean and jerk weightlifting was 266 kg until 1992, 262.5 kg until 1997, and currently stands at 257 kg. No, not typos, nor redefinition of the kilogram. The International Weightlifting Federation restructured its weight classes in 1993, 1998 and 2018, each time nullifying earlier records.
The current price of a kilo of lead is US$2.173. At the time of writing, a kilo of gold costs US$39,325.83. Oddly enough, I couldn’t find the price of a kilo of feathers.
An elephant weighs about 5,443 kilos. A mouse between 17 and 25 grams. The world’s lightest living adult person weighs 5.5 kg. The world’s heaviest person recorded was estimated to be 635 kg. The largest mammal is the blue whale, the largest weighed was 189,999 kg. The record for the heaviest pumpkin is 1,190.49 kg, the heaviest turkey, 39.09 kg. The heaviest weight held by the eyelid is 3.51 kg; the heaviest deadlift with little finger 110 kg. A kilo of tea makes 500 cups.Share this: