Quick Fun Facts

We all have those days where we hear something and we say to ourselves 'You know,I've heard that somewhere before' but you just can't remember what it is. I created this thread because we all encounter cool facts throughout our lives. Like today i learnt what a Fathom (ftm) is.
One fathom is equal to:

• 1.8288 metres exactly (1 metre is about 0.5468 fathoms)
• 2 yards (1 yard is exactly 0.5 fathoms)
• 6 feet (1 foot is about 0.1667 fathoms)
• 18 hands
• 72 inches

It is usually used to measure depth of water.
So lets use this thread to post what i call "Fun Facts". It doesn't have to be engineering at all. keep it short please.
This is a good way to keep the mind sharp and to make learning fun 👍

Bessemer Process
Inventor = Sir Henry Bessemer
Principle = Oxidation of impurities in molten pig iron to produce steel. Uses an egg shaped vessel called the Bessemer Converter. Air (containing oxygen) i introduced from the bottom of the converter and as it passes through the molten iron it oxidises impurities such as carbon, manganese and silicon. Carbon monoxide burns off in a blue falme and the rest of impurities form slag. the heat from oxidation keeps the mass molten during operation.

Open Hearth Process
The Open Hearth Process preceded the Bessemer Process in 1860.
In this process the pig iron is mixed with steel scrap, limestone and other elements in an open bowl. Preheated fuel and air enter at one end of the bowl and ignite and is directed downward on the surface of the metal and melted. Carbon and other impurities are burnt out and steel is produced. This process is much slower but this makes it much easier to control and thus makes quality control easier.

Anthropologists are of the view that the term 'Homo technologicus' (those who use technology), is a better way of defining humans, as opposed to 'Homo sapiens' (those who are wise).
they belive we may not actually be as wiser than animals than we think we are but do some serious and sustained tool-making.