How can you have anything colder than zero? Who decided something was zero and screwed up.?

Answer 1

Zero Celsius is the freezing point of water at one atmosphere, nobody screwed up. When measuring anything you need a standard which in this case in the freezing and boiling point of water at one atmosphere pressure.

The Fahrenheit scale was a bit of a screwup, the scientist who devised the scale put the numbers on it before inserting in in water at the freezing point which is why water freezes at 32 degrees in the scale.

Related to the Celsius scale, is the Kevin scale which using the same distance between degree marks but starts at absolute zero, which is theoretically the temperature at which all motion in an atom stops, effectively destroying matter. Zero Kelvin has not ever achived

Answer 2

I love it. Two questions, with more than two answers! My kind of questions, though.

If you live in the part of the world that is standardized (or in the UK, standardised) on the metric system for temperatures, you use Celsius, and zero Celsius is the temperature where water freezes. Only it's not that simple. The water has to be fresh (not salt), it has to be still (not moving) and it has to be at sea level (not in the mountains, for example). If it's salt, it takes a lower temperature to freeze. If it's at higher altitude, it will freeze at a slightly lower temperature (and boil at a lower temperature). If it's moving, it can get colder than zero degrees Celsius without freezing.

If you live in the US, you are talking about Fahrenheit. Zero Fahrenheit is somewhat colder than zero Celsius. The above definition of freezing water happens at 32 degrees Fahrenheit (with all the caveats). Every 5 degrees of change in temperature in Celsius is reflected by a 9 degree change in Fahrenheit. So you get some brainteaser conversions between the two:

C -> F:
Divide by 5, multiply by 9, add 32.

F -> C:
Subtract 32, divide by 9, multiply by 5.

Seriously messed up. Supposedly, the scale originated with zero being the coldest temperature he could measure outside at the time, and 100 being his body's temperature (now considered normal at 97.4 F, but back then, he was probably sick, as it was a cold winter!).

Then, there's a THIRD system, called Kelvin. One degree change in Kelvin is reflected by one degree change in Celsius...but zero Kelvin is also called Absolute Zero and is a LOT colder, at −273.15 °Celsius, or −459.67 °F! This is defined (and was designed) as the lowest temperature possible, so it "fixes" the problem you are lamenting!

The FOURTH system is called Rankine, and is to Fahrenheit what Kelvin is to Celsius...Zero degrees Rankine = Zero degrees Kelvin, but each degree of Rankine is 9/5 of a degree Kelvin. It also sets zero at that point where we maintain nothing can get colder.

Now, who?

Celsius used to be known as the Centigrade scale...with zero set at the freezing point of water and one hundred set at the boiling point of water. But a Swedish astronomer Anders Celsius (1701 – 1744) developed a similar temperature scale two years before his death, hence Celsius.

Fahrenheit is named after the German physicist Daniel Gabriel Fahrenheit (1686–1736), who proposed it in 1724. There's a long history about it on Wikipedia (one of my sources).

Kelvin is named after the Irish physicist and engineer William Thomson, 1st Baron Kelvin (1824 – 1907), who wrote of the need for an "absolute thermometric scale."

Rankine is a thermodynamic (absolute) temperature scale named after the Scottish engineer and physicist William John Macquorn Rankine, who proposed it in 1859.

There are also Rømer and Réaumur scales, but this is getting too long. :-P

Wikipedia has some great background and conversion tables for these and other scales. Bottom line, different groups, countries and professions refuse to change their scales, sort of like US pounds versus UK stones versus French kilos.

Answer 3

If you're talking about Celcius, it is possible to have anything colder than below freezing. The lowest we had was 15°F (-9°C) in December 2005 in Texas.

Answer 4

It depends on the definition of "zero"... the coldest temperature you can get down to is "Absolute Zero" which is the complete absence of heat and it's something like minus 400 degrees Farenheit.

Answer 5

it is based on the property of something, example Celsius is based on water where zero is where water freezes and 100 is where it boils, i believe kelvin has the true zero for absolute zero which is so cold the atoms stop moving