Because physics uses Kelvin for high temperatures, and electron volts for really high temperatures.
Because kilodegrees sounds funny. But megadegrees really sounds volcano lair evil.
Megadegrees sounds like something graduates from Trump University got for finishing a retreat. They are the highest quality degrees - so good they deserve to have their own name!
Going back to temperature though, it would be odd-sounding to say the Sun can get as hot as 15 megadegrees at it’s core.
Give it a few kilomonths
First of all, the °C is not the metric SI unit for temperature. K (Kelvin) is.
Second, even with Kelvin, nearly all temperatures that matter for normal human issues happen to be below 4000K, usually way below that mark. And with most of those temperatures, about all digits usually count. A core body temperature of 310K or 313K makes a BIG difference for the person involved.
Celsius is the SI unit of temperature. Kelvin is the SI unit of thermodynamic temperature. They’re both defined in SI.
https://en.m.wikipedia.org/wiki/International_System_of_Units
Kelvin is the base unit. Celsius is a derived unit, just like Watt or Newton. But they’re all SI.
Celsius uses an arbitrary reference point (freezing point of water). Kelvin uses the same sized units, but is referenced from absolute zero. While this seems just as arbitrary, it actually makes some scientific calculations a lot easier.
Basically, scientists have been working to slot the various base units together in a neat and orderly manner. Kelvin fits this far better than Celsius, and so became the baseline SI unit.
Would just be confusing. Temperatures above a few hundred degrees have no place in most people’s daily lives, so that would be mostly for scientific notations, and scientists use Kelvin anyway for precision.
The use of kelvin over Celsius has nothing to do with precision. They’re the same thing, with different offsets.
Technically yes and no. Kevin is absolute temperature, since the offset is zero it measures the total temperature. Celsius is relative, since the offset places its zero at a conventionally useful place it measures deviation from that baseline. That’s why you have temperatures always in K and never °K, but always in °C and never just C. But yes, the sizes of the units are the same.
Kelvin and Celsius can both be used interchangeably and you can always get the same answer every time using either; they are equally as precise. So is fehrenheit for that matter, although the conversion would get even more complicated.
It’s just usually using the one with zero offset makes the math easier, which is why it tends to be the one used for scientific calculations.
