How can 1000 K be warmer than 5000 K ?

[Birna Rørslett]

There evidently has been a touch-up of nomenclature here.

Degrees Kelvin (depreciated) ---> K  (unit symbol) == kelvin (unit designation)

No degree sign any more.

[Nikkor Shooter]

Not really sure about this, AFAIK when a unit name is derived from the surname of a scientist (Ampere, Joule, Volt, Watt, Pascal, Curie, Ångstrom, Kelvin...) it keeps  the capital. Other uits of measurement do not necessarily have a capital letter (meter, gram, second, hour, ...) Ciao from Massimo

I read as well that it should be written small but makes no sense to me.

[JohnMM]

Not really sure about this, AFAIK when a unit name is derived from the surname of a scientist (Ampere, Joule, Volt, Watt, Pascal, Curie, Ångstrom, Kelvin...) it keeps  the capital. Other uits of measurement do not necessarily have a capital letter (meter, gram, second, hour, ...)

Ciao from Massimo

CERN : https://writing-guidelines.web.cern.ch/entries/units
IUPAC : https://iupac.org/100/stories/the-new-si/
National Institute of Standards ... (US) : https://www.nist.gov/pml/weights-and-measures/metric-si/si-units

......

[JohnMM]

I read as well that it should be written small but makes no sense to me.

I'm not sure about the logic either. However use of an upper case initial letter would give the unit the status of a "proper noun". Proper nouns are usually reserved for specific examples. So there is only one Lord Kelvin, the person after whom the unit is named. However there are very many examples which use that unit of measurement, the "kelvin", and here a "common noun", with a lower case initial letter, is used.

[pluton]

Whatever the relevant authority tells us is the current usage.... is the current usage.
How about the 'decibel'?
Written:  decibel.  Original unit, the 'bel', is not commonly used.
Abbreviated: dB 
Named after:  Alexander Graham Bell, inventor of the American telephone (and other devices).

[Erik Lund]

National Institute of Standards ... (US) : https://www.nist.gov/pml/weights-and-measures/metric-si/si-units

......

And they go on and write it as kelvin in the text and then Kelvin in the table  omg,,,

[JohnMM]

And they go on and write it as kelvin in the text and then Kelvin in the table  omg,,,

Which table is that ? Do you mean the list on the left hand side on this page https://www.nist.gov/si-redefinition/road-revised-si ?

This is simply title capitalisation. All units in the list, whether named after a person or not, are given an initial upper case letter.

[Erik Lund]

I just think it's interesting/amusing to proofread such texts  There are so many pitfalls and exceptions 

Here on this page below, they write it Kelvin in the table although they stress in the text it should be kelvin 
https://www.nist.gov/pml/weights-and-measures/si-units-temperature

 

[Nikkor Shooter]

There are so many pitfalls and exceptions

The two symbols of kelvin and kilo for thousand
should be the same? "k". no sense to me

[Erik Lund]

The two symbols of kelvin and kilo for thousand
should be the same? "k". no sense to me

It's kelvin and then you use as a unit K
So 1,000 kelvin is 1kK
Boltzmann constant is k,,, see why I think this is an entraining sport 

[Erik Lund]

Which table is that ? Do you mean the list on the left hand side on this page https://www.nist.gov/si-redefinition/road-revised-si ?

This is simply title capitalisation. All units in the list, whether named after a person or not, are given an initial upper case letter.

Yes I get that

[Wannabebetter]

Once upon a time... 
The short of it: We were [sic] messing with cyanobacteria and all manner of blind, troglobite amphibians and similar chordates; subjecting them to variable degrees of gain, amplitude and waves of light spanning 380nm to 780nm; controlling or otherwise attenuating ambient room/environmental temperature and barometric pressure (dear Lord!) to within a ridiculously invariable margin; concluding two things. A lot of money was spent spent affirming what any of us would have freely admitted if not held hostage and that we would have much preferred spending our last moments on Earth inebriated. (Someone got a PhD or a p-h something or another. Bath salts? Anyway the algae were happy. The salamanders weren't saying, but I could tell blue was the new black in their world.)