Question

What is correct: To mention temperature in deg K (°K) or in just K?

Asked by: Prof. C. F. Desai

 Answer

The correct one is just K, not degrees K.

The confusion arises due to the other common temperatures scale, the Celsius scale (based on the old Centigrade scale). This scale was derived from getting a mercury-in-glass thermometer and marking the ice-point and steam-point on it. The distance between these points is then divided into 100 divisions or degrees. The units used here are thus called degrees Celsius.

However, Kelvin, the SI unit of temperature, is based on the triple point of water (The temperature where water can exist in all 3 states). 1 K = 1/273.16 of the triple point of water. Kelvin, as an SI unit is similar to the metre and the second, and we don't say degrees metre, or degrees second do we?

Note from the editor: Degree K or °K was actually used in the past but it became obsolete by international agreement in 1967.

Answered by: Simon Hooks, Physics A-Level Student, Gosport, UK

Search

Loading



Sponsors

USC University of Southern California Dornsife College Physics and Astronomy Department McMaster University Physics and Astronomy Department

Science Quote

'I believe there is no philosophical high-road in science, with epistemological signposts. No, we are in a jungle and find our way by trial and error, building our road behind us as we proceed.'

Max Born
(1882-1970)

Deal of the Day

Image of Hover Craft Kit. Click on this image for more info. Hover Craft Kit
Regular Price: $29.99
Today's Price: $12.00
Learn the science behind hover craft technology with this cool kit! Buy it now! Deal ends at midnight!

Top Selling

Here are our physics & astronomy bestsellers:
Mini Plasma Ball
Slide Making Kit
Top Secret - Spinning Top
Wood Grain Newtons Cradle
Deluxe 3D Mirascope
Solar Radiometer
Periscope
Solar Science 4M Kit
Ultimate Chemistry Set CHEM C3000
3D Magnetic Field Tube