# What is Absolute zero?

Updated on March 14, 2011

## Absolute zero is....

Well to start with absolute zero is the coldest temperature theoretically possible. It is considered to be a theory because it has not been reached by natural or artificial means. Technically it is the temperature marked at 0 entropy. The precise definition of absolute zero is 0 K or 0 Kelvin. In the celsius measurement scale this temperature is -273.15 and -459.67 in Fahrenheit.

## To Chill a King

On a hot summers day, in 1620 the alchemist Cornelius Drebbel successfully to chill a King. His attempt chilled the air in the largest interior space in the British Isles, the Great Hall of Westminster, with the hope of shaking the King to his core. The experiment did indeed prove effective in cooling the air for King James the First and his entourage.

Like most alchemists, Drebbel kept his methods secret. If Drebbel had written up his great stunt he may have gone down in history as the inventor of air conditioning. It would be almost three centuries before this idea would take off.

## The race to Absolute Zero

Now that we have the nuts n bolts of what Absolute Zero is lets dive into the history a little bit.

As early as 1665 the concept of a 'primum frigidum' or absolute lowest temperature was a well known concept. In New Experiments and Observations touching Cold, by Robert Boyle discussed the disputes about this zero point temperature. It had been contended that an absolute minimum temperature occurred with the earth as one of the so called four elements. Others believed this temperature to be within water, or air but all seemed to agree that there is some body or other that is of its own nature supremely cold and by participation of which all other bodies obtain that quality.

The concept of a lowest temperature was refined and first tackled properly by the french physicist Guillaume Amontons in 1702. On Amontons scale that zero value was the equivalent to about -250 on the Celsius scale. This close approximation was improved upon in 1779 by Johann Heinrich Lambert and the lowest temperature dropped to -270.

I hope that I have not bored you with this slight history lesson, these people do deserve their place in the history of absolute zero. It is easy to say that the race to Absolute Zero started with Lord Kelvin, so lets say that the great minds already covered were the builders of the race track and Lord Kelvin the starter shot.

What makes Lord Kelvin so special is that his approach to this question came from an entirely different point of view. He based his scale solely on the fundamental laws of thermodynamics instead of considering the properties of particular substances. This leap forward in understanding was made possible by J.P. Joule, who determined the mechanical equivalent of heat. The basic concept is often taught in schools and relates heat to the motion of molecules.

## Lowest temperatures observed

In nature as we have already discussed the temperature does not reach absolute zero. The average background temperature of the universe today stands at 2.73 kelvin, but has spatial fluctuations. An example I have only just learned of is the Boomerang Nebula. This Nebula has been spraying out gas at a 500,000 km/h over the last 1,500 years. Astronomical observation has calculated that this has cooled space down to 1k.

Lower temperatures have been achieved in a laboratory. The current world record (as of May 2009) was set in 1999 at 100 picokelvin and was achieved by cooling a piece of rhodium metal. From laboratory experiments that have innovated refrigeration, air conditioning and advancements in medicine to the future innovations that may lead to quantum computers we have many reasons to thank the first scientists for starting this race to zero K.

28

12

114

13

778

## Popular

31

19

• ### What is Universal Indicator and How To Use it

8

0 of 8192 characters used
• hoveluke

6 years ago

why not outside the universe, becuase the universe is expanding therefore expanding into something, assuming this something has no matter or energy or anything, the temprature at this point in nothingness would be 0 k ??????

• AUTHOR

kirstenblog

8 years ago from London UK

sic334 - I am into all sorts of crazy stuff LOL :D

Anything that tantalizes the imagination and inspires a greater understanding of this crazy old world of ours.

• slc334

8 years ago from Canada

Hey kirstenblog, you might also find "negative temperature" interesting. It seems that you're into that sort of crazy physics!

• AUTHOR

kirstenblog

8 years ago from London UK

sic334 - I did wonder about absolute hot back when I wrote this, cannot remember if I found anything on it or not. I would image that absolute hot would be be a theory that is likely to be hotly contested in the scientific community! I do image that after a certain temperature we are talking about pure plasma such as is found in the sun. I think I shall go have a little search and see if I can dig anything good up :D.

• slc334

8 years ago from Canada

Great article! You might enjoy looking at the Wikipedia page for "absolute hot"!

• dbclark

9 years ago

kirstenblog - It would seem that matter and its associated "temperature" (AND the space in which matter exists!)would have been created all at the same time during the Big Bang. And if the theorized Higgs Boson "gave mass to particles", the hoped for discovery of the Higgs by the Large Hadron Collider should give us a pretty good idea where gravity came from(???) I wonder if discovery of the Higgs will give cohesion to the rules of particle physics OR will reveal whole new "layers" of "elementary" particles that we have not dreamed of? Thinking about this certainly must create some new wiring in our brains, eh?

• AUTHOR

kirstenblog

9 years ago from London UK

dbclark - your comment has me wondering if the physical existence of matter creates 'temperature' possibly as a part of the gravity inherent in all matter. Fun stuff to think about eh? :D

• dbclark

9 years ago

If the Heisenberg Uncertainty Principle holds at all temperatures (including zero K), then there must ALWAYS be some degree of uncertainty (both experimentally AND "absolutely") in the position or motions (e.g. vibrations) of any atom or molecule. Thus we must accept that there is no way to completely remove ALL motion attributable to any particle. In 1927 or thereabouts, quantum mechanical calculations indicated that even a single electron, which has no apparent substructure, must "tremble". If "temperature" is associated with motion, Absolute Zero must remain an unobservable theoretical concept - I guess!

• ss sneh

9 years ago from the Incredible India!

Hi! Great hub! Well researched historical data!

Absolute zero is a theoretical concept which can never be achieved practically!

Absolute zero is like infinity which can never be reached!

Absolute zero is like singularity which is a mathematical concept that can never be achieved in reality as singularity will always lie in the past or in future and never in the present.

At absolute zero there will be zero disorder (zero entropy) which is not possible practicably due to quantum rules.

At absolute zero things have to be at absolute rest which is not possible due to quantum rules.

Absolute zero can't be reached as it requires infinite energy input.

The lowest temperature achieved by humans is in the creation of BOSE-EINSTEIN Condensate for which Nobel prize have been given. -- Thanks

• mrpopo

9 years ago from Canada

Mind boggling indeed! Loved the Hub, thanks for sharing!

• AUTHOR

kirstenblog

9 years ago from London UK

Jawed, I find this sort of thing totally fascinating and sometimes just a touch mind boggling! I am glad you enjoyed this hub :D

• Jawed Iqbal

9 years ago

Very intriguing indeed. Something new to learn everyday.

The coldest temp. I've had to bear has been -58 degrees celsius (up in northern Alberta) but -273.15?!! That's just wicked!

Thanks for the insight Kirsten.

working