<P> On 3 January 2013, physicists announced that they had created a quantum gas made up of potassium atoms with a negative temperature in motional degrees of freedom for the first time . </P> <P> One of the first to discuss the possibility of an absolute minimal temperature was Robert Boyle . His 1665 New Experiments and Observations touching Cold, articulated the dispute known as the primum frigidum . The concept was well known among naturalists of the time . Some contended an absolute minimum temperature occurred within earth (as one of the four classical elements), others within water, others air, and some more recently within nitre . But all of them 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 ." </P> <P> The question whether there is a limit to the degree of coldness possible, and, if so, where the zero must be placed, was first addressed by the French physicist Guillaume Amontons in 1702, in connection with his improvements in the air - thermometer . His instrument indicated temperatures by the height at which a certain mass of air sustained a column of mercury--the volume, or "spring" of the air varying with temperature . Amontons therefore argued that the zero of his thermometer would be that temperature at which the spring of the air was reduced to nothing . He used a scale that marked the boiling - point of water at + 73 and the melting - point of ice at 51, so that the zero was equivalent to about − 240 on the Celsius scale . </P> <P> This close approximation to the modern value of − 273.15 ° C for the zero of the air - thermometer was further improved upon in 1779 by Johann Heinrich Lambert, who observed that − 270 ° C (− 454.00 ° F; 3.15 K) might be regarded as absolute cold . </P>

Where have scientists achieved the temperature called absolute zero