NEW DELHI: Scientists at an Italian institute have set a world record of the lowest temperature ever achieved in the universe. They cooled a copper vessel with a volume of one cubic meter to -273.144 degrees celsius. This is stunningly close to ' absolute zero ', which is equal to -273.15 degrees celsius. Theoretical physics says that temperature can never go below this limit.No experiment on Earth has ever cooled a similar mass or volume to temperatures such a low; similar conditions are also not expected to arise in nature. This gives CUORE the distinction of being the coldest cubic meter in the known universe.The cooled copper mass, weighing approximately 400 kg, was the coldest cubic meter in the universe for over 15 days.The experiment was carried out under the CUORE collaboration, located at the National Nuclear Physics Institute's Gran Sasso National Laboratory. Gran Sasso is the highest peak in the Apennines some 120 kilometres distant from Rome.CUORE (which stands for Cryogenic Underground Observatory for Rare Events, but is also Italian for Heart) is an international collaboration involving some 130 scientists mainly from Italy, USA, China, Spain, and France. Its objective is to study the properties of neutrinos and search for rare processes.The CUORE cryostat is the only one of its kind in the world, not only in terms of its dimensions, extreme temperatures, and cooling power, but also for the selected materials and for the building techniques that both guarantee very low levels of radioactivity.Absolute zero — considered the lowest possible temperature — is -273.15 degrees celsius or zero on the Kelvin scale, named after 19th-century Irish engineer and physicist William Thomson, 1st Baron Kelvin, credited with establishing the correct value of the temperature.