Heike Kamerlingh Onnes

Heike Kamerlingh Onnes

A Dutch physicist who discovered superconductivity and pioneered the science of cryogenics.

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Process

CONSEQUENCES

BIOGRAPHY

EXPERIMENTS

Annexe

An explanation of his main experiences

To Take it a step further

An Introduction to Heike Kamerlingh Onnes's life.

His influence on science

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Experiments

Liquefaction of Helium (1908)

Discovery of Superconductivity (1911)

Development of Cryogenics

Measurement of Electrical Resistance at Low Temperatures

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Biography

Heike Kamerlingh Onnes (1853–1926) was a Dutch physicist renowned for his pioneering work in the field of low-temperature physics. Born in the Netherlands, Onnes began his studies at the University of Groningen, where he later became a professor. His interest in the properties of materials at very low temperatures led him to develop experimental techniques for liquefying gases such as helium. This groundbreaking work paved the way for his later achievements, most notably in the discovery of superconductivity.

Annexes: Complementary Information and Sources

Nobel Prize Citation (1913): "For his investigations on the properties of matter at low temperatures which led, inter alia, to the production of liquid helium." Key Publications: Kamerlingh Onnes, H. (1911). "The Superconductivity of Mercury." Communications from the Physical Laboratory of the University of Leiden, No. 122. Kamerlingh Onnes, H. (1913). "The Liquefaction of Helium." Communications from the Physical Laboratory of the University of Leiden, No. 123. Related Concepts: Superconductivity: A state in which a material can conduct electricity with zero resistance at very low temperatures. BCS Theory (1957): A microscopic theory of superconductivity, explaining the phenomenon in terms of quantum mechanics and electron pairing. Cryogenics: The science of low temperatures, particularly the study of materials and their behavior at temperatures below -150°C.

How He Did It:

Onnes created one of the first cryogenic laboratories, developing the ability to reach extremely low temperatures. He used liquid helium and advanced techniques like closed-cycle refrigeration to cool materials to near absolute zero. His work involved building special cryostats to contain and measure substances at ultra-low temperatures, enabling precise studies of material properties like resistance and magnetism at low temperatures. This laid the groundwork for the field of cryogenics and many technological advancements.

How He Did It:

Onnes used a precision resistance measurement method to study the electrical properties of metals at low temperatures. By passing a constant electrical current through materials like copper, gold, and mercury, and measuring the voltage drop, he calculated their resistance at different temperatures. He found that while most materials showed reduced resistance with cooling, mercury was unique in that its resistance dropped to zero at 4.2 K, leading to the discovery of superconductivity.

How He Did It:

Onnes was the first to liquefy helium, a gas with a very low boiling point. He used adiabatic expansion, where a gas expands and cools rapidly, and Joule-Thomson expansion to cool gases to extremely low temperatures. After successfully liquefying hydrogen in 1903, Onnes adapted his techniques to helium. In 1908, he managed to liquefy helium by cooling it to below 4.2 K, using a regenerative cooling system that involved repeated expansion and compression of helium gas.

How He Did It:

Onnes studied the electrical resistance of materials, particularly mercury, at very low temperatures. He used liquid helium to cool mercury to around 4.2 K. When measuring its resistance, he observed that it suddenly dropped to zero, a phenomenon previously unknown. This was the first discovery of superconductivity, where materials exhibit zero electrical resistance when cooled below a critical temperature.

Consequences for His Life and for Science

Nobel Prize (1913): His discovery of superconductivity earned him the Nobel Prize and spotlighted the emerging fields of cryogenics and low-temperature physics. Impact on Quantum Physics: Onnes' work laid the foundation for quantum mechanics, with later developments like the BCS theory explaining superconductivity in quantum terms. Technological Impact: His discovery enabled advances like powerful electromagnets, MRI machines, and potential energy-efficient power transmission. Cryogenics as a Field: Onnes' research established cryogenics as a crucial area of study, impacting modern fields like quantum computing, material science, and space exploration.