Heike Kamerlingh Onnes

Heike Kamerlingh Onnes loved the cold.

He was a scientist from a land called the Netherlands.

He found a way to make helium turn into liquid. This made things very cold. It was the coldest thing on Earth at that time.

He also studied how electricity moves. He found that some metals let electricity flow easily. This happens when things are very cold.

Because of his work, he won a big prize. This prize is called the Nobel Prize. It is a very special honor.

Many people still remember him today. A large crater on the Moon has his name. He helped us learn about the world.

Heike Kamerlingh Onnes was a scientist from the Netherlands.

He loved to study how things work in the cold. In 1908, he became the first person to turn helium into a liquid. He did this by using special cooling steps. He reached a temperature near 1.5 kelvin. This was the coldest temperature ever found on Earth at that time.

To do this work, he needed lots of helium. He got it from a company that worked with thorium. Helium is often found near radioactive material.

In 1911, he studied how electricity moves through metals. He used liquid helium to make mercury very cold. He found that the electrical resistance in the mercury vanished. Resistance is what slows electricity down. When it vanishes, the metal enters a state called superconductivity. This means electricity flows through it perfectly.

He won the Nobel Prize in Physics in 1913 for his work. People still honor him today. A crater on the Moon has his name. There is also a large building named after him in Leiden.

Heike Kamerlingh Onnes was a famous Dutch scientist. He spent his life studying the physical world. He was a physicist who focused on very cold temperatures. This field of study is called cryogenics.

His work helped us understand how matter behaves when it is freezing. He wanted to see what happened to things at the lowest temperatures possible. His discoveries changed how we think about electricity and gases.

In 1908, he achieved a huge goal by liquefying helium. To do this, he used several pre-cooling stages. He used a method called the Hampson–Linde cycle. This process relies on something called the Joule–Thomson effect. He lowered the temperature to the boiling point of helium, which is -269 °C or 4.2 K. By reducing the pressure, he reached nearly 1.5 K. This was the coldest temperature ever recorded on Earth at that time.

Kamerlingh Onnes was born on 21 September 1853 in Groningen, Netherlands. His father, Harm, owned a brickworks. He studied at the University of Groningen and the University of Heidelberg. In 1879, he earned his Ph.D. with a thesis about how the Earth rotates. He later became a professor at Leiden University in 1882. He stayed there until 1923. In 1904, he built a large laboratory for his research.

In 1911, he made another massive discovery. He was testing how electricity moves through solid mercury. Some scientists thought electricity would stop moving in extreme cold. However, Onnes found that electrical resistance suddenly vanished at 4.2 K. This special state is called superconductivity. He also noticed helium behaving strangely, which is called superfluidity. He won the Nobel Prize in Physics in 1913 for his work.

Today, we still remember his name in many places. There is a crater on the Moon named after him. His old laboratory building in Leiden is now a law school. It is called the Kamerlingh Onnes Gebouw. You can see his old machines at the Museum Boerhaave. His work with helium and cold temperatures helps us understand the tiny parts of our world.

Heike Kamerlingh Onnes was a pioneering Dutch experimental physicist. He is best known for his groundbreaking research into extremely low temperatures. This specific field of science is known as cryogenics.

His work allowed scientists to explore how matter behaves when it is near absolute zero. By studying these extreme conditions, he unlocked secrets about gases and electricity. His discoveries changed the way we understand the physical properties of the universe.

In 1908, Onnes achieved a major scientific milestone by liquefying helium. To reach such extreme cold, he utilized several pre-cooling stages. He employed the Hampson–Linde cycle, which is a process used to produce liquid gases. This cycle relies on the Joule–Thomson effect to lower temperatures. He first cooled the gas to the boiling point of helium, which is -269 °C or 4.2 K. By then reducing the pressure of the liquid helium, he reached nearly 1.5 K. At that time, this was the lowest temperature ever recorded on Earth.

To conduct this research, Onnes required large amounts of helium. He obtained the gas through specific industrial processes. In 1911, he sourced helium from Welsbach's company. This company processed a mineral called thorianite to produce thorium for gas mantles. Helium was produced as a side product of this work. Previously, Onnes had obtained helium by processing monazite. He would trade the processed monazite, which still contained thorium, to acquire the helium. On Earth, helium is usually found alongside radioactive material because it is a product of radioactive decay.

Onnes's most famous discovery occurred in 1911 during experiments with electrical conductivity. He was investigating how electricity moves through pure metals like mercury, tin, and lead. At the time, there was a scientific debate about what would happen at absolute zero. Some scientists, including Lord Kelvin, believed electrical resistance would become infinitely large. They thought electrons would simply stop moving. However, Onnes believed that electrical resistance would steadily decrease. On 8 April 1911, he proved his theory correct. While using a solid mercury wire immersed in liquid helium, he found that resistance suddenly vanished at 4.2 K. He called this new state superconductivity.

During these same experiments, Onnes observed another strange phenomenon. Just before reaching approximately 1.8 K, he noticed the boiling of the helium bath suddenly stopped. Instead, the liquid visibly shrank through a process of evaporation. This was the first observation of superfluidity. This discovery added to our understanding of how fluids behave in extreme cold. His work in 1911 provided a deep look into the different states of matter. These observations helped define the boundaries of modern low-temperature physics.

Kamerlingh Onnes had a distinguished academic career. He was born on 21 September 1853 in Groningen, Netherlands. He studied at the University of Groningen and the University of Heidelberg. In 1879, he earned his Ph.D. with a thesis regarding the Earth's rotation. In 1882, he became a Professor of Experimental Physics and Meteorology at Leiden University. He held this position until 1923. In 1904, he founded a massive cryogenics laboratory in Leiden. This facility became a central hub for researchers worldwide. It is now known as the Kamerlingh Onnes Laboratory.

His contributions earned him the highest honors in science. In 1913, he was awarded the Nobel Prize in Physics. The Nobel Committee recognized his investigations into the properties of matter at low temperatures. This work specifically led to the production of liquid helium. His legacy continues through various scientific honors. There is a crater on the Moon named after him. The Kamerlingh Onnes Award and the Kamerlingh Onnes Prize were also established to recognize advances in low-temperature science. His original laboratory building in Leiden now serves as the university's Law Faculty. You can still see his scientific instruments at the Museum Boerhaave.