Sometimes scientists need to break down small things into even smaller things. Blood needs to become platelets, plasma, and cells. Cells need to become organelles. Gases need to become isotopes. One of the best ways to achieve this is to put these items into a centrifuge, spin them around at super high speeds, and use the force of that movement to break them up into their individual parts.
The first centrifuge was created by Antonin Prandtl, a German cafe owner. According to a biography written by Prandtl's grand-niece, the design of the device, which he published in a polytechnical journal, was for a machine that worked continuously to separate milk from its fat. There is little known about Antonin or his design, but it likely was created sometime during the mid-1800s (possibly around 1850). Much more is known about Antonin's nephew, Ludwig, an engineer and Nazi sympathizer who would eventually become one of the world's experts on fluid dynamics. Ludwig's father, Antonin's brother, ultimately took most of the credit for the design of the first centrifuge by perfecting the mild-separating system and showing it at the 1875 World Exhibition in Frankfurt.
The next big upgrade to the device, and the one that brought the centrifuge into the laboratory, was invented by Swedish Chemist Theodor Svedberg. In his lab Svedberg was studying colloids -- a substance, which, in the simplest possible terms, is made up of matter in one type of state evenly dispersed within matter that is in another type of state. (Whipped cream, for example, is a colloid of gas and liquid.) Svedberg wanted to better understand the (much more complex than whipped cream) colloids he was studying and so he created a device that would separate the colloids out into their individual parts.
In 1924 his ultracentrifuge, as it was called, was built to spin substances at forces up to 10^6 gravity. The findings that came from his use of the centrifuge, that particles settled based on their size and weight, which could be used as a method to measure them, eventually won him the 1926 Nobel Prize in Chemistry.
Over the next many decades the centrifuge saw a whole series of updates by several different researchers. One researcher used compressed air to make it move at higher speeds. Others figured out the steps necessary to use the device collect the sediment that was separated out after the centrifuging was complete. And one team discovered how to use it to filter out viruses using a vacuum.
The next big step forward in the design of the centrifuge would be an innovation that, without which, we would not have nuclear reactors or nuclear weapons. In the 1950s Gernot Zippe, a German researcher living and working at a Russian prison camp for POW scientists, was tasked with finding out a way to isolate Uranium-235. Getting access to the isotope was considered a big prize because its particles could very easily be split to produce atomic energy.
According to a New York Times story about Zippe, he and a team of 60 researchers realized that to concentrate enough of the U-235 they would need hundreds or thousands of them spinning continuously for years. Zippe told the Times: "Everybody was laughing and said, 'This will never work. I was a young man. I had no idea how to do it. But I decided to do my best."
After several years of work, the team of scientists managed to perfect what would later be called the Zippe-Type Centrifuge. The device uses a magnetic field and heat to achieve the separation of U-235 from uranium gas. Though Zippe wasn't allowed to take any of his notes with him when he left the Soviet camp, he eventually made his way to the US where he reconstructed the design for the US government from memory.
Today, centrifuges are controlled by microprocessors. Some can be used under high pressure or super cooled. And there's even one on the International Space Station, called the NanoRacks Astrium Centrifuge, which simulates Earth's gravity and microgravity for different experiments. The devices are so common and ubiquitous you can even buy one on Amazon.
Science could never get done without the right tools. And all that gear has to come from somewhere. Many of the gadgets sitting on laboratory shelves around the world have histories just as interesting as the discoveries they've made. Each month we're telling the stories of how the most important lab tools came to be.