This is how the chain fountain effect behaves in space
British science communicator Steve Mould – one of the most popular science YouTubers with 3.44 million subscribers – has teamed up with NASA astronaut Don Pettit aboard the International Space Station (ISS) to study the so-called chain fountain effect in zero gravity for the first time.
Mould discovered the phenomenon by chance about ten years ago: when a chain of beads is pulled from a cup, it briefly rises above the rim before falling – an effect that initially seemed to defy classical mechanics. He later demonstrated that the impact of the chain links on the container’s edge generates an additional upward force – a finding that has since been confirmed by physical models.
With the new experiment, Mould aimed to observe how the effect behaves in a zero-gravity environment. Through the European Space Agency (ESA), he got in touch with astronaut Samantha Cristoforetti, who brought a four-meter chain aboard the ISS. As her schedule left little time for experiments, she passed the project on to NASA astronaut Don Pettit, who conducted it under Mould’s guidance via a Microsoft Teams call.
In zero gravity, it quickly became clear that setting up the experiment calmly was nearly impossible. The chain moved unpredictably, behaving in a “molecule-like” manner. With no energy loss in weightlessness, objects continue moving indefinitely. After several failed attempts, Mould and Pettit decided to form the chain into a closed loop – allowing it to move more smoothly without tangling.
The result was surprising: the chain “flowed” through its own loop exactly as Mould’s theory had predicted. At first, the loop maintained a more angular shape, but over time it gradually rounded out due to friction between the links and slight air currents. In the end, Mould concluded that the experiment confirmed his prediction – a chain in zero gravity retains its shape as long as it moves uniformly and remains free from external forces.
The response to the video has been overwhelmingly positive. Viewers praised Mould’s enthusiasm and Pettit’s childlike excitement – while joking about Microsoft Teams in space (“Even in space, you can’t escape Teams”). For Steve Mould, the project marked a personal milestone: “I wanted to be an astronaut as a kid – and now I’m doing science with one.”
Source(s)
Steve Mould via YouTube
