Steve Mould

Steve Mould is a British science communicator who produces a YouTube channel covering physics, mathematics, and related topics through physical demonstrations and experiments. He graduated from Oxford with a degree in physics and has worked in science entertainment through live shows and television alongside his YouTube work. His channel launched around 2009 and has grown to several million subscribers.

His most referenced contribution is the "Mould Effect" — a demonstration of self-siphoning bead chains, in which a chain pulled from a container rises in an arc before falling. The video attracted significant attention and subsequently prompted academic physicists to publish papers examining the mechanics of the phenomenon, which represented an unusual case of a YouTube demonstration generating formal scientific interest. The papers confirmed and extended the explanation Mould provided in the original video.

His videos are distinguished by a hands-on approach using physical apparatus rather than primarily animation-based explanation. Topics include fluid dynamics, electromagnetism, wave phenomena, and mathematical concepts demonstrable through physical setups. His background in physics provides technical grounding for his explanations, and his content is generally considered accurate by viewers with physics backgrounds who engage with it.

Mould also performs at science festivals and has appeared on UK television in science communication contexts. His channel is one of several physics-focused YouTube channels run by UK-based science communicators with academic backgrounds, and his publishing pace is moderate rather than high-frequency.