Why do teapots dribble?

Nothing ruins a tea party more than dripping tea on a pretty tablecloth. You would think that it’s possible to prevent teapots from dripping, but the fluid dynamics of the tea spout is fiendishly complicated, and it’s not easy to predict or control. In fact, the “teapot effect”, describing the way tea drips from the … Continue reading Why do teapots dribble?

What causes the oily film on black tea?

If you’re a black tea fan, you may have noticed the thin, oily film that sometimes forms on the top of the drink. Why does this happen? According to new research, the answer lies not only with the chemistry of the tea, but its physics: specifically, its fluid dynamics. The oily film on black tea … Continue reading What causes the oily film on black tea?

How stingrays became such sleek swimmers

With their smooth bodies and flexible fins, stingrays are among the slickest swimmers in the sea – but do their protruding eyes and mouths hinder their movement? Scientists and stingray enthusiasts alike have long wondered this, and physics now has the answer: no. “The influence of 3D protruding eyes and mouth on a self-propelled flexible … Continue reading How stingrays became such sleek swimmers

Manipulating molecules with fluids

Fluids are fiendishly unpredictable, but fluid dynamics is a very useful area of science. With a machine called a Vortex Fluidic Device, it’s possible to manipulate molecules in very neat and specific ways – like refolding proteins to unboil an egg. “How fluid flows is one of the grand challenges of science,” says Colin Raston, … Continue reading Manipulating molecules with fluids

Alcohol beats the coffee ring effect

The “coffee ring effect” is one of the most puzzling phenomena in fluid mechanics. A quick Google search will unearth any number of scholarly articles about what it is, what it does and how to try to beat it. One thing it has done, says a team of researchers led by the University of Cambridge … Continue reading Alcohol beats the coffee ring effect

Why you should close the toilet lid

Physics has been surprisingly prominent in the flurry of scientific activity to understand COVID-19 and its real and potential impacts. Researchers have, for example, used computational fluid dynamics simulations to study how far droplets fly when we cough, and mathematical models to investigate how long these droplets take to dry in different situations and even … Continue reading Why you should close the toilet lid

Watch the art of Roman Hill on film

Roman Hill’s canvas is eight square millimetres of glass and his media are commonly available: oil, water, ink, paint and alcohol. Combined, they are aesthetically awesome examples of the principles of fluid dynamics – the field concerned with the movement of liquids and gases, and thus encompassing everything from the evolution of stars and plate … Continue reading Watch the art of Roman Hill on film

Galaxies under glass

Roman Hill’s canvas is 8mm2 of glass; his media commonly available: glycerine, ink, paint and alcohol. Combined, they are aesthetically awesome, and fascinating examples of the principles of fluid dynamics – the field concerned with the movement of liquids and gases, and thus encompassing everything from the evolution of stars and plate tectonics to blood … Continue reading Galaxies under glass