Skip to Content
Uncategorized

The Secrets of Raindrop Seed Dispersal

High-speed video photography reveals how flowers exploit the kinetic energy of raindrops to disperse seeds

The plant world has evolved numerous ingenious ways to distribute seeds. But one of the least known and least celebrated is raindrop dispersal.

Just a couple of dozen plants are known to exploit the kinetic energy of rain drops to disperse their seeds. And they do it remarkably well. These plants tend to be small, none of them grow taller than 35 cm and their average height is just 12cm. And yet their dispersal mechanisms jettison seeds over distances of up to a metre.

The question we look at today is how. The answer comes courtesy of Guillermo Amador and buddies at the Georgia Institute of Technology in Atlanta. These guys have used a 3D printer to recreate the cup-shaped flowers of these plants. They then filled the cups with water and seeds, and then filmed what happens as drops fall into the cups.

They’ve discovered that when a drop lands in the centre of the cup, water splashes out in all directions at about the same speed as the drop.

But when the drop lands off-centre, the water tends to splash out of the opposite side of the cup. What’s more, the shape of the cup directs and accelerates the water so that its exit speed can be up to five times the velocity of the incoming drop.

Finally, the angle of the cup sides needs to be about 45 degrees to maximise the distance the jettisoned seeds can travel.

Simple really!

All this is captured beautifully in a video for this year’s Gallery of Fluid Motion, organised by the fluid dynamics division of the American Physical Society.

Ref: arxiv.org/abs/1110.3993: How Flowers Catch Raindrops
Hi-res video
Lo-res video

Deep Dive

Uncategorized

Five poems about the mind

DREAM VENDING MACHINE I feed it coins and watch the spring coil back,the clunk of a vacuum-packed, foil-wrappeddream dropping into the tray. It dispenses all kinds of dreams—bad dreams, good dreams,short nightmares to stave off worse ones, recurring dreams with a teacake marshmallow center.Hardboiled caramel dreams to tuck in your cheek,a bag of orange dreams…

Work reinvented: Tech will drive the office evolution

As organizations navigate a new world of hybrid work, tech innovation will be crucial for employee connection and collaboration.

lucid dreaming concept
lucid dreaming concept

I taught myself to lucid dream. You can too.

We still don’t know much about the experience of being aware that you’re dreaming—but a few researchers think it could help us find out more about how the brain works.

panpsychism concept
panpsychism concept

Is everything in the world a little bit conscious?

The idea that consciousness is widespread is attractive to many for intellectual and, perhaps, also emotional
reasons. But can it be tested? Surprisingly, perhaps it can.

Stay connected

Illustration by Rose WongIllustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.