What is Surface Tension? | Richard Hammond's Invisible Worlds | Earth Science

00:03:51
https://www.youtube.com/watch?v=5NCOnr3VSAY

Summary

TLDRThis video examines the unique abilities of water striders, insects known for their remarkable speed and ability to walk on water. It reveals that these creatures can move at nearly two meters per second, thanks to the surface tension of water, which acts like an elastic film, allowing them to skim the surface without sinking. Through slow-motion footage, the biomechanics of their movement are demonstrated, illustrating how they leverage this surface tension to propel themselves at speeds compared to about 600 miles per hour. The video showcases the invisible forces at play in a seemingly ordinary pond.

Takeaways

  • 🐜 Water striders can move almost 2 meters per second.
  • 💦 They walk on water due to surface tension.
  • 🔬 Surface tension acts like an elastic film.
  • 🚀 Their movement can be compared to 600 miles per hour.
  • 🎥 Slow-motion reveals the mechanics of their legs.
  • 🌊 The milk drop experiment demonstrates surface tension.

Timeline

  • 00:00:00 - 00:03:51

    The video explores the extraordinary abilities of water striders, which can move across the surface of water at astonishing speeds of nearly two meters per second. It highlights the mystery surrounding their locomotion and introduces the concept of surface tension, which allows these creatures to walk on water without sinking. The video illustrates this phenomenon through slow-motion footage of a milk droplet hitting the water surface, demonstrating how surface tension behaves like an elastic membrane, enabling the water strider to propel itself at remarkable speeds, equivalent to about 600 miles per hour. It emphasizes the unseen forces at play in nature, showcasing the water strider as a high-speed artist of the invisible world.

Mind Map

Video Q&A

  • What are water striders?

    Water striders are insects known for their ability to walk on water.

  • How fast can water striders move?

    Water striders can move nearly two meters per second.

  • What allows water striders to walk on water?

    Surface tension of water acts like an elastic film, preventing them from sinking.

  • What is surface tension?

    Surface tension is a property of liquids that causes their surface to behave like a stretched elastic membrane.

  • How does the milk drop illustrate surface tension?

    The milk drop bounces back instead of breaking, demonstrating the elastic nature of the water surface.

  • What happens at 600 miles per hour with water striders?

    Their leg movements allow them to effectively catapult across the water's surface.

View more video summaries

Get instant access to free YouTube video summaries powered by AI!
Subtitles
en
Auto Scroll:
  • 00:00:04
    by looking into the invisible world of
  • 00:00:07
    high speed we discover extraordinary
  • 00:00:10
    events even in something as ordinary as
  • 00:00:13
    a garden pond these little creatures
  • 00:00:18
    water Striders had long been a bit of a
  • 00:00:21
    mystery
  • 00:00:22
    nobody could work out quite how they
  • 00:00:24
    could propel themselves across the
  • 00:00:26
    surface of the water so quickly
  • 00:00:31
    they can scoot forward nearly two meters
  • 00:00:34
    every second
  • 00:00:42
    and they're achieving something of
  • 00:00:45
    biblical proportions actually walking on
  • 00:00:48
    water skating across the surface without
  • 00:00:52
    sinking only by seeing what time usually
  • 00:00:57
    renders invisible to us can we
  • 00:01:00
    understand what's really going on and
  • 00:01:02
    it's got something to do what's about to
  • 00:01:05
    happen here normally this is too fast to
  • 00:01:17
    see but watch what happens in slow
  • 00:01:21
    motion as the droplet of milk hits the
  • 00:01:23
    water surface
  • 00:01:25
    [Music]
  • 00:01:36
    [Music]
  • 00:01:47
    instead of breaking the water surface
  • 00:01:50
    stretches bouncing the milk drop back up
  • 00:01:54
    into the
  • 00:02:03
    [Music]
  • 00:02:11
    [Music]
  • 00:02:28
    the water behaves as if it has a thin
  • 00:02:31
    elastic film on the surface it's called
  • 00:02:35
    surface tension and it's this elastic
  • 00:02:43
    membrane that allows the water Strider
  • 00:02:45
    to stand on the water rather than
  • 00:02:49
    sinking into it
  • 00:02:53
    he's also using that elastic surface
  • 00:02:57
    tension to catapult himself across the
  • 00:03:00
    pond at the equivalent of about 600
  • 00:03:03
    miles an hour
  • 00:03:04
    [Music]
  • 00:03:15
    in colored water we can see the force of
  • 00:03:20
    the Striders legs as they push across
  • 00:03:22
    the surface
  • 00:03:23
    [Music]
  • 00:03:26
    a high-speed artist of the invisible
  • 00:03:29
    world
  • 00:03:32
    [Music]
  • 00:03:36
    you
Tags
  • Water Striders
  • Surface Tension
  • Biophysics
  • High Speed
  • Nature
  • Insects
  • Garden Pond
  • Motion
  • Elastic Film
  • Slow Motion