Can someone explain why a longitude wave can pass through the liquid, but a transverse wave can't. And can someone recommend some good animation of these processes.


1 Answer 1


To answer your question, first let's see how transverse waves or S-Waves propagate, so in simple terms we can state that, S-Waves or transverse are shear waves, whose particles move perpendicularly to their direction of propagation.

Now, let's see why can they propagate through solids. They can propagate through solid because solids have enough shear strength. The shear strength is one of the forces that hold the solid together, and prevent it from falling apart.

The case with liquids is that, liquids do not have that much shear strength: for example consider this, if you take a glass of water and suddenly, somehow you remove the glass, the water will not keep it's shape and will just flow away. So in fact it just boils down to the fact that transverse-waves need a medium rigid enough to propagate, which liquids can't provide.

Also remember that not all transverse waves require a rigid medium to travel. Transverse waves can also travel along the surface tension of the ocean, creating water waves. Light and electromagnetic waves are also transverse waves, however they are self-propagating, meaning that they sustain themselves due to the magnetic field they create, and thus can travel through a vacuum, only slowing down slightly when passing through water or air.

Hope it helps!




Some videos:



  • $\begingroup$ But why longitude wave could? Liquid doesn't have enough shear strength to vibrate vertically, but what about horizontally? It has enough strength? $\endgroup$
    – user40003
    Feb 12, 2015 at 15:40
  • $\begingroup$ Longitudinal waves travel in a different way than as transverse wave does. $\endgroup$
    – ritvik1512
    Feb 12, 2015 at 16:01
  • $\begingroup$ More information here $\endgroup$
    – ritvik1512
    Feb 12, 2015 at 16:02
  • $\begingroup$ @user40003 longitudinal waves rely on the compressive strength/elasticity of the material which liquids have plenty of. Note that the orientation relative to gravity is irrelevant (so horizontal and vertical don't really mean anything unless you're talking about gravity waves) In longitudinal waves the motion of the particles is parallel to the propagation of the wave, whereas for transverse it's perpendicular. $\endgroup$
    – Rick
    Jul 10, 2015 at 13:39
  • 1
    $\begingroup$ Ocean waves are not propagated through surface tension, but rather they are gravity waves $\endgroup$
    – Rick
    Jul 10, 2015 at 13:42

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