Wave Propagation and

Huygens’ Principle

Waves in the Third Dimension

Circular Waves

So first, let’s start with the circular

wave. When an object is dropped in

the water, the wave moves solely on

the surface.

With a special focus on spherical waves

Yay!

Like the circular wave, spherical waves start at a single point.

BUT, a single point of sound.

Hence, the mic.

• Sound waves can propagate in uniformly in three

dimensions

• Each crest creates a spherical wave front

• This spherical wave front radiates outward from the point

source

• Is a function of x, y, z, and t because it moves in three

dimensions

• Amplitude decreases as it moves outwards

Spherical Waves

Huygens’ Principle

• Christiaan Huygens saw that:

• 1. Propagation of wave could be

described as every point on wave

front to be a source of spherical

waves, and

• 2. Resulting wave is found from

the sum of all the point sources

Procedure for Huygens’ Principle

To apply Huygens’ Principle:

1. Choose a set of equally spaced

points on a wave front.

2. Draw a set of circles of same

radius, centered at different

points.

3. Complete the resulting wave by

drawing tangents. From Physics for Scientists and Engineers: An Interactive Approach. p. 429

https://www.youtube.com/watch?v=OnmFn7bvIrA

Works Cited

• Slide 1 concert photo: http://upload.wikimedia.org/wikipedia/commons/1/1c/Paramore_Concert.jpg

• Slide 2 ripple photos:

– Physics for Scientists and Engineers: An Interactive Approach. p. 428

– http://thumbs.dreamstime.com/x/metallic-circular-waves-16755394.jpg

– http://www.rpi.edu/dept/phys/ScIT/InformationTransfer/waves/images/wavefrontf.gif

– http://ks.kumu.net/Units/Waves/images/SphereFronts/Ripples.png

• Slide 4 curtain photo: http://plywoodpeople.com/wp-content/uploads/2013/03/documentaries.jpg

• Slide 5 mic photo: http://fc07.deviantart.net/fs71/f/2013/049/f/0/lws9890_by_lucianow-d5vedi3.jpg

• Slide 6 concert photo: http://calenarts.com/wp-content/uploads/2014/09/bg.jpg

– Spherical wave: Physics for Scientists and Engineers: An Interactive Approach. p. 428

• Slide 7 Huygens photo:

http://www.esa.int/var/esa/storage/images/esa_multimedia/images/2002/01/christiaan_huygens_1629-

1695/9155400-5-eng-GB/Christiaan_Huygens_1629-1695_medium.jpg

– Chalkboard: http://www.teca-sf.org/wp-content/uploads/2014/01/chalkboard.1440x900.jpg

• Slide 9 concert photo: http://images6.fanpop.com/image/photos/34500000/Concert-Images-imagine-dragons-

34544053-3264-1836.jpg