# Why does sound wave suffer more diffraction than light waves generally?

Why do sound waves suffer more diffraction than light waves generally ?

I would like more of a logical explanation rather than mathematical .

As a general guide, if we consider diffraction of a wave with wavelength $\lambda$ from an object of size $d$ then the characteristic angle of the diffraction is given by:

$$\sin\theta = O\left(\frac{\lambda}{d}\right)$$

where the $O()$ symbol means of order i.e. roughly the same as. So for example in a Young's slits experiment, where $d$ is the slit spacing, the angle of the first maximum is given by:

$$\sin\theta = \frac{\lambda}{d}$$

Alternatively, the diffraction pattern from a pinhole of diameter $d$ has the first minimum at:

$$\sin\theta \approx 1.22\frac{\lambda}{d}$$

It should now be obvious why diffraction of sound is so commonly observed in everyday life. The wavelength of sound is of order one metre, so objects around a metre in size will diffract it strongly. By contrast the wavelength of light is around half a micron, so you need to get the size down to the micron scale before light starts scattering strongly.

Because Light Wavelength is actually less than a sound wave.

And Diffraction is more in longer wavelength waves, as is less in wider slits.

The wavelength of sound is of the order of 1 meter. So any objet visible to the eye can deflect it.

In the case of light , we need sofisticated equipment to observe the effect of diffraction. Diffraction of light an be best observed when a small slit is used. THe slit should be the order of few microns. Then the light is diffracted which is observed in the screen.

Light waves has a very small wavelength compared to that of sound waves. The effect is that since it is compulsory for the wavelength of a waves to be greater than the length of the opening before diffraction can occur, it is then clear that light waves will only be diffracted by very small openings while sounds waves suffers diffraction evening on wider openings... In summary it is due to the wide range of difference in their wavelength..