# Question #20441

##### 1 Answer

Because they are too big to be quantum mechanical.

An object with mass **de Broglie Relation**:

#lambda = h/(mv)# where

#h = 6.626 xx 10^(-34) "J"cdot"s"# is Planck's constant.

Say a cricket ball was moving at an ordinary speed of

So, the **wavelength of a typical cricket ball** is:

#color(blue)(lambda) = (6.626 xx 10^(-34) cancel"kg"cdot"m"^cancel(2)"/s")/(0.1559 cancel"kg" xx 40.2336 cancel"m/s")#

#= 1.056 xx 10^(-34) "m"# ,

or

#= color(blue)(1.056 xx 10^(-25) "nm")# .

In the EM spectrum, gamma rays have the lowest wavelength on the order of

So, cricket balls have much, much shorter wavelengths (and thus much, much higher frequencies) than we can observe. It is literally outside the EM spectrum.

We say then that they have no observable wave properties.

In analogy with sound, human beings can only perceive down to about

#["20 s"^(-1) / (34300 "cm/s")]^(-1) = "1715 cm"# which is shorter wavelength than AM but longer than FM radio.

We physically can't hear frequencies *lower* than that, and thus we physically can't hear wavelengths *above*

Similarly, we cannot perceive the **low** wavelengths, or **high** frequencies, of cricket balls and big objects like that, because they are too high.