Question

The water droplets appear to be causing patterns of black and bright blue fringes. in terms of water in the real world (in a bowl, sink or pond), what do the bright blue and black colors mean?

Answer 1

The bright blue and black colors represent the following:

Constructive and destructive interference are represented by the blue and black colors, respectively. When two water waves collide constructively, the resultant wave is bright blue, while when they collide destructively, the resultant wave is black in color.

Step-by-step explanation:

When two propagating waves with the same frequency (say,
`\\u`) and wavelength (say,
`\lambda`) but slightly different amplitudes (say, A 1 and A 2) traveling in the same direction interfere or are superimposed on each other (that is incident at the same point or object), a third resultant wave with a different amplitude (increased or decreased) but same wavelength and frequency is generated.

The direction difference between the two waves determines whether they intervene constructively (increasing the amplitude of the resultant wave) or destructively (increasing the amplitude of the resultant wave) (decreased amplitude of the resultant wave). To put it another way, when the difference in direction between the two waves is of the form -

`\Delta x = n\lambda , n=0,1,2,.....` is the order of interference.

The two waves are then assumed to be in phase, and the interference is constructive, resulting in the resultant wave having a larger amplitude (which is the sum of the two amplitudes
`A_1 +A_2` also known as a maxima). When the difference in direction between the two waves is in the form -

`\Delta x = (2n-1)(\lambda)/(2) , n=0,1,2,.....` is the order of interference.

The two intervening waves are then said to be out of phase, and the interference is disruptive, resulting in the resultant wave having a lower amplitude (which is the difference between the two amplitudes
`A_1+A_2`, also known as a minima).

Hence , the graphical representation of constructive (blue )and destructive (black) is attached.