## Diffraction patterns

Tatiana 4B
Posts: 30
Joined: Fri Sep 28, 2018 12:28 am

### Diffraction patterns

How exactly does a wave go from constructive to destructive interference?

Danielle_Gallandt3I
Posts: 70
Joined: Fri Sep 28, 2018 12:24 am

### Re: Diffraction patterns

So interference requires at least two separate waves interacting with each other to occur. Constructive interference is when two waves have the same phase length, so their waves will combine to a larger total wave. Destructive interference occurs if two waves go out of phase with each other, so they no longer have peaks at the same point in time. If this occurs then the waves will become a smaller wave.

Elaine Pham 2E
Posts: 58
Joined: Fri Sep 28, 2018 12:28 am
Been upvoted: 1 time

### Re: Diffraction patterns

A wave does not necessarily "go" from constructive to destructive interferences. These types of interferences describe what happen when waves meet up with each other, or interact with each other.

mahika_nayak_3L
Posts: 60
Joined: Fri Sep 28, 2018 12:26 am

### Re: Diffraction patterns

Waves don't exactly transition from constructive to destructive, as these are two separate types of wave interactions. In constructive interference, the peaks and troughs of waves line up and make an overall larger amplitude. Destructive interference is when the two waves are out of phase with one another, and they combine to form an overall smaller amplitude of the resulting wave. Diffraction refers to either wave interaction, and depending on how the phases of the wave line up, it can result in either constructive or destructive interference.

https://study.com/cimages/multimages/16 ... esults.jpg

this might help

Brian Chang 2H
Posts: 65
Joined: Fri Sep 28, 2018 12:17 am

### Re: Diffraction patterns

TL:DR

Constructive interference is when the wave crests are in sync thereby creating waves of higher amplitudes.

Destructive interference occurs when the wave crests are out of sync, thereby creating waves of lower amplitudes.

armintaheri
Posts: 68
Joined: Fri Sep 28, 2018 12:26 am

### Re: Diffraction patterns

If two waves are in phase (peaks line up with peaks perfectly), the waves will interfere constructively and result in a wave of greater amplitude. If the waves are out of phase by half a wavelength (assuming they have the same wavelength) then they interfere destructively (peaks line up with troughs and cancel out), resulting in a wave with smaller amplitude. Those are the only scenarios where you will have completely constructive or completely destructive interference. Any other arrangement will result in constructive interference at some points along the wave, and destructive interference at other points.

Connie Chen 3D
Posts: 31
Joined: Mon Jan 08, 2018 8:12 am

### Re: Diffraction patterns

Constructive and destructive interference are both diffraction patterns but they do the opposite of one another. Constructive occurs when two waves line up exactly (they overlap) and thus the resulting wave is a combination of the two original waves. Destructive is the opposite. Two waves overlap by do no line up, meaning that the trough and the peaks of each wave are alternating with one another. This causes the waves to sort of cancel each other out. The resulting wave is a wave that is the difference of the two original ones.

705152867
Posts: 28
Joined: Fri Sep 28, 2018 12:18 am

### Re: Diffraction patterns

An easy way to remember the difference between constructive (in phase) and destructive (out of phase) waves is that, in constructive waves, the peaks interact with the peaks and troughs interact with the troughs. Because of this interaction, they're in phase with each other. Deconstructive waves' peaks do not interact with the peaks, but instead, the troughs and vice-versa. They are out of phase with each other.

Nell Mitchell 1E
Posts: 31
Joined: Fri Sep 28, 2018 12:16 am

### Re: Diffraction patterns

Constructive versus destructive interference are not an either/or situation - the combinations of outcomes when waves interfere exist in a gradient. When the waves peak simultaneously they are perfectly constructive, and when one peaks and the other troughs at the same time AND they are equal frequency waves, they are perfectly destructive. But every combination in between - not perfectly aligned or destructive with one wave having a greater frequency - will exist on that gradient.

lukezhang2C
Posts: 59
Joined: Fri Sep 28, 2018 12:18 am

### Re: Diffraction patterns

Constructive interference simply means that an addition of the two waves results in a larger amplitude, while destructive interference is the opposite. The two are not mutually exclusive and can be in conjunction with one another.