User:Skoch3/2012 PHYC102 Wave Inteference

These are a collection of good answers to 2012 September 11 "Wave Interference" Homework Assignment

Lauren Smith

http://www.rhythmodynamics.com/Gabriel_LaFreniere/sa_quarks.htm

http://www.youtube.com/watch?v=PCYv0_qPk-4

(Andruw Nez found above link also)

Kyle Molina

beating guitar strings

Alex Salazar

Myth busters sonic boom: http://www.youtube.com/watch?v=GvtAElaDVz8

Edgar Borrego

duck pond pebbles

Ryan Coblentz

wave spinning wire http://vimeo.com/12075151

James Edmond

clapping in a silent hallway / echoes interfere

Candace Krubsack

interference in ocean waves -- white caps

Allie Fullerton

http://www.schooltube.com/video/5dedd32ef392ad1a5dd4/

Slinky constructive / destructive interference

Mathias Lam

constructive wave interference" to make songs louder.

Cheryl Davis

ocean in a bottle: http://www.youtube.com/watch?v=iHh5bPKYe5c&feature=fvwrel

Sara Osusky

in another class, "lecture hall acoustics"

Angelica Torrez

LIGO

Kelley Devlin

Ipod app

Rachel Hellmer

http://www.youtube.com/watch?v=wm2_qmC0qq4 (laser patterns off reflective speaker)

http://www.youtube.com/watch?v=5hxQDAmdNWE beat frequency explanation

Deandra Rodriguez

noise-cancelling headphones image

Nathalia Martinez Moldonado

http://www.youtube.com/watch?v=J_xd9hUZ2AY old-school ripple tank

John Buckovetz

Musical saw (I search youtube and easily found lots of videos, for example Ave Maria played on a saw)

Gabrielle Lopez

http://www.youtube.com/watch?v=c3074eM5AeY

Michael Gallegos

bathtub, ripples from pebbles and golf balls

Christopher Rowe

drips in a pool out of phase

Henry Doonan

Dripping water off a pencil onto surface of water

Mathew Arrellin

In music, there are consonances and dissonances, in terms of intervalic relationships between notes. Basically that means this: Which notes sound good when played together, and which notes do not? The ones that do not are, as you may have already guessed, called dissonances. There are four dissonances commonly used in music: 2nd, perfect 4th, 7th, and the tritone. It's difficult to explain this in scientific terms, since I'm not a scientist or even remotely scientific, but I will do my best. There are major intervals and minor intervals. Let's just deal with the majors because I don't want to deal with minors, as that would double my work here. So an example of a major second would be this: A4 (440Hz) to a B4 (493.88Hz). An example of a Perfect 4th would be A4 (440Hz) to a D5 (587.33Hz). An example of a major 7th would be A4 to G#5/Ab5 (830.61Hz). A tritone, also referred to as "Diabolus in Musica," or "Devil in Music," would be like an A4 (440Hz) to a D#5/Eb5 (622.25Hz). The number next to the note (i.e. A4, B4, etc.) refer to which octave the note is on the piano. Now, A4 is 440Hz, right? And A5 is 880Hz, double the frequency of A4. So that gives you a little bit of perspective. Now, finally to discuss how this relates to the topic of this homework assignment: wave interference. I find it interesting that the mind perceives these particular harmonic intervals as "dissonances" but as I've so elaborately written out for you, they appear to be just random numbers. In scientific terms, they're just more data. But are they? When you look at the wave patterns of a consonance like a major 3rd or something, like A4 (440Hz) to C#5 (554.37Hz), the waves line up in some way or form. They perfectly mesh to create a pleasant sounding chord. When you look at the wave patterns of a dissonance, like the "Devil in Music," you would see two waves fighting for the spotlight. They never mesh perfectly. They don't line up like the consonance does.

That's all I have to say about that. I apologize if it's too much to take in, but I explained it as best I could. Thanks for sticking around to the end. (If you read this, I'm assuming you stuck around.)