"George Dishman" wrote in message ...
"sean" wrote in message om...
"George Dishman" wrote in message ...
"sean" wrote in message om...

...
Refarding the resonance point I just did a google search on
`resonance` and the few things I found were all describing resonace as
a function of waves overlapping. thats why I couldnt understand dlzs
claim that resonance couldnt be described as waves

I happened to come across this recently, it might help:

http://colos1.fri.uni-lj.si/~colos/C...resonance.html

Read what I could without going into the details of the equations .It
still seems that david is wrong about resonace not being a wave
phenomena? as this url also explains resonance in terms of amplitude,
frequency, harmonics etc. All wave compatible descriptions


While the two concepts are related, they are not the same.
Resonance is a term that relates to a fixed system such as
a pendulum, mass and spring, etc as listed on the web page.
It refers to a system that has a natural mode of oscillation
that can store energy in one place.

When people talk about waves, they usually mean something
with a repetitive characteristic that also moves. Waves can
carry energy from one place to another.

Consider an example of a weighted buoy on the sea. In flat
calm water, if you hit the buoy, it will bob up and down at
some rate. The energy you gave it in the initial impact is
stored as a combination of kinetic and potential energy and
is slowly lost to heat in the water.

If waves hit the buoy at that same rate as it bobs, then
they can give it more energy than it loses in each cycle so
the amplitude will increase. At any other rate the waves may
at first add energy but as they get out of phase they tend
to remove it.

So David is right, a pendulum for example is a resonant
system but it is not a 'wave phenomenon'. To put it crudely,
waves travel, pendulums don't.

The equation for the swing is:

y(t) = a * sin(w*t + p)

where a is the amplitude, w is the angular frequency, t is
time and p is the initial phase. For a wave it is:

y(x,t) = a * sin(w*(t-x/v) + p)

where v is the speed of the wave and x is a distance.

George

Hi George

Yes I can understand that an object can have or generate `resonance`
but it is true also to say that standing waves and vibrating nodes in
mediums like sand water etc also can be said to be resonant systems
and store energy and be measured in the same terms of frequencies
oscillations as objects. These phenomena are also essentially
identical to what would be termed a wave only atom or `particle` .
They are stationary and point like but are not objects like pendulums
or particles but superimpositions of many waves on a point source.So
it seems to me that for david to say only particles can explain
resonance is incorrect and wave only models seen classically as
standing wave s are also resonant systems
Sean