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OT: Spacial aliasing (or so they claim)

Started by Jerry Avins August 15, 2011
A beautiful demo of many oscillators with a common sub-period:
http://tinyurl.com/3ee2eya

Jerry
--
Engineering is the art of making what you want from things you can get.
On Mon, 15 Aug 2011 08:03:48 -0700 (PDT), Jerry Avins <jya@ieee.org>
wrote:

>A beautiful demo of many oscillators with a common sub-period: >http://tinyurl.com/3ee2eya > >Jerry >-- >Engineering is the art of making what you want from things you can get.
That's pretty cool, and the "aliasing" is easily seen as the spatial frequency sweeps through and back. This one isn't quite the same, but has a similar aesthetic: http://www.youtube.com/watch?v=vh2a4a6JPM8 Eric Jacobsen http://www.ericjacobsen.org http://www.dsprelated.com/blogs-1//Eric_Jacobsen.php
On Aug 15, 11:03&#2013266080;am, Jerry Avins <j...@ieee.org> wrote:
> A beautiful demo of many oscillators with a common sub-period:http://tinyurl.com/3ee2eya > > Jerry > -- > Engineering is the art of making what you want from things you can get.
That's pretty F***in' cool! I wonder how long it took to "tune" it?
>On Aug 15, 11:03=A0am, Jerry Avins <j...@ieee.org> wrote: >> A beautiful demo of many oscillators with a common
sub-period:http://tiny=
>url.com/3ee2eya >> >> Jerry >> -- >> Engineering is the art of making what you want from things you can get. > >That's pretty F***in' cool! I wonder how long it took to "tune" it?
I imagine that tuning was unnecessary. Its just a matter of careful assembly, to keeps the balls in a nice straight line. I wonder how much practice it took to get a clean release of the entire row, though? :-)
On Mon, 15 Aug 2011 19:04:41 -0500, "steveu"
<steveu@n_o_s_p_a_m.coppice.org> wrote:

>>On Aug 15, 11:03=A0am, Jerry Avins <j...@ieee.org> wrote: >>> A beautiful demo of many oscillators with a common >sub-period:http://tiny= >>url.com/3ee2eya >>> >>> Jerry >>> -- >>> Engineering is the art of making what you want from things you can get. >> >>That's pretty F***in' cool! I wonder how long it took to "tune" it? > >I imagine that tuning was unnecessary. Its just a matter of careful >assembly, to keeps the balls in a nice straight line. I wonder how much >practice it took to get a clean release of the entire row, though? :-)
Probably not much. It looks like the technique using the board is pretty common looking at some similar vids on YT. http://www.youtube.com/watch?v=1M8ciWSgc_k&feature=related Eric Jacobsen http://www.ericjacobsen.org http://www.dsprelated.com/blogs-1//Eric_Jacobsen.php
On Aug 15, 8:04&#2013266080;pm, "steveu" <steveu@n_o_s_p_a_m.coppice.org> wrote:
> >On Aug 15, 11:03=A0am, Jerry Avins <j...@ieee.org> wrote: > >> A beautiful demo of many oscillators with a common > > sub-period:http://tiny= > > >url.com/3ee2eya > > >> Jerry > >> -- > >> Engineering is the art of making what you want from things you can get. > > >That's pretty F***in' cool! I wonder how long it took to "tune" it? > > I imagine that tuning was unnecessary. Its just a matter of careful > assembly, to keeps the balls in a nice straight line. I wonder how much > practice it took to get a clean release of the entire row, though? :-)
I think the tuning wasn't easy. The period is proportional to the square root of length, but the effective length is the distance from the support attachment to the center of percussion, a point somewhat beyond the center of mass, and closer to it with the longer strings. It is easy to get close with a little calculation, but that's like trying to tune a guitar with a tensimeter. Jerry -- Engineering is the art of making what you want from things you can get.
>On Mon, 15 Aug 2011 19:04:41 -0500, "steveu" ><steveu@n_o_s_p_a_m.coppice.org> wrote: > >>>On Aug 15, 11:03=A0am, Jerry Avins <j...@ieee.org> wrote: >>>> A beautiful demo of many oscillators with a common >>sub-period:http://tiny= >>>url.com/3ee2eya >>>> >>>> Jerry >>>> -- >>>> Engineering is the art of making what you want from things you can
get.
>>> >>>That's pretty F***in' cool! I wonder how long it took to "tune" it? >> >>I imagine that tuning was unnecessary. Its just a matter of careful >>assembly, to keeps the balls in a nice straight line. I wonder how much >>practice it took to get a clean release of the entire row, though? :-) > >Probably not much. It looks like the technique using the board is >pretty common looking at some similar vids on YT. > >http://www.youtube.com/watch?v=1M8ciWSgc_k&feature=related
Does that "probably not much" thing work with other stuff I see people doing on youtube, like playing guitar or piano at breakneck speed? :-\ Steve
On Aug 15, 9:47&#2013266080;pm, Jerry Avins <j...@ieee.org> wrote:
> On Aug 15, 8:04&#2013266080;pm, "steveu" <steveu@n_o_s_p_a_m.coppice.org> wrote: > > > > > > > >On Aug 15, 11:03=A0am, Jerry Avins <j...@ieee.org> wrote: > > >> A beautiful demo of many oscillators with a common > > > sub-period:http://tiny= > > > >url.com/3ee2eya > > > >> Jerry > > >> -- > > >> Engineering is the art of making what you want from things you can get. > > > >That's pretty F***in' cool! I wonder how long it took to "tune" it? > > > I imagine that tuning was unnecessary. Its just a matter of careful > > assembly, to keeps the balls in a nice straight line. I wonder how much > > practice it took to get a clean release of the entire row, though? :-) > > I think the tuning wasn't easy. The period is proportional to the > square root of length, but the effective length is the distance from > the support attachment to the center of percussion, a point somewhat > beyond the center of mass, and closer to it with the longer strings. > It is easy to get close with a little calculation, but that's like > trying to tune a guitar with a tensimeter. > > Jerry > -- > Engineering is the art of making what you want from things you can get.- Hide quoted text - > > - Show quoted text -
At school, we have a large version of Newton's Cradle with about 15 balls. Each ball is suspended from two strings just like in the video, and I know from experience that setting each to the correct height takes some work and with the Cradle, they all just simply have to be the same length. With these pendula one can use an optical timer for each one but even it still must be a "bit fiddly" setting all of the lengths to the correct periods. Clay
On Mon, 15 Aug 2011 08:03:48 -0700 (PDT), Jerry Avins <jya@ieee.org>
wrote:

>A beautiful demo of many oscillators with a common sub-period: >http://tinyurl.com/3ee2eya > >Jerry >-- >Engineering is the art of making what you want from things you can get.
BTW, just saw this today, and while mostly unrelated it is a neat roundabout way to demonstrate Fourier Series: http://www.youtube.com/watch?v=muCPjK4nGY4 Eric Jacobsen http://www.ericjacobsen.org http://www.dsprelated.com/blogs-1//Eric_Jacobsen.php
On Mon, 15 Aug 2011 23:11:51 -0500, "steveu"
<steveu@n_o_s_p_a_m.coppice.org> wrote:

>>On Mon, 15 Aug 2011 19:04:41 -0500, "steveu" >><steveu@n_o_s_p_a_m.coppice.org> wrote: >> >>>>On Aug 15, 11:03=A0am, Jerry Avins <j...@ieee.org> wrote: >>>>> A beautiful demo of many oscillators with a common >>>sub-period:http://tiny= >>>>url.com/3ee2eya >>>>> >>>>> Jerry >>>>> -- >>>>> Engineering is the art of making what you want from things you can >get. >>>> >>>>That's pretty F***in' cool! I wonder how long it took to "tune" it? >>> >>>I imagine that tuning was unnecessary. Its just a matter of careful >>>assembly, to keeps the balls in a nice straight line. I wonder how much >>>practice it took to get a clean release of the entire row, though? :-) >> >>Probably not much. It looks like the technique using the board is >>pretty common looking at some similar vids on YT. >> >>http://www.youtube.com/watch?v=1M8ciWSgc_k&feature=related > >Does that "probably not much" thing work with other stuff I see people >doing on youtube, like playing guitar or piano at breakneck speed? :-\ > >Steve
I think that hand-held board launch technique at the beginning of the vid isn't very comparable to a skilled musician. Eric Jacobsen http://www.ericjacobsen.org http://www.dsprelated.com/blogs-1//Eric_Jacobsen.php