# Just a random idea

Posted: 1/24/2017 4:29:11 AM

From: Oak Harbor, WA

Joined: 12/26/2013

I don't know if the technology is out there... I assume so. But has anyone ever really seen the waves emitting from the Theremin? As well as visually seen what the human interaction looks like too?

Someone at work asked me and I actually felt a little stumped on the questions.... Anyone take a crack at it and I'll be more than glad to keep educating people.

Thank's ya'll.

-Sean

Posted: 1/24/2017 1:31:27 PM

From: Lausanne, Switzerland

Joined: 3/15/2005

Not sure that there are any waves emitted!

Posted: 1/24/2017 1:36:01 PM

From: Northern NJ, USA

Joined: 2/17/2012

It's an electric field:

https://en.wikipedia.org/wiki/Electric_field

Granted, it's AC rather than DC, but it's all pretty much the same as the AC is low frequency as these things go - specifically, the skin effect (where all the conducting electrons and such in the conductor "pile up" at the outer edges, causing the inner part of the conductor to be more of an insulator) probably isn't too dominant.

From the wiki:

Normally the field lines go straight out perpendicular to the surface and out to infinity.  This forms the intrinsic capacitance.  But when two oppositely charged conductors approach each other more and more of the lines are shared between them, which lowers the intrinsic but increases the mutual.  Fortunately for us the mutual dominates, so total capacitance as seen by the antenna increases as the hand approaches the antenna.

You could probably get some kind of 2D or 3D view of the electric field from a capacitance simulator.

The image is for DC, for AC the field lines would be going one way on the positive cycle of the antenna, the other way on the negative cycle, and would disappear (i.e. all the lines would become intrinsic) when the antenna is at the point in the cycle where it is the same voltage as the hand.  These transitions would all happen smoothly if the antenna waveform is sinusoidal.

The wiki has a short clip where you can "see" the electric field via little stuff floating in oil.  Rather the same as "seeing" a magnetic field with iron filings on paper, or even more interestingly with ferrofluid on a glass plate.