Rock throw against an invisible barrier. Invisible thread question

[maskedwarrior]

Hello Theory 11 forum, I am Anthony and this is my second post here (my first was this post, but in the wrong forum!)

I am not a what I'd describe as a magician, I am a theatre-maker and I am fascinated by the idea of incorporating some magic into my next production.

Basically, I'd like an (imitation) rock to be thrown onstage and seemingly collide with an invisible wall. This will be a 2 man storytelling show utilising mime, puppetry and audience imagination to portray complex scenarios... One such scenario will be a 'wall' appearing out of nowhere, trapping a character behind it. It will mostly be portrayed using mime and will be entirely imaginary and invisible. However, I would love it if they could pick up a 'rock' and throw it at the wall, and have it impact on an invisible surface and bounce off.

To do this I figure some sort of invisible string/thread could be attached to this (imitation) rock. The rock would be set at the side of the stage, and wait there until needed.

This action will all happen on stage, with an audience sitting in the auditorium some feet away. It won't be up close and personal.

Does anyone have any suggestions on a material I could experiment with, that'd be strong enough to resist the inertia of an (imitation) rock, and 'ping' it back on itself? And also not be too fiddly to work with or easily tangled on itself?? Oh and of course, be as invisible as possible!

Thank you very much,
Anthony

 

[WitchDocIsIn]

Kevlar thread would probably do the trick. Coiled properly it will unwind effortlessly. The tricky part will be physically blocking the movement so as to prevent the tangling and keep it from being too obvious.

I would say put the "rock" upstage from the actor, and if possible have a horizontal post of some sort to loosely drape coiled thread on. Actor grabs the rock and throws in one underhand motion. As long as the tread is well anchored that should be plenty to cause it to bounce back. Very astute observers may be able to tell the difference between something bouncing off a wall and something being stopped by a thread, but I wouldn't worry about it. The thread can be loosely coiled and left on the floor as well, as long as everyone is careful not to mess it up by walking over it.

With practice you could manage to handle the rock more without tangling the thread. Kevlar is pretty thick as far as IT goes, and handles almost like rope.

The issues you will have to overcome then are that a foam rock will bounce once it hits the floor, and it won't make the "Thunkathunkskitter" sounds a real rock would make when bouncing off a wall and hitting a wood floor. These could both be solved by having the actor catch the rock, then throw it into the wings and have someone there drop a real rock.

Another option is to use a real, small-ish rock and make sure the actor doesn't throw it too hard.

 

[RealityOne]

You are going to want to use black elastic cord with the thickness corresponding to the weight of the rock. Anchor the cord about one third the distance between where the person throwing the rock is standing and the imaginary wall. The lighting and backdrop need to accommodate the black of the cord. You also need the rock and elastic to have the appropriate balance so that the pull back of the rock by the elastic approximates the bounce of the rock off the wall. I would bottom weight the fake rock so that it makes a loud sound when it hits the floor. It is probably easier to "fake" a brick than a rock. That said, I wonder if you could use a plate or something that breaks when it hits the floor.

 

[maskedwarrior]

Hello Christopher T & RealityOne,

Please forgive the horrendously long delay getting back to this!

Thank you for your suggestions. I particularly like the sound of Kevlar Thread... and your suggestions on its use, Chris, really helped me visualise working with this new material.

I would probably try kevlar before elastic, or at least try some combination of the two, as I want the "rock" to snap back at a predictable point along its travel, as if it has impacted against something physical and hard. Also it will be a lot easier to sync up a sound with the visual cue if the cord is as unstretchy as possible. However, incorporating a small stretch of elastic might serve as a shock absorber if the thread is apt to break, or the "rock" is apt to separate from the cord!

Ha ha, LOVE "Thunkathunkskitter". New favourite word.

As this is a piece of family theatre, with an emphasis on storytelling and imagination, I think the sudden 'surprise' factor of the spontaneously rebounding rock, coupled with the more impressionable age of a lot of the audience, will help mask any perceived flaws which a more cynical observer might point out!

I really appreciate you taking the time to help me on this, I will update and probably pose some more questions in time to come!
Best wishes,
Anthony