What is the term for constantly teetering on the brink of change?

[whitelighter]

I have a question that I am sure is easy to answer.

I am looking for a word used to describe a state of Teetering or Brinkmanship.

examples:
hmmmm...

Trying to balance a sharpened pencil on it's tip. The pencil is always teetering.

Paying golf, the ball in flight is always suseptable to any wind changes etc...( damn that wind)

A rocket is fired to travel 1,000,000 light years but ends up 10,000 light years off course because a small meteorite hit is 1000 kms into it's journey.

A pendulum on a string swings to it's highest point and at this point neither wants to go up or down.

I am sure you get the drift of what I'm looking for.

I've been calling this effect a "Teetering" point in that the object is constantly in a state of potential movement.

Any ideas?

 

[selfAdjoint]

There are several terms for the kind of thing you describe. "Sensitive dependence on initial conditions" - one of the characteristics of Chaos - is one of them. Instability is another.

And in special circumstances they use a term very close to your "teetering"; they say "tipping point". When you pile up a sand hill grain by grain, the sides of it will be stable for a time, but finally when you add the next grain, the side will collapse in an avalanch. That is the tipping point.

 

[motai]

I've been calling this effect a "Teetering" point in that the object is constantly in a state of potential movement.

I may be confusing myself here, but:

On the molecular level I believe these are called zero point energy fluctuations. These fluctuations produce a "jittering" effect (Zitterbewegung is the offical name for it I think). This probably just applies to particles on the quantum level (like the atoms on the tip of the pencil), and probably not something like a golf ball in flight.

I guess maybe it could also be viewed as a state of equilibrium. It is stable until certain conditions affect it, thus causing the equilibrium to shift to a different position.

 

[whitelighter]

could a global statement like

"The universe is in a constant state of "teetering", "tipping over", verging on instability"

To me it suggests that the universe is extremely "reactive". Maybe this is stating the self evident.

Cause and effect is a reactive state but I question just how reactive?

Could a value be given? Infinitely reactive...finitely reactive?