Is it possible for a stable system

  • Thread starter bill nye scienceguy!
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    Stable System
In summary, a stable system is one that remains stable even when an external force acts on it. However, systems can also be conditionally stable, meaning they are stable in one state but not in another. It is possible for a system to spontaneously develop an instability without external forces, but this is generally not the case. The stability of a system refers to its ability to return to its original state after a small input of energy. In the example of a person in a box, the system is conditionally stable, meaning it can tip over if certain conditions are met, but small external inputs will not cause it to tip over.
  • #1
bill nye scienceguy!
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to spontaneously develop an instability, i.e. without some external force acting on it?
 
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  • #2
A stable system remains stable even when an external force does act on it. That is the definition of stability. Systems can be conditionally stable, e.g. stable in one state but not in another.
 
  • #3
bill nye scienceguy! said:
to spontaneously develop an instability, i.e. without some external force acting on it?
Do you mean like if you lock me up in a box sitting on the floor, is it possible for me, inside the box, to tip the box over?
 
  • #4
In general it is always possible to add enough energy to a system to destabilize it. Stability refers to a system that returns to its original state after a small input of energy.

A box on the floor is stable, if you tip it a bit it will rock back in place. It is possible to add enough energy to tip the box completely over or even break the box.
 
  • #5
DaleSpam said:
In general it is always possible to add enough energy to a system to destabilize it. Stability refers to a system that returns to its original state after a small input of energy.

A box on the floor is stable, if you tip it a bit it will rock back in place. It is possible to add enough energy to tip the box completely over or even break the box.
I'm pretty sure the point of the OP's question is to ask if this can happen without introducing energy from an external source.
 
  • #6
I agree that it sounds to be, by definition, impossible.
 
  • #7
russ_watters said:
I agree that it sounds to be, by definition, impossible.
What about the example in post#3 of me inside the box?
 
  • #8
you can't create energy, so no it can't be
 
  • #9
AFG34 said:
you can't create energy, so no it can't be
Who said anything about creating energy? Is there anything that says the closed system cannot contain stored energy, like say, a bored Web Developer with a point to make?


Hello? Is this thing on?
 
  • #10
If you manage to tip the box over, its only because of the force of the floor, which is an external force.

To imagine a closed system, imagine trying to tip the box over in intergalactic space (impossible).
 
  • #11
DaveC426913 said:
What about the example in post#3 of me inside the box?
If it is possible to tip the box over, then it isn't stable.
 
  • #12
bill nye scienceguy! said:
to spontaneously develop an instability, i.e. without some external force acting on it?

I think this is a matter of definition: a stable system is by definition something that doesn't develop spontaneously an instability.
 
  • #13
I would say that a person in a box is a conditionally stable system. The condition being that the person keeps themselves within certain bounds (below a certain height and velocity etc.) within the box. If the person exceeds those bounds then the box can spontaneously tip over, but if the person does not exceed those bounds then small external inputs will not result in the box tipping over.
 
  • #14
Crosson said:
If you manage to tip the box over, its only because of the force of the floor, which is an external force.

To imagine a closed system, imagine trying to tip the box over in intergalactic space (impossible).
Not at all. If I turn myself in a circle inside the box, it will rotate in the opposite direction. True, its CoM will not have moved, but its orientation has.


russ_watters said:
If it is possible to tip the box over, then it isn't stable.
You sure about that definition?
 
  • #15
DaveC426913 said:
You sure about that definition?
The way the question in the OP is worded, it is basically the same as asking if it is possible for 1 to equal 2. We don't need to nitpick the definition when the OP used two words with opposite meanings and asked if they can be equal.
 
  • #16
DaleSpam said:
I would say that a person in a box is a conditionally stable system. The condition being that the person keeps themselves within certain bounds (below a certain height and velocity etc.) within the box. If the person exceeds those bounds then the box can spontaneously tip over, but if the person does not exceed those bounds then small external inputs will not result in the box tipping over.

Exactly, I'd just like to word it differently. The system of the person is conditionally stable, the condition being if the net external force on the system is zero. When you push the box sideways, you're inducing gravitational force that would otherwise be canceled out by the normal force. Now if the system were isolated, that's a completely different story.
 

1. Is it possible for a stable system to become unstable?

Yes, it is possible for a stable system to become unstable. This can happen if external factors or disturbances disrupt the equilibrium of the system, causing it to deviate from its stable state.

2. What factors contribute to the stability of a system?

The stability of a system can be influenced by several factors, such as the structure and design of the system, the control mechanisms in place, and the presence of any external disturbances or feedback loops.

3. How can we determine the stability of a system?

The stability of a system can be analyzed by studying its behavior over time and assessing its response to disturbances. Mathematical models and simulations can also be used to predict the stability of a system.

4. Can a stable system be improved upon?

Yes, a stable system can be improved upon by identifying and addressing any weaknesses or vulnerabilities that may compromise its stability. This can involve implementing new control measures, optimizing the system's design, or reducing the effects of external disturbances.

5. What are the consequences of an unstable system?

An unstable system can have various consequences, depending on the type of system. In some cases, it may lead to system failure or malfunction, which can have serious consequences in critical applications. In other cases, it may cause disruptions or inefficiencies in the system's functioning.

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