Non-equilibrium

[CatzGrad2016]

Hi, we just got done covering "reaction kinetics" and equilibrium but when I tried talking to my physics teacher about when matter starts from a non-equilibrium state in an isolated system, it spontaneously moves towards its own state of equilibrium, he didn't feel the need to tell me. I asked him about reactions always finding equilibrium except for the universe. Because I remember my chemistry teacher telling us the universe is the only isolated system technically. When I tried to ask him why we spend time calculating equilibrium when the only true example of an isolated system isn't in equilibrium? How can the laws of the universe hold everything in equilibrium except for itself? It seemed weird to me because if the entire universe doesn't go by equilibrium, how can we say many of it's parts are always in equilibrium. When I tried talking to him about it, he got mad, just like my grandma did when I asked about Jesus having siblings? I figured my teacher would just explain why it makes sense, and didn't expect him react like my bible thumping grandma.

 

Can anyone explain?

[swansont]

Most systems in science cannot be solved exactly — they are very complex. Only simpler systems and conditions can, so we study those, and then have a chance at solving systems that are well-approximated by them. In physics we study systems with frictionless surfaces even though there is no such thing. But it helps us understand systems to initially leave this complication out of it.

 

Similarly, even if neither equilibrium nor an isolated system ever truly exists on a small scale, we come very close to them in such a way that we can understand what's going on.

[studiot]

Can anyone explain?

 

 

 

What exactly is your question? I am having trouble understanding your point about equilibrium or non equilibrium.

 

I am very pleased that my house is in equilibrium so that it will not fall down around my ears and I am even more pleased that the Severn Bridge is in equilibrium when I cross the Severn so I do not get dumped half a mile out into the estuary.

 

I am just as pleased that my pizza in the oven is in non equilibrium when I put it in, so it heats up for me to eat hot, rahter than cold.

 

Did you by any chance interrupt the lesson or did you ask at the appropriate time?

[CharonY]

swansont explanation is right on the spot. In biology we often assume steady state conditions for metabolic fluxes, which is obviously almost never true, but it allows to come to do calculations (of, say, flux into a certain metabolite) that we then can measure. The results will never be 100% identical, but it will help us to understand whether our current model is seriously lacking (if the deviation is huge) or reasonably accurate.

Unfortunately that way of thinking is common in the science world, but sometimes teachers (and students) overlook that part because pre-college education tends to be too focused on simple right and wrong answers.