Open Systems

[tinman]

MH Tinman has gotten himself really, really lost.  He'll find out sooner or later just how badly he has deceived himself when he tries to make something based on his misconceptions work.

Im lost? lol.
Quote MarkE-When you let the piston move out unopposed to its original position, then to your great surprise you would find that the pressure is greater than the 5psi gage that you had at the start.

Wow Mark,you have just invented an OU device. We now have more stored force than we started with. How did you do that when it was clearly stated that it was a frictionless device.

Tinman I really do not know what has gotten into you.  You have become obstinately ignorant and shrill.

Well if that isnt the pot calling the kettle black.
You shun my work simply because it dosnt comply with your 200 year old physics. If we dont all agree with you,then we become shrills--.now that is being ignorant. By the way,many of us are still waiting for your physics to tell us what the magnetic force is,as your physics knows all about magnetic fields!right?!

If you choose to act like a jerk at the same time, then again so be it.

A jerk would be some one that just believes what they read,and that is the be all and end all-->not having done any experimental work at all on the system in question.

I've explained to you repeatedly what would occur in your set-up

im sorry,but !Elvis has left the building! is just not enough. Tell me exactly what energies you think have been depleted(or transfered outside the system) in my system when the piston is opperated.
I will then show you that Elvis is dead,and simply cannot leave the building.

It is funny as an engineer watching you physics guys meassureing small parts of a system after an action within that system has taken place,while over looking everything that took place over the system as a whole after that action. You deal in ideals that dont exist,and messurements are made from these ideals. Then you have variables to make things work out when things dont quite add up. As an engineer,we deal in absolutes,and systems as a whole.

Just found this

A real process exchanges work with the outside world, specifically, the piston is supposed to do something useful when it moves, the energy to do that cools the gas, just like a can of dusting spray cools when gas is released, and the n*R*T has now gone down inside Tinman's system, meaning that it has given up the energy that performed the external work:

This is a clasic example of what i was saying in the above statement-failing to look at the complete process.-->The total heat energy is still in the system as a whole-->no heat energy has left the system-Elvis is dead,and cannot walk. This is where your 200 year old physics,and your own blindness Mark,MH and the new guru libre are going to come unstuck. This is the very same attitude that holds all man kind back from being free of fossil fuels. 365 days in a year-oh but every 4 years we have to throw another day in there to make things all work out--screwed up with out time definitions there some where-->but hey,what the hell,it's all good.

Now,which of you knows about/or the mathematics to equate total force within a sealed vessel?-->you know,force per unit area x area total. And which of you is able to calculate total heat energy within a given volume? Lets put engineering up against your physics,and we'll see where that lead's us.

[tinman]

googlegasms ?  . We used the knowledge modelling heat engines on software and then actually building,  instrumenting and testing them.

The agreement of the theory to practical experiment was as accurate then as it is today.

but I can still remember learning this as part of an engineering degree some 30 years ago

Well it's time you went back to engineering school,as things have changed. We now look at systems as a whole,and all events that will take place around that system in question. Foe example,when meassureing pressure in a sealed vessel,it is no longer acceptable to use psi. You now have to account for total force over a given(total) area.

[profitis]

Here is a diagram of the direction of environmental heat flow contribution to and from the tinman device derived exclusively from phase-change liquid>gas gas>liquid

[MarkE]

Mark,, don't take this the wrong way,, but,, I get a kick out of it when someone smarter than me is making the same mistake as I was.

We all make mistakes.  But I assure you there is no mistake here.

You are confusing "heat" with "temperature".

Not at all.  Heat is energy. (More specifically it is thermal energy in the process of moving from a higher to a lower temperature.  In most discussions where the term "heat" is used we are really talking about the internal energy:  nRT.)  Temperature is a measure of the intensity of heat energy: Its ability to convey energy to its surroundings.   The faster the motion of molecules in a gas the easier it is for them to transfer energy to their surroundings, the hotter they are, and the higher their temperature.   In order to get the quantity of energy we usually call heat we need to know how many molecules we have:  the "n" in nRT.

Heat,, in a very simple way of looking at it, is the rate of motion.

No, that is temperature.  The rate of motion is proportional to how easily a mass can give off energy.  We have to know how much "stuff" is moving at a given average speed to know how much energy there is.  The grade school explanation compares a red hot nail to a bath tub of lukewarm water.  The red hot nail has a high temperature.  The bath tub has many times more internal (heat) energy.

Temperature,, in a very simple way of looking at it, is the rate of collisions. 

See above.

I suppose that Feynman could be wrong on that.

No, he isn't.  You should reread him.

[MileHigh]

Tinman:

I have been doing this stuff in my head mostly, trying to rely on my wits.  I have looked at formulas from time to time but it's mostly from thinking through the problem.

Going back to the transparent cylinder with the piston, I said that if you let the heat escape from the compressed gas first, and then let the piston return by itself, it would not return all the way back in one stroke. It would slowly creep back last 1/4 of the way.  We are assuming the plunger is frictionless, but otherwise it's a real bench setup.

Do you agree with that?  If yes, when the piston stops after moving 3/4 of the way back to the start position, what is the temperature of the gas?

MileHigh