thermodynamics an analogy & its constructs mr. gibson for all science disciplines at selected...

Thermodynamicsan Analogy & Its Constructs

Mr. Gibson For

All Science Disciplines at Selected Times

Simple Overview/Study of Thermodynamics

Thermodynamics is really – quite simply put –

the study of one of the forms of energy called “HEAT”.


“HEAT”

To simplify our study we will use an “analogy” by equating “Heat” [to] liquid water.

Hopefully this will make it easier by visualizing liquid water & using this mental image and our experiences to better follow along with the constructs of “heat”.


“HEAT”

However, before we go on -- let’s clarify a common “mistake” people make when talking about “Heat”…


“HEAT”

People commonly confuse what “Heat” is -- with another construct called “Temperature”.


“HEAT”

It is natural for people to confuse “Heat” with “Temperature”.

That’s because we all know as you “heat” something up… its “temperature” goes up too.


“HEAT”

But it is scientifically known and proven – “Heat” and “Temperature” are NOT the same thing!!!


“HEAT”

To show that – “Heat” and “Temperature” are NOT the same thing we will now use our “water” analogy to get this idea firmly established in our mind before

we go on to study the FOUR laws of Thermodynamics.


“HEAT”

In our analogy with water…

“Heat” – is a FORM of ENERGY –And it acts just like liquid water…

… it FLOWS


“HEAT”

“Temperature” is just like the HEIGHT LEVEL of liquid water… • something that is both quantified (how high) and;• measured (using an instrument of some kind).


“HEAT”

A DIFFERENCE in “TEMPERATURES” makes; the energy form of “HEAT”

[to] flow.


“HEAT”

•Using the diagram to the right.•Water in the

-- u-tube in the middle – when uncapped; the level of water would drop on the right side and would raise up on the left until it looked like the u-tube on the left.


“HEAT”

•Using the diagram to the right.•Water in the --

u-tube on the far rightwould level out in the opposite direction.• [Because] water flows FROM the HIGHER level[to] the LOWER level.


“HEAT”

• Like the water in the u-tubes…• HEAT energy flows from the HIGHER temperature [to] the LOWER temperature… always.


“HEAT”

• It was the DIFFERENT water level heights in the u-tubes that determined which way each of the sides would flow…


“HEAT”

•And so it is with TEMPERATURE… it is the DIFFERENCES in TEMPERATURES that CAUSES the ENERGY to FLOW from the HIGHER (level) temperature [to] the LOWER (level) temperature…


• You can melt a lot more ice using 1000 gallons of 90 degree water than you can with one spoonful of 200 degree water.

• Just because the spoonful is “hotter” (measured temperature)… it doesn’t mean it has a lot more “heat” (energy form) than there is in all those gallons of “colder” water (to melt the ice).

“HEAT”

In short ---

Heat is an energy form that flows and temperature differences makes it flow.


“HEAT” – To visualize and explain heat flow let’s use another example of the water flow analogy. Suppose you have two cylinders of water connected by a pipe at their base, as shown (viewed from the side) below.

Highest LEVEL of water

Most AMOUNT of water

Left cylinder side view Right cylinder side view


“HEAT” – •The cylinder on the left has the HIGHEST level of water.•The cylinder on the right has the MOST amount of water.




Simple Overview/Study of Thermodynamics “HEAT” – Therefore; in our visualization

Level = Temperature -&- Amount = Heat•The cylinder on the left has the HIGHEST level of water.•The cylinder on the right has the MOST amount of water.




Simple Overview/Study of Thermodynamics “HEAT” – • The water flows from the left cylinder (highest level) into the cylinder on the right (most amount) • BECAUSE there is a DIFFERENCE in the LEVELS of water between the two cylinders… NOT from a difference in the amounts of water.





“HEAT” – • It doesn’t matter if there is MORE water in the cylinder on the right… the water will continue to FLOW until the levels in each cylinder are EQUAL.





“HEAT” – • Water does not continue to flow until the AMOUNTS of water are equal in each cylinder. Water flows until the LEVELS of water in each cylinder are equal.





“HEAT” – Like water… “energy” flows in such a way until the TEMPERATURES (levels) are equal or uniform. When uniform or equal… the Heat energy flow stops.



Both cylinders’ water levels are equal

No - flow



“HEAT” – Using the example of liquid water as an example

Water: Clues & Questions Graphic Organizer1. Starting at a ___________ level, water will always flow to a lower level.2. Water in two connected cylinders will stop flowing when the (levels, amounts) in both cylinders [ circle one] are ___________.3. Heat energy is like water because they both ________ from higher levels to lower levels.4. Water flows because of the _____________ in levels.



Water: Clues & Questions Graphic Organizer1. Starting at a higher level, water will always flow to a lower level.2. Water in two connected cylinders will stop flowing when the (levels, amounts) in both cylinders [ circle one] are ______.3. Heat energy is like water because they both _____from higher levels to lower levels.4. Water flows because of the __________ in levels.



Water: Clues & Questions Graphic Organizer1. Starting at a higher level, water will always flow to a lower level.2. Water in two connected cylinders will stop flowing when the (levels, amounts) in both cylinders [ circle one] are equal.3. Heat energy is like water because they both ______from higher levels to lower levels.4. Water flows because of the __________ in levels.



Water: Clues & Questions Graphic Organizer1. Starting at a higher level, water will always flow to a lower level.2. Water in two connected cylinders will stop flowing when the (levels, amounts) in both cylinders [ circle one] are equal.3. Heat energy is like water because they both flow from higher levels to lower levels.4. Water flows because of the ___________in levels.



Water: Clues & Questions Graphic Organizer1. Starting at a higher level, water will always flow to a lower level.2. Water in two connected cylinders will stop flowing when the (levels, amounts) in both cylinders [ circle one] are equal.3. Heat energy is like water because they both flow from higher levels to lower levels.4. Water flows because of the differences in levels.



Energy: Clues & Questions Graphic Organizer1. Starting at a ___________ temperature, energy will always flow to a lower temperature.2. Energy flowing from a high temperature source will ________flowing when the surrounding area’s temperature is __________ to it.3. Heat energy is like water because it ________ from higher temperatures to lower temperatures.4. Energy flows because of the _____________ in temperatures.



Energy: Clues & Questions Graphic Organizer1. Starting at a higher temperature, energy will always flow to a lower temperature.2. Energy flowing from a high temperature source will _____flowing when the surrounding area’s temperature is ______ to it.3. Heat energy is like water because it ______ from higher temperatures to lower temperatures.4. Energy flows because of the ____________ in temperatures.



Energy: Clues & Questions Graphic Organizer1. Starting at a higher temperature, energy will always flow to a lower temperature.2. Energy flowing from a high temperature source will stop flowing when the surrounding area’s temperature is _______ to it.3. Heat energy is like water because it _______ from higher temperatures to lower temperatures.4. Energy flows because of the _____________ in temperatures.



Energy: Clues & Questions Graphic Organizer1. Starting at a higher temperature, energy will always flow to a lower temperature.2. Energy flowing from a high temperature source will stop flowing when the surrounding area’s temperature is equal to it.3. Heat energy is like water because it _______from higher temperatures to lower temperatures.4. Energy flows because of the _____________ in temperatures.



Energy: Clues & Questions Graphic Organizer1. Starting at a higher temperature, energy will always flow to a lower temperature.2. Energy flowing from a high temperature source will stop flowing when the surrounding area’s temperature is equal to it.3. Heat energy is like water because it flows from higher temperatures to lower temperatures.4. Energy flows because of the ____________ in temperatures.



Energy: Clues & Questions Graphic Organizer1. Starting at a higher temperature, energy will always flow to a lower temperature.2. Energy flowing from a high temperature source will stop flowing when the surrounding area’s temperature is equal to it.3. Heat energy is like water because it flows from higher temperatures to lower temperatures.4. Energy flows because of the differences in temperatures.


Up until now in your school careers you have heard about & studied Newton’s THREE Laws of Thermodynamics.


• The 0th Law of Thermodynamics

I am going to introduce the 0th Law of Thermodynamics discovered after the first three laws.

We will begin there.

3rd Law

1st Law

0th Law

2nd Law



There are four laws of thermodynamics which build upon each other. •They are numbered 0 through 3 because the most fundamental law was discovered after the First Law had already been given the number 1. •Therefore, they had to assign the most fundamental law the number 0.



The Zeroth Law simply says: there is no heat flow between objects that are the same temperature.

In essence, the Zeroth Law is just a definition of what temperature

is.

0th Law

Simple Overview/Study of Thermodynamics 0th

Law

T1 = T2No energy flow.


• The 1st Law of Thermodynamics

The First Law simply says: heat (energy) cannot be either “created” or “destroyed”

This is also known as:

The Law of the Conservation of

Energy



The First Law simply says: heat (energy)

cannot be either “created” or “destroyed”

0th Law 1st Law


Amount of energy is “fixed”



The First Law also tells us…

“Heat” (energy) can only FLOW from place to place

-or- Change “forms” (of

energy) but;

It cannot be created from “nothing” or

reduced to “nothingness”




What is “work” (as defined by this law & science?

Scientists (physicists actually) have also developed another term from this 1st

Law of Thermodynamics.

The term is called “work”.




“work” occurs when energy flows from one place to another per science.

Scientific “work” will be done (or wasted) when “Heat” flows

or transfers from one place to another.





0th Law 1st Law



& “work” = energy flow




Work in terms of Potential Energy

To put it another way...

When “heat” energy is waiting to flow

from a higher level (temperature) to a

lower level (temperature)… it can also be viewed as “work waiting to

happen”.




Work as PE

And; When “work is

waiting to happen”...

… we can also call this (in a loose

manner of speaking) POTENTIAL ENERGY

OrPE





0th Law 1st Law


PE = “work” waiting to happen


& “work” = energy flow




“work” as KE

And by extension;When “work IS

happening” –or- flowing…

… we can also call this (in a loose

manner of speaking) KINETIC ENERGY

Or KE




“work” as KE

In simple terms… “Heat” usually shows

up in nature as the Kinetic Energy (KE) or

rates of movement of molecules in their gaseous, liquid, or

solid states of matter.





0th Law 1st Law




& “work” = energy flow& T1>T2 “work flows” =

KE




Now… Let’s go back to our

classroom “Twin-burn” candle

experiment/demo.




At the beginning of our “Twin-burn”

candle experiment/demo; the unlit candle at room temperature had some chemical

energy in the wax of the candle. But there is no heat flow from an unlit candle, so it can’t do any work..




A burning candle does not create heat

because…According to the 1st

Law of Thermodynamics

heat (energy) cannot be created or

destroyed.




A burning candle liberates heat.

Heat that already was in the candle (in the form of chemical energy) flows out..




The melted wax is hot because heat has

changed to a form that can escape.




Heat has merely moved from a hot

place to a cold place, making the hot place cooler and the cold

place warmer...




When both places are the same

temperature there will still be the same amount of heat as

there was before the candle was lit. The only difference is

that the heat is less well organized than

it was.




Previously the heat was concentrated in

the candle…




After the candle burns out, and everything

reaches the same temperature, the

heat is moreUniformly distributed.

It is more disorganized because it isn’t localized

in one place…… it is “spread out”.


• The 2nd Law of Thermodynamics

The Second Law simply says: heat (energy) in a “closed system” - one that does not exchange any energy with the surrounding environment – distributes itself out from a “Higher” organized state to a “Lower” disorganized state.








The fancy term for this spreading out or distribution of organized heat energy to a lower form of disorganized energy is - ENTROPY








The 2nd Law of Thermodynamics says this “spreading out” of

higher level organized energy into lower level disorganized energy is called: ENTROPY…

… always INCREASES in a Closed System.

The results of countless calculations have shown

that every time heat flows from a hot spot to

a cold spot, entropy increases.

Every time heat flows from a cold spot to a hot spot, entropy decreases.



The 2nd Law of Thermodynamics says ENTROPY…

… always INCREASES in a Closed System.

The Second Law says that entropy always increases

in a closed system.

The universe is a closed system because there is nothing outside of it to

exchange heat with.



Says: heat in a “closed system” distributes itself out from being

“highly organized” to “uniformly

organized” with its surroundings

0th Law 1st Law



energy amount is “fixed” /”work” =

energy flow& T1>T2 “work flows”

= KE

2nd Law

“organized” “disorganized” =

“entropy”




higher level organized energy into lower level disorganized

energy –or- ENTROPY…… always INCREASES in a Closed

System.


in a closed system.

Entropy can decrease in an open system only if energy is received from

an outside source. Whenever energy is received by an open

system, the sum of the entropy of the open

system plus the entropy of the outside source

increases.






System.


in a closed system.

Entropy can decrease in an open system only if energy is received from

an outside source.






System.


in a closed system.

And whenever energy is received by an open

system from an outside source; the sum of the

entropy of the open system plus the entropy

of the outside source – in total -- increases.


• The 3rd Law of Thermodynamics

The 3rd Law of Thermodynamics says “work” can be 100% efficient ONLY IF the final

temperature level is ABSOLUTE ZERO

The Third Law says all “work” processes are impossible to be 100%

efficient therefore, heat/work is lost each

time and this “loss” adds up over time.





This means ALL energy flows are irreversible. At some point in the future everything will be at a uniform temperature

level thus no “work” will be possible.

Simple Overview/Study of Thermodynamics • The 3rd Law of

Thermodynamics

Says: “Work can only be 100% efficient (no work lost) IF

the lower temperature = Absolute Zero;

Which is impossible due to ZPE &

subatomic motion.

0th Law 1st Law



energy amount is “fixed” /”work” =

energy flow& T1>T2 “work flows”

= KE

2nd Law

“organized” “disorganized” =

“entropy”

3rd Law

“Work” < 100% Efficient & over time all “work”

will stop as T1 = T2





When the temperature level of the universe

reaches uniformity – no work is possible and; the

universe will suffer a “heat death” of non-

existence.





Absolute Zero is the theoretical point where

all motion stops.

There would be no “flow” of energy.





The Study of Absolute Zero;

And with it ZPE (Zero Point Energy and its

impact upon the motion of electrons) as well as the Casimir Effect –or-

the magnetic “attraction” between

two “neutral” plates in a vacuum will be studied later by the Advanced

Science class.


The Laws of Thermodynamics

The 0th Law says: The energy of the entire universe flows irreversibly in one direction only;

The 1st Law says: We all have a “stake in the game”;

The 2nd Law says: We cannot get out of the game;

The 3rd Law says: We cannot possibly win…

In summary --



The 0th Law says: The entire universe flows irreversibly in one direction only;




In summary –1.There is a fixed amount of heat in the universe. Heat is neither created, nor destroyed.







In summary –2.Heat is "organized" when there are some places that are hotter or at a higher temperature than others.







In summary –3.Heat always tries to disorganize itself by moving from a higher temperature hot place to a lower temperature cold place. And because of this temperature difference; spreading itself out as evenly as possible.







In summary –4.Entropy is a measure of how evenly spread out the heat is. (In other words, entropy is a measure of heat disorder.)







In summary –5.As heat flows from one place to another, it either does work or wastes the opportunity to do work







In summary –6.Natural processes cannot violate these laws.

Simple Overview/Study of Thermodynamics 0th

Law


PE

1st Law

2nd Law

3rd Law


KE

Energy spreads out to uniform

randomness = Entropy

Energy “flow” (work) is < 100% efficient and will ultimately

stop.

thermodynamics an analogy & its constructs mr. gibson for all science disciplines at selected...

Documents

level of water

water analogy

energy form of heat

heat energy form

laws of thermodynamics

water flows

proven heat

constructs of heat