Physics for HVAC&R Techs

[DTLarca]

I'm going to be writing a series of articles on specifically HVAC&R physics that might last 12 months, maybe 24 or maybe even beyond 36 months. I will write the first one, the intro, this Friday. The idea is that by the end of the series any level 3, 4 or 5 tech who says he/she does not understand all the physics and formula used in HVAC&R will no longer have any valid excuse. No lecturer should ever after say they have no easy to understand material to teach thermodynamics (including PH charts and Psychrometrics) or fluid dynamics etc with/from.

<Moderators remove if necessary>
The articles will be published in the ACR Today magazine - I make no money out of writing these articles - I just get to enjoy a few more hours a month thinking
</Moderators remove if necessary>

Does anybody have any ideas about what of physics they would like to read about?

Is physics easy but boring? Is it interesting but too difficult? Or are there other opinions/perceptions?

[Gary]

'How things work' is interesting... 'physics' is boring. Figuring it out is interesting. Calculation is boring. Understanding it is interesting. Memorizing it is boring. Interesting is not too difficult, boring is too difficult.

[DTLarca]

'How things work' is interesting... 'physics' is boring. Figuring it out is interesting. Calculation is boring. Understanding it is interesting. Memorizing it is boring. Interesting is not too difficult, boring is too difficult.

I like it - that is the sort of approach I am looking to take - short little essays with diagrams that illustrate the real field life events of a Technician but from a view that invokes a sort of "Damn - so that's how it goes - that's so easy but also so useful - I could have worked that out myself - well - I'll work the next one out myself"

I might copy and paste your words into the article Gary - crediting you and where you said it of course

[nevgee]

'How things work' is interesting... 'physics' is boring. Figuring it out is interesting. Calculation is boring. Understanding it is interesting. Memorizing it is boring. Interesting is not too difficult, boring is too difficult.

Gary does have a point here, however defining it a different way, I notice people clam up at the thought of such subjects . . "physics" .... algebra .... etc

They say "I don't do algebra .... can't do math" but the reality is so not true. When it's pointed out they do algebra every waking moment, and they see "physics" in action all the time but just don't realise it. It's just that they've never seen the connections. Bringing the connections between simple analogy to the compex technical description is one of those routes of understanding and exploration that enlivens the mind.

And so another way forward.

[Gary]

Telling someone that frog legs tastes like chicken is meaningless to someone who has never tasted chicken. He can memorize the phrase, but he doesn't understand it. Then moving on to explain the subtle differences in flavor has him completely lost. Each bit of knowledge must be linked to previously held knowledge, which is ultimately linked to sensorial input or there is no learning and no teaching, there is only preaching to the choir.

You may find this more difficult than you imagine. The opening post in my "Refrigeration 101" thread would be an example of my feeble attempt to begin with sensorial input and then progress step-by-step to the more complex.

http://www.refrigeration-engineer.co...ad.php?t=19701

[nevgee]

Telling someone that frog legs tastes like chicken is meaningless to someone who has never tasted chicken. . . . . . . You may find this more difficult than you imagine. The opening post in my "Refrigeration 101" thread would be an example of my feeble attempt to begin with sensorial input and then progress step-by-step to the more complex.

You're quite right ..... hence my point about the day to day analogy, it's essential to bring the connections to the known knowledge then building the connections by creating more of the links.

It's just a mental jigsaw really, identify the colours, join them up to create a picture with supporting over views.

Never the less it's often very interesting to be able to read or hear someone else's approach in describing a process or technical feature. There are often little gems in there that hadn't been considered previously.

[desA]

The shape of the fabric of space-time & its effect on RHVAC systems, would be of interest. You may wish to cover that topic in your latter articles - as required.

Of practical interest:
1. 2nd law of thermodynamics;
2. Various refrigeration cycles & associated log(p)-h, T-s diagrams etc.;
3. Use of Coolpack & other process simulation tools.

[DTLarca]

You're quite right ..... hence my point about the day to day analogy, it's essential to bring the connections to the known knowledge then building the connections by creating more of the links.

It's just a mental jigsaw really, identify the colours, join them up to create a picture with supporting over views.

Never the less it's often very interesting to be able to read or hear someone else's approach in describing a process or technical feature. There are often little gems in there that hadn't been considered previously.

Just to add to yours and Gary's comments...

John Locke's Tabula Rasa http://en.wikipedia.org/wiki/Tabula_rasa

David Hume's "Impressions versus Ideas" http://en.wikipedia.org/wiki/David_Hume

Man can predict nothing about the natural world by merely rational means. Empiricism wins every time.

The rationalists say that the sun orbits the earth, that heavy stones fall faster than light stones, that the planets have to orbit in perfect circles, that if you fire one electron at a time at a double split you will have no interference patterns etc etc. But the empiricists find, when they test these thesis experimentally, that the arguments and evidence always point to something quite clearly the opposite of common sense.

Two of Socrates dialogues called Meno and Theaetatus are devoted to the theory of knowledge (Epistemology)

http://www.sacred-texts.com/cla/plato/meno.htm
http://www.sacred-texts.com/cla/plato/theaetet.htm

In the Meno Socrates explains that people are able to work many things out for themselves but only if they experiment and never if they just sits and thinks alone. He gives the example of a square having it's sides or peripheral dimensions being doubled - he is explaining to a slave boy how it works but not by telling the slave - instead he asks the slave to calculate the new surface area if the dimensions are doubled. The slave replies quickly that of course it is common sense that the area will also double. Then Socrates says lets test your hypothesis experimentally at which stage the slave boy quickly sees his mistake and goes on to suggest an alternate hypothesis for Socrates.

Nothing can ever be known for certain - nothing at all. Nothing can be known ever at all except through at least one of the senses. Our senses deceive us more often than they inform us - so we have a duty to throw away all thoughts and theories that cannot thoroughly be supported by hard solid evidence.

[nevgee]

Just to add to yours and Gary's comments...

John Locke's Tabula Rasa http://en.wikipedia.org/wiki/Tabula_rasa

David Hume's "Impressions versus Ideas" http://en.wikipedia.org/wiki/David_Hume

Man can predict nothing about the natural world by merely rational means. Empiricism wins every time.

The rationalists say that the sun orbits the earth, that heavy stones fall faster than light stones, that the planets have to orbit in perfect circles, that if you fire one electron at a time at a double split you will have no interference patterns etc etc. But the empiricists find, when they test these thesis experimentally, that the arguments and evidence always point to something quite clearly the opposite of common sense.

Two of Socrates dialogues called Meno and Theaetatus are devoted to the theory of knowledge (Epistemology)

http://www.sacred-texts.com/cla/plato/meno.htm
http://www.sacred-texts.com/cla/plato/theaetet.htm

In the Meno Socrates explains that people are able to work many things out for themselves but only if they experiment and never if they just sits and thinks alone. He gives the example of a square having it's sides or peripheral dimensions being doubled - he is explaining to a slave boy how it works but not by telling the slave - instead he asks the slave to calculate the new surface area if the dimensions are doubled. The slave replies quickly that of course it is common sense that the area will also double. Then Socrates says lets test your hypothesis experimentally at which stage the slave boy quickly sees his mistake and goes on to suggest an alternate hypothesis for Socrates.

Nothing can ever be known for certain - nothing at all. Nothing can be known ever at all except through at least one of the senses. Our senses deceive us more often than they inform us - so we have a duty to throw away all thoughts and theories that cannot thoroughly be supported by hard solid evidence.

Empirically, I recon that was a sort of an affirming comment

[DTLarca]

Empirically, I reckon that was a sort of an affirming comment

Indeed, each concept (universal) must be founded upon an already agreed, by empirical means, concept. No causal concepts can be known a priori.

Each concept (principle) must be presented in a form tech's are familiar with.

[Aik]

Empirically, I recon that was a sort of an affirming comment

May be you want to process theory with some formulas...
http://www.refrigeration-engineer.co...ad.php?t=25601

[DTLarca]

May be you want to process theory with some formulas...
http://www.refrigeration-engineer.co...ad.php?t=25601

What I imagine happening here is the combination of impulse (rate of change of momentum) and vapour compression as in a shock absorber.

F = dP/dt (Force = rate of change of momentum)

dP = m dv (Change in momentum = mass (density) x change in velocity)

work to slow liquid = kJ = s dp/dt (Distance x force)

work to compress vapour in Tee = PV (y/y-1)[(P1/P2)^((y-1)/1) - 1]

There has to be enough vapour in the Tee such all the kinetic energy in the liquid line is absorbed in the compression of the vapour in the Tee top.

All this would only be covered in perhaps the second or third year of articles and it might take 2 or 3 articles to draw out in layman's terms all the principles here.

[desA]

Use the same theory as used for water pipelines. It's generally well covered in hydraulics theory literature at most technical colleges, or universities.

Nice idea, by-the-way. Would have suspected that the height & diameter of the device would be pretty important, though.

[DTLarca]

The shape of the fabric of space-time & its effect on RHVAC systems, would be of interest. You may wish to cover that topic in your latter articles - as required.

Of practical interest:
1. 2nd law of thermodynamics;
2. Various refrigeration cycles & associated log(p)-h, T-s diagrams etc.;
3. Use of Coolpack & other process simulation tools.

Oh yes - maybe not so much from coolpack, not sure yet, but there are so many "but why?" questions that are asked by students when it comes to the likes of PH charts - so the articles will be looking at many of those.

Use the same theory as used for water pipelines. It's generally well covered in hydraulics theory literature at most technical colleges, or universities.

Nice idea, by-the-way. Would have suspected that the height & diameter of the device would be pretty important, though.

Height and diameter? Surely not - Pascals Barrel comes to mind

[DTLarca]

Gary does have a point here, however defining it a different way, I notice people clam up at the thought of such subjects . . "physics" .... algebra .... etc

They say "I don't do algebra .... can't do math" but the reality is so not true. When it's pointed out they do algebra every waking moment, and they see "physics" in action all the time but just don't realise it. It's just that they've never seen the connections. Bringing the connections between simple analogy to the complex technical description is one of those routes of understanding and exploration that enlivens the mind.

And so another way forward.

People might "see" that there is "physics" all around them but people don't automatically see physics as in what actually happens all around them.

What is an enlightened person? Perhaps the best definition of an enlightened person is someone who has read "The Outlines of Skepticism" by Sextus Empiricus - the book that not just freed Europe from the tyranny of religion but because of this Europeans rediscovered Greek science - Galileo rediscovered Epicurus (all weights fall at the same speed in a vacuum) and Newton/Leibniz brought back to life Archimedes calculus. Darwin was accused of simply paraphrasing Epicurus's 3rd century BC theory of evolution. It's fascinating stuff reading how Eratosthenes calculated the circumference of the earth already in about 270BC http://en.wikipedia.org/wiki/Eratosthenes

All of this and much more Greek science was lost at the utter collapse of European civilisations when the nonsense of monotheistic religions came into place. The dark ages were indeed very dark.

But, after Galileo, an enlightened person was one who not only learned that all religiously motivated metaphysics were logically contradictory but also understood such things as that throwing an apple twice as hard was not the same thing as twice as fast and that throwing an apple twice as fast did not carry it twice as far - in other words an enlightened person was one who realised that common sense had only ever brought ignorance and misery and that is why the Greeks, before but especially Socrates, battled against it. Because common sense is false and leads to amplified falsities, it is what governments govern nations with - one fools a nation by constantly appealing to common sense - while in fact doing something very different.

But a mind is enlivened, as you say, when taking the time to understand especially energy. If you understand energy you immediately understand for instance the difference between throwing a ball twice as hard and twice as fast. I have not yet spoken to a person who understands energy - and I have spoken to many degreed engineers. They use physics like I use a hammer - they cannot build tools out of physics like I cannot build my own hammers (metallurgy).

[desA]

Height and diameter? Surely not - Pascals Barrel comes to mind

You may want to elaborate further.

There is a difference between steady, or quasi-steady processes, & time-variant processes. Water hammer is a wave phenomenon & is therefore time-variant.

Management methods for each may be different, hence the diameter/height discussion. This can interrupt wave timing...

[mad fridgie]

When doing this type of article/training you need to start at the very beginning with each level reinforcing the previous level.
Examples; Already you are talking about P H diagrams, what is P or H, why do P and H change, then after clearly explaining apply to a common refrigeration (AC) system which is used all the way through.

[Aik]

Use the same theory as used for water pipelines. It's generally well covered in hydraulics theory literature at most technical colleges, or universities.

About theory I have the same opinion...

Nice idea, by-the-way. Would have suspected that the height & diameter of the device would be pretty important, though.

I have some interesting information:
-height of Tee is about 3-5 diameters of tube.
- distance between solenoid and Tee is about 5-7 diameters of tube.
Also I suppose that tube plug on Tee must be spherical...
It's data without theory, I prefer understand in detail...

[Peter_1]

I've written for school in Dutch the beginning of a manual/course starting from scratch.

I entirely explain the log p/h starting from water. Latent heat principle: how many heat there must be removed to freeze water, how many water must be removed to vaporize water....steady boiling and freezing temperature at at certain pressure.
Water boils at 100°C at 10313 Pa, at the Mount everest it boils at 80°C (forgot exact figures), in an old fashioned steampot on 2 bar at 120°C. These are figures mot understand and knows or have heard of.
Give them saturated tables of water and explain all the columns.
Explaining what saturated tables are.
Then give them empty log paper and they then have to make the 2 axis on it, P and h.
Then let them point 20 points out of the table and they then draw the 'bubble' on the log p/h.
Explaining the other way of visualizing the same tables in a log /h bubble.
Then make a cooling chamber with the water, with ice,.. the figures coming out of the book from Dossat.
The the switch to R134a and again making a cooling plant exactly the way Dossat is describing it. I like Roy's approach of this.
And so on.

[DTLarca]

You may want to elaborate further.

There is a difference between steady, or quasi-steady processes, & time-variant processes. Water hammer is a wave phenomenon & is therefore time-variant.

Management methods for each may be different, hence the diameter/height discussion. This can interrupt wave timing...

I was being a little pedantic.

The diameter would not matter and nor would the length though only so long as you have sufficient trapped vapour volume in the vertical stub. But the stub could be say 3/8" on a 1-1/8" liquid line so long as its height creates sufficient compressible vapour. So its the volume of the stub and its ability to retain vapour that matters only.

The Tee'd stub, for instance, would be of no use if it was orientated downward from the pipe.

The liquid should be flowing from where above it there is vapour - for this reason we do not need to worry about the sound-wave properties causing impulse damage back up stream at the other end.

[DTLarca]

I've written for school in Dutch the beginning of a manual/course starting from scratch.

I entirely explain the log p/h starting from water. Latent heat principle: how many heat there must be removed to freeze water, how many water must be removed to vaporize water....steady boiling and freezing temperature at at certain pressure.
Water boils at 100°C at 10313 Pa, at the Mount everest it boils at 80°C (forgot exact figures), in an old fashioned steampot on 2 bar at 120°C. These are figures mot understand and knows or have heard of.
Give them saturated tables of water and explain all the columns.
Explaining what saturated tables are.
Then give them empty log paper and they then have to make the 2 axis on it, P and h.
Then let them point 20 points out of the table and they then draw the 'bubble' on the log p/h.
Explaining the other way of visualizing the same tables in a log /h bubble.
Then make a cooling chamber with the water, with ice,.. the figures coming out of the book from Dossat.
The the switch to R134a and again making a cooling plant exactly the way Dossat is describing it. I like Roy's approach of this.
And so on.

Though as Mad Fridgie implies - we are already very advanced by the time we get to that level if our aim is to impart a true and full unforgettable understanding - we still then get questions such as "what is pressure?" and "why do we refer to pressure as energy?" And "if two different rigidly sealed containers each hold a different gas but each of equal volume and temperature do they have the same kJ as in the same kJ/m³ but not the same kJ/kg?" Or then "Why do different gases have different specific heat capacities but all have the same thermal coefficient of expansion?".

[desA]

I was being a little pedantic.

The diameter would not matter and nor would the length though only so long as you have sufficient trapped vapour volume in the vertical stub. But the stub could be say 3/8" on a 1-1/8" liquid line so long as its height creates sufficient compressible vapour. So its the volume of the stub and its ability to retain vapour that matters only.

The Tee'd stub, for instance, would be of no use if it was orientated downward from the pipe.

The liquid should be flowing from where above it there is vapour - for this reason we do not need to worry about the sound-wave properties causing impulse damage back up stream at the other end.

I would respectfully disagree.

There will be two potential mechanisms at work here:
1. Physical compression of a vapour located towards top of vertical tube (interesting for a RHVAC circuit);
2. Tube length tuned to disrupt water-hammer frequency. (Wave phenomenon, remember).

[DTLarca]

I would respectfully disagree.

There will be two potential mechanisms at work here:
1. Physical compression of a vapour located towards top of vertical tube (interesting for a RHVAC circuit);
2. Tube length tuned to disrupt water-hammer frequency. (Wave phenomenon, remember).

On point 2 we would be looking to affect wave interference patterns so that the sound wave from the tee section cancels that from the solenoid valve in which case the length and diameter would be important - the length related to the speed of sound for the liquid and the diameter to the wave energy required to interfere with that coming back from the solenoid valve. The wrong length could in fact double the wave energy going back up the liquid line. But this sort of arrangement is not relevant to vapour free piping system that are all liquid with no vapour area back behind the liquid up in the condenser. It depends, I guess, on whether the purpose of the Tee is to reduce the noise of liquid hammer or the mechanical damaging forces experienced by the solenoid.

[mad fridgie]

Though as Mad Fridgie implies - we are already very advanced by the time we get to that level if our aim is to impart a true and full unforgettable understanding - we still then get questions such as "what is pressure?" and "why do we refer to pressure as energy?" And "if two different rigidly sealed containers each hold a different gas but each of equal volume and temperature do they have the same kJ as in the same kJ/m³ but not the same kJ/kg?" Or then "Why do different gases have different specific heat capacities but all have the same thermal coefficient of expansion?".

I think !!!!!!!!!!!?????? that you should undertake a sample, we can then look at your method or appraoch and comment on this side more, than the particular data. You use "note" statements to show common beliefs, or used terms,

[desA]

On point 2 we would be looking to affect wave interference patterns so that the sound wave from the tee section cancels that from the solenoid valve in which case the length and diameter would be important - the length related to the speed of sound for the liquid and the diameter to the wave energy required to interfere with that coming back from the solenoid valve. The wrong length could in fact double the wave energy going back up the liquid line. But this sort of arrangement is not relevant to vapour free piping system that are all liquid with no vapour area back behind the liquid up in the condenser. It depends, I guess, on whether the purpose of the Tee is to reduce the noise of liquid hammer or the mechanical damaging forces experienced by the solenoid.

Good. A useful explanation.

[DTLarca]

I think !!!!!!!!!!!?????? that you should undertake a sample, we can then look at your method or appraoch and comment on this side more, than the particular data. You use "note" statements to show common beliefs, or used terms,

I have no doubts about my methods - they have been tried numerous times.

I'm wondering what particular topics are commonly misunderstood

[mad fridgie]

I have no doubts about my methods - they have been tried numerous times.

I'm wondering what particular topics are commonly misunderstood

Yet to be proved, not your knowledge, I will let others "blow you" on that count, but if the reader can not absorb the information, then it does not matter how good your knowledge is.

[desA]

I have no doubts about my methods - they have been tried numerous times.

I'm wondering what particular topics are commonly misunderstood

Makes me wonder how confident the ancient Greeks were in their knowledge.

[DTLarca]

Makes me wonder how confident the ancient Greeks were in their knowledge.

The Greeks argued that absolute knowledge is impossible. Socrates said "If you do not know what you are looking for then how do you know where to start looking for it, if you know that you do not know everything then how do you know that nothing will come along sometime and completely overturn your so far "absolutely true" knowledge?"

Sextus Empiricus summed their positions up thus...

When they propose to establish the universal from the particulars by means of induction, they will effect this by a review of either all or some of the particulars. But if they review some, the induction will be insecure, since some of the particulars omitted in the induction may contravene the universal; while if they are to review all, they will be toiling at the impossible, since the particulars are infinite and indefinite.

Epicurus (300BC), who got almost as far as Darwin on the theory explaining why there exists undubitable facts such as that life evolves just that we do not know exactly how it evolves, also explained the following in 300BC:

- The Atom
- The Molecule
- Law of Inertia
- Principle of Universal Natural Law
- Rain Cycle
- Sound as a Pressure Wave in Air
- Light Composed of Particles
- Sense of Smell Caused by Shape of Molecule Fitting Shape of Receptor in Nose
- Lightning Caused by Friction between Storm Fronts
- Lightning Composed of Tiny Particles
- Earthquakes Caused by Slipping Fault Lines
- Nile Rises from Snow Melting at its Source
- Animals & Men Evolved by Natural Selection
- Matter is Mostly Empty Space
- Magnetism Caused by Exchange of Particles
- Fire is not an Element
- No Center of the Universe
- Other Planetary Systems
- Speed of Light is Finite
- Theory of Relativity
- Quantum Indeterminism
- Brownian Motion

So why were we not on the moon then 400 years later in about 100AD?

Well...

Epicurus developed a system of philosophy and a way of living that claimed many thousands of committed followers all over the ancient Mediterranean world in cooperative communities that lasted for hundreds of years until being closed down by the Christian Church because they were not just atheists but because they we converting thousands of Christians to Epicurianism. Epicureans almost never switched their allegiance to other philosophical systems whereas other schools regularly lost students to the Epicureans. For one, Epicurus did not think it right to put one's possessions into a common fund, as did Pythagoras with all his hundreds of followers - Epicurus thought it a mark of mistrust and if there is mistrust there is no friendship.

Epicurus started studying philosophy (the works of Democritus) when he was 12 and opened his own "academy" when he was 32.

His followers would walk through the streets telling others "Do you want to be happy? Of course you do! Then what's standing in your way? Your happiness is entirely up to you. This has been revealed to us by a man of divine serenity and wisdom who spends his life among us and showed us, by his personal example and by his teaching, the path to redemption from unhappiness.- his name is Epicurus".

The fundamental obstacle to happiness, says Epicurus, is anxiety, no matter how rich or famous you won't be happy if you're anxious to be richer or more famous. No matter how good your health is, you wont be happy if you're anxious about getting sick. You can't be happy in this life if you're worried about a next life. You can't be happy as a human being if you're worried about being punished or victimised by powerful divine beings. But you can be happy if you believe in the four basic truths of Epicureanism:

1) There are no divine beings which threaten us, there is no next life.
2) What we actually need is easy to get, what makes us suffer is easy to put up with.
3) Happiness is having just enough to be moderately comfortable, having a few very good friends to philosophise with.
4) Living an analysed life analysing all of your thoughts for truthfulness and meaning and sharing such analysis with your friends and neighbours.

Science does not know why stuff has mass. Science does not know what causes gravity. Science thus is merely a descriptive discipline - we employ algebra to describe physical phenomena. This then makes physics merely the science of proportions or the language of ratios. This is the first requirement when looking to understand physics - you must be fluent with fractions. If a person does not see how we move from m/s/s to m/s² then they are not going to get any further in physics than understanding, distance, time, weight, velocity, the relation between dimensions of squares and cubes and area and volume and finally conservation of momentum - they will not yet properly be able to understand temperature except to measure it. In the language of fractions this phenomena happens in such and such a proportion relative to that phenomena - increase this one then that one also increases either in direct proportion or by the square or the cube or by pi or by the inverse square or to the base e etc etc but why is, for instance, the gravitational constant what it is and not some other number we just do not know - we cannot explain why for anything in physics we can only ever so far simply describe what happens.

[Gary]

Some things are highly likely. Some things are highly unlikely. And everything else is somewhere in between.

[nevgee]

Some things are highly likely. Some things are highly unlikely. And everything else is somewhere in between.

Be careful now Gary ... "Opinions" ( if they exist) are ( can be ) like blue touch paper .... Oops that may be an opinion ....

[DTLarca]

Be careful now Gary ... "Opinions" are like blue touch paper ....

Gary is pretty much right.

The situation is like this...
Facts can be true or false but arguments can never be true or false - arguments can only have degrees of success or failure but can never be proved right or wrong - only better or worse.

Arguments can never have proofs - only mathematics has proofs. Nothing can prove that the sun will for certain rise again tomorrow but we can prove that the angles in a triangle add up to 180°.

[nevgee]

Well .... I was only playing .... however, I am aware the Greeks did their stuff I don't see how writing long comments on the classics and the methodologies applied thereto can be of any help in your quest.

I can see lots of "Tech" people doing a lot of yawning

[monkey spanners]

Friend of mine was teaching his apprentice basic physics, went a little like this....

"touch that pipe wayne"

wayne "OUCH!!"

"don't touch that pipe, its hot"

"touch that pipe wayne"

wayne "OUCH!! my fingers stuck!!!"

"thats frost wayne, don't touch that pipe"

Repeat for all the common hazards

[nevgee]

Philosophically outlined . . .

Gary is pretty much right.

Facts can be true or false but arguments can never be true or false - arguments can only have degrees of success or failure but can never be proved right or wrong - only better or worse.

.

Empirically tested by Monkey Spanner's mate ...... with the conclusive retort "Ouch!"

I can see how the "Classics" can be applied now. . .I like this edification stuff. Real kool

[mikeref]

Monkey S, its human nature to have sticky fingers, i know what your saying but if Wayne were to learn everything by feel, he might be worse for wear. Take the poor old sparkie, he is forbidden to feel his way around an electrical circuit. As we cannot see electricity, we can only observe its effects,so to speak, but the newbe forgets this or does not believe his tutor and tests for himself. BAM!! I'm sure all of us have had a taste of the invisible force at one stage or another,, C'mon, fess up..mike.

[Brian_UK]

Facts can be true or false but arguments can never be true or false - <snip>

Sorry, wrong.

A false Fact is an oxymoron. Facts can only be true.

[stufus]

Physics 101
"Magnetism, as you may recall from physics class, is a
powerful force that causes certain items to be
attracted to refrigerators

[DTLarca]

Sorry, wrong.

A false Fact is an oxymoron. Facts can only be true.

Yes, indeed, nicely spotted - very true when considered in that form

But what is meant is rather that propositions or assertions of a factual nature are either true or false.

"The light IS on" is an assertion proposing a matter of fact and thus can be either true or false.

"This light has always been on this time of the night when I walk past therefore it will be on again this time tomorrow night when I walk past" is not an assertion proposing a matter of fact but is rather an argument for which it just would not make any sense at all to say that it is either true or false but rather that it is relatively strong or weak.

[mikeref]

'How things work' is interesting... 'physics' is boring. Figuring it out is interesting. Calculation is boring. Understanding it is interesting. Memorizing it is boring. Interesting is not too difficult, boring is too difficult.

Gary, i wish i had thought of thoes words for my signature. How about classrooms are boring in longwinded sessions but practical experience goes all too fast. Textbooks are boring when various examples do not include suitable illustrations to break up the endless sentences. Also, skimming over important basics like Q=MC deltaT, then using change in temperature in degrees K but later it changes to degrees C, where did that come from? 5/9(f-32)=degreeF to degreesC, do we need to have that crammed in as well, Maybe? Going out on a limb here(pointing to branch bending), the average human retains around 10% of information provided in a so called lecture so its necessary to reinforce information provided.. mike.

[desA]

The more you learn, the more you realize how little you know.

It takes a certain amount of learning to realize how ignorant you really are.

[Gary]

When you know all the answers, that means you don't know all the questions.

[Peter_1]

Well, well ,w ell, what a philosophic thread this has become.
But....nice to read.

[buddy]

Well, well ,w ell, what a philosophic thread this has become.
But....nice to read.

Dont forget Pragmatism.


Definition - The doctrine that practical consequences are the criteria of knowledge and meaning and value.

[DTLarca]

Dont forget Pragmatism.


Definition - The doctrine that practical consequences are the criteria of knowledge and meaning and value.

Pragmatism is one ism in answer to the problem of the seeming impossibility of acquiring certain knowledge. There are quite a number of ism's offered in answer. But all have both Pro's and Con's and to me the best seems to be Coherentism operating under the roof of contextualism.

http://en.wikipedia.org/wiki/Epistemology

[buddy]

[QUOTE=DTLarca;216235].
Epicurus (300BC), who got almost as far as Darwin on the theory explaining why there exists undubitable facts such as that life evolves just that we do not know exactly how it evolves, also explained the following in 300BC:

- The Atom
- The Molecule
- Law of Inertia
- Principle of Universal Natural Law
- Rain Cycle
- Sound as a Pressure Wave in Air
- Light Composed of Particles
- Sense of Smell Caused by Shape of Molecule Fitting Shape of Receptor in Nose
- Lightning Caused by Friction between Storm Fronts
- Lightning Composed of Tiny Particles
- Earthquakes Caused by Slipping Fault Lines
- Nile Rises from Snow Melting at its Source
- Animals & Men Evolved by Natural Selection
- Matter is Mostly Empty Space
- Magnetism Caused by Exchange of Particles
- Fire is not an Element
- No Center of the Universe
- Other Planetary Systems
- Speed of Light is Finite
- Theory of Relativity
- Quantum Indeterminism
- Brownian Motion

So why were we not on the moon then 400 years later in about 100AD?

Well...

The reason we were not on the moon 400 years later in 400 AD is because cumilatively not enough knowledge had been aquired by mankind to achieve that feat.

On average lets say for arguements sake that "original" thinkers whose ideas have a profound and life changing effects on the human race only 10 are born every century.

So through the ages it took only approx a couple of thousand original thinkers to put us on the moon.

And then you have the innovators who take advantage of these original ideas and so on so its all a team effort and of course conditions and the motivation has to be there in the first place.

Agree about the Catholic Church cult, mankind would have been better off with out it.

Evolution is all about diversifying, splitting into different species, we are now Homo Sapiens, what are we go to split into?
2 different human species...is it happening now?...now theres a thought!

[desA]

...as Darwin on the theory explaining why there exists undubitable facts such as that life evolves just that we do not know exactly how it evolves,...

A theory, at best. The humanists would love to prove that no Intelligent Designer is responsible for the splendour of creation.

The fact is - they are completely blind-sided by their arrogance, ignorance & rebellion. Man was simply created in The Designer's image. Once you can accept that God is completely responsible for our little time-capsule on planet Earth, then a lot more begins to make sense.

Anyway, I digress.

[Gary]

If the splendours of the universe implies a superior creator, then that creator must necessarily have a superior creator, which in turn implies the creator's creator's creator, which in turn implies... etc... etc... etc... ad infinitum.

[desA]

We digress. Apologies to Marc.

[Gary]

If we are to say that the wonders of the universe are evidence of a creator, then we must say the the wonders of that creator are evidence of the creator's creator and so on...

Any evidence of a creator must necessarily be evidence of a creator's creator.

Or we must say that the wonders of the universe are not evidence of a creator. There is no evidence of a creator.