For those with good imaginations . . .

DanHolohan

Tell me how you would explain The Second Law of Thermodynamics to a five-year-old so that she or he would get it and then be able to explain it to another kid.

MarkS

Ginsberg's Theorem might be a little too simplistic:

1) You can't win.
2) You can't break even.
3) You can't stop playing the game.

https://en.wikipedia.org/wiki/Ginsberg%27s_theorem

Paul48

If you leave your cold soda in a warm room, the soda will get warm, because hot always goes to cold. That is the Second Law of Thermodynamics. The only exception to that is your mommy. If you don't clean up after yourself, she will go from being cool, to very hot, always.

DanHolohan

But don't leave it on the end table without a coaster! ;-)

DanHolohan

MarkS said:

Ginsberg's Theorem might be a little too simplistic:

1) You can't win.
2) You can't break even.
3) You can't stop playing the game.

https://en.wikipedia.org/wiki/Ginsberg%27s_theorem

Leave it to Alan to come up with that one.

DanHolohan

Have you guys seen the book, Thing Explainer? I'm in the middle of that and it's fascinating. That's what got me thinking about the question I asked.

We need to find simpler ways of explaining what we do to people who are not in the business.

bob_46

For a five year old I think I would do Humpty Dumpty . Ask him if he thinks a raw egg dropped on the floor could ever be made whole again. Some things can't go backwards .

DanHolohan

Good one, Bob.

Abracadabra

If you see a video of a cannonball blasting thru a pirate ship, is it possible that you are actually seeing the video in reverse and the pirate ship is forming around the cannonball as it comes out of the pirate ship?

Although it's possible it's more likely probable that the pirate ship is being destroyed by the cannonball.

From order to disorder.

DanHolohan

Well, that would certainly get the kid's attention.

Gordy

Why is it that when you leave an ice cube at room temperature, it begins to melt? Why do we get older and never younger? And, why is it whenever rooms are cleaned, they become messy again in the future? Certain things happen in one direction and not the other, this is called the "arrow of time" and it encompasses every area of science.


Maybe?

DanHolohan

Ohooo! I like that. Thanks, Gordy. An arrow of time. Gosh!

jumper

Sorry. A simple explanation of 2nd Law is incorrect. I've heard too many professional engineers misconstrue it.

DanHolohan

That's the thing, Jumper. Exactly the thing. How can we better explain things to people who are good at stuff other than engineering? How can we paint better word-pictures?

If they don't understand, they will never say so, and they will never buy.

Harvey Ramer

Heat is like a little wanderer, that can never find a home. It is always to hot and looking to cool off, so it will keep on moving to cooler things leaving a little bit of heat everywhere it goes. The only time it stops to rest a bit is when it can't find a cooler place because everything around it feels the same as where it's at.

I guess that's how I would try to explain it, Dan.

SlamDunk

Second Law of Thermodynamics: In any cyclic process the entropy will either increase or remain the same. Entropy: a state variable whose change is defined for a reversible process at T where Q is the heat absorbed. Entropy: a measure of the amount of energy which is unavailable to do work.


id like someone to explain it to a 50yr old!

jumper

DanHolohan said:

That's the thing, Jumper. Exactly the thing. How can we better explain things to people who are good at stuff other than engineering? How can we paint better word-pictures?



If they don't understand, they will never say so, and they will never buy.

Some of my clients bought because they didn't want to understand.Cheap & fast & be patient with collecting your fee.

To understand something one has to want to understand enough to take time to think it through. Only after I retired and read your (Holohan's) books and articles did I realize that I didn't really understand what I was doing.

DanHolohan

Thanks, Jumper. I think there is romance, beauty and whimsy in explaining things in ways anybody can understand, and there is also great power in this for the person receiving it.

DanHolohan

Harvey, I love the idea of heat as one who litters. Thanks for that!

DanHolohan

SlamDunk, yes, yes, yes. We have to read it again and again and again to grasp its meaning. Most folks won't bother. We need to be better story-tellers.

Robert O'Brien

http://www.livescience.com/49610-scientists-unboil-egg.html

Paul48

As can be seen by SlamDunk's post, sometimes you are better off making sure that people the get gist of an idea. There will always be those that want to further explore every aspect of it, but they will be few and far between. More will merely say, OK and move on.

jumper

Dan is a talented writer but 2nd Law is just too counter-intuitive even for him.Entropy increases as temperature increases.But everything cools off if it can while entropy increases. For something to cool off something else has to warm up and the thing cooling off loses less entropy than the entropy the thing warming up gains.Anyone still with me will ask what's entropy? Well entropy is something for which everything has a numerical value. And chemists can measure the change in that value in their lab by following specific procedures.

Forget kids.The best way to understand thermodynamics is to apply it incorrectly and then figure out your mistake.

DanHolohan

Good thoughts, guys. Keep 'em coming.

DanHolohan

Jumper, I gotta pass on applying it incorrectly. Mistakes are too dangerous.

JUGHNE

OK, I know there is no such thing as "cold", only absence of heat.
This is what I tell people all the time to explain any problem.

But, over 20 years ago, I had one of those early morning almost waking up dreams where I suddenly felt I had the complete answer to heat loss calculations. In the dream I imagined a new particle of physics called a "Coldtron", (already the spellchecker doesn't recognize the spelling), but I digress. We are all familiar with electrons, protons and neutrons. But this particle has not been discovered yet. And the reason that fiberglass insulation works is that the insulation is itchy and these Coldtrons don't like it any more than we do and consequently stay outside. (Therefore the new non-itch FG isn't as effective as the old.)
That morning I called a supply house for an order and we chatted about this "dreamland theory", he said that made sense to him and he would expect the entire heat flow theory to be upset with in a few years. Well nearly 30 years have passed and I must have missed the news. .......but as far as dream analysis goes, I believe this is a sign of someone who literally takes his occupation to bed with him.

So don't use this logic!

However, you could present this theory to more than half the people in the country and it would fly.

unclejohn

Ok heat always goes to cold. Why? Because I told you so. Ok. But why doesn't cold go to heat. Because heat is energy and cold is absents of energy. You get tired when you run around, and when you sit still, you want to run around. When you sit down grandpa you fall asleep. Never mind.

Gordy

I would say we are all above a 5 year olds attention span. All though some would surprise us.

It's really quite shocking once you have the thirst to want to understand just about anything. Hydronics in general is over powering. Addictive.

Mark Eatherton

"If you can't explain it simply, you simply don't understand it" Albert Einstein...

Life is full of positives and negatives. The world is full of invisible energy. Energy flows from positive to negative because Mother Nature despises any differences in anything, and wants everything to be the same. So,

Temperature: Flows from high to low
Humidity: Flows from high to low
Pressure: Flows from high to low
Light: Flows from high to low
Life: Flows from live to dead.

Our job is to overcome Mother Nature, and to create conditions that are favorable to long term human growth. We can't stop her, but we can slow her down, and enjoy the ride during that short slowdown in the flow of energy.

And per Gil Carlson, "In order for there to be a difference, you must MAKE a difference."

Thanks for making a HUGE difference in our lives Dan.

Merry Christmas to you and yours.

ME

DanHolohan

Thanks, Mark!

SlamDunk

very tuff proposition.

I keep wondering how sherriff andy taylor would explain it to opie and barney.

"What it is, is the second law of thermodynamics.

See here now, When you want to stay warm, you put on a jacket, right?

That's to keep your body heat inside your jacket and close to your body.

But if you are hot, you take your jacket, off and let all that body heat escape.

If that don't work, you might take off your shirt. And you are still feeling warm, you might just jump in the creek!"

Nope, I have no imagination at'all. Sorry Dan, I'll leave the creative writing to you. Looking forward to what you come up with!

Gordy

Mark's takes the prize. Thing is I know that. Why it escaped me I'll never know. Over thinking a five year olds ability to absorb I guess. Mother Nature likes balance.

DanHolohan

Great stuff, guys! Fine imaginings indeed. Thanks for playing. We'll all be better at splaying in the days ahead. :-)

Paul48

My father's best friend was a technical writer for Sikorsky Helicopter for years. He re-wrote technical manuals, so human beings could understand them. As a kid I was amazed at how fast the man could type.

bmwpowere36m3

Entropy is putting a numerical value on "disorder" and it only increases… with time. Basically matter and energy grow further "apart" and thus entropy or "disorder" increases. At least that's what I remember from by thermo class.

I saw an interesting show about life on earth and discussion of entropy. The jist was, with time, things "fade away"…. iron/steel rusts, brick/mortar/stone erodes, paper breaks down…. every thing we build and create, with time breaks down. So it takes energy to recreate that iron, paper, bricks, etc… Eventually we won't have the energy to recreate those things.

Basically alluding to the fact that you cannot stop entropy… we as humans can only "manage" a small portion of the matter/energy that's in the entire universe. Eventually all the matter/energy in the universe will spread out… like a gas. Basically ends life as we know it, sounds sad just typing that. However the our Sun will likely give out before that point, so life at least on earth will end.

Hilly

I like that 'wandering man' concept @Harvey Ramer . As soon as I read your comment I could already picture @DanHolohan taking that idea and running with it. It'll be his next 'Btu Train'.

Hilly

I couldn't stop pondering Harvey's little wanderer today and he has evolved. I now see the wanderer in green tights armed with a bow and arrow. Heat Transfer is now Robin Hood in my mind and he is stealing from the heat and giving to the cold.

ttekushan_3

Just catching up on Wall reading when this post caught my eye. Sometimes an imperfect interpretation is a "foot in the door" to understanding.

So @SlamDunk commenting on the jacket reminds me of a fable that I heard when I probably was 5 or 6. It's the one about the wind versus the sun. Goes something like this:

The sun and the wind are discussing their abilities when they spy a man walking below them, wearing a cloak. The wind says, "I'm stronger than you. I can blow that man's cloak right off his back. I'll bet you can't do that!" The sun says, "that's true but I'll take your bet." So the wind proceeds to blow harder and harder to dislodge that man's cloak. But the man grips his cloak ever more tightly and won't let go. The sun says, "are you done? And the wind says, "well, I did everything I could do- that man will never loosen his grip!" So the sun proceeded to gently shine on the man and then with just a little more brightness, the man began to feel the comfort of the sun's warmth. With that, the man took off his cloak. The sun's warmth prevailed where the wind's force couldn't.

The moral of the story is that later in life you might have a chance of understanding the 2nd law of thermodynamics.

Somewhere in this "fractured fairy tale" version is a lesson in the direction of heat flow etc. Now where was I going with this?

DanHolohan

Beautiful, Terry. Thanks!

LarryK

"Time flies like an arrow, fruit flies like a banana" Groucho Marx? I don't know if that is appropriate but left alone the banana will get pretty runny and it's sure hard to make it go the other way!

I think most people have an intuitive idea of heat flow. More technical ideas of entropy are harder to grasp. Latent heat is a dark mystery to 99%, how do you get that across?

jumper

Very smart guys said or wrote the following:

Thermodynamics is a funny subject. The first time you go through it, you dont understand it at all. The second time you go through it, you think you understand it, except for one or two small points. The third time you go through it, you know you donít understand it, but by that time you are so used to it, it doesn't bother you any more. (Physicist Arnold Sommerfeld (1868-1951))

A good many times I have been present at gatherings of people who, by the standards of the traditional culture, are thought highly educated and who have with considerable gusto been expressing their incredulity at the illiteracy of scientists. Once or twice I have been provoked and have asked the company how many of them could describe the Second Law of Thermodynamics. The response was cold: it was also negative. (C. P. Snow in 1959 Rede Lecture entitled The Two Cultures and the Scientific Revolution).

If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations, then so much the worse for Maxwell's equations. If it is found to be contradicted by observation, well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics, I can give you no hope; there is nothing for it but to collapse in deepest humiliation (Sir Arthur Stanley Eddington in The Nature of the Physical World, 1915)

Herbert Callen,a respected thermodynamicist, told me that thermodynamics explains what happens in a laboratory but that it's only an assumption that the universe behaves like a system on your table.