# Can you explain the 2nd Law of Thermodynamics to a non-scientist?

• foxandthehen
In summary: For instance, when you say "hot objects become 'cold,' or would it be better to say that they cool to ambient temperature?" you could say, "In summary, the Second Law of Thermodynamics explains how hot objects become 'cold,' and how ambient temperature is gradually increased over time."
foxandthehen

## Homework Statement

Question: Give an explanation of the 2nd law to an intelegent non-scientific lay-person, drawing ideas from the K-P Statement, C's Statement and the Law of Increasing Entropy.

None

## The Attempt at a Solution

http://www.mediafire.com/?sharekey=c7f7dd04c5befe5ed9d5c56d04dfa8b0e04e75f6e8ebb871

Any comments (good or bad) would be very much apreciated, but please don't post revisions of any of my paragraphs, as I don't want to plagerise anyone elses ideas.

Thank you everyone! :D

This is good, foxandthehen; the examples are familiar, and you've incorporated several implications of the Second Law, as required in the assignment. I have just a couple minor comments:

- I strongly disagree with your statement that "...the second law of thermodynamics doesn’t look to tell us anything the average person doesn’t already know though observations of the world." I hope you, as a university physics student, don't really believe this; there are tons of non-intuitive implications of the Second Law (which either of us should be able to provide upon request). I think you might rephrase it to say instead that the Second Law explains many observations that the average person might make about the world.

- Proofread, check your grammer (e.g., one of your essay's central ideas, "Area of high energy will naturally diffuse into areas of lower energy over time if allowed too," has a couple of errors), and choose your terms precisely (e.g., do hot objects become "cold," or would it be better to say that they cool to ambient temperature?).

Be prepared for the occasional mischievous reader to ask you why oil and water don't stay mixed together.

To start off... Thank you so much! and I am 'sadly' dislexic and this is a first first draft (have only spend about 20mins on it), so I will be sitting down with someone to go through the grammar errors which MS word hasn't picked up, so thank you again for putting up with it!

I did think about the oil and water example, but I am hoping by putting it into the context of a cup of tea and milk, this becomes a consideration which is left to one side (wishful thinking perhaps as there is always one! :p)

and as for the "...the Second Law of Thermodynamics doesn’t look to tell us anything the average person doesn’t already know though observations of the world." your so very right... now that I read it again and I'm thinking about how important the 2nd is outside of everyday observations and i will seriously revise that sentence!

I am curious if anyone thinks I should be including more to do with the ideas of kenetic energy of single molecules and its transmitance, or if a lay-person would be very turned off by this idea, which altough is important, perhaps isn't in the contexts of this assignment?

I think somewhere you should state the law itself, and show how these examples fit with it, otherwise a person not familiar with it may think that the Second law of Thermodynamics deals exclusively with heat transfer when really it deals with Entropy (there can be entropy transfers w/o heat transfer, namely the entropy of mixing which you mention but may sound out of context in the sea of heat transfer examples).

Matterwave said:
I think somewhere you should state the law itself, and show how these examples fit with it, otherwise a person not familiar with it may think that the Second law of Thermodynamics deals exclusively with heat transfer when really it deals with Entropy (there can be entropy transfers w/o heat transfer, namely the entropy of mixing which you mention but may sound out of context in the sea of heat transfer examples).

Hi! I once saw a list called something like 101 ways to express the second law of thermodynamics... so, I can't really state the law of thermodynamics because its accepted wording ranges from the law of increasing entropt, to the K-P statement, to C's statement, etc...

or have i missed something?

ps. we are asked not to be quoting the statements we used to build our explataion on as it needs to be an explation in our own words, not an explation of what the statements mean.

Well, then come up with your own. But I think it needs a statement that goes over all your examples. As you have it right now, it's somewhat like "example, example, example, example". Someone who hasn't heard of the second law before would have to find what those examples have in common, and that's not always easy.

Matterwave said:
Well, then come up with your own. But I think it needs a statement that goes over all your examples. As you have it right now, it's somewhat like "example, example, example, example". Someone who hasn't heard of the second law before would have to find what those examples have in common, and that's not always easy.

On second thoughs, good point! Perhpas I am taking the term lay-person a little to seriously when I have used examples to explain my final point! Thank you.

1.

## What is the 2nd Law of Thermodynamics?

The 2nd Law of Thermodynamics states that the total entropy of an isolated system will always increase over time, or at best remain constant. This means that energy will always flow from a higher temperature to a lower temperature, resulting in a gradual loss of usable energy.

2.

## What is entropy?

Entropy is a measure of the randomness or disorder within a system. The 2nd Law of Thermodynamics states that the total entropy of an isolated system will always increase, meaning that the system becomes more disordered over time.

3.

## How does the 2nd Law of Thermodynamics relate to energy?

The 2nd Law of Thermodynamics explains how energy is transferred and transformed within a system. It states that energy will always flow from a higher temperature to a lower temperature, resulting in a decrease in usable energy and an increase in entropy.

4.

## Can the 2nd Law of Thermodynamics be violated?

No, the 2nd Law of Thermodynamics is a fundamental law of nature and cannot be violated. While it may seem like some processes, such as the creation of order or the production of work, may go against the law, they are ultimately balanced by a larger increase in entropy.

5.

## How does the 2nd Law of Thermodynamics impact real-world systems?

The 2nd Law of Thermodynamics has a significant impact on real-world systems, such as engines and machines. It limits the efficiency of these systems, as some energy will always be lost in the form of heat and increase the overall entropy of the system. This law also plays a crucial role in fields such as biology, chemistry, and ecology, where it helps explain the direction of certain processes and the overall increase in disorder over time.

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