## KnitWit one year ago I have to write an essay, but I get to pick the subject, within four chapters. Three of them have to deal with thermodynamics (Expansion and Temperature, Thermal Energy and Heat, and Thermodynamic Laws), and the fourth has to do with fluid mechanics. I'm trying to come up with an essay question for myself, but for the life of me, I can't figure out anything that would make a good paper. Any ideas?

1. UnkleRhaukus

Maybe something about how the properties of water change depending on temperature

2. KnitWit

Possibly. But can I make a long paper out of that?

3. UnkleRhaukus

The one of the strange things about water is that when it is between 0 and 4 °C , volume shrinks with temperature, but when it is above 4°C it expands with temperature,

4. KnitWit

Yeah, that is strange. It points that out in my book. In a lake, above that temperature, the coldest water is at the bottom, but when it is lower, it is at the top. :)

5. UnkleRhaukus

Maybe that would take a few chapters to explain fully? Just an idea.

6. LastDayWork

How about an essay on the concept of temperature ? (Zeroth Law of thermodynamics)

7. KnitWit

Yeah, that would be interesting. I'll add it to my just-beginning list.

8. LastDayWork

To be more specific; why we does the Kelvin scale enjoys such a special status when we could use any (monotonically increasing/decreasing) property of any material to measure temperature (assuming it to have a linear dependence).

9. LastDayWork

* omit we :)

10. KnitWit

That's true. Thanks, both of you, but my father just gave me one. :)

11. KnitWit

Expansion of Solids Pertaining to Construction Practices (esp. Suspension Bridges)