UCI Physics Science Behind Phase Transitions Essay

Physics Writing Assignment

Logistics. Due Sunday, November 8 at midnight on Gradescope. Submit a paper of no more than three single-spaced pages as described below. Use a standard, serif font in size 12 and a standard academic citation format of your preference. You’re welcome to discuss this assignment with your classmates, but your writing must be your own. Plagiarism of any kind will not be tolerated.

Assignment description. Our everyday experience teaches us that matter or “stuff” comes in qualitatively different forms. We learn early on in school that these different kinds of stuff are called phases or states of matter. We learn their names and heuristic ways of distinguishing them: solids are rigid and maintain their shape and volume; liquids can flow and take the shape of their container but maintain a definite volume; gasses can flow like liquids, but they don’t have a fixed volume.

The goal of this assignment is to delve a little deeper into exactly how we distinguish these everyday phases of matter. In a paper of no more than three pages, explain the distinction between solids, liquids, and gasses from the perspective of quantitative experimental measurements. (The elementary school heuristics sketched out in the previous paragraph will not be enough.) You will need to do a little research for this paper, so make sure to cite your sources for anything that is not your own original work. (You don’t need to delve too deep—this is standard textbook material, although you won’t find enough detail in our textbook.) Feel free to include any figures from your references as long as you provide a citation for them.

You may want to use the following questions, among others, to guide your reading and writing.

• What is a phase transition? How does one detect or measure the occurrence of a phase transition in general?
• Whatobservablepropertiescharacterizethesolid-liquidandliquid- gasphasetransitions? How are these different from other kinds of phase transitions and from each other?
• What quantitative measurements can one make to determine if a particular macroscopic system is a solid, liquid, or gas?
• What is the role of symmetry in these phase transitions or in phase transitions in general?It may help to focus on a particular example material or materials, like water or argon. (For example, solid water has as many as 18 distinct crystalline structures that can form under different conditions. Do these crystals correspond to distinct phases of matter, and why or why not?) If you focus on an example like this, you will want to discuss what aspects of your example do or do not apply to the solid-liquid-gas distinction in general.

Please make sure to write in your own words; try to digest what you learn and don’t just copy and reword your references. I will be grading you on your ability to clearly, accurately, and concisely summarize your findings in your own words. The more detail

you can give, the better. However, if you feel like you don’t understand something well enough to write about it clearly and accurately, explain it only to the extent that you do understand it. (You could even admit that you don’t understand something and explain what it is you’re confused about.) That is, I would prefer you err on the side of being correct rather than comprehensive.

If you are able to connect your findings to 5B concepts, so much the better, but it’s not a requirement. (The connection to latent heat/heat of transformation is a very easy one to make.)

Finally, as an alternative, you’re welcome to pick any other phase of matter or type of phase transition and try to explain its quantitatively measurable properties. Nature provides us with a vast array of phases of matter: plasmas, liquid crystals, Bose-Einstein condensates, superfluids, superconductors, metals and insulators, magnetically ordered systems like ferromagnets and antiferromagnets, and many more. I expect this would be more of a challenge, with the potential payoff of an interesting and unique write-up.