Well, I hope everyone has a chance to rest and recover from all the camping this week, I know that most of you are still in the wilderness (or just preparing to go) as I write this. While you are all out there enjoying nature, I've been in the office correcting your pre-tests. It seems that an unusually high number of you do not know the answer to question (31) "Energy inefficiency in food webs is an expected outcome of the...". An explanation should make the correct answer clear.
A. The second law of thermodynamics is often simply, and somewhat misleadingly, expressed as, "all things tend toward entropy." But what does that mean? Many people, including some scientists I know, will define entropy as disorder. Wrong. Entropy is the measure of spontaneous dispersal of energy; the heat energy that radiates into the cool (low energy) night air from the hot (high energy) campfire fire is an example of entropy. That's very different from "disorder." I prefer this well known observation as a description of the second law: Nature abhors a vacuum. Think about what this means in relation to the above question. As energy is transferred between one entity and another, it is exposed to a lower energy environment during the transfer and some of it escapes.
I hope this makes the answer more clear, if not, please feel free to respond or to email me with your questions. For your journal: What are the ways in which energy is exchanged in the systems you are studying?
1 comment:
Well said.
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