Last week, I asked a question about an everyday physical phenomenon (In aluminum, how does electricity travel through the surface oxide layer?). I was fortunate enough to get two answers and some comments offering possible explanations. All of the proposed explanations seem at least somewhat reasonable to me, and both answers and a comment have attracted a positive score. Unfortunately, they don't agree with each other, and now I'm not sure which answer to accept.
- One answer says that the aluminum oxide layer is porous and contains moisture, which causes it to conduct electricity.
- Another answer says that the oxide layer is thin and fragile enough to be easily pushed aside when another metal conductor is connected.
- A comment (which probably should have been an answer) attributes the observed conductivity to electrical breakdown of the oxide layer.
I tried offering a bounty (is that an appropriate thing to do?), but I haven't received any new answers and there is only one day left.
This isn't an opinion-based question; in principle, it would be possible to conduct an experiment to determine the correct answer (which might be a combination of several explanations that apply in different conditions). Also, I don't think my situation is covered by Which answer should we accept if multiple answers address the question? I can't tell which answer is most helpful because I don't know which one is correct. (If I knew, I wouldn't have asked the question!) Finally, I don't feel comfortable choosing based on the number of upvotes alone. Votes are a useful signal about the opinion of the community, but truth isn't determined by majority vote.
Naturally, feedback is welcome about the question itself. If you feel that it's unanswerable or that I wrote it in an unclear way, please say so! However, if possible, I think it would be best to avoid debating the physics of aluminum oxide here on Meta. That way, the discussion will be useful for future users who are in similar situations.
