Is a suction cup at the bottom of a bathtub subject to an upward force from the surrounding water, even if there is no water under it? A student question, posted in a teacher facebook group on a Monday morning, led to a discussion involving 21 comments with 225 replies offered by 16 teachers during the next few days, including several simple experiments, as well as modeling, to evaluate different arguments. The discussions, summarized in this paper, provide an example of how social media can provide an ‘extended teacher room’ where teachers can explore and refine their understanding in a safe and mostly supportive environment, and also find ways to give more elaborate answers to challenging student questions.

中文翻译：

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阿基米德原理是自然定律吗？在“扩展老师室”中的讨论

即使浴缸下面没有水，浴缸底部的吸盘是否也会受到周围水的向上作用？周一上午，一个学生问题在教师Facebook小组中发布，引发了讨论，涉及21条评论，随后几天内16位老师提供了225条回复，包括几个简单的实验以及建模，以评估不同的论点。本文总结了这些讨论，提供了一个示例，说明社交媒体如何提供“扩展的教师室”，教师可以在安全的，主要是支持性的环境中探索和完善他们的理解，还可以找到方法以更详尽地回答挑战学生问题。