Feedback.

This article from New Scientist's "Feedback" section highlights various topics of interest. It mentions the existence of a public toilet in Nelson, New Zealand called the Black Hole Public Toilet, which is a humorous play on the concept of black holes. The article also discusses a study on Veress needles used in laparoscopic surgery, exploring the need for a better design and the surgeons' opinions on needle insertion. Additionally, it mentions the terms "gangue" and "goaf" in the context of mining waste material. The article concludes by mentioning the work of Marlin E. Plank, a research forest products technologist, who focused on estimating the amount of usable wood from different tree species. Lastly, it briefly mentions the potential privacy concerns of video chats and reflections on eyeglasses. [Extracted from the article]