Talk:Orthogonal transformation

Latest comment: 5 years ago by Felix Tritschler in topic Reflections ...

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The text of this article was an almost exact copy of the Mathworld article. As of today, the difference consisted of the leading words "In linear algebra,", a misspelling (or a grammatical error), and a single sentence deleted.

I can't believe this does not violate copyright.

I have written a new article with similar contents. The sources I have used are mostly other related Wikipedia articles, as well as the Mathworld article for the exact definition. Cacadril (talk) 00:44, 27 May 2012 (UTC)Reply

Reflections ...

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The sentence "Reflections are transformations that exchange left and right, similar to mirror images." is not correct. It should, instead, e.g. say:

"Reflections are transformations that reverse the direction front to back, orthogonal to the mirror plain, like (real-world) mirrors do."

Mirrors don't "exchange left and right" - convince yourself: Write your name on a piece of paper, then look at it in a mirror, but don't turn the paper towards the mirror, like you probable intuitively would do, namely about the vertical axis, instead, turn it about the horizontal axis. What you will then see in the mirror, is your name turned upside down. The mirror didn't change up and down, either, you did!

But what a mirror and a reflection in geometry change is front and back. I changed the sentence accordingly.

--Felix Tritschler (talk) 13:52, 29 March 2019 (UTC)Reply