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Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by tgb on Wednesday October 07, 2020 @09:52AM (#24708185)
Absolutely, this is a pretty solid explanation and HN (and similar places) always have the bizarre take on explaining of paradoxes to shout "It's not a paradox!" Paradoxes are about appearing, at first thought, to be impossible, not it being literally impossible. In this case, it's the two observations:

1) A mirror is rotationally symmetric so should treat left/right the same as up/down.

2) A piece of paper with writing held up to a mirror reads right-to-left instead of left-to-right. But it does not read bottom-to-top.

This asks for an explanation - one that the article gives. Why do so many here feel the need to say that since this has an explanation, it is not a paradox? Outside of fiction, every paradox has an explanation and, moreover, we're discussing an article that gives that explanation.

But: a mirror does flip something, it flips in-and-out. Mirror images are not the same.

Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by plorkyeran on Wednesday October 07, 2020 @11:02AM (#24708971)
The (perhaps overly) charitable take on "It's not a paradox!" responses is that it's something which didn't appear impossible or weird to that responder, and the article failed to make the case for why there's even something that needs an explanation.
Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by tedunangst on Wednesday October 07, 2020 @11:39AM (#24709333)
I'm curious to know what percentage of commenters who know exactly how mirrors work can perform simple tasks like assembling a puzzle with the same speed only looking through a mirror.
Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by kroltan on Wednesday October 07, 2020 @12:05PM (#24709577)
I don't think that would prove anything at all, since knowing how something works doesn't mean you can use it in place of your usual behaviour. You also have to unlearn manipualting things in non-mirror space.

Smarter Every Day actually has a video demonstrating a similar thing: https://www.youtube.com/watch?v=MFzDaBzBlL0

Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by kortilla on Wednesday October 07, 2020 @01:24PM (#24710513)
I know how a blindfold works and I can’t assemble a puzzle with a blindfold on. Is that curious?
Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by bigbubba on Wednesday October 07, 2020 @12:18PM (#24709729)
> Paradoxes are about appearing, at first thought, to be impossible, not it being literally impossible.

That's not true, or at least it's not the whole truth. Real paradoxes do exist: A barber shaves everyone who doesn't shave themselves, who shaves the barber?

So if true paradoxes do exist, it seems fair to call out alleged paradoxes for not truly being paradoxes.

Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by prower on Wednesday October 07, 2020 @12:55PM (#24710169)
> Real paradoxes do exist: A barber shaves everyone who doesn't shave themselves, who shaves the barber?

I'm clearly missing something but how is that a paradox?

Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by bigbubba on Wednesday October 07, 2020 @01:05PM (#24710292)
If the barber doesn't shave himself, then he must shave himself because he shaves everyone who doesn't shave themselves. But he only shaves those that don't shave themselves, so he cannot shave himself....

https://en.wikipedia.org/wiki/Barber_paradox

Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by prower on Thursday October 08, 2020 @03:23AM (#24716744)
From your wikipedia link: The barber is the "one who shaves all those, and those only, who do not shave themselves". The question is, does the barber shave himself?

If the answer is "no", then he's shaved from another barber and the problem is solved. Nowhere is stated there's only one barber in the world.

Tattoo artists don't tatoo themselves but they're not living paradoxes. How is this different?

Again, I'm sorry for the obvious elephant in the room I keep missing.

EDIT: I see your answer to sumtechguy, I understand now it's more metaphorical than pratical. In my understanding, the paradox seems to arise when you try to put all your existing elements to fit one of 2 kind of boxes, which are clearly not enough.

Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by sumtechguy on Wednesday October 07, 2020 @01:24PM (#24710515)
Or there is a second barber and they shave each other? If there is only one barber then it is a paradox.
Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by bigbubba on Wednesday October 07, 2020 @01:30PM (#24710569)
There is only one barber and he's not bald or otherwise excluded from the 'everybody' in "he shaves everybody who doesn't shave themselves." It's not a lateral thinking problem, or a matter of thinking outside the box. The scenario described is simply impossible. Everybody, including the barber, is either shaved by the barber or [XOR] shaves themselves, which is impossible in the case of the barber.

See also: https://en.wikipedia.org/wiki/Russell%27s_paradox

Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by SAI_Peregrinus on Wednesday October 07, 2020 @06:43PM (#24713677)
Parent poster forgot a critical condition for it to be a paradox. As they stated it's not, a second barber could shave both themself and the first barber.

The paradoxical statement would be "A barber shaves all those, and only those, who do not shave themselves. Who shaves the barber?" Without the second condition (only those who don't shave themselves) it's non-paradoxical.

Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by bigbubba on Wednesday October 07, 2020 @07:00PM (#24713819)
Replace 'A' with 'The' and it works. Tbh I assumed people were already familiar with the Barber Paradox and didn't word it defensively, but if you take 'a barber' as referring to a specific barber then it's a paradox.
Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by crowbahr on Wednesday October 07, 2020 @12:56PM (#24710186)
Better paradox:

This statement is false.

Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by tgb on Wednesday October 07, 2020 @01:11PM (#24710359)
Show me such a barber and I'll agree that they exist.
Re:Why Do Mirrors Flip Things Horizontally but Not Verticall... by bigbubba on Wednesday October 07, 2020 @01:16PM (#24710421)
The paradox exists and consequently, the barber cannot.