The Mirror Effect: The rise of mirrors in the fifteenth century | Hacker News Reader

The Mirror Effect: The rise of mirrors in the fifteenth century

laphamsquarterly.org

103 pointsquickfox50 comments

Fun fact: we are used to seeing our own faces in the mirror image of how others see us. Thus, if you have a picture of yourself which you really dislike, mirror it and see if it helps - on photos we see our faces mirrored from what we're used to, hence why they look off so often, and why it can feel so difficult to get the right picture from ourselves taken.

For several years, I parted my hair the way I liked the look. I'm embarrassed to say how long before I realized and reversed sides.

I didn't realize the connection until now (even though I understand the way mirrors work). Weird how one often doesn't take that one last obvious step of an inference.

I guess now I'll use a smartphone camera instead of a mirror for grooming.

Most front facing cameras reverse the image to make it look like you are looking into a mirror.

Yes. I just tried that now, and unfortunately, my S7 does reverse the image from the front camera :/.

There should be an option to flip the image somewhere though, to be the right way around.

Use a webcam with the always included AMcap application. Or skype, with the mirror option disabled.

I did this too but I also realized "the way I've always parted my hair" is likely also "the way other people are used to seeing me" and thus "the way other people like it" too. So although I like it "to the left" everyone else likes it when I have it "to the right". I am the only one who doesn't care for that, but I also never see it other than flipped!

Also a fun fact; you can make a non-reversing mirror by putting two mirrors perpendicular to each other at 90°. When you look head on into both mirrors where they meet, you will see your image the same as others see it.

That is cool. Are there other ways to make a non-reversing mirror?

I was thinking of car mirrors.

I have a mirror trick of my own.

You know how there is one way mirrors, when used between two rooms they rely on one room being lighter/darker in order to work.

Well if you purchase a special mirror it is possible to make an optical illusion with three rooms in a row involved.

Each of the rooms furthest from each other can see into the interior room, but not into each other. This makes the sense of space much larger. I must talk to a magician or illusionist to see what other ways exist to achieve similar effects.

A few years ago, a Dr. R. Andrew Hicks of Drexel University designed a non-reversing mirror that is a single sheet of glass. The reflection is slightly distorted, however.

News coverage: http://techfragments.com/inventions-non-reverse-mirror/ https://www.newscientist.com/gallery/dn16585-amazing-mirrors

Photo from his website: http://www.math.drexel.edu/~ahicks/images/opticks.jpg

Very clever!

Aside from illusions there are many interesting proposals using mirrors.

I think most people don't think you can use mirrors with fibre optics to bounce daylight directly into people's houses for indoor lighting. There is also this cool trick you can do by using something called a 'cold mirror', where the visible spectrum is tapped into for lighting but at the same time the IR portion of the spectrum passes through the cold mirror and onto a solar thermal tank for making hot water.

All this, with mirrors!

> That is cool. Are there other ways to make a non-reversing mirror?

I don't know if that counts, but:

Get in front of your webcam and watch yourself on the screen. If your laptop screen is too small, note that modern large screens (usually sold as "TV") are larger than typical mirrors.

If all you need is a quick hand mirror, just use your smartphone in selfie mode.

Note that some phones do mirror the front-facing camera view (though actual photos taken are not mirrored) [0]. Both my Nexus phones have done this, so I assume it's a common Android feature. I don't know about iPhones.

Regarding webcams: Hangouts also mirrors your camera to you during video calls. [1]

[0]: https://www.quora.com/Why-are-selfie-pictures-mirror-images-...

[1]: https://productforums.google.com/forum/m/#!topic/hangouts/Ia...

Doesn't work for my particular application but I'm sure others will find it useful, assuming they don't run into the technological conspiracy to hide reality enigmango discovered ;-)

> Each of the rooms furthest from each other can see into the interior room, but not into each other.

I'd imagine this works with polarising glass rather than actual mirrors. Regular unpolarised light will go (partially) through polarising glass, but once the light has been polarised it won't pass through a second polarising filter that's at a 90° angle from it.

You could try that with two camera polarising filters.

That sounds like useful information, thank you.

I actually find it weird even just seeing myself in a mirror. It's a bit like hearing your own voice in a recording.

The recorded voice thing is similar to the mirror thing. That is how everyone else hears you, but you hear yourself via vibration too, which is missing in the recording and so you sound oddly different to yourself.

Nice article but I doubt the premise. Rich people had their portraits and sculptures made long before the invention. Think on Nefertiti or the multiple depictions in Egypt. Still in Egypt, there are Fayum Portraits. https://en.wikipedia.org/wiki/Fayum_mummy_portraits

In Ancient Greece and especially Rome, there were hyper realistic sculptures of the rulers, generals and rich people. Pompeii art is realistic. Instead the article follows the path claiming that a technological invention brings with itself a change in human nature, a dubious argument always.

Even today with all the selfies, people still relate to themselves in relationship to how they are perceived by others. And there are a lot of beautiful people who think they are ugly...

The point of the article was that regular, ordinary people didn't see their own faces clearly until fairly recently, and when that happened it shifted the sense of self and identity with long-term ramifications.

Good point, I still doubt the premise. Because you can claim by extension that photography was as radical a change. And there is little evidence to the fact. I claim that humans still primarily identify through the relationship with the others. Before or after the mirror.

P.S. Fayum portraits that I mentioned where of all people, rich and poor.

> P.S. Fayum portraits that I mentioned where of all people, rich and poor.

From your own link:

> The patrons of the portraits apparently belonged to the affluent upper class of military personnel, civil servants and religious dignitaries. Not everyone could afford a mummy portrait; many mummies were found without one. Flinders Petrie states that only one or two per cent of the mummies he excavated were embellished with portraits.

You can always just look at your reflection in a dark, still, liquid, like soup, or dirty water, or clear liquid in a dark container, etc. Sure you're looking down and it's kind of inconvenient, but it's not like people couldn't see themselves ever.

Yeah, this was never a secret. The myth of Narcissus has him trapped by his own reflection in a pool of water.

Household mirrors go way back, although the quality of the reflection you could get was well below where it is now.

How would one characterize the difference between publications like Lapham's Quarterly or Nautil.us and publications like the New York Times or the Washington Post?

I've been trying to discover publications that are more like the former and less like the latter, but I'm not sure how to differentiate between the two well enough for, say, a Google search. Searches along the lines of "publications like Lapham's" haven't done the trick.

You'll probably like Cabinet Magazine as well. I'd refer to them as "art and culture publications", "literary publications", "alternative".

I think the best way of discovering interesting publications is to visit bookshops that carry ones that you've already discovered and grown to like. Generally independent bookstores around major universities will carry a lot of literary magazines, and other alternative low-circulation publications.

I never would have thought that brick-and-mortar would be the way to go. Thanks for the insight!

Also, I just gave Cabinet a peak, and it definitely looks interesting. Thanks again!

In regards to the print edition, Lapham's is notably devoid of commercial advertisement.

Same with Nautilus. There's just a few pages in the back.

Fun fact: mirrors don't reverse anything. Easily proven, raise your right hand while looking in the mirror. The hand in the right side goes up. No reversal.

What's gets reversed is when an observer looks at you. Since an observer is facing the opposite direction, his left side is aligned with your right side.

Alternate view: if a mirror really did reverse left from right, why don't they reverse top from bottom as well? Because they don't reverse anything. On the other hand, if an observer were turned upside down, you'd appear upside down to him.

I think you're forgetting a dimension.

This description is missing a key part which explains why it appears to reverse left and right. Mirrors reverse something: the direction perpendicular to the mirror. Mirrors can also reverse up-and-down just as easily as left-and-right. Imagine holding text printed on a clear sheet up before so that you can read it. Now look in a mirror that's behind the sheet. The text in the mirror is so readable, since it's reversed in the one dimension it has symmetry in (the thickness of the sheet). But now if the sheet were opaque, you'd only see the back of the page in the mirror and no text. So you flip the page around to read it. Now you've rotated AND mirrored the text and it looks swapped left to right instead of by the mirror's perpendicular direction: the rotation changes which axis was mirrored. Start again with the text facing you ready for reading, but now rotate the text to face the mirror again but this time do so in the 'unusual' manner of flipping it head over heel. Now the text in the mirror is mirrored upside down! Which rotation you apply changes which axis is apparently inverted. We're just so used to rotating things about their vertical axis that everything looks mirrored left and right.

Also there are mirrors which do reverse specifically left and right in the manner that you debunk above, but they are nonsymmetrically concave.

The way I try to explain it is in absolute (ish) coordinates:

If you face north, your image faces south. Your left hand is on your west side. The reflection of your left hand is also on the west side. If you grab the mirror and turn so you face west, your reflection faces east and both your left hand and the reflection are on the south side.

If you reset the mirror and then stand sideways (facing east, mirror to your north), your left hand is to the north and right hand is to the south. In the mirror, the image of your left hand is to the south and right hand, to the north. But your reflection is facing east, just like you are.

I think this is good too, but it leaves the reader with the original question "Okay, if the mirror doesn't reverse left-and-right, then why does it appear to do so?" A question which left me scratching my head for a while and frustrated that explanations given in otherwise excellent sources like Martin Gardner's The Ambidextrous Universe never actually addressed.

This is a good question and I think it's the perception that the person you see as a reflection is actually a clone turned around to face you. When you raise your left hand, your "clone" (if it is a clone) raises their right hand. If you imagine stepping through the mirror and turning around to stand next to your reflection you really will be reversed laterally compared to your reflection-twin.

Ah, but they do reverse something... here, listen to Feynman. https://www.youtube.com/watch?v=msN87y-iEx0

Mirrors reverse the handedness of your coordinate system.

I wonder what effect the new convenient cheap mirror had on the profession of barber.

Did people shave themselves before mirrors became widely available?

In many years it will be interesting to read what the effect of social medias have had on humanity. I'm suspecting not so good as initially thought.

Cool article. I think I got my fill of general knowledge for today.

I've often said to my friends and family, during more philosophical discussions, that the one object that has caused the most destruction to the human species is the mirror ..

Would you care to elaborate on that?

>Previously the parameters of individual identity had been limited to an individual’s interaction with the people around him and the religious insights he had over the course of his life. Thus individuality as we understand it today did not exist: people only understood their identity in relation to groups—their household, their manor, their town or parish—and in relation to God.

This is a ridiculous argument. But par for the course for what passes as serious scholarship in the humanities these days.

See: https://en.wikipedia.org/wiki/Sokal_affair

And Richard Dawkin's great piece: http://www.physics.nyu.edu/faculty/sokal/dawkins.html

And your post is equally ridiculous as critique.

If you disagree with the assertion post some disputed evidence. If you just want to dismiss it with a virtual eye roll then just ignore it instead.

The essay made me think about the rise of selfie culture and its impact. On a recent trip at every cultural vista I would say 80% of the cameras were pointed at their owners with the landmark posing as a simple adornment of their own face.

Snapchat has made billions on this recognition. That you huff and puff about scholarship "these days" like a grumpy old man is largely irrelevant to the value of the linked article.

>That you huff and puff about scholarship "these days" like a grumpy old man

Are you really going to defend the state of the humanities disciplines? I'd love to read your attempt at a reasoned defense of postmodernist drivel.

The humanities are incredibly diverse fields filled with tens of thousands of very different scholars- dismissing all of their work because you've seen a couple of silly examples purposefully chosen to be inflammatory is anti-intellectual by very definition.

Wait. Why, exactly, is this argument ridiculous? Your references are about the Sokal hoax; are you claiming this is a hoax too? Is your only evidence an unrelated 20 year old hoax?

I'm somewhat credulous about the original assertion myself, but what is just as bad as shoddy humanities scholarship is the out of hand dismissing of all humanities scholarship as shoddy.

The argument is ridiculous because it's saying that people had no sense of self and identity until mirrors are invented. This is plainly false to anyone who is a human being. It is also plainly false with a cursory look at ancient literature, which is full of characters with strong egos.

That's not actually what the article says. It's saying the that sense of identity was mostly experienced as a set of relationships and roles and that an identity distinct from any role or relationship became more common place after mirrors and the clear self picture that provided to people.

It's also not "plainly false" ... most people identify themselves by their roles and relationships. If you ask people to describe themselves they will universally use role and relationship descriptors: computer programmer, cop, Catholic, mother, grandfather, ... It is common for people who retire to have difficulty with the loss of identity that their job and role their occupation provided.

Reply on news.ycombinator.com