Wikipedia:Reference desk/Archives/Miscellaneous/2010 November 15

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November 15

TWO WAY MIRRORS

I was just wondering if there was a way telling if I'm looking into a two way mirror so I can tell if my paranoia is real or not. —Preceding unsigned comment added by 99.149.37.198 (talk) 20:58, 15 November 2010 (UTC)

I had been taught that you put your finger on the mirror and look at the gap between your finger and its mirror image; but this Snopes column says that this is false, and toward the end has some tips. It ends by recommending you not test the mirror by throwing a chair into it. Comet Tuttle (talk) 21:00, 15 November 2010 (UTC)

If you can block enough of the reflection from your side, you can see the light transmitted from the other side, assuming there's enough of it to see. Usually putting your head right up against it and cupping your hands over your forehead will work, though of course it depends on the details of the situation. Of course it's kind of obvious what you're doing. --Trovatore (talk) 21:02, 15 November 2010 (UTC)

Cup your hands around your face as you hold it close to the glass, blocking most light from your side. If you can see through the glass to people on the other side, it's a two way mirror, if it's just dark, it's a normal mirror. When you discover your paranoia is not real, and the mirror is a mirror, please consider whether this is becoming a problem you should discuss with a qualified professional. 86.164.144.120 (talk) 21:04, 15 November 2010 (UTC)

If you discover it is in fact a two-way mirror, that is also something to take up a qualified professional. 96.246.58.133 (talk) 21:44, 15 November 2010 (UTC)

You know, I've done this on occasion at places like Target, because it's really amusing to see the reaction of the guys sitting on the other side of the mirror. They are so used to being the invisible watcher that when they suddenly become the visible watchee it unnerves them. They do tend to get annoyed about it, though, so I wouldn't make a habit of it at stores you visit frequently.

P.s. These are called one-way mirrors. a two-way mirror would generally be called a window. --Ludwigs2 22:47, 15 November 2010 (UTC)

No, they are two-way mirrors. A one-way mirror is an ordinary mirror — it works as a mirror in only one direction. A two-way mirror works as a mirror in both directions. --Trovatore (talk) 22:50, 15 November 2010 (UTC)

We have an article on the Two-way mirror which should make it clear why it's called by that term. Presumably a standard mirror would be a "one-way" mirror. ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:32, 16 November 2010 (UTC)

Trovatore, you surprise me. It's a mirror in one direction but just a pane of glass in the other direction. It has a dual function, which is presumably where the "two-way" bit comes from, but you're suggesting that people on either side will see their own reflections, which is not the case. -- Jack of Oz ... speak! ... 01:46, 16 November 2010 (UTC)

No, actually, it isn't. This is a key misunderstanding. It is a mirror in both directions, and it is also a pane of glass in both directions.

The device has (in principle) no directionality whatsoever, in and of itself. If from one side it transmits 30% of the light, reflects 60%, and absorbs 10%, then from the other side it also transmits 30%, reflects 60%, and absorbs 10%.

The apparent directionality is actually all in your sensory apparatus. If you're in the bright room, the light is still coming through from the dark room. But you can't pick out the signal in your eye or brain; it's drowned out by the reflection on your side. --Trovatore (talk) 02:03, 16 November 2010 (UTC)

Hmm, I must ask Barbra Streisand about this next time I see her. -- Jack of Oz ... speak! ... 02:26, 16 November 2010 (UTC)

Yes, say hello to Babs for us. If I interpret the article correctly, a two-way mirror is a pane of glass with a certain percentage of reflecting material on it. If one side of the glass is brightly lit and the other is in darkness, it looks like a mirror to the one side and a window to the other. Presumably, if the lights were on on both sides, it would look pretty much like an ordinary window. ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:29, 16 November 2010 (UTC)

Well, it would actually be a Tinted window. WikiDao ☯ (talk) 14:00, 16 November 2010 (UTC)

Well, a really shiny window, maybe. If the light is equal on both sides, when you look at the mirror, you should see your reflection superimposed on whatever's in the other room.

I think part of the reason people have trouble believing that the mirror is nondirectional is that they don't have an intuition for how much brighter a bright room actually is than a dark one. If the bright room is 100x brighter than the dark one, maybe you think it's only twice as bright (the actual numbers are made up, but the idea should be clear), because your eyes adjust.

So when you look at the mirror from the bright room, your reflection is 100x as bright as the image from the dark room, which basically means you can't make out the latter at all. And conversely for why you don't see much of your own reflection in the dark room. But intuitively, you don't realize that the difference in the brightness is so large, so it seems that the mirror must somehow be doing something to make the images appear as they do, which it really isn't. --Trovatore (talk) 02:35, 16 November 2010 (UTC)

A practical parallel I can think of: During the daytime on a sunny day, I can look out my office windows and it's unlikely any passersby will see me unless one or both of us is very close to the window. The reverse is true after sunset, when the building's lights are all on for the cleaning crew, and you can see into the building, but they can't see you unless they get close to the window and cup hands around their faces. The glass walls act as a two-way mirror. ←Baseball Bugs ^{What's up, Doc?} carrots→ 02:45, 16 November 2010 (UTC)

Well, your paranoia is real, but is it substantiated? To tell if you are being watched, stop looking at yourself. There is nobody "out there." Everything we see or feel is just a reflection of what we see or feel about ourselves. Interestingly enough, this can be called mirroring. schyler (talk) 04:12, 16 November 2010 (UTC)

I think a practical answer to the OP's question is "turn the lights out". Then you should be able to better tell if that mirror is one-way or two-way. ←Baseball Bugs ^{What's up, Doc?} carrots→ 05:17, 16 November 2010 (UTC)

Solipsism is easy to misconceive, schyler, and there is something to be said for Objective reality. What I think the OP meant is: is his/her apparent paranoia actually astute observation and clever reasoning that can be checked by experiment, and how to carry out the appropriate experiment in this case. WikiDao ☯ (talk) 14:00, 16 November 2010 (UTC)

Exactly WikiDao! You're the only one who gets it. lol So, is there any experiment I can do do find out if its a two way mirror besides turning off the lights?

Terminology

As the two-way mirror article says, the term "one-way mirror" is used with the same meaning. Both meanings are logical. It is "two way" because there are two different ways it behaves: from the dark side you can see through it, and from the lighted side you can't. It is "one way" because, when the correct lighting is set up, you can only see through it one way. Repeating that one or the other term is wrong is not helpful to anyone.

--Anonymous, 06:33 UTC, November 16, 2010. 208.76.104.144 (talk · contribs)

I disagree. It's not a two-way mirror because it works two different ways. It's a two-way mirror because it's bidirectional, exactly symmetrical in both directions. People who say one-way mirror mostly don't understand how it works — they think it has some directionality, which it does not. --Trovatore (talk) 08:19, 16 November 2010 (UTC)

This is not a forum for your opinions. I cited a reference that both terms are used. Please cite an authority for what you are insisting on, or shut up. --Anonymous, 14:37 UTC, November 16, 2010. 208.76.104.144 (talk · contribs)

You cited a reference that both terms are used. I agree they are both used. You cited no reference for the claim they are both logical. I say the prevalence of one-way mirror comes from the fact that people don't understand how it works. This is no more an opinion than your claim that it's logical. --Trovatore (talk) 20:03, 16 November 2010 (UTC)

Please try to avoid using uncivil phrases like "shut-up" at the Ref. desk. Thank you. WikiDao ☯ (talk) 14:43, 16 November 2010 (UTC)

• Look, a mirror is just something that reflects light, and so all mirrors are at least one-way. A normal everyday mirror will have some opaque backing behind the reflective material so that only reflected light is observed. If that backing were removed and the mirror placed in the center of a room, one could walk to either side of it and see both reflected and transmitted light.
• As two-way mirror indicates, what is meant by "two-way mirror" is the system of mirror (without opaque "backing"), light room, darkened room, and observer's eye (which adjusts to the level of light in either of the rooms it is in).
• See also mirrored sunglasses.
• It is possible that "two-way" is meant to refer not to reflection but transmission of light, which makes it not a mirror but a tinted window. "Two-way" seems more likely to be used in this case to mean something more like "dual-use" – the system of rooms-and-mirror is used as a mirror in one way, as an observation window in another. WikiDao ☯ (talk) 14:17, 16 November 2010 (UTC)

Why do you think that "dual use" seems to be the "more likely" explanation? 90.195.179.106 (talk) 21:32, 16 November 2010 (UTC)

Because "two-way" applied to "mirror" could mean that both sides are being used as a mirror. But that is not what is meant. What is meant is that one side is being used as a mirror and the other as an observation window, which is more like "dual use" than a literal interpretation of "two-way". WikiDao ☯ (talk) 02:53, 17 November 2010 (UTC)

Both sides are a mirror. You just can't pick out the image on one side. But that has nothing to do with the mirror itself. --Trovatore (talk) 08:42, 17 November 2010 (UTC)

It seems you're just stating your opinion on why it's more likely to be "dual-use". I always thought the logical reason for it being called "two-way" is that it works both ways, but that's my opinion too. Unless either of us can provide a source, the etymology of this one can't really be determined. 90.195.179.106 (talk) 13:36, 17 November 2010 (UTC)

The OED says:

• "two-way mirror, a mirror which lets through enough light for an observer at the back to see through it, without being seen from the front."

and lists first use as

• "1967 J. GARDNER Madrigal i. 3 They directed total concentration through the sighting side of a two-way mirror."

Which establishes that the term refers to a use of an inherent property of a ("partial") mirror. The term has directionality of use as part of its definition: in one direction it is used as a mirror, in another as an observation window, as already stated. You and Travatore are saying that it could work like a mirror from either direction, which I agree with and have also already stated. But what the OED and I are saying is that what is meant by "two way" is that it can be used in two different ways, one of which ways is as a mirror. WikiDao ☯ (talk) 13:52, 17 November 2010 (UTC)

Actually, neither of them speaks directly to the reason for the term. The OED gives a definition (kind of a bad one, but anyway), not an etymology. The Gardner usage similarly does not imply a reason for it to be thus called.

It kind of sounds like Gardner may not have understood the gadget, in spite of calling it a two-way mirror. And in fact, while I think most people who call it one-way mirror misconceive it, I suppose that's probably also true for those who call it two-way mirror. The difference is that one-way mirror tends to reinforce the misconception, whereas those who ask themselves how it's a "two-way mirror" may, if they think about it, hit on the right answer. That's the most important reason that it's the better term. --Trovatore (talk) 19:30, 17 November 2010 (UTC)

Yes. It ought to be called something like an "observation mirror" or "security mirror", perhaps. A "one-way window" makes more sense, in a sense, but then people would have the same problem about how it is not really only "one-way" but could in fact be used as a window from both directions. The "way" qualifier is meant to describe its use and not its physical properties, though, and I agree it should do so less ambiguously. WikiDao ☯ (talk) 22:15, 17 November 2010 (UTC)

How do you know that? Its use is an "accident" rather than an "essence" as Catholic theologians would say; it's not intrinsic to the device itself. --Trovatore (talk) 22:18, 17 November 2010 (UTC)

I'm just going by the OED definition which, like it or not, is the OED definition (which is usually considered a reliable source). The definition is not "any plane mirror that is permitted to reflect light from both its sides" (which is the opposite of what is meant) but rather "a mirror which lets through enough light for an observer at the back to see through it, without being seen from the front" which is pretty clearly about use. The distinction the qualifier is "meant" (rightly or wrongly, poorly or well) by definition to make from just the word "mirror" is in how it is used to distinguish it from just any mirror and not about a physical property that it has that distinguishes it from just any other mirror. WikiDao ☯ (talk) 22:42, 17 November 2010 (UTC)

As I say, I don't think it's a very good definition, but in any case it makes no claim to be the reason for the name; it's just trying to convey what object it is that the name signifies. --Trovatore (talk) 22:44, 17 November 2010 (UTC)

I lost my high school diploma and certificate

hi,well,i lost my high school diploma and certificate when i was moving to a new place,i graduated from canoga park high school in 2008,canoga park is a los angeles neighborhood, i need them to go to college,but i don't know how to get replacements or a copy.i want to attend university in Mexico,they ask me for my high school certificate but i lost it,i want to get them back.so can anyone help me and tell me what to do,please.thank you —Preceding unsigned comment added by 63.112.48.34 (talk) 21:07, 15 November 2010 (UTC)

You will have to call the school high school office on the phone and ask them what to do. You're not the first person who has needed this, and they will be able to help. Comet Tuttle (talk) 21:19, 15 November 2010 (UTC)

The high school keeps such records, get in touch with them. --Mr.98 (talk) 21:35, 15 November 2010 (UTC)

Du'oh =) ResMar 03:45, 16 November 2010 (UTC)

but do i have to pay a fine? —Preceding unsigned comment added by 76.79.129.82 (talk) 03:48, 16 November 2010 (UTC)

Any situation where you could conceivably need to prove your high school education will require an official transcript anyways. That pretty piece of paper looks nice in the frame, but it doesn't actually do anything for you. Any job you get or college you apply to will want a copy of your official high school transcript, sent directly from your high school. And, once you have a college degree, no one will care one bit about your high school at all; they'll only want a copy of your college transcript. --Jayron32 04:05, 16 November 2010 (UTC)

Your situation may differ slightly but from my experience, Jayron is right. When I applied to my first college, I had to submit a form at my high school that told them where I needed transcripts sent to. When I applied to my second college, I submitted an online form with my first college and they sent my college transcript to the second college. I think my high school diploma is at my dad's house but I don't know where. I've never needed it. And nobody has ever asked to see any diplomas. In short, nobody cares about your diploma, they only care about your transcript. Regarding the "fine", no there should be no fine. But you will probably have to pay $10-20 for each copy of your transcript to cover the high school's cost of keeping the records, looking them up, sending them out, etc. Dismas|^(talk) 04:39, 16 November 2010 (UTC)

Fines are for people who've done something wrong, broken some law etc. There's no law against misplacing your diploma, so there's no fine. But they might charge an administrative fee for the cost of replacing it. -- Jack of Oz ... speak! ... 08:59, 16 November 2010 (UTC)

Right. There might be some kind of transcript request fee. I know there usually is at the college level, anyway. --Mr.98 (talk) 16:00, 16 November 2010 (UTC)

BTW, what are these transcripts whereof people speak? I don't think we have them in Britain. DuncanHill (talk) 22:19, 17 November 2010 (UTC)

It's a record of what classes you took and the grades that you got in them. It will include your overall grade point average as well. Dismas|^(talk) 22:23, 17 November 2010 (UTC)

In fact, we have an article. Dismas|^(talk) 22:25, 17 November 2010 (UTC)

Thanks, no we don't have those (the ECTS mentioned in the article is for HE, not FE). We don't have grade point averages either. I would be very surprised if schools kept such records for any significant period of time, to do so would be contrary to the principles of data protection. We take exams and get certificates, the examining boards can provide confirmation of the results on request, subject to satisfactory proof of identity. DuncanHill (talk) 22:30, 17 November 2010 (UTC)