Author |
Topic: Mirror inversion (Read 22026 times) |
|
udippel
Newbie
Posts: 30
|
 |
Re: Mirror inversion
« Reply #25 on: Feb 1st, 2003, 2:19am » |
 Quote  Modify
|
Now we seem to drift off, somehow ?
I do agree with redPEPPER (if he doesn't mind) on the subjectiveness of 'handedness'.
Standing in front of my course, when I move to the right of the stage, the students have to turn (at least their eyes) to the left. For them it's left where I'm heading. Do I walk up the stairs to the last, uppermost row, at least everyone perceives me going 'up'; irrespective if the students sit below or above the row that I've just reached.
The very moment I'll see my image (actually it is not an image!) in the mirror in the morning raising the left hand when I raise my left hand - that is the *other* side ! - I'll definitively stop taking booze. *That* would be inverting left and right, right? But as long as my left hand still shows up on my left side, even 'in' the mirror, I'll be fine.
And my mirror at least doesn't fail me here even if I turn the horizontal orientation of my eyes by 90°. Don't know what your mirrors do, but mine still shows the - then - upper hand to be upper; just like the left hand earlier was still the left hand. So the mirror in this household at least does *not* treat left/right different to up/down.
|
|
 IP Logged |
|
|
|
Chronos
Full Member
 
Gender: 
Posts: 288
|
|
Re: Mirror inversion
« Reply #26 on: Feb 3rd, 2003, 5:31pm » |
Quote Modify
|
Quote:| A quick google search tells me that only left-handed subatomic particles and right-handed antiparticles partake in weak interactions. |
|
Yes, but then you have to tell them which are the particles and which are the antiparticles. It can still be done, though, since there are subatomic processes such as the decay of the long-lived K meson which do make a very slight (on the order of one part in a thousand) distinction between matter and antimatter.
The bit about light degrading certain chiralities of molecules more than others, though, I would suspect is a myth. Chirality preference only shows up in the weak interaction, which is almost completely negligible in chemistry.
|
|
IP Logged |
|
|
|
Bored to Death
Guest
|
My goodness.
Why do we all get into this sort of discussion? The reference point of the reflected image is meaningless. (Its left, right, up, or down.)
If you are not convinced, read the post by udippel.
And think hard. Very hard.
I’m sure there are other posts, but I don’t think the puzzle deserves any more attention. So, I didn’t bother to read them all.
|
|
IP Logged |
|
|
|
Interesting...
Guest
|
I found another good example when I was thinking about this, and before I read this page and forum:
Look a text in a mirror, than rotate the text 90 degrees. The mirror inverts the text in exactly the same way, and thus makes no difference between up/down and right/left. Purely cultural.
|
|
IP Logged |
|
|
|
deoBRAT
Newbie
Posts: 2
|
|
Re: Mirror inversion
« Reply #29 on: Feb 6th, 2006, 11:45pm » |
Quote Modify
|
Hey, seems there is a lot of heated discussion going on. I have a fairly simple explanation (though I am not sure if its enough)
A mirror, by definition inverts the plane perpendicular to it and leaves the one that is parallel to it.
If we stand in front of the mirror, Vertical plane will remain unchanged, but the horizontal plane gets rotated 180 degrees.
Thats the reason why right seems to be left (becuase its in the horizontal plane, and it gets rotated 180 degrees) and up remains up (cause its in the vertical plane) in the mirror.
|
| « Last Edit: Feb 6th, 2006, 11:47pm by deoBRAT » |
IP Logged |
|
|
|
rmsgrey
Uberpuzzler
    
Gender:
Posts: 2873
|
|
Re: Mirror inversion
« Reply #30 on: Feb 7th, 2006, 6:00am » |
Quote Modify
|
on Feb 6th, 2006, 11:45pm, deoBRAT wrote:Hey, seems there is a lot of heated discussion going on. I have a fairly simple explanation (though I am not sure if its enough)
A mirror, by definition inverts the plane perpendicular to it and leaves the one that is parallel to it.
If we stand in front of the mirror, Vertical plane will remain unchanged, but the horizontal plane gets rotated 180 degrees.
Thats the reason why right seems to be left (becuase its in the horizontal plane, and it gets rotated 180 degrees) and up remains up (cause its in the vertical plane) in the mirror.
|
|
There are an infinite number of planes perpendicular to most mirrors - including at least one vertical one. If you have a mirror that isn't itself vertical, then there is no horizontal plane perpendicular to it; if the mirror is actually horizontal, then all the perpendicular planes are vertical.
And the one thing a (single, plane) mirror definitely does not do is rotate anything.
If you hold something between you and a mirror, you see the near side "live" and the far side reflected - the mirror doesn't change left and right or up and down, but does switch front and back.
A simple experiment to demonstrate this is to take an arrow and a mirror, and see how the direction of the arrow compares to that of its image in the mirror - I find that an arrow pointing up, down, left, right or anything in that plane parallel to the mirror points in the same direction in the mirror as in real life, while anything pointing towards the mirror points away, and vice versa
|
|
IP Logged |
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: Mirror inversion
« Reply #31 on: May 16th, 2006, 4:57am » |
Quote Modify
|
In fact, the mirror doesn't reverse anything. The mirror is a tool that lets you see around a corner, so to say. If you think you see "through" the mirror, you haven't really understood what it does. What you see is yourself, located on this side of the mirror. If you don't locate that image correctly, if you think that what you see is behind the mirror, and as a result label "left" what is in fact "right", it is your own mistake.
The day you really see a mirror for what it is, you see it as opaque as a wall.
|
|
IP Logged |
|
|
|
alien
Guest
|
Just turn your back to the mirror and the mirror will, for once, reflect the way it should. Maybe the mirror is gay.. If so, I am not turning my back to it. No sir, not a chance.
|
|
IP Logged |
|
|
|
uk9raine
Newbie
Posts: 2
|
|
Re: Mirror inversion
« Reply #33 on: Dec 1st, 2006, 9:45pm » |
Quote Modify
|
I'm really sorry, but, did I read that you have a PhD in optics? ....And this has been troubling you?.....  ....And your professor friends couldn't explain this to you either?.... WOW ! Here's one for you then, fella!...
"If your body's core temp is 98.6F ..... then why do we sweat when its only 80F outside, yet, we'd get hypothermia if we were in 80F water for too long?"
|
|
IP Logged |
|
|
|
ThudnBlunder
wu::riddles Moderator
Uberpuzzler
The dewdrop slides into the shining Sea
Gender:
Posts: 4489
|
|
Re: Mirror inversion
« Reply #34 on: Dec 2nd, 2006, 5:37am » |
Quote Modify
|
on Dec 1st, 2006, 9:45pm, uk9raine wrote:| . "If your body's core temp is 98.6F ..... then why do we sweat when its only 80F outside, yet, we'd get hypothermia if we were in 80F water for too long?" |
|
Air is a poor conductor of heat (hence string vests in winter), water is not.
|
|
IP Logged |
THE MEEK SHALL INHERIT THE EARTH.....................................................................er, if that's all right with the rest of you.
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: Mirror inversion
« Reply #35 on: Dec 4th, 2006, 1:58am » |
Quote Modify
|
80°F = 26.6°C
98°F = 37°C
makes it much clearer 
|
|
IP Logged |
|
|
|
towr
wu::riddles Moderator
Uberpuzzler
Some people are average, some are just mean.
Gender:
Posts: 13730
|
|
Re: Mirror inversion
« Reply #36 on: Dec 4th, 2006, 2:32am » |
Quote Modify
|
I don't think I'd get hypothermia any time soon in water with a temperature of 26.6 C (80F)
also
Quote:Expected Cold Water Survival
Temperature Fahrenheit-------------------------Exhaustion/Unconscious--------------- ---- --Expected Survival
32.5------------------------------------------------------------ <15 min. ------------------------------------- 10 to 45 min.
32.5 - 40------------------------------------------------------ 15 - 30 min. ------------------------------- 39 to 90 min.
40 - 50--------------------------------------------------------- 30 - 60 min. -------------------------------- 1 to 3 Hours
50 - 60--------------------------------------------------------- 1 - 2 Hours -------------------------------- 1 to 6 Hours
60 -70---------------------------------------------------------- 2 - 7 Hours --------------------------------- 2 to 40 Hours
70 -80---------------------------------------------------------- 3 -12 Hours --------------------------------- 3 to Indefinitely
Over 80-------------------------------------------------------- Indefinitely --------------------------------- Indefinitely
|
|
(http://www.walrus.com/~belov/hypothermia.html)
|
| « Last Edit: Dec 4th, 2006, 2:33am by towr » |
IP Logged |
Wikipedia, Google, Mathworld, Integer sequence DB
|
|
|
BNC
Uberpuzzler
Gender:
Posts: 1732
|
|
Re: Mirror inversion
« Reply #37 on: Dec 4th, 2006, 6:59am » |
Quote Modify
|
on Dec 1st, 2006, 9:45pm, uk9raine wrote:| I'm really sorry, but, did I read that you have a PhD in optics? ....And this has been troubling you?..... ....And your professor friends couldn't explain this to you either?.... |
|
Yes, yes, and yes.
surprised?
Quote:WOW ! Here's one for you then, fella!...
"If your body's core temp is 98.6F ..... then why do we sweat when its only 80F outside, yet, we'd get hypothermia if we were in 80F water for too long?" |
|
I beleive the answer was provided, but do tell: how does it relate to original question?
|
|
IP Logged |
How about supercalifragilisticexpialidociouspuzzler [Towr, 2007]
|
|
|
Bobishkindaguy
Newbie
Gender:
Posts: 1
|
|
Re: Mirror inversion
« Reply #38 on: Oct 7th, 2007, 7:56pm » |
Quote Modify
|
I've been reading all the explanations, but I'm not sure I understand it yet.
Standing in front of the mirror, it's true, you move your left hand and the hand of the "guy in the mirror" that is on your left also moves.
It's also true that front-to-back are "reversed". That is, point everywhere and the image points to the same place, except when you point toward the image, and in that case, in that plane of pointing, the image reverses and points, not in the direction you are pointing, but back at you.
And yes, if you rotate things on their horizontal axis instead of their vertical axis, then the imaginary "reflection" that results would be "waving the same hand" as you are.
BUT I cannot escape the simple truth that if I'm a gas station attendant named "Bruce", (which is a legal name, even outside of Australia), (no offense, just kidding; monty python silliness), and I stand in front of the mirror, my image in the mirror's name on his name label on his chest is BACKWARDS.
How about this hypothesis:
The "world" inside the mirror has an opposite frame of left-right reference to "our world". This sounds ridiculous, but think about it: There really is no "person" there, anyway, right? The "world" in the mirror is imaginary anyway, so we have to "invent" a set of laws of physics for that "world".
I know, I know. But Biff is my supervisor, so I just can't stand this level of confrontation with my mirror image. I'm afraid this puzzle has driven me crazy la la la la la la
|
|
IP Logged |
|
|
|
blacksabbath8907
Newbie
Posts: 2
|
|
Re: Mirror inversion
« Reply #39 on: Oct 22nd, 2007, 11:02pm » |
Quote Modify
|
Alright I'm sorry if this is wrong or incomplete or anything but I thought about it and so far no one has proved this wrong. So here is my idea.
To help you understand what is happening, you must understand the two events that are occurring. First there is a mirror image made, second that image is moving while you move. I will first explain how the motion works.
What you must first consider is what the mirror is actually representing. To explain what it is representing, I will first explain to you how the mirror is working. The mirror can be considered a two-dimensional plane existing in a three-dimensional universe. Before you can understand this concept it would probably be easier to imagine a one-dimensional mirror in a two-dimensional world.
Imagine an x-axis and a y-axis on a graph. This will be our two-dimensional world. Now imagine that there is a mirror that runs parallel to the y-axis and perpendicular to the y-axis. An example of this in the real world would be a wall mirror and your floor, negating the width of the mirror. The floor will be our x-axis and the wall with the mirror will be our y-axis. Now pretend that there is a ball on the floor that can only move towards and away from the wall and up and down. This is our two-dimensional system. Now pretend that the ball is moving away from the mirror. In the mirror it appears that the ball is moving opposite of the direction our ball is moving, but also moving away from the mirror on its side, in other words the motion is inverted. This is a simple property of light; as an object moves away from the observer it appears smaller because less light waves are able to hit it and bounce back towards our eyes and this is how we are able to perceive things in three dimensions. This is what happens when an object moves perpendicular to the reception of the light. Now when the ball moves up, instead of the ball in the mirror moving down it moves up as well. This is because the distance between the observer and the ball remains constant, but it is a matter of placement within this constant distance that changes, it is because motion is in the dimension parallel to the mirror. This explains why it is that the mirrored movement is not universally related to the movement of the object.
Now that you have understand the concept of a two-dimensional system with the one-dimensional mirror all you need to do is add in one extra dimension. Now we have the x-axis, the y-axis and also the z-axis. We are now going to find out why the three-dimensional actions are exhibited in the way they are. Pretend that our one-dimensional mirror is now a two-dimensional mirror, with an x-axis and a y-axis, as our mirrors are. Rather than it just being a line up and down, it now has width and we can consider this a plane. Now we are looking at this two-dimensional plane from its z-axis, a two-dimensional object in a three dimensional world. Now what we have is another axis, z, perpendicular to our mirror. Based on our knowledge of how a perpendicular axis relates motion in the world to that of its reflection, we can determine that the motion of the z-axis will be inverted on the mirror. The x-axis and y-axis, however, are both parallel and therefore will not be influenced by the reflection (see image 2.)
Now that you understand how motion works, there can still be a question about how the image is made on the mirror. An assumption people make is that when you see into a mirror, you are seeing the z and the y or x-axis flipped, but cannot explain why the other axis isn’t flipped. (If you don’t yet see this problem pretend that you are cut into half, keeping only your left half. Now on the mirror your reflection will have the right half of its body. Your heart will still be on your left, but the reflection will have it on its right side.) The problem is that you are not actually flipping anything, rather you are inverting it. To better understand this, pretend that you can see every particle on your body. Now in order to make a perpendicular reflection, rather than flipping anything left to right or top to bottom, you take each particle and move it to a depth on the mirror equal to the depth from you to the mirror. Rather than the reflection moving in a normal three-dimensional world though we can say that it is moving in a negative three-dimensional world (however this is only an illusion because the mirror is two-dimensional.) The mirror can actually represent negative space, which is why things appear to be flipped on one axis, but not the other. If you are having difficulty understanding why it is that the mirror represents a negative space, think about the z-axis. It protrudes out towards the observer from the mirror. When you come into contact with the mirror, you are zero spaces from the mirror and there is no light. You are now on unit zero on the z-axis. In order to move in positive units you go out from the mirror, but on the mirror it actually moves the opposite way (toward the negative space.)
This also can explain your problem about the name tag. The backward name tag is merely an inverted image, nothing is flipped or rotated. It is inverted.
Again I'm sorry if this is restating anything or wrong, its just something I thought up. I'm not even sure if it is appropriate to call it "negative" virtual space (I don't consider it actual space it is sort of a representation) but its what made sense to me.
|
|
IP Logged |
|
|
|
towr
wu::riddles Moderator
Uberpuzzler
Some people are average, some are just mean.
Gender:
Posts: 13730
|
|
Re: Mirror inversion
« Reply #40 on: Oct 23rd, 2007, 1:22am » |
Quote Modify
|
on Oct 22nd, 2007, 11:02pm, blacksabbath8907 wrote:| as an object moves away from the observer it appears smaller because less light waves are able to hit it and bounce back towards our eyes |
|
If it were merely that fewer light particles hit the eye, the image would seem dimmer, not smaller. It appears smaller, because the angle under which the rays of light are perceived is smaller.
Quote:?!
|
|
IP Logged |
Wikipedia, Google, Mathworld, Integer sequence DB
|
|
|
alien2
Uberpuzzler
Gender:
Posts: 6986
|
|
Re: Mirror inversion
« Reply #41 on: Oct 23rd, 2007, 6:19am » |
Quote Modify
|
The mirror is treacherous. Don't trust the mirror. Don't trust anybody and don't trust anything. Open your heart and meditate..
|
|
IP Logged |
|
|
|
Grimbal
wu::riddles Moderator
Uberpuzzler
Gender:
Posts: 7527
|
|
Re: Mirror inversion
« Reply #42 on: Oct 23rd, 2007, 6:49am » |
Quote Modify
|
That is a deep reflexion.
Yeah. Mirrors. When I take a picture and turn it around, it is upside down. If I take a mirror and turn it upside down, it is not! There must be some piece of lead inside the image that pulls the bottom of the image down, just to confuse us.
|
|
IP Logged |
|
|
|
blacksabbath8907
Newbie
Posts: 2
|
|
Re: Mirror inversion
« Reply #43 on: Oct 23rd, 2007, 9:49am » |
Quote Modify
|
sorry the smaller thing I didn't pay attention to and when i wrote that up I had a couple of pictures which didn't paste onto here and I forgot to remove all the "see image" deals... other than that though does it sound right?
|
|
IP Logged |
|
|
|
malchar
Junior Member
Gender:
Posts: 54
|
|
Re: Mirror inversion
« Reply #44 on: Jun 27th, 2008, 8:06am » |
Quote Modify
|
on Oct 7th, 2007, 7:56pm, Bobishkindaguy wrote:How about this hypothesis:
The "world" inside the mirror has an opposite frame of left-right reference to "our world". This sounds ridiculous, but think about it: There really is no "person" there, anyway, right? The "world" in the mirror is imaginary anyway, so we have to "invent" a set of laws of physics for that "world".
|
|
Many years ago, I saw an episode of Goosebumps the TV series, or some rip-off of that series. In the story, a kid finds a magical mirror and his reflected image trades places with him or kills him or something like that. The image was left-handed where the original kid was right-handed, and the words on his shirt were backwards too.
Anyway, I had this same mirror debate with some relatives a few years ago. I ended up concluding that the mirror reverses front-back, which basically turns the image inside-out. It has all been said before, but a mirror just reflects back the light that hits it. Consider how a small hand-held mirror works when you use it to reflect light around a dark room.
|
|
IP Logged |
|
|
|
|
RIDDLES SITE
WRITE MATH!
Home 
Help 
Search 
Members 
Login 
Register
Reply
Notify of replies
Send Topic
Print
Remove