A reflection ON a reflection OF a reflection...

[InfiniteNow]

So, you know when you go to get your haircut... there is a mirror in front of you and a mirror behind you, and you can see multiple reflections? My question is, do the repeating reflections EVER stop, or do they instead go on forever? Further, is there perhaps some "in-between" stage I may have missed? :xx:

 

 

Cheers. :xx:

[Tormod]

A mirror does not reflect 100% of the light that hits it. There will be a slight degradation of the image for each mirror. You will notice that the image looks darker the further "in" you look.

[Buffy]

From a theoretical standpoint, it will go on forever, in fact this is a pretty cool example of a fractal! Practically speaking what you can see of it is limited by the glass not being perfectly clear, and it gets smoggy out there. In addition, at some point the reflections, since they get visually smaller, will bump up against the size of a photon, and you'll end up with a dot that's the "last" reflection...

 

Opaquely,

Buffy

[InfiniteNow]

It's odd thinking of my own reflection at a Planck-Wheeler type size... Yikes...

 

 

Thanks both. :xx:

[Queso]

Ok now close your eyes in front of this mirror,

And talk.

 

Mirrors are reflective surfaces when it comes to sound as well,

and if you listen to can hear them bounce back and fourth SO FAST.

 

ok ok just taking other senses into consideration..

[Qfwfq]

The real trouble is that of increasing distance of images, including those of the mirror and hence of the "window" your are looking through.

 

If we don't take curvature into consideration, imagining the mirror surface perfectly flat, the images would all be the exact same size but further and further away. This gives them a smaller angular size in tour eye's view, the same reason why those huge vast things up there look like tiny little dots in the sky, but the actual size of the image won't become comparable to the size of a photon. :confused:

[Boerseun]

Saw this thread referenced from another, and it made me think:

 

Ever wondered why mirrors change left and right around, but leave top and bottom intact?

 

I'm probably incredibly stupid.

[Qfwfq]

Once, on an evening with some of the old freinds from physics, one guy asked that question and we spent the rest of the evening before everyone got it straight. I first pointed out the answer but it took a lot of effort to get them all to listen to my argument and understand it. Actually it's very simple. If you want the answer and don't want to think first, highlight below:

 

When you compare the object with its image, you are turning your head around a vertical axis.

 

If that doesn't help all the way, you can ask for more details.

[Boerseun]

I could understand the 'vertical axis' bit if the axis was a vertical line drawn in the middle of the horizontal line between your eyes. But if I close one eye the axis is gone - but the mirror still only flips left/right, not up/down.

 

Yep. I must be dumb or sumtin'.

[pgrmdave]

But mirrors don't flip anything - that's why it seems flipped. Look at yourself in the mirror, and you'll notice that your right arm is on the right, and your left arm is on the left. It only really seems flipped because we think of our reflection almost as a person, and can imagine "his" left arm, and "his" right eye. It would be very odd indeed if when you moved your left arm, the arm on the right started to move!

[Boerseun]

See - I told you I was stupid. Thanks, Dave - all we need is a bit of common sense every now and then.

 

I'm a brain donor. Problem is, I'm post-op.

[Qfwfq]

But mirrors don't flip anything

They dooooooo!!!!!

 

Except not left to right, or up-down, but back to front... you and your mirror image are staring each other straight in the face!

[Qfwfq]

It only really seems flipped because we think of our reflection almost as a person, and can imagine "his" left arm, and "his" right eye.

But why do ambulances have the word backwards, instead of upside down? It's the same thing, even for a meaningless object with no symmetry.

[Jay-qu]

I think the term is your body is not chiral, there are biases, non-symetric..

[pgrmdave]

you and your mirror image are staring each other straight in the face!

 

Exactly - there is no flipping involved.

[Qfwfq]

YOu and the image are facing each other, means facing opposite ways. This is the true flip.

 

Put something just in front of the mirror and look at both object and image from a transverse angle, in this case it is obvious. stand just off the perpendicular and it becomes less obvious unless the object is partly transparent. When it's a paper with writing, you obviously don't compare the writing as seen form the wrong side of the pare, you compare via a rotation.

 

But which rotation? Why don't they paint the word 'ambulance' with an up-down flip? It would be just as specular as the left-right flip but it wouldn't be nearly as immediate to read in your rear-view mirror.