"shpuker" (shpuker)
04/21/2016 at 15:03 • Filed to: None
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"shpuker" (shpuker)
04/21/2016 at 15:03 • Filed to: None | 6
| 3 |
Jason Torchinsky never claimed to be a man of science, but that doesn’t make !!!error: Indecipherable SUB-paragraph formatting!!! . Lets break down what exactly causes each effect on these images.
First things first lets go over the basics.
When light strikes a curved mirror it comes off at an angle that allows it to pass through its focal point (whether real or virtual, we’ll get to that) exactly once.
If an object is at a distance that is equal to its focal point no image will form because of rule 1.
An mirrors focal point is 1/2 its radius, so a 2" radius gives a 1" focal.
That should help create a fairly stable foundation to step from. Now lets dig into concave mirrors specifically. A concave mirror has a focal point that sits on the objects side of the mirror, forming a focal point that looks like this.
Here we see rule 1 explained fairly well, with the object never producing an image as light leaves the focal point. Now how about the scenario we see in the images of the Cherokee?
When you have an object that sits between the radius and focal point you end up with an image that is both inverted and larger than the original object, whereas an object that sits outside the radius and the focal point will yield an image that is also inverted, but is smaller than the original object. Or in other words...
“In the bouncing-off process, the light rays that hit the bottom bounce up to the top, and vice versa, creating an inverted image. “
While that isn’t complete bullshit by any means it really fails to explain what’s actually happening.
Something a bit more interesting than this however is the idea of virtual images. A virtual image forms from an object that sits inside the focal point of a mirror.
A virtual image will appear to be upright and larger than the original. This really just breaks down to the concept that light HAS to pass through, or at least behave as if it passed through, its focal point. Thus as light hits the mirror you’ll see an image that actually appears to be on the other side of the mirror, and upright.
But possibly the most painful line from the entire bit:
“The result is a small image, and, in this case, squashed-looking because the mirror ‘cylinder’ is so small.”
Again it’s not “technically” wrong, but it’s technically wrong. The image shrinks due to the relative difference between the distance from the object to the mirror and the radius of curvature. As you move an object closer and closer to a convex mirror it will appear closer and closer to its actual size, regardless of the actual size of the mirrors “cylinder.”
As to why the images appear distorted and elongated or smashed, well that just comes down to the fact that these “mirrors” only curve in a single dimension. Thus the image only distorts in that one dimension.
You could take this even farther and get into why most images appear to be flipped and some don’t, focal blind-spots, and a whole shit load of other technicalities that I’m not about to dive into right now, but that should help develop a better understanding of what’s actually going on.
P.S. If you want to see this phenomenon for yourself just get a spoon and move it progressively closer to your eye. if you start at say an arms length and move in you’ll be able to watch the inverted image of your eye go from tiny, to real size, to larger than actual size and then gone altogether. then as you keep getting it closer, your eye will appear upright and larger than real size.
OPPOsaurus WRX
> shpuker
04/21/2016 at 15:17 |
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one of my daughters got a huge laugh out of this when she was getting out of the car the other day. she looked at her reflection and started giggling cuz she had no head and a big belly... shes 3
cazzyodo
> shpuker
04/21/2016 at 15:29 |
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Oh lens diagrams...
It’s fun to project images of candles or lightbulbs. A teacher would yell out different set-ups and we’d have to come up with where, how big and/or what orientation the image would be. It was pretty entertaining to hear all the answers being shouted.
Textured Soy Protein
> shpuker
06/28/2016 at 13:00 |
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Can confirm this is real. Last week I was driving with a coworker to a lunch meeting. I pulled up behind a Cherokee at a stoplight and noticed, and commented on, the reflection of my car being upside down.