The discussion of whether an object seen in a mirror is two-dimensional or three is fascinating.
It is really about at what point does something go from an object to an image to a perception and back to an object in our minds.
Consider this - in a significant way, you don’t really “see” an object. Light rays strike an object, bounce off of the object differentially based on the material and physical form of the object (not to mention the light source, etc). Those light rays strike the light receptors in your eyes (which are in a single layer on the back surface of your eyeball), which are turned into neural impulses that go through several filters (including but not limited to binocular processing). These impulses are finally interpreted into a concept of what you are seeing.
When you see an object in a mirror, the only things that have changed are context and your perception of what an image is versus an object. Is it two dimensional or three dimensional? I say that depends on whether you perceive that you are seeing an object whose image just happens to be reflected off of a mirrored surface, or if you are seeing the a mirror that has an object reflected in it.
It is the fact that seeing happens mostly in the brain, even though we perceive that what we are seeing is mostly external that allows optical illusions to have their power.
I read all about rods and cones in my physics, chemistry and biology classes, and how you see in monochrome if it’s dark enough, but I’ve never observed that. I can’t remember ever being in a place dark enough that my cones shut off and I only saw in monochrome. How do you do it? Shutting off a room at night, closing all the windows/doors etc., and then turning off the light doesn’t work; my alarm clock’s digits are still green.
Yes, please! I had enough of that in intro Physics (and will have enough of it again in not-so-intro Physics).
They are their own light-source.
You kinda have to avoid synthetic lightsources, which can be difficult in cities and suburbia. It also helps if you don’t know what color something is to begin with, as your brain can add the remembered color by itself (Can someone confirm this?).
I have seen dramaticly lowered saturation levels at night, but never complete desaturation. (I have experienced total loss of all light, but that’s another story)
Ron Burgundy: I’m a man who discovered the wheel and built the Eiffel Tower out of metal and brawn. That’s what kind of man I am. You’re just a woman with a small brain. With a brain a third the size of us. It’s science.
This is just wrong; the image isn’t ‘in’ the mirror (except semantically); the mirror merely reflects light; you’re seeing the object (or perceiving its image) in every bit as real a sense as if you were seeing it through a window, or viewing it directly.
Remember that term? It refers to images such as that in the flat mirror, where the apparent location of the image in the field of view is not where the light beams hitting your eye are really coming from.
This seems to be a concept that is hard to get across. You see something, reach out and touch it an your touch confirms that it is shaped like you see it. However, it we “saw” only in the ultra violet things would look entirely differently and many of them would disappear.
One more time. All we ever see are images and the image from a mirror is the same as any other image.
Well, not really. I just wanted to make a really simple point that the question, as asked, does not imply one clear factual answer, simply because the terms being used are not necessarily precise. Rather than citations for clear, decisive, commonly-known definitions of “image” that demonstrates the original question’s precision, I get explanations of mirror, parallax, reflection, and light. That stuff is orthogonal to the point wanted to make.
People are not blanketly stupid because they think being economically rational means caring about how much money they have. (Although, economists are blanketly stupid for not teaching the proper definition of “rational”. It’s so annoying.) It’s a term of art, and I cannot expect the average person to know a term of art. If image is a term of art, then it needs to be clearly explained, otherwise, not using it properly is not moronic, because it is not obvious that it implies what some consider it to imply. I’ve been trying give a contrary understanding of the term image to make that specific point.
(Unlike what seems to have been too many threads, where I’ve explained rational repeatedly, only to have the definition rejected as not fitting so-called common sense. In that case, rejecting a term of are is indeed moronic. But that’s just a huge pet peeve of mine.)
It seems to me that the original question clearly concerned an “image” as the optical counterpart of an object that is formed by optical devices acting on the light reflected by the object. For the images that we see with our vision this needs to be extended to include the eye converting the light into electrical impulses and the brain assembling them into vision.
The placenta is there to support the baby until birth and comes out whether the birth is vaginal or cesarean. When the placenta separates from the uterine wall, it leaves a bit of a wound. The lochia is what seeps from the wound until it finishes healing.
I once went on a hike so early it was still pitch-black. As dawn came I was shocked to discover that everything was black and white. Then the sun came up some more and I started seeing colours. That was the only time I’ve ever seen in pure monochrome.
Cool. I’ve been looking into getting my remaining strabismus corrected (it was partially corrected when I was 18 months old) because I read that adult correction can improve stereoscopic vision, which they didn’t use to think it could do.
But this is vacuously true - obviously the mirror is flat. It’s not something someone could sensibly argue about.
The only thing we could sensibly argue about is whether the reflection you see in the mirror has depth. Before, people were arguing that no, the reflection has no depth because the surface of the mirror has no depth. It was pointed out to them that we still perceive depth in the reflection the same way we do if the light rays were coming to us directly, unreflected in the mirror, and unlike a still image such as a photograph.
Moving along, here’s a way for someone with no depth perception, such as me, to demonstrate this to themself. Look at a painting or photograph, then move to the side of the image so you are looking at it from an oblique angle. You will see that it flattens out. Now look at a mirror from a similar angle; you will see that the image is still completely realistic, as if you were looking through a window at the room. I don’t think even a 3-D movie can do this.
Returning to the originally scheduled thread, the one about silly scientific beliefs …
I once worked with a college-educated total ditzoid. She was from Texas, with the big accent (pronounced “ack SAAAY ent”), big heart, big blond hair, big wide eyes, and not 3 brain cells-worth of sense.
One day somebody mentioned that nautical miles used for distance measurement at sea were about 15% longer than statute miles used for the same purpose on land.
She thought about this new nugget of knowledge for a couple minutes, then her face brighthened & she said “I know!!”, like Archimedes announcing Eureka!
Her theory was that the extra distance was needed to make up for the fact that ships slip backwards a little each time they climb up the front of a wave. This slippage amounted to about 15%.
She was crestfallen when I pointed out that ships ought to slide ahead the same amount when going down the back side of the same wave.
Aaah, SCIENCE!!
I don’t recall now whether she was an Aggie or not, but she was always good for a laugh.
I worked with a woman who was convinced and convinced many who worked with us that the black 100% cotton t shirts given to us to wear inside the un air conditioned building, made us feel hotter becasue " black absorbs heat" When she was given the opportunity to wear what she wanted as long as she was appropriately covered, she wore a dark blue polyester blouse. Yep I bet she felt way cooler in that. Of course she also thought she should make more money than me because she had six kids. Experience, ability and willingness to do my job not withstanding, she deserved it.
I knew the placenta came out regardless, I just wondered if it got pulled out the c-section incision or is "delivered’ vaginally. Thanks for the lochia info.
