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#53712 02/03/15 10:34 PM
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monica1 Offline OP
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Hiya smile

do we see with eyes or the brain?

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monica1 #53715 02/04/15 08:04 PM
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Some of both. The eyes are the sensors that determine what image is provided. The brain then does a lot of high powered processing to convert that into vision.

The eyes are really very poor sensors, when compared to a modern camera. They have blind spots, the nerves run across the front of the retina so that they cover a large part of the sensing area, and the focus is really pretty poor. However, the visual part of the brain has been evolved to compensate for all of those defects and we wind up with a really remarkable sense of vision.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
Bill #53716 02/05/15 01:01 PM
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monica1 Offline OP
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Hiya again, so we don't see by the constant energy transmission medium having carrier signals from an object modulated onto the light and through the transmission medium to our brains? smile

monica1 #53718 02/05/15 05:02 PM
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On a course designed for people working on the boundary between mental illness and other problems, the tutor told us of a man who was sitting watching television when he saw herd of horses enter through one wall and exit through another. He was referred to the MH Service and tested for all kinds of things. Eventually it was decided that he had a problem with his optic nerves, rather than a MH problem. I mention this only because I wondered at the time how much of this could be attributed to his eyes, and how much to his brain.


There never was nothing.
Bill S. #53722 02/06/15 11:38 PM
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monica1 Offline OP
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Great story, thank you for the reply wink

Do your eyes do anything more than acting has a sensor?

Is it not a circuit board on a television that decodes the information the remote sensor receives?

monica1 #53723 02/07/15 02:39 PM
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Originally Posted By: monica1
Hiya again, so we don't see by the constant energy transmission medium having carrier signals from an object modulated onto the light and through the transmission medium to our brains?


I'm afraid I don't quite understand what you are trying to ask. Obviously we see the light that enters our eyes. The rods and cones in the eye transform the light into nerve signals which the brain then interprets so that we can tell what we are seeing. The brain does not directly detect light.
Originally Posted By: monica1
Do your eyes do anything more than acting has a sensor?

The eyes are primarily detectors. I wouldn't bet that they don't have some other function, a lot of our organs manage to do something else, but their main function is to detect the light coming from the objects we see.
Originally Posted By: monica1
Is it not a circuit board on a television that decodes the information the remote sensor receives?

If you are trying to make a comparison between the television and your brain then I will say that to some small extent you are correct. The main difference between the television system and the eye brain system is that the television just recreates the pattern of light and dark that is received by the camera, it doesn't do any further processing. It basically produces a one to one representation of the scene in front of the camera. The brain does a lot more. The brain analyzes the image and assigns values to what is in the image. For example it says that is a tree, that is a car, that is a tiger. This is a much more complex process than producing a picture on a TV.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
Bill #53724 02/07/15 03:37 PM
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monica1 Offline OP
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Hiya, you say that our eye's ,that the The rods and cones in the eye transform the light into nerve signals which the brain then interprets so that we can tell what we are seeing.

When you say transform the light into nerve signals which the brain then interprets so that we can tell what we are seeing, are you saying that light is not a thing? because how can it be light if it is our brains that interpret what we see.
Would our brains not also be interpreting it to be light?

You also say the brain analyzes the image and assigns values to what is in the image, how does the brain see light because in a space light is seemingly colourless?

''Hiya again, so we don't see by the constant energy transmission medium having carrier signals from an object modulated onto the light and through the transmission medium to our brains?''

The part you did not understand, I was considering fibre optics and how information can be sent by using light and considered light in a space and the difference of an objects light and colour compared to the light in a space. I thought the light in a space seemed visually clear and a sort of transmission constant. So I was wondering if an object some way transferred a signal through the transmission constant?

monica1 #53733 02/08/15 02:54 PM
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I think we need to start at a slightly lower level here. First let's talk about light. Light is an electromagnetic wave (or particle, it is both). The color of light depends on the wavelength of the light. White light is light that has a great many colors in it. For a more complete discussion try checking out the Wikipedia Page on Light. The eye has cells which when they are stimulated by light of a certain wavelength generate an electrical pulse which is transmitted along the optic nerve to the brain. The more light hits each cell the stronger the signal sent to the brain. There are a lot of these cells on the retina of the eye. Different cells are sensitive to different colors so the eye can detect how much of each color is present in the view. The brain then processes the electrical signal and we perceive the result as a picture that we understand. For more about how vision works try the Wikipedia article Vision Perception.

Originally Posted By: monica1

The part you did not understand, I was considering fibre optics and how information can be sent by using light and considered light in a space and the difference of an objects light and colour compared to the light in a space. I thought the light in a space seemed visually clear and a sort of transmission constant. So I was wondering if an object some way transferred a signal through the transmission constant?

I still don't understand what you are talking about. When you say light that is all there is. Light is light, no matter where it is. As far as an objects color. The color of an object depends on what wavelengths of light it absorbs or reflects. Objects that are red absorb most wavelengths except those that our eyes and brains interpret as red. Likewise for blue. White objects reflect all wavelengths and we interpret that as white. Well, I say absorbs or reflects. The other side of that is that something that is glowing is emitting the light and the color depends on what wavelengths it is emitting.

Hope that helps.

Bill Gill


C is not the speed of light in a vacuum.
C is the universal speed limit.
Bill #53735 02/08/15 10:36 PM
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monica1 Offline OP
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Hiya, thank you for your reply again. smile


You say ''The color of light depends on the wavelength of the light. White light is light that has a great many colors in it.''


I will try to start from here with what I am asking.

White light, I presume you mean the light from a light bulb that illuminates my room compared to the colours in my room of objects?

The white light has a mixture, we do not see a mixture of colours, we see clear light?

I can see through the dark when I have my light turned on, when I turn the light off, I can no longer see the wall through the dark.

The white light is what I am referring to has the constant transmission medium.


I was asking then if in some way, that the wall modulates a signal back through itself to your eyes?

My little boy has got a set of night vision goggles, at night it looks light, so I suppose I was asking when the light is turned on and the brain interprets all the information, are we not just seeing in the dark?

monica1 #53737 02/09/15 02:57 PM
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When I say white light I mean any light that contains all the visible colors at approximately the same level. So we can get white light from a bulb, or from light that is reflected off of some white surface, such as a white wall or a piece of white paper. Colored light is light that does not have all of the colors in it. Colored light can be from a colored source, such as a red LED or it can be from a surface that absorbs all the other colors. For example a red apple is red because if you let a white light fall on it all the colors except red are absorbed. That is the way the colors of the objects in your room work.

I think we may be having a slight problem with the way you are using the word 'clear'. Clear light doesn't have much meaning to me. I just think of light as light. Clear to me means something like a window which is clear because it doesn't block the passage of light. And light is any light that we can see, it can have any color.

The only transmission medium that is concerned with light is basically space itself. I want to keep this as simple as possible so I won't go into a discussion of the transmission of light.

Back to color. Have you ever had an art class where the teacher explained how colors work? You may recall the primary colors Red, Blue, and Green. In art you make up different colors by combining those three primary colors. White is the combination of all three colors. That is how, for example whatever device you are seeing this on works. It has very small dots of the 3 primary colors. The colors you see depend on how much of each of those colors is turned on. That is how light and color work. Light is just waves in space. Color depends on the wavelength of those waves. Different combinations of those colors are perceived as different colors. So the colors of objects are not modulations of the light but simple reflection and absorption. And darkness is simply the absence of light.

I think you may be being confused by your sons night vision goggles letting him see in the dark. That requires a bit more explanation. I have been talking about visible light. But visible light isn't all there is. Light is electromagnetic radiation. That can be a big subject, but keeping it as simple as possible. I mentioned the wavelength of light. Electromagnetic radiation exists with many wavelengths that we cannot see. If you have a radio then the radio waves that come through the air to your radio are electromagnetic waves with much longer wavelengths than what we can see. If you have ever had an X-ray the X-rays are electromagnetic waves with much shorter wavelengths than what we can see. All around the wavelengths that our eyes can perceive there are others that are invisible to us. You sons night vision goggles can detect some of these wavelengths in what are called the infrared (IR) spectrum. They are also what you feel as heat if you stand in front of a radiant heater. Anything that is warm radiates infrared wavelengths. The warmer it is the more it radiates. The goggles detect these wavelengths and through the magic of modern science presents the pattern of the detected IR on screens in the goggles. That way he can see what is warm around him. So in the visible dark, there is no light, but in the IR there is still 'light' to be detected. It isn't really that he is seeing in the dark. He is just seeing the light that is there, but our eyes can't detect.

Here is a link to the Wikipedia article on Infrared

If you need more clarification, and you might I'm not a real teacher, don't be afraid to ask.

Bill Gill

Last edited by Bill; 02/09/15 02:58 PM.

C is not the speed of light in a vacuum.
C is the universal speed limit.
Bill #53738 02/09/15 04:21 PM
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monica1 Offline OP
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Hiya again, smile

Thank you for your great explanation. The one point I am trying to ask about is this from your post.

'' Clear to me means something like a window which is clear because it doesn't block the passage of light. And light is any light that we can see, it can have any color. ''

You say the dark is just the absence of light, is dark not a state behind the light?

Is dark not like a window to light and allows the light from my light bulb to pass through it which then when lit allows me to see through the dark?


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