A couple of years ago I had eye surgery to repair a macular hole. This involves draining the eye and refilling it with a gas that is gradually absorbed. Part way through, you have an eye with liquid at the bottom and gas floating on top.
Except of courses the gas appears to be at the bottom, because our eye lenses work just the same as all the others. A neat demonstration, but not one I can really recommend. Many years ago when I was a schoolboy in fact many, many years ago , we were shown a series of films by the Moody Scientific Institute Chicago? One of the films described an experiment in which an individual was fitted with a head mounted binocular that turned the world upside down. After a period of wearing it, the individual started to see the right way up again because his brain compensated.
The problems really started however. Without conscious presence of the something justifying the effect, his brain couldn't cope and he went through a period of severe mental disturbance.
Not one to try at home I guess. I don't think I explained it very well. Things looked their normal way up. The gas bubble was at the physical top of my eyeball and therefore aligned with the bottom of what I was looking at, so it appeared at the bottom of my vision If you really want to experience queasy, the operation is performed under local anesthetic, so you can see what is happening.
Originally Posted by James G. Dave that's weird and somewhat disturbing What does interest me though, is that you perceived the change in orientation and your brain did not 'normalise'.
How long did it take to get back to normal vision? Just interested in a somewhat ghoulish fashion. How could you use different tools to observe the world around us? Hint: The brighter the environment outside your box, the easier it will be to see! Try pointing your pinhole out the window! National Geographic Pinhole Camera. Details Activity Length 60 mins.
In this activity, we will make a basic camera obscura out of a cardboard box. Objectives Describe how light travels to create a projected image. Materials Per Camera Obscura: medium-sized cardboard box e.
What To Do Cut a piece of white paper to the size of one of the inside walls of the box. Tape it flat onto the inside wall. This will be the screen that your image is projected on.
On the opposite wall to your screen cut away a small square 3cm of the cardboard. On the same wall as your foil cut away another small square 3cm of cardboard. This will your viewing hole. This allows the angle of view of the camera to be changed and also the effective f-stop ratio of the camera.
When you place an object in front of the pinhole camera, a clear image is formed on the screen. The image formed on the pinhole camera is inverted. If the distance between the pinhole and screen is reduced, the size of the image will decrease and the image will become bright since the light spreads over a small area. Using a larger pinhole gives you a brighter image, since it lets in more light, but increases the overlapping of images. Yes the image can be bigger than the object by increasing the distance of the screen from the pin hole.
A pinhole camera is a simple camera, without lens, in the shape of a box. One of the sides has a small hole and it produces an inverted image of the outside world at other side. The image of the outer object is created inverted on the inner box translucent screen. Like your eyes, the camera needs light to operate. Light moves into the eye through the pupil, a hole that is made smaller or larger by the iris.
Put a lamp in the room and turn it on. Point the side with the pencil hole at the lamp; place the blanket over your head and half of the shoebox.
Look at the wax paper screen and you should see the inverted image of the lamp. Using an sewing needle, pierce a tiny hole in center of the aluminum foil. Now darken the room as best you can. Allow your newly constructed camera obscura to look out a window. You will see an upside down image of the outside world projected on the tracing paper.
Insert into the camera with light-sensitive side facing the pinhole. Close the lid and make sure the pinhole shutter is closed. Slide the shutter open and start timing. The depth of field is less for a lens camera than for a pinhole. Objects emit light in all directions, only some of which enter the camera.
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