why don't we have an empty space in our visual field?
479638
We do, but our brains mask the lack of information.  Use my source link to get more information.
20752
Yep and there is nothing there..just this empty space between your ears
8548
Close.  I would say it's because the photons from the object hit a smaller area of the cornea.  If you think of the surface of the cornea as a screen onto which the world in front of the viewer is projected through a lens, as an object is moved away the angle between its top and bottom gets smaller and so the relative size of the object in that projection gets smaller.
575853
that means empty space
861756
When you look out of the window, you think that you see an image with your eyes, as this is the way that you have been taught to think. However, in reality this is not how it works, because you do not see the world with your eyes. You see the image created in your brains. This is not a prediction, nor a philosophical speculation, but the scientific truth. \n\n     This concept can be better understood when we realize how the visual system operates. The eye is responsible for transforming light into an electric signal by means of the cells in the retina. This electrical signal reaches the sight center in the brain. The signals create the vision you see when you look out of the window. In other words, the sights you see are created in your brain.
264522
The healthy human eye is only restricted by external factors (ie.: poor visibility due to haze, dust or fog), just think how far the stars are!
449566
The Brain is the least understood part of human anatomy.  Considering this as a fact, and that the eyes (like all other parts of the body) are controlled by the brain, reality is all about perception of senses.  We as humans can be tricked into believing that things are three-dimensional, floating, transparent, or even close to us (how close are stars to earth?)....\n\nI guess you could contemplate anything as reality...so you could see nearly anything...or if you contemplate nothing you could see nothing.\n\n    This message is not really here...it's all perception.\n\nAre you reading this?
250715
Atoms do have empty spaces but these spaces are according to their size not ours let me elobrate first that we are not composed of atoms we are composed of cells if any one says atoms then tell that person that atoms are non living whereas cells are living some part of our body are dead cells like nails hairs dead skin at the knuckles etc but the rest is all living cells.\n\n\nThings don't fall through other things because they are levitating on an electrostatic field! I am not kidding! When you sit on a chair, you are not really touching it. You see, every atom is surrounded by a shell of electrons. This electron cloud presents a rather negative face to the world. Remember that like charges repel each other. When two atoms approach each other, their electron shells push back at each other, despite the fact that each atom's net charge is 0. This is a very useful feature of nature. It makes our lives a lot easier.\n\nNow the question you should be asking is, if atoms push away from each other, why doesn't the entire universe just blow away from itself? The answer is that some, actually most atoms' electron shells are not full. When two atoms come together and have empty spaces in their electron shells, they will share electrons to fill in the spaces in both of their shells. Yes, the electrons really do go back and forth between atoms and they do so pretty fast. Electrons tend to be kind of mobile, which is also a very nice feature of nature, since without it your walkman would not work. Once both atoms' outer shells are full due to this electron sharing, they go back to their usual repulsive behavior. This, by the way, is how we get molecules and the secret to understanding Chemistry. It's all about the electrons!
1021700
such a waste of space if we were alone.\n\n if you could just imagine yourself looking on our milky way from another outside.. \n\nhow infitestimally small we truly are... we are nothing but dust on a small rock revolving a small star..
26407
Well, according to most theories, the Universe does not have a 'wall', if by wall you mean boundry.  However, solar systems do have a 'wall'.  This wall is called the heliopause, and marks the boundry where a star's solar winds fade into the interstellar void (the space between the stars).  Any object passing through the heliopause is believed to experience a termination shock.  This is caused by the preasure difference between the solar winds and the void NOT because the object is actually hitting a wall or other physical barrier.  Today, many theories also (as the previous post mentions) suggest that the Universe is both finite yet boundless.  What does this mean?  First, 'finite' means that the Universe is not infinate in size (theoretically we could then assign a number to the its size, much like we assign a number to the size of a piece of land).  However, the Universe has no boundries - it is 'boundless'.  How can something have a finite size and no boundry?  One theory is that the Universe has a shape like a ball.  Imagine you are a tiny person walking on the surface of a basketball.  Assume you can only walk and not fly, jump, etc. No matter how much you walk in any direction, you'll never find an 'edge' (to you, the basketball has no boundry).  However, if you remove the skin from the basketball and lay it flat, it is apparent that the basketball _does_ have a finite (limited) size.  It's hard to imagine it, but picturing the Universe 'flat' and 'wrapped around' itself in a ball (a closed Universe) will allow you to have a Universe without boundries, but with a definate size.  Our minds are not equiped to visualize objects beyond the 3rd dimention (for example, we can't 'see' space-time), so most modling of the Universe makes the most 'sense' when done in calculations.
1056452
It is partly a matter of scale, and partly because of local relief in the landscape. \n If you were to stand on a perfectly flat plain or on the surface of an ocean, the farthest point you could see would be approximately 30 miles distant.  \n Also, because of changes in elevation over smaller distances, and/or obstructions to our field of vision, we tend to see even smaller 'chunks' of curvature, which our brains interpret to be flat.
609606
light is needed for viewing objects, but not for virtual ones. see our dreams are a interaction of waves produced in the brain. when there is interaction in the mind there is no need of light in that.
10093
Over everything else, our brains are pattern recoginition machines.  They are very, very good at filling in blanks -- even if they shouldn't.  The usefulness of this comes when coupled with our reasoning ability to figure out if things are important illusions, i.e. if the sabre-toothed tiger went around that side of the rock, he didn't just disappear, he's probably also coming out on the other side... but he can't see me right now either.
1148896
this is one of phylosophical questions i really like! but i also don't know the answer for sure. just according to my logical mind, i think the answer is YES. if it's not something, people will not be willing to find a word to describe it. and the space is not nothing because without it everything will be crazy.
12959
the answer to this question is not really well-known by the scientific community.  there are a number of competing models for explaining the energy  of empty space.  a good place to start learning about it would be to look up the cosmological constant, which is incorporated into general relativity.  it can be measured and is proportional to the energy density of empty space.  see the link below for more details.
612672
well unfortunately, outerspace is a whole lot of nothing, so it doesnt have to take up any space.  granted there are molecules floating around out there, but for the most part there isnt any matter in empty outer space
497775
Stars, except for the Sun, although they may be millions of miles in diameter, are very far away.  They appear as point sources even when viewed by telescopes.  The planets in our solar system, much smaller than stars, are closer and can be resolved as disks with a little bit of magnification (field binoculars, for example).\n\nSince the Earth's atmosphere is turbulent, all images viewed up through it tend to "swim."  The result of this is that sometimes a single point in object space gets mapped to two or more points in image space, and also sometimes a single point in object space does not get mapped into any point in image space.  When a star's single point in object space fails to map to at least one point in image space, the star seems to disappear temporarily.  This does not mean the star's light is lost for that moment.  It just means that it didn't get to your eye, it went somewhere else.\n\nSince planets represent several points in object space, it is highly likely that one or more points in the planet's object space get mapped to a points in image space, and the planet's image never winks out.  Each individual ray is twinkling away as badly as any star, but when all of those individual rays are viewed together, the next effect is averaged out to something considerably steadier.\n\nThe result is that stars tend to twinkle, and planets do not.  Other extended objects in space, even very far ones like nebulae, do not twinkle if they are sufficiently large that they have non-zero apparent diameter when viewed from the Earth.