[QUOTE=Michael MacFarlane]Pretty sure it'd just look like a cube to you.[/QUOTE]

But would it FEEL like a normal cube? That's the point of holding it. That, and I'd be holding a 4-d object. Just knowing that would be cool. You know, assuming everything isn't 4-d and I just don't know it

Everything is 4d. If the dimension exists, it's part of everything. Imagine a hypothetical 2d object (Which don't actually exist). It's still a 3d object - it just has a size of 0 in the 3rd dimension. That third dimension is still there. It's the same for the fourth dimension. Except, of course, 'in real life' there is no such thing as a size of 0 in the third dimension - why would it be any different for the fourth?

A 2D object would make an AMAZING knife blade.

just get a ZPM lol

More likely it would be a bad knife blade. Since it has a size of zero, it would just move between the molecules of an object without separating them. Therefore, no cutting.



I think, it's late.

Yeah, that's why a one-dimensional object would make a poor blade. But imagine if you had something like a meat cleaver with a 2-D blade.

Yeah, but you could move it between the molecules of the object then move it away from the rest of the object.

-Cutted!

Though we don't know how a 2D object would handle in a 3D world. It would have to be totally stiff.

Well, it would be.

-I mean, after all, if it bended, it would have three dimensions.

we see in three dimensions because we have two eyes, each seeing space from a different angle simultaneously. people blind in one eye see in only 2 dimensions.

the second dimension does exist, but only with atoms/molecules/whatever that are coplanar. the same way the first dimension exists only with things that are colinear. so these dimensions exist all around us. it's just the fact that it is hard for more than 2 atoms to be exactly colinear because of the possibility for it to be infinitely small distances off that line. the same is true for finding coplanar atoms or molecules.

Okay I think this needs to be put to rest.

The back of each of our eyes is coated in light-sensitive cells which act like a CCD. The lens on the front of your eye focusses the light onto the cells in back, just like a camera. A camera produces a two-dimensional image; so do our eyes. However, we have two eyes that are offset from each other, and it is this offset that allows us to calculate distances in the third dimension.

Thankfully for people who've lost an eye, the human brain is very very good at using other clues to determine distances. Focal lengths, size of common objects, relative motion, etc. This also comes in handy when playing video games, which are obviously two-dimensional.

but though it is using those other clues, it is still only seeing whatever is rendered on that screen in the second dimension. it's just the fact that it is changing in real time that allows us to percieve a third dimension. which is why it would kick *** to have videogames rendered in, like, holograms or something.

Oh, for sure. But then again, maybe not. I mean, you SAY that, but I didn't see you rushing out to purchase one of those 3D monitors that came out a couple of years ago...

Once again, we do not see in 3D. If we saw in 3D, we would know what is in front of and behind any given object. Our brain receives two 2D images taken at different angles, splits each in half, so each half of the brain is processing half of each image, and blurs together both 2D images to better understand the 3D world around us. One last time, we see in 2D.

No. Atoms exist in all dimensions. They have a breadth, a width, and a depth. Therefore, anything they form will also have a breadth, a width, and a depth. The idea of a point, a line, or a plane are merely mathematical constructs.

The only non-3 dimensional object known to exist is the black hole, which by virtue of occupying an infinitly small space actually occupies no space, and thus has zero dimensions. The behavior of light around it (Odd, actually - light doesn't seem to actually fall in, it just red shifts until it has infinite wavelength...) suggests that it also occupies zero time.

Therefore, a black hole can represent a point. Similarily, the event horizon of a blackhole has no width. It is an infinitly thin surface. But it is also not a physical object.

As for our eyes; the image is also highly distorted, and has a maximum resolution. The surface receiving the projection isn't flat at all either. The result, were the cells in our retina mapped onto an evenly-spaced 2d grid, is a sort of fish-eye lens effect. Our visual cortex opperates on very primitive data. It detects edges where the color changes. Different neurons fire depending on which way the edge is oriented. Other neurons fire depending on the pattern of edge-detecting neurons, and still more fire based on the pattern of THOSE neurons - until, a few million neurons later, a group fires that represents 'face' instead of 'a million tiny edges'.

Er, black holes are not known to exist. There is visual evidence that supports the theory, but nothing concrete...

Just for the record.

On a semi-related note, can we please dispense with the idea that light and time are some how magically connected? Einstein made that connection in order to make his theory work (postulates are 'things that have to be true in order for the thoery to be valid'...assumptions, really) yet never gives us an explination of how he logically reached that conclusion beyond mathamatical fiddles (which String Theory proved the danger of using mathamatical fiddles in an attempt to prove a theory).

A lot of things aren't concrete, but we'd like to see a better idea.

lol f=mv of course

so what would it take to see in 3d? a third eye? just more work for your brain. i still believe wee see in 3d. the reason you think what you do about seeing all aspects of an object is that the object will never be directly in between our eyes, in which case all aspects would be visible. the only way to truly see in front of and behind any given object would be to see an object from every possible angle simultaneously, which is impossible. just by having two eyes though, we see more aspects of an object than we would with only one eye. just try the cross eyed trick with your finger. as you bring your finger from far away closer and closer to the bridge of your nose, each of your eyes will see parts of the finger that the other can't. it's just that, having two reference points, that creates the 3d sight we have.

A 3rd eye? Are you not listening to me? 2D images in each eye. You could throw in a million eyes and it still wouldn't be 3D. 3D vision is unknown. No one knows what the hell that'd look like. I can't explain that any other way. 2D images in each eye.

To see in 3d you'd need 4 eyes, of which 3 would probably have to be on stalks. If you could position them about an object with each eyeball in a position corresponding to a point on a tretrahedron about it, you would be able to see all outer surfaces of that object. God knows what things would look like outside of your 3D zone of vision. Perhaps your brain would be able to reconstruct the images into a 3D concept except you would be missing information as to what the rear surface of an object looked like.

EDIT: after reading subsequent posts I realise the above is a load of bollocks

Math is what makes the world go round. You shouldn't go dismissing things just because you don't understand how they work.

Echolocation would be roughly 3d. Sonar bouncing around an object could create a "visual" of what's on the other side.

-A gazillion eyes would be cool though.

To truly see in 3 dimenions, wouldn't you need 4-dimensional eyes?

Yes. Although we do have machines that can see in three dimensions (MRI machines, CT scanners, etc.).

Imagine trying to comprehend all the data from a MRI scan as a single "image"; that would be seeing in 3-D.

Since when has 3d vision and X-ray vision been the same thing?

To see in 3D, you wouldn't just see surfaces. You would see every point in 3D space simultaneously. That is what the aforementioned machines do.

Why is omnipotence a requirement to see in 3d? How does preventing me from seeing every side of a block at once keep me from recognizing how far away it is from me and how tall and wide it is?

[QUOTE=Kieran Horn]Why is omnipotence a requirement to see in 3d? How does preventing me from seeing every side of a block at once keep me from recognizing how far away it is from me and how tall and wide it is?[/QUOTE]

Who ever said you needed to be omnipotent?

http://forums.massassi.net/vb3/attachment.php?attachmentid=14160&stc=1

-click it

so, each of your eyes has a line of sight to where it is looking. sight, to the same place as the other eye. these lines of sight are not parallel, because they cross at the point of observation. peripherally each eye sees a two dimensional image. that image is perpendicular to the line of sight of the eye which is seeing it. these two "non-parallel" planes (planes being 2d) create a 3d image (3d being non-coplanar). our vision moves from 2d to 3d when we discern points in space that are not coplanar.

kyle90, you say that to see in 3d we need to be able to discern every point in space simutaneously. does that mean we need to be able to discern every point across a plane simultaneously to see in 2d? no. we only have to see those points which partake in the object or scene we are observing.

remember. only a sith deals in absolutes.

That's not what he means. Imagine trying to comprehend all of the data (every angle and position) of a 3D MRI scan all at once, as ONE image. That would be seeing in 3D.

Maybe think of it this way...say you have a one dimensional image, like this:

--x------

Then another one offset like this:

------x--

If you combined the image of those, it wouldn't become 2D. It doesn't add another dimension. It's still 1D. I dunno if that helps, but I can't think of anything else right now.

Two 1D images does not create 2D. Two 2D images does not create 3D, etc.

I see it like this: If you stack a bunch of sheets of paper (presume they are just 2d), you're increasing in the 3rd dimension by making your pile thicker. So for the 4th dimension, I imagine everything having sort of another property of thickness. It's hard to explain.

You demonstrate your ignorance in spades. Mathematics IS demonstrating how he logically reached his conclusions. You just don't understand how he got to those conclusions.

I considered this a while ago, actually - the possibility that even if the perception of 3D objects isn't complete (that is, it only has certain surfaces facing a certain direction, rather than every point in space), it can still be a 3D 'image'.

Each point on the 2D images we perceive has various properties such as colour and lightness. Depth is one of those properties. The brain compares the two images to calculate this property. It is still a 2-dimensional property, though. It just allows us to interpret the 2D images in terms of 3 dimensions, and also, combined with the proprioceptive sense, it gives us a spatial sense of our surroundings.

So whether we see in 3d or not really depends on how you define 'see'.

Like "I saw your mom naked last night"?

-Oh snap.

Well I "saw" an MRI of your mom.

Daaaaaaaaamn is she one nasty ***** on da inside.

Just like Mathematics demonstrated how apparently 7+ different string theories could all be right? Their idea of "Appyling Math to demonstrate proof of their Theory" was by getting to a point where they couldn't go any further, and then make an assumption that another dimension must exist. This works fine, at first, until they hit another dead. Well I guess another dimension must exist, right? String Theory was the single most largest embarrassment to the Scientific Community. Again, it also proved the danger of relying on Math to "Prove" something exists. Rational people call this a 'Reasoning Fallacy' where someone believe that an idea or concept could possibly ever "prove" that something exists. What makes it worse is simply how easy it is to "fiddle" with the math to "make it work"...because, you know, there just "MUST" be another dimension...

Math assumes a Finite universe (look up the 0.[...]999 = 1 and 0.[...]001 = 0 debates/studies). There is not a 1 to 1 ratio between the concept of math and the physical universe.

Ummm what? There's no debate that 0.99999(repeating) doesn't equal 1.

At least I hope not because it would pretty much render all of calculus irrelevant.

Just for the sake of arguement, on the assumption that Time is the 4th dimension, I argue that we see in 4 dimensions.

Proof:
Light travels at finite velocity c. c is represented by two varibles, distance and time. The further an object is from us, the longer it takes for us to see it's movements after it has already occured. Thus not only can we dicern 3 dimensions, but we also can see into the past the further away an object is from us.

One could also contend that we see in 5 dimensions, because we are able to dicern all of these distant event occuring in their respective time index occuring at the same time as our specific index.