I can't really say to much about this because I'm not to familar with this subject (which is why I'm asking it ).

Basically, there are 3 known dimensions; Width, Heigth, Depth. But, is there a theoretical 4th dimension? Some people define the 4th dimension as the "physical" characteristics of an object. Others say it is "time" itself, but time could be just a percievence and not really exsist. I myself am not really sure...

So, I ask you:

What is the 4th dimension?

Well.. it is not time... time doesn't even have a correct definition in the dictionary... and well I have no idea what the 4th demension could be...

It is another direction.
Like in the 3rd Dimension there is

foward to back
left to right
up and down


In the 4th dimension there is another direction
What is it.......... I have no idea

the fourth dimension is time. its been theoritically proven. its based on the the fact that time is realtive(Einstein's Theory). If it is, then time at two different points can be different. Hence, since its different, it can be changes - a fourth dimension.

its a really complicated theory and i suggest you read this book - "A Brief History of Time" by Stephen Hawking.

ya i always thought the fourth dimension was time as well, forgot where i got it from tho...i think either physics or astronomy class...

I've read something else, and it had something to do with perception. If a human beeing looks at a rope, he sees a round and long object. But if you put a little ant on the rope, and you look through the eyes of the ant, you'd see like one large road. I don't know exactly how to put it, but this had something to do with a different dimension

ive seen a diffferent version of this theory. It's been proclaimed in certain things that if 3-D can be when you view something as if it has depth and volume, then the 4-D is when you can feel the object's depth and volume. Not sure if im making myself clear but i try hehe

Main Entry:dimension
Function:noun

1 a (1) : measure in one direction; specifically : one of three coordinates determining a position in space or four coordinates determining a position in space and time


Main Entry:fourth dimension
Function:noun

1 : a dimension in addition to length, breadth, and depth; specifically : a coordinate in addition to three rectangular coordinates especially when interpreted as the time coordinate in a space-time continuum
2 : something outside the range of ordinary experience



GREAT page with very good visual representations!!! Also see the pages branching off. This follows midnightrun's description. Who's seen "HyperCube"? I did awhile ago when we had the SciFi channel.

Well, that about sums it up

okay so we know its an addition and how it would "look" per say to us, but ...im still not clear on what that 4th dimension is?

This is one of the theories. The more common one is the fourth dimension being time. According to the hypercube the 4th dimension is where you are able to walk, let's say, forward and left at the same time.

wouldnt that just be walking diagonally...hmm

i dun think its time. Coz if 3d is how length and width relates to time..then 4th dimension wouldnt be time coz its the variable by which the dimensions compare to.

Agreed. I was going to post the comment about it being equivalent to walking 'diagonally' but it's not... it's walking directly forward and left simultaneously (not diagonal).

but that just means ur movement overall is diagonal..say ur walking forward but the floor under u is movign to the right. U are still making a movement to a diagonal point.

That's true. It's very difficult to grasp but it's not diagonal. It's like a half of your body is moving forward while the other half is to the left. Not the resultant in vector addition.

Einstein proved the 4th dimension is time. I know very little about Einstein; my dad told me.

ah ic. So ur basically on two planes of reality at the same time and hence why it said the square A would only see the edges of the 4d sphere.

I don't know, this part confused me a little, it's very difficult to understand considering the fact that we are not 4d creatures.

indeed. If we know of a 4d shape, then we didnt notice when we saw it coz we couldnt have recognized it.

yea, the fourth dimension is time, in order to define an object you need x,y,z and time.

whatever that means

well, it has to be time. its been theoritcally proven. U could go forward or backward in time. You wouldnt be able to 'see' a fourth dimension as such, since you exist only in 3 dimensions, one cant even comprehend what its like (unless ur really brainy).

Consider this example:-
let us assume a 2d dog. Now this dog cannot possibly have a gullet passing thru his entire body, bcuz in a 2d world that would split him in half. Similarly, in a 4d world u could to things u cant even begin to imagine..

i like these serious questions....beats talking about computers all day.

Any how. 4th dimension....hmm

depending on what your modeling..i.e doing a schrodingers equation or a spatial/time equation then yes time is called the 4th dimension.

The main are of physics where multidimensionalism is used is in string theory which requires many more dimensions than we know of. Look up the book "The elegant universe" which is like the brief history of time on steroids ;¬)

Is is hypothesised that these extra dimensions exist on such a small scale that they are undetectable by any means available to us at the moment. (They are thought to be tighlty wound up)

The reason we cant get our heads around it is that we are beasts locked into a 3d world so while we can imagine 2d or 1d worlds its impossible to truly comprehend a spatial 4d world. If you can tell me how you do it ;¬)

okay...one point perhaps of contradiction here. U are saying that the 4th dimension is time... Yet then you are telling me we are locked in a 3d world. But if the 4th is time, all u need is to create a forwards and sideways movement (3d) over a certain period of time and u have right there all 4 variables. However, u then speak of a 4d world we cannot conceive, but if the 4th dimension is merely time, then that wouldnt change the world around us, wouldnt that just be time included in the equation? im not sure if im making myself clear.

when i talk of 3d I mean SPATIAL dimensions. Time is a different fish and you can call it the 4th dimention. For the purposes of the prevous posts I was dismissing the inability of us to comprehend a 4th spatial dimension.

We have freedom to move in the 3 spatial but no choice in the time one, but here's the cool bit, by being near a huge black hole that drastically distorts space/time it is (theoretically) possible to fix one of the spatial dimensions and have freedom of movement in the the other 2 and time.

I really recommend doing some reading on this cos none of us will be able to explain it as good as the books....also getting a degree in it helps.

but then again...through study of relativity...cant we somehow reach a conclusion that time doesnt really exist since its a man made variable dependant on how close an object's mass is to the speed of light?

Yes.. Deftone is right... Time is not really existant.. but speed of light is distance not time.....

indeed. but basically as you near speed of light time goes by differently, hence time is not really a constant true variable but something made up by us to determine certain things like the rate of decay of bodies, or rate of boiling for substances..etc...

So really...i think the reason we dun understand the 4th dimension (if it is indeed time) is because it doesnt really exist..we created it just like we created time..

You make some very good points, Deftone.
I agree with your point on moving through time and therefore satisfying all variables but this doesn't seem to be the issue at hand; it's whether or not we can impede or stop the influence altogether.

A good definition of time would be

"natures way of stopping everything happening at the same time"

The greatest minds have tried to wrestle with this problem of defining time but its so bloody difficult.

Did you ever go at the speed of light? Did you? How is it possible for us to know what difference there'll be if we go at that speed, since we never even came close to it? It's all speculations, so that argument doesn't really help us in this. You can't say "The fourth dimension IS time". Who told you there are only four?
But let's just pretend time is the fourth dimension. What is it then that we see as "time"? Maybe it's a large bubble of 4D matter that comes by, and as it goes away, there won't be time anymore. I don't know, I try to think about this, but it's all so confusing. I'd like to know what you people think about that...

dude psych..time doesnt exist..its just something we created. as for speed of light, its more than just speculations, there are theories with equations, thats a bit more than a random guess. If we dunno thats necessarily true, then we cant even talk about a 4th dimension either.

I'm skeptical on the whole 'time' concept as well, Deftone, but how do you explain the sense of moving through the day. I believe this to be the clock in your brain. Time in the physical sense is man-made. We were watching a video in psychology awhile ago where an individual lived in a cave for maybe 7 months. Even though he saw no light or lack of light he fell asleep around the same time as if he were above ground; although he was on a 23hr clock instead of 24.

Einstein has proven 'time' is the 4th dimension, supposedly. The case with me is this... I can't stand accepting things if my mind cannot grasp it or it seems absurd from what I can grasp.. Also, I'd like to see (with my own eyes) Einstein's work into how he derived this conclusion. It's documented I'm sure so I'll just have to accept it at face value.

i dun think there is really time. Stuff just grows and decays, to that we call time. The amount of time it takes...seee u cant even define it without using the word again in the definition. I think thats the flaw with time, its self contained.

You could use the word duration. Overall, I know what you mean although it's irrelevant to whether time exists or not.

duration is relevant to time...rate is relevant to time...no word u can use there is independent of time.

Oh, I didn't know you were included similar words. However, it's still irrelevant to whether time exists or not.

it isnt...if u cant define it but by usign words that are derived from it, then it cant really exist but as something we just accept is without having definate proof, soemthing we need to describe a fenomenon we cannot grip. Time cannot be a dimension, if the other 3 are physical and one is ethereal, there is no comparisson. If it is time, then we already live in a 4d world really coz we can move in 3d in a certain spacial time.

I have to say your arguments are good. However, I don't feel like this is a scientific question anymore. It has become more of a philosophical question. Does time exist? What is time? Why can't we explain it wihout using it? Lots of questions, it seems more questions suddenly appear when the first ones are (supposedly) answered.

This doesn't make the discussion any less interesting though.

Let me try to give a definition of what time is :
Time is a difference. The difference between any possible state, and even the same state. See time as something that goes forwards as anything in the entire universe moves in one of the other dimensions. That could be a plausible explanation

PS : I'm just trying to come with a theory of my own

A very fitting definition from what I can tell. Well, since the 4th dimension has been proven to be time, we are now discussion is this is feasible. Deftone more than me it appears.

philosophy can go hand in hand with science, heck it is a science in way, the science of knowledge, wisdom and understanding. Ppl are wrong when they think things like this cannot go hand in hand. As for time, I thought it had only be theoretically proven to be the 4th dimension, aka "not sure yet" so to determine anything at this point would be premature. If men who have studied this for years are still doing so, what do we, kids have to say about it?

if time is the fourth dimension and we can travel back and forth in all the other dimensions does that mean that we can travel back in time? think about it might warrant a response

here's a question that has been of particular interest to me personally, if the speed of light is the speed limit of the universe as suggested by certain scientists (my physics prof is one of them) how would you explain such a situation, say u have a train or a platform that could travel at the speed of light (theoretically) relative to the earth, and you had a space shuttle that could travel at the speed of light relative to the platform, what would the speed of the space shuttle be relative to the earth?

Light speed is not constant as for time its not constant either and both can be mesured... Atomic clocks use cesium decay to mesure time. Light travels 2X's faster in open space then say through a ruby crystal how do they know this you ask ? simple Set up an electronic device with a light emiter on one end and a reciever on the other set a syncronized time and mesure away... and as for there only being 4 dimensions there are an infinate number of dimensions

can you say exactly what you mean by dimension cause the way i see it, you would have to understand both the concept of time and dimension to be able to answer the question of time as a fourth dimension. maybe if we were all on the saqme wavelength with regards to dimensions we'd get more answers, just a suggestion. and i think when I refer to light speed i mean the speed of light through empty space which is 299 792 458m/s

...or about 186,000 MPH

Multiple dimensions give me a headache... lol

If there really is a 4th dimension, say it is time, then there also has to be a way to manipulate this dimension, being time. So, if time is a dimension that can be manipulated like the other 3 dimensions (Height, Width, Depth), then people should be able to,in theory, control time at their own lesuire in a way that no one else would be affected.