# What is 4th dimension: Definition and 51 Discussions

A 4th Dimension roller coaster is a type of steel roller coaster whereby riders are rotated independently of the orientation of the track, generally about a horizontal axis that is perpendicular to the track. The cars do not necessarily need to be fixed to an angle.

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1. ### A Metric of a Moving 3D Hypersurface along the 4th Dimension

Consider a hypothetical five dimensional flat spacetime ##\mathbb{R}^5## with coordinates ##x, y, z, w, t##. Now imagine that the hypersurface ##\Sigma =\mathbb{R}^3## of ##x, y, z## moves with constant rate ##r## along the coordinate ##w##, i.e. ##dw/dt=r##. Assuming that ##t \in (-\infty, +...
2. ### I If a 4th dimension existed would universe expand anisotropically?

Suppose the universe were described by internal geometry by a ball, i.e. the metric where : $$diag(1,r^2,r^2 sin(\theta)^2)$$ Now if we go to exterior geometry and suppose there existed a 4th timelike dimension the manifold were for example modelized by : \left(\begin{array}{c}...
3. ### I What's the name of a 2-torus looped in the 4th dimension?

To form a 2-torus, a narrow tube can be bent into a loop and joined end to end: But instead of forming this loop in our three-dimensional space, the loop can also be formed in a direction perpendicular to three-dimensional space, moving it into the fourth dimension of space. What's the name of...
4. ### Green's function and the resistance across a Hypercube

Homework Statement: I do know how to solve the resistance network problem in two dimensions. However, in this problem they want it in 3 dimensions and higher and I don't know how to do that Homework Equations: - In the picture you can see the solution to the two dimensional version
5. ### B Moving in the 4th Dimension -- Does Time have a velocity?

Hello all, i read several threads concerning the a.m. topic, but are still not sure if i got it right. Is "passing time" or moving in the 4th dimension in relativistic means a real changing of position in grade 4 spacetime or is it just a mathematical effect ? Why asking: If i understood...
6. ### I How would a 4th Dimensional Object Move?

I want to know how a 4D object, (specifically a tesseract) would move in the space of t, not x, y or z.
7. ### Is gravity a function of the 4th dimension?

I recently came across an example of a fictional 2 dimension being and how that being would experience 3 dimensional interaction. In this is example the 2d being was on a pool table and would only see flashes of the pool balls as they interact with the 2d plane. Is gravity similar; however, a...
8. ### Exploring the 4th Dimension: A Discussion

Hello, I have recently been very interested in learning about the 4th dimension (well the little we know about it) I have listened and discussed in some conversations about the topic and have a few thoughts and it questions. -From my understanding the Tesseract is a 3rd dimensional Shadow...
9. ### Question about higher dimensions and what connects them

It's my understanding that, if we ignore the temporal dimension and just focus on spatial ones, then you get to the third dimension by starting with a point and adding perpendicular lines to them. Once you've done this a couple of times, you get three dimensions. Obviously, to the layman, it...
10. ### What is the 4th Dimension - 3D World + Time or 4 Axis?

Some people say that it's the 3D world we live in + time but others say that it's 4 dimensional as in it as new axis. Which one is true?
11. ### Black holes are the shadows of 4D objects (idea)

this is the idea...
12. ### Time dilation why or how, Special Relativity causes

I understand the theory of special relativity and the mathematics which support it. I even understand that the time dilation has been proven. Therefore I am going to ask a question which on first blush may appear that I disagree with it but that is not the case. The question I can not seem to...
13. ### Exploring the 4th Dimension: Understanding Time in Spatial Dimensions

Homework Statement is there a 4th dimension. if yes can anyone explain it ?Homework EquationsThe Attempt at a Solution 4th dimension includes time also am i right ? which is X,Y,Z + time
14. ### Exploring the 4th Dimension: Questions and Answers

Hey guys here is my question. 1D = Line 2D is a plane. 3D is space. So shouldn't a fourth dimension be something else? Is there really such a thing as fourth dimensional space. There is no such thing as a 3 dimensional plane. Though you can have a 2D plane in 3D space. Next question leads to...
15. ### Can You Imagine a Fourth Dimension?

Hey there peers :smile: I'm really keen on explaining science to others and I've been practicing it with my classmates lately, so I thought why not give it a try and make my first ever youtube video about a seemingly hard concept which is a space of 4 dimensions. I made this post just because...
16. ### What is the 4th dimension n terms of visualization ?

I want sthg I can visualize in order to understand , I keep asking and am always told time , so how is time a 4th dimension ? I try my best but my mind is too weak to visualize things more complex than disney (so please , I want sthg in that standard ,consider me a curious 6 year old child)
17. ### What is the concept of multiple orthogonal time dimensions?

Hey Guys, I, FYI not a physicist, recently got a fascination to dimensions, and for the life in me I can't seem to wrap my head around the fact that time is the 4th dimension. From what I can understand, the spatial dimensions can completely perceive the dimension below, but perceive an...
18. ### Understanding Hypercubes: Exploring the Concept of 4th Dimension

Hello everyone once again. If I remember correctly, hypercubes are said to have 4th dimension. But as far as I know, the 4th dimension is time. So, when we're describing the 4th dimension I guess we can say, " Let's meet at my house at 12.20 pm". When I say "at my house" I'm talking about the...
19. ### What is the 4th dimension and why is it so intriguing?

I know little about this topic, yet it interests me beyond imagining. What can you guys tell me about it? Anything at all
20. ### Mirror image inversion in the 4th dimension.

I don't really know where this topic belongs. Let's say you're an ugly asymmetrical person, with your right hand much larger than the left. A 4th dimensional being removed you and "flipped" you in the 4th dimesion, then put you back. Would you come back with a large right hand...
21. ### Practical Applications of the 4th Dimension (and beyond)

It's hard to convince people that they should hear and/or learn about the 4th dimension, string theory, and all of the like without giving them real world examples as to why these are all important. I've been trying to find a way to incorporate the 4th dimension in particular into a short...
22. ### Exploring the Existence and Mystery of 4th Dimension Space

Not sure if its the right place to post but still:- I am confused over 4th dimension space( not time ). Does 4th dimension space really exist? If it exists why we cannot see or visualise the 4th dimension?
23. ### Is the Universe Expanding Into 4th Dimension?

a)since universe is expanding is today's 1 meter different from tomorrow's 1m? b)since distant between any 2 points is increasing is the universe expanding into 4th dimension?
24. ### What Does It Mean to Travel at the Speed of Light in the 4th Dimension?

How is it like to travel at the speed of light in the 4th dimension? and according to general relativity, the 4th dimension is time, what does that mean ?...and why? :rolleyes:
25. ### Perspective of 3-dimensional objects from the 4th dimension

This question will probably make the most sense to those who have read Edwin Abbott Abbott's novel Flatland. But I'm sure many others know the answer. To explain, I'll have to use some dimensional analogy. Let's say you're a 2-dimensional being. You live in a two dimensional world and thus...
26. ### What are the Four Dimensions in Our Space-Time Continuum?

Is the 4th dimension time? 0D = dot 1D = line 2D = plane 3D = sphere 4D = time Am I correct?
27. ### Exploring 4th Dimension in General Relativity

hi, what do you think that in general relativity, since space is curved, the curvature could be interpreted as a 4th space dimension "hyperspace"? in other words, the 4th space dimension would take the place of time, for a coordinate observer?
28. ### Is 4th Dimension Time? Exploring the Possibilities

So do we know for sure what the 4th spatial dimension is? I have read in many places that it is time. I would say this makes sense because we are perceiving time in 3 dimensional slices in our dimension. The same way a 2D being would perceive 2D slivers of a 3D object in its own dimension.
29. ### Does the 4th dimension mean our universe is definite?

I've recently been learning about relativity and quantum physics. I understand it quite well now but i have a thought experiment that doesn't make sense. If i travel into the future through a high speed train and see the world blown up by some epic disaster, doesn't this mean that this was...
30. ### Is Time the Fourth Dimension in Euclidean Space?

Is it the additional dimension, Time, added to the Euclidean (x,y,z) 3-D space? Or does it even make sense to ask this question? And instead consider 4D space-time (Minkowski Space) as a manifold in which 3D is embedded? I'm confused. :(
31. ### How to describe the 4th dimension?

what is 4th dimension? is it just 1 dimensional space? how come time is described as the 4th dimensional path? thanks..
32. ### What is the fourth variable in the 4th dimension?

is it time? what's your theory on the study of other dimensions? and applications from them?
33. ### Exploring the 4th Dimension of Electromagnetic Waves

So I've been told that electromagnetic waves oscillate like flicking a rope up and down or a ripple in a pond. In the first example, from a side view, the rope can be considered to be a line, or 1-dimensional. However, once the ropes starts oscillating to represent waves, width must also be...
34. ### The 4th Dimension: Exploring Human Curiosity & Its Theories

Hello, I am in the process of reading Black Holes, Wormholes & Time Machines and am somewhat confused, even though it is aimed at people like myself who have very little knowledge on the subject. I am reading about the 4th dimension now but I do not understand the relevance of researching into...
35. ### Exploring the 4th Dimension: My Theory on Energy's Role

I have no schooling in physics but for the past 3 years I have had this idea floating around in my head and figured i'd tell somebody and see what they thought. my theory is about the 4th Dimension. I believe that energy is the 4D and not time. Energy can be measured like width, heigth and...

37. ### Why is Planck time measured differently from other dimensions?

Hi, I'm new here. I've loved all the qualitative aspects of physics for a while now and I'm just starting to get into some of the more quantitative aspects of physics, the actual math. I'm such a complete amateur at all this and I'm only in high school so please excuse my question if it seems...
38. ### A completely different look at the 4th dimension

I have an idea that completely renivents the idea of the 4th dimension that has absolutely nothing to do with time. BUt however, it will be easier to first think about the lower dimensions. imagine a perfectly 2 dimensional universe which can be represented with a xy plane where -10 meters <...
39. ### Exploring the Possibility of a 4th Dimension

Does a dimention other than the third dimention possibly eixist? For some thing to exist doesn't it need thickness width and length?.People say time is the 4<sup>th</sup> dimention is there any kind of proff for it:confused: .
40. ### What is a black hole in 4th dimension looks like?

If there is a black hole in the 4th dimension, how will it looks like in the observer in 3rd dimension?
41. ### Thoughts on visualizing the 4th dimension

Just an idea: It occurred to me that people can't see the fourth dimension because, in reality, we can't even see the third. Think about it. When you're looking at something, each of your eyes registers a 2D image, and the sense of depth (the third dimension) is inferred from the two 2D...
42. ### Can we comprehend the 4th dimension.

If we exclude time as the fourth dimension, is it possible that over many years of trial and study, that our thee-dimensional brains can comprehend a higher dimension? :bugeye:
43. ### Why do we consider time as the 4th dimension?

Time is not the 4th dimension. Well... depends on perspective. Why do people say time is the 4th dimension? I know you can say it's a dimension and there are already 3. But why not say mass is a dimension? Each point in space has a certain mass. What's the difference? Einstein said it and it...
44. ### What is the relationship between time and the 4th dimension?

Hello, this is my first time posting, I do hope I've found the right place. I have relatively no knowledge of physics but am about to minor in it in college. The questions and ideas I am about to set down concern time, an issue of which I again know very little. While sitting idle one day...
45. ### Can someone explain what the 4th Dimension is?

Can someone explain what the 4th Dimension is?
46. ### 4th DIMENSION EQUATIONS CALCULUS HELP

4th DIMENSION EQUATIONS! CALCULUS HELP I have to explain the 4th dimension and hyper-space using for my High School calculus AP final project. IF someone can give me some insight or some equations to help me see and learn more about the 4th dimension it will be greatly appreciated. Some...
47. ### Is Time Travel Possible Through Mental Projection?

Time is just a way of measuring the velocity of the motion of an object through the 3 real dimensions. In order to go into the future you would have to stop your particles for the desired amount of time (basically cryogenics). Your particles weren't present to have their effect on the future so...
48. ### Einstein's Space-Time Continuum: Is Time a 4th Dimension?

Did Einstein meant by space-time continuous that time is just another dimension, like the other 3? If so, why are we experiencing this one that differently? (Should this have gone in the phylosophy section?)
49. ### Exploring the 4th Dimension: Properties & Links

has anybody done any thinking on the properties of a universe with four "normal" spatial dimensions? I've done a bit and some interesting properties have surfaced. I've discovered that rivers don't need bridges, sponges and screens can pass through each other, and there are several types of...
50. ### Exploring the 4th Dimension: What Is It?

hey, anyone out there care to offer their thoughts on the fourth dimension? as in what would it be, all I have is that a fourth dimensional object would seem like a 3 dimensional object moving down and then disapearing?