What is the 4th dimension n terms of visualization ?

In summary, dimension is a number that tells you how many numbers you need to pinpoint the location of any point on a shape or in the universe. In our universe, there are three space dimensions and a time dimension. The volume of a ball increases with the radius of the ball proportional to the radius^dimension. A 1D object acts as a boundary in a 2D shape, and a 2D object acts as a boundary in a 3D space. A 3D space acts as a boundary in a 4D hyperspace or manifold. There is no "the 4th dimension" and dimensions are an arbitrary mathematical concept used to define abstract variable spaces. The concept of time as the fourth dimension is simply
  • #1
kira506
84
0
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)
 
Physics news on Phys.org
  • #2
A simple definition of dimension is, dimension is a number that tells you how many numbers you need to pinpoint the location of any point on a shape (or in the universe). In our universe, you have three space dimensions and a time dimension to describe exactly where and when something is.

There are more sophisticated definitions of dimension if you are interested. The volume of a ball increases with the radius of the ball proportional to the radius^dimension. A 1D object acts as a boundary in a 2D shape. A 2D object acts as a boundary in a 3D space. A 3D space acts as a boundary in a 4D hyperspace, or manifold.
 
  • #3
Dimension is an arbitrary mathematical object to define an abstract variable space. There is no "the 4th dimension". We have three spatial dimensions. They are neat because they are independent of each other (orthogonal... at 90 degree angles from each other). There's nothing inherently special about dimensions.
 
  • #4
Khashishi said:
A simple definition of dimension is, dimension is a number that tells you how many numbers you need to pinpoint the location of any point on a shape (or in the universe). In our universe, you have three space dimensions and a time dimension to describe exactly where and when something is.

There are more sophisticated definitions of dimension if you are interested. The volume of a ball increases with the radius of the ball proportional to the radius^dimension. A 1D object acts as a boundary in a 2D shape. A 2D object acts as a boundary in a 3D space. A 3D space acts as a boundary in a 4D hyperspace, or manifold.

Thank you so much ! Now I understand , the boundaries example helped me a lot along with the radius part , now I'm kinda able to visualize it c: thanks a lot !
 
  • #5
Pythagorean said:
Dimension is an arbitrary mathematical object to define an abstract variable space. There is no "the 4th dimension". We have three spatial dimensions. They are neat because they are independent of each other (orthogonal... at 90 degree angles from each other). There's nothing inherently special about dimensions.
hehe , may be , but me and my brother keep obssessing over them don't know why ! We're so fascinated by the thought of the presence of multi-dimensional planes ! Thank you though , the definition really helped me in forming the image in my brain c:
 
  • #6
"Time is the forth dimension" is only referring to time as an arbitrary dimension in addition to the 3 spatial dimensions we are used to. There is nothing spatial about it in the sense of the 3 spatial dimensions we exist in.

Considering spatial dimensions you should think in terms of right angles (actually othogonality). 1 dimension is a line. 2 dimensions is a right angle to the 1st line (creating a plane). 3 dimensions is a right angle to both lines, creating the corner of a cube (3 orthogonol dimensions). 4 dimensions is a right angle to all three lines (impossible in the 3 dimensional world), creating the corner of a tresseract (google "tesseract" and "klein bottle"). There is no limit to how far you can go with spatial dimensions.

Based on this, try to think about a 4 dimensional chess board and see if your brain explodes.

Obviously we can only see a tesseract it terms of its 3 dimensional or 2 dimensional projection. This is in much the same way we view the projection of a cube on a 2 dimensional piece of paper.
 
  • #7
I agree with what krashishi and Pythagorean said but, since you posted this in physics, I would point out that, in Albert Einstein's words, "we live in a four dimensional space-time continuum".

To label points on the floor of the room you are sitting on uniquely, we could measure the distance from one wall and the distance from another wall at right angle to the first. Two numbers, so that is two dimensional. To label points any where in the room, we could drop a line from the point perpendicular to the floor. The two numbers identifying the point on the floor, together with the height from the floor, uniquely identify that point. Three numbers, so three dimensions.

Physicists study "events"; things that happen at a specific location at a specific time. It takes, of course, three numbers to identify the location and a single number to specify the time. A total of four numbers so the "world of physics" is "four dimensional".

(I remember watching the very first "Dr. Who" episode, "An Unearthly Child". (No, not its first airing!)
The Dr's Granddaughter, who is a student in an Earth secondary school objects to her teacher talking about "four dimensions" saying "what about the fifth dimension?". When asked what the "fifth dimension" is, she responds "space"! That's the problem having dialog for "advanced beings" written by not-so-advanced beings!)
 
  • #8
meBigGuy said:
"Time is the forth dimension" is only referring to time as an arbitrary dimension in addition to the 3 spatial dimensions we are used to. There is nothing spatial about it in the sense of the 3 spatial dimensions we exist in.

Considering spatial dimensions you should think in terms of right angles (actually othogonality). 1 dimension is a line. 2 dimensions is a right angle to the 1st line (creating a plane). 3 dimensions is a right angle to both lines, creating the corner of a cube (3 orthogonol dimensions). 4 dimensions is a right angle to all three lines (impossible in the 3 dimensional world), creating the corner of a tresseract (google "tesseract" and "klein bottle"). There is no limit to how far you can go with spatial dimensions.

Based on this, try to think about a 4 dimensional chess board and see if your brain explodes.

Obviously we can only see a tesseract it terms of its 3 dimensional or 2 dimensional projection. This is in much the same way we view the projection of a cube on a 2 dimensional piece of paper.


It explodes everytime I try to think about it , taht's why I imagine it as a cube enveloppping the other 3 dimensions and perpendicualr to each , that's why time is the first candidate , it kinda envelops them in my opinion , I'll google them , and I'm sure my mind will explode even more than before xD and I'll have to reassemble my concept once again
 
  • #9
HallsofIvy said:
I agree with what krashishi and Pythagorean said but, since you posted this in physics, I would point out that, in Albert Einstein's words, "we live in a four dimensional space-time continuum".

To label points on the floor of the room you are sitting on uniquely, we could measure the distance from one wall and the distance from another wall at right angle to the first. Two numbers, so that is two dimensional. To label points any where in the room, we could drop a line from the point perpendicular to the floor. The two numbers identifying the point on the floor, together with the height from the floor, uniquely identify that point. Three numbers, so three dimensions.

Physicists study "events"; things that happen at a specific location at a specific time. It takes, of course, three numbers to identify the location and a single number to specify the time. A total of four numbers so the "world of physics" is "four dimensional".

(I remember watching the very first "Dr. Who" episode, "An Unearthly Child". (No, not its first airing!)
The Dr's Granddaughter, who is a student in an Earth secondary school objects to her teacher talking about "four dimensions" saying "what about the fifth dimension?". When asked what the "fifth dimension" is, she responds "space"! That's the problem having dialog for "advanced beings" written by not-so-advanced beings!)


Rofl XD yeah , because the other 3 dimensions are not enough for space , si ,I kinda agree with them too , time is the non-spatial dimension accompanying the 3 dimensions or any nth dimension which appears and it will be no.s indentifying location of dimensions * time , thank you so much for the explanation c:
 
  • #10
kira506 said:
It explodes everytime I try to think about it , taht's why I imagine it as a cube enveloppping the other 3 dimensions and perpendicualr to each , that's why time is the first candidate , it kinda envelops them in my opinion , I'll google them , and I'm sure my mind will explode even more than before xD and I'll have to reassemble my concept once again

The spatial dimensions are orthogonal and fundamentally independent. I don't see time as being analogous. If you had 5 spatial dimensions, they could all independently vary in time.

Regarding "enveloping", I have similar philosophical musings, that moving in time is somehow perpendicular to the three spatial dimensions. But, I don't think they are sound.

I see a conflict in that I can play 2,3,or 4 dimensional chess and the game requires time. In the physical world, spatial dimensions are just plain different than time.

http://www.math.uiuc.edu/~reinige1/Chess/chess-basicmath.pdf is interesting.
 
  • #11
The easiest way to visualize extra dimensions is what I call the library analogy. A book has 3 dimensions - page number, line number and row number. You can find any word in a book this way. For four dimensions, you merely add another book - call it volume 2. Now you have 4 dimensions - volume, page, line and row. It is easy to see how you can add more dimensions [shelf, bookcase, floor, etc.]
 
  • #12
But to visualize a state trajectory through 4 dimensions isn't terribly easy with the book analogy.
 
  • #13
meBigGuy said:
The spatial dimensions are orthogonal and fundamentally independent. I don't see time as being analogous. If you had 5 spatial dimensions, they could all independently vary in time.

Regarding "enveloping", I have similar philosophical musings, that moving in time is somehow perpendicular to the three spatial dimensions. But, I don't think they are sound.

I see a conflict in that I can play 2,3,or 4 dimensional chess and the game requires time. In the physical world, spatial dimensions are just plain different than time.

http://www.math.uiuc.edu/~reinige1/Chess/chess-basicmath.pdf is interesting.
I guess you're right , time varies with all dimensions and doesn't define their shape , thanks for correcting me :D
 
  • #14
Chronos said:
The easiest way to visualize extra dimensions is what I call the library analogy. A book has 3 dimensions - page number, line number and row number. You can find any word in a book this way. For four dimensions, you merely add another book - call it volume 2. Now you have 4 dimensions - volume, page, line and row. It is easy to see how you can add more dimensions [shelf, bookcase, floor, etc.]


Thaaanks , it facilitates visualizing how we can add up dimensions but as simple is it might sound , still visualizing them together is difficult but thanks c:
 
Last edited:
  • #15
Pythagorean said:
But to visualize a state trajectory through 4 dimensions isn't terribly easy with the book analogy.


I agree with you on this one
 
  • #16
The point has been made, but "dimensions" is a general concept that can apply to anything. Number of variables = number of dimensions. What each dimension (variable) represents can be assigned to anything you choose.

Spatial dimensions are but one example. For spatial dimensions, each variable represent an orthogonal physical space. Dimensions 1,2 and 3 are pretty easy to visualize (look at the vertex of a cube). Dimension 4 is orthogonal to the vertices of a cube, so is somewhat imaginary in our world and difficult to visualize.
 

What is the 4th dimension?

The 4th dimension is a theoretical concept that refers to a spatial dimension beyond the three dimensions of length, width, and height that we are familiar with in our everyday lives. It is often represented as time or a mathematical construct in physics and mathematics.

How can the 4th dimension be visualized?

The 4th dimension cannot be directly visualized as it is a theoretical concept. However, mathematicians and scientists have developed various methods to visually represent the 4th dimension through analogies, projections, and computer-generated graphics.

What is the difference between the 4th dimension and time?

The 4th dimension and time are often used interchangeably in common language, but in physics and mathematics, they have distinct meanings. Time is a measurable quantity that represents the progression of events, while the 4th dimension is a theoretical concept that extends beyond the three dimensions of space.

How does the concept of the 4th dimension impact our understanding of the universe?

The concept of the 4th dimension has had a significant impact on our understanding of the universe, particularly in the field of physics. The theory of relativity and quantum mechanics rely on the idea of multiple dimensions to explain the workings of the universe, and the concept of the 4th dimension has also been used in string theory and other areas of research.

Can the 4th dimension be proven or observed?

As a theoretical concept, the 4th dimension cannot be proven or observed directly. However, the effects of the 4th dimension can be observed and measured through various mathematical and scientific models, such as in the study of spacetime and the behavior of particles at the quantum level.

Similar threads

Replies
2
Views
177
  • Other Physics Topics
Replies
20
Views
3K
  • Other Physics Topics
Replies
6
Views
2K
  • Other Physics Topics
Replies
15
Views
2K
  • Beyond the Standard Models
Replies
2
Views
2K
  • Other Physics Topics
Replies
2
Views
2K
  • Special and General Relativity
Replies
14
Views
2K
Replies
9
Views
3K
  • Special and General Relativity
Replies
11
Views
1K
  • Other Physics Topics
Replies
5
Views
2K
Back
Top