# What Is the Fourth Dimension and How Does It Work?

• B
• eggy
eggy
Based on info found in this forum, I have compiled info along with personal thoughts and observations in attempt to understand the fourth dimension better

Thanks! My notes below:Observations:

Move up/down

Move left/right

Move forward/backward

(Age [one direction])
2d circle in 1 dimension is a line getting larger and smaller

3D circle in 2 dimensions is a circle getting larger and smaller

4d sphere in 3 dimensions is a sphere growing and shrinking

What does 4d shape look like? Tesseract? Hypercube?

How does it work?
Possible dimension- Time

Visualized in 2d as a straight line

Visualized in 3D as a straight line

Conclusion: time is a straight line which any point can be accessed through any point all the time.
Time never started and never stops (different from eternity) TIME OPERATES IN A LOOP (time never started and never stops but with infinite time matter will reassemble itself into every single possible combination) given that time is relative and infinite. Light and time are distorted in a black hole (general relativity)
2d timeline is 2d, only exists in 2+ dimensions (too simple) 3D timeline only exists in 3+ dimensions (2d cannot hold due to lack of dimensions.) proposed 4d timeline only exists in 4+ dimensions (3D cannot hold due to lack of dimensions)

Does not exist in any dimension above current dimensionUndefined

Cannot be defined

Time is not infinite (nor finite)
There is Never nothing. Point=0 dimensions

eggy said:
2d circle in 1 dimension is a line getting larger and smaller
The way you would say this technically is that the foliation of a 2D disk into an ordered series of 1D submanifolds is a line segment that gets larger and smaller as you progress along the series.

eggy said:
3D circle in 2 dimensions is a circle getting larger and smaller

4d sphere in 3 dimensions is a sphere growing and shrinking
Similarly with these.

eggy said:
What does 4d shape look like? Tesseract? Hypercube?
What does a 3D shape look like? I don't think this is a well formed question.

eggy said:
How does it work?
How do 3D shapes work? I don't think this is a well formed question either.

eggy said:
Time never started and never stops (different from eternity) TIME OPERATES IN A LOOP
It is certainly possible to produce solutions to the Einstein field equations with closed timelike curves. But there is no experimental indications that support the idea that such spacetimes represent reality in any way.

eggy said:
Undefined

Cannot be defined

Time is not infinite (nor finite)
There is Never nothing. Point=0 dimensions
None of this communicates anything that I can tell.

these were mostly just brain dumps i did in geometry class. I am a freshman in high school and was just asking for input (which you provided). I have virtually no knowledge of any theoretical physics, yet have a huge interest in it. Thank you for the input, is there any way you could include some links to things that i could use to grasp this idea?

Dale

## What Is the Fourth Dimension?

The fourth dimension is often referred to as time in the context of physics and relativity. It extends the three-dimensional space (length, width, and height) into a new dimension, allowing for the concept of spacetime where events are described not just by their spatial coordinates but also by the time at which they occur.

## How Does the Fourth Dimension Relate to Spacetime?

In the theory of relativity, proposed by Albert Einstein, spacetime is a four-dimensional continuum that fuses the three spatial dimensions with the temporal dimension (time). This concept helps explain how objects move and interact in the universe, with time being treated as a dimension similar to the spatial ones.

## Can Humans Perceive the Fourth Dimension?

Humans are inherently three-dimensional beings and cannot directly perceive the fourth dimension. Our perception is limited to three spatial dimensions, and we experience the passage of time linearly. However, we can understand and describe the fourth dimension mathematically and theoretically.

## What Are Some Practical Applications of the Fourth Dimension?

The concept of the fourth dimension is crucial in various scientific fields, particularly in physics and cosmology. It is essential for understanding the behavior of objects at high velocities, gravitational fields, and the overall structure of the universe. Technologies like GPS also rely on relativistic corrections that account for the effects of spacetime.

## Is There a Way to Visualize the Fourth Dimension?

Visualizing the fourth dimension is challenging because it extends beyond our three-dimensional experience. However, mathematicians and physicists use analogies and models, such as tesseracts (four-dimensional hypercubes), to help illustrate the concept. These models provide a way to grasp the properties and implications of higher dimensions.

• Introductory Physics Homework Help
Replies
1
Views
500
• Cosmology
Replies
6
Views
2K
• Other Physics Topics
Replies
6
Views
2K
• General Math
Replies
2
Views
776
• Sci-Fi Writing and World Building
Replies
9
Views
2K
• Other Physics Topics
Replies
19
Views
2K
• Classical Physics
Replies
5
Views
2K
• Other Physics Topics
Replies
16
Views
4K
• General Math
Replies
1
Views
1K
• Science Fiction and Fantasy Media
Replies
0
Views
1K