Can We Visualize Spatial Direction in Space?

[USCadam89]

I have looked at this forum for over a year. One thing that has always confused me is spatial direction in space. Thinking in terms of the balloon model: what represents the part in front/beyond if we are on the edge looking out. If we are looking out why can't we "turn around" and see the other way. I understand that when the balloon first starts expanding this is t-0 and representive of the big bang. Space is 3 dimensional why can't we see in front of us, or is this where time/speed of light is involved. Is there no real spatial model that can depict this? In the balloon model I feel we should be able to see beyond the outer latex(if we are indeed a fixated galaxy representive of a coin) and not just distant light from our past. We do a 360 rotation in space and see all parts of our galaxy from any point on the earth, what's representive of top, bottom, edge, or is there no such thing? Is this all to do with the speed of light? Please tie up my loose ends and confusion. I have the classic biology mindset, some of this hard for me to visualize.

Thank you all for this forum,
Adam

 

[tiny-tim]

Hello Adam! Welcome to PF!

… Thinking in terms of the balloon model: what represents the part in front/beyond if we are on the edge looking out. If we are looking out why can't we "turn around" and see the other way. … Space is 3 dimensional why can't we see in front of us, or is this where time/speed of light is involved.

in the balloon model (2D or 3D version), there is no edge

in 2D, we can't look "out", we can only look in 2D, ie along the surface of the balloon: we can't look in 3D

in 3D also, we can't look "out", we can only look in 3D: we can't look in 4D

the "3D balloon" is expanding in 4D

 

[Chalnoth]

Hello Adam! Welcome to PF!


in the balloon model (2D or 3D version), there is no edge

in 2D, we can't look "out", we can only look in 2D, ie along the surface of the balloon: we can't look in 3D

in 3D also, we can't look "out", we can only look in 3D: we can't look in 4D

the "3D balloon" is expanding in 4D

I think more accurately, the dimension being referred to is time. We can look into the past (similar to looking inward in the balloon analogy) simply by looking far away. But we cannot look at photons emitted from the future (the outward direction), because time has a definite direction.

As for why there's a direction of time, I think Sean Carroll has written a number of good articles on the subject, such as this blog post:
http://blogs.discovermagazine.com/cosmicvariance/2007/12/03/arrow-of-time-faq/

 

[USCadam89]

thank you both.
this will help me better visualize other things within cosmology
without this foundation it's hard to understand further topics

Adam.

If anyone has any further input, it would be greatly appreciated.

 

[sardar]

I understand your confusion and the difficulty in visualizing spatial direction in space. It is a complex concept that even experts in the field struggle with. Let me try to provide some clarification.

Firstly, it is important to understand that the balloon model is just a simplified analogy for the expansion of the universe. In reality, the universe is much more complex and dynamic. It is not expanding into anything, but rather the space itself is expanding. This means that the concept of "beyond" or "in front" is not applicable in the traditional sense.

Secondly, our ability to see in a particular direction is limited by the speed of light. Light travels at a finite speed, and it takes time for light from distant objects to reach us. This means that when we look out into space, we are actually looking back in time. The farther we look, the further back in time we see.

As for your question about seeing beyond the outer latex of the balloon, it is important to remember that the balloon model is just an analogy and does not accurately represent the complexity of the universe. In reality, there is no "edge" or "boundary" to the universe, and our observable universe is limited by the distance that light has had time to travel since the beginning of the universe.

In terms of directionality in space, it is also important to understand that our perception of direction is relative. There is no absolute "up" or "down" in the universe. What is considered "up" in one part of the universe may be considered "down" in another part. Our perception of direction is also affected by the gravitational pull of nearby objects.

In summary, the concept of spatial direction in space is a complex one and can be difficult to visualize. It is important to remember that our understanding of the universe is constantly evolving and our models and analogies are just simplified representations of the complex reality. I hope this helps to clarify some of your confusion.