I There must be a center of the universe....?

[rootone]

T... Rootone is in danger of giving carte blanche to the posting of a personal theory of a new member who may not be aware of PF's policy on personal theories.

No!, it may have seemed that way I can see your point.
I was not inviting personal theories, just asking what Infinitelycurio meant by proposals being rejected,
and trying to convey that it shouldn't be surprising if untestable ideas are not given much credibility as science.

 

[AgentSmith]

Instead of considering the universe, let's just consider the question of shapes and geometry.

In two dimensions: a disc (the area within a circle) has a centre that is part of the disc, but the centre of a circle is not part of the circle. If you were compelled to live on a circle, there would be no centre that you could visit.

In three dimensions, you have the same situation with a solid sphere (the centre is part of the sphere) and a spherical surface (its centre is not part of itself).

In higher dimensions, you have similarly the concept of a hypersurface.

To begin with, you could expand your knowledge of shapes and geometry. Then use this knowledge to understand what people are saying about the universe.

Are you saying the universe is the surface of a 4-D sphere?

 

[PeroK]

Are you saying the universe is the surface of a 4-D sphere?

No. Why would you think that?

 

[DaveC426913]

No. Why would you think that?

It's a logical deduction when projecting 2D geometry to 3D geometry.

Are you saying the universe is the surface of a 4-D sphere?

It turns out that the geometry of curvature works perfectly well without having to invoke a 4th dimension. This has been demonstrated mathematically.

 

[phinds]

Update on my recent reply. I see what you mean now by 'preferred frame' in the context of the cosmological principle. There are several googled articles [2011-2012] which mention 'preferred frames' in the context of 'asymmetrical expansion'. So yes, I agree with you in that context.

You are not being clear here as to whether or not you still argue that the universe has a center. Are you now convinced that it does not?

 

[OCR]

Thanks for responding, Dave...

That was a "thanks for responding" to my post... post # 90.

I wasn't making a response about our good friend, Rootone... honest ! ...

Rootone is in danger...

https://www.physicsforums.com/threa...er-of-the-universe.845032/page-5#post-5308128I know, I know... I should shut up now, but ... lol

Because, you see, I still don't get... if

..."time" has changed (passed), does your starting point actually still exist?

I will shut up now... interesting thread, though...

Carry on...

 

[Orodruin]

The OP has been answered several times over: No, expansion does not require a center of the universe and no this is not a matter of opinion.

Thread closed.