Why would the uniform expansion of space produce redshift?

[Aiden]

I have two questions:

 

1. If I understand redshift properly,

it is the result of expanding space "stretching out" a wavelength of light along its axis of propogation.

Why wouldn't the wavelength of light be stretched out uniformly along all its axes?

 

2. If space is expanding uniformly, how could this expansion be observable from within a closed system?

When I build a 3D model of a set of objects,

and then scale them all uniformly,

their size:distance relationships do not change.

 

Were I to be inside the model and scale myself along with the rest of the model,

I would not perceive any change had occurred,

and be unable to measure the effect from within.

 

Can you shed any light on these questions?

[Jacques]

1- We can measure only the wave length of light

2- You are not scaled: gravity and other force keep you from expanding

[Greg H.]

2- You are not scaled: gravity and other force keep you from expanding

 

To expand on this, think of like this. The "expansion" only happens at the level of galactic super clusters. Individual items, even individual galaxies are free to move closer together, as the Milky Way and Andromeda galaxies are currently doing. Additionally, the objects in the universe are not getting bigger. Envision how the Atlantic Ocean is currently getting larger due to the pressures from the mid-ocean ridge, slowly driving Europe and North America further apart. Yet neither continent is growing, only the space between them.