Red Shift & Time: Can Time Be Expanding Too?

[Exmech]

Hello! I'm brand new to the forum and have a question that has been nagging at me for some time. I've read a great number of articles regarding the red shift, as well as time being a dimension. I was wondering if anyone has addressed the possibility that time might also be subject to the red shift. That is, the dimension is expanding at the same rate as the 3 spatial dimensions. Any literature anyone has on this would be most appreciated.

 

[Chalnoth]

Hello! I'm brand new to the forum and have a question that has been nagging at me for some time. I've read a great number of articles regarding the red shift, as well as time being a dimension. I was wondering if anyone has addressed the possibility that time might also be subject to the red shift. That is, the dimension is expanding at the same rate as the 3 spatial dimensions. Any literature anyone has on this would be most appreciated.

If you make it so that all dimensions expand equally, it turns out that nothing physical changes: all you've done is made a change in your equations that rescales the coordinate system. Instead, an expansion is only physical if some dimensions expand relative to other dimensions. In our case, it is usually written as the three dimensions of space expanding relative to the time dimension. Of course, if you wanted to, you could massage the equations so that the time dimension would instead change while the spatial dimensions remain the same, but that would be a much less intuitive way of understanding the physical behavior.

 

[sylas]

I agree with Chalnoth's answer.

A simpler answer is just no. This avoids getting into co-ordinate transformations or definitions. The universe expands, which means things are moving apart from each other. There's nothing funny going on with time or clocks.

 

[Exmech]

If you make it so that all dimensions expand equally, it turns out that nothing physical changes: all you've done is made a change in your equations that rescales the coordinate system.

That, my friend, is what I surmised when I began thinking about this. However I recognize I'm not the cleverest person in the world. Thank you.