Questions about (potential) variations in the Fine Structure Constant

[Lino]

I have read an amount of material on (potential) variations in the Fine Structure Constant. The majority of the material seems cautiously positive in declaring support for the potential variations, but I have a couple of question that you may be able to help me with.

1) Am I correct is believing that the possibility of variation in the constant over the evolution of the universe is generally supported? If anyone can point me at articles that look unfavourably at this possibility, I would appreciate it so that I can have a balanced view (I think that everything that I have read is broadly supportive).

2) From what I understand, the primary evidence is based on the absorption lines associated with Magnesium (and associated isotopes). Why was / is Magnesium the element used?

Thanks for all you help.

Regards,

Noel.

 

[Naty1]

Some insights that may be of interest here:

Is the fine structure constant actually constant?
http://en.wikipedia.org/wiki/Fine_s..._fine_structure_constant_actually_constant.3F

 

[Lino]

Thanks Naty1. That was very helpful, and the references (especially 41 & 42) are just what I was looking for. I knew that no matter what I found I would need to do more reading on this... but everything I was reading seemed so supportive - I knew that there had to be more questioning material outthere but just wasn't finding it!

Thanks again.

Regards,

Noel.

 

[Chalnoth]

I'd just like to point out that this result is largely considered to still be rather unlikely. It is prudent to continue to consider it unlikely until we get an independent measurement of the same result, using a different sort of evidence.

 

[Lino]

Thanks Chalnoth. Understood and agreed (which is why I was surprised that all of the material I was reading seemed broadly supportive, with little questioning / challanging).

Regards,

Noel.

 

[skydivephil]

I would have thought this is an incredibly profound result if confirmed. I am wondering does anyone know if there are any other teams trying to replicate the results?

 

[mfb]

It is likely that there are. However, I don't know any specific one.

Am I correct is believing that the possibility of variation in the constant over the evolution of the universe is generally supported?

The current laws of physics don't allow variations, but that has a simple reason: We didn't see any variation so far, and the laws were constructed to reflect this.
Time- and space-dependent variations can be a bit tricky as there is no universal flat spacetime. However, if variations are measured, I am sure it is somehow possible to include them into the theories.

 

[Chalnoth]

It is likely that there are. However, I don't know any specific one.


The current laws of physics don't allow variations, but that has a simple reason: We didn't see any variation so far, and the laws were constructed to reflect this.
Time- and space-dependent variations can be a bit tricky as there is no universal flat spacetime. However, if variations are measured, I am sure it is somehow possible to include them into the theories.

As I understand it, the way this game is played is that a scalar field is proposed which couples with the interaction term, and the dynamics of that scalar field determine how the interaction in question changes with time and space. For example, it's possible to write down a scalar field which makes it so that the electromagnetic force is slightly stronger in strong gravitational fields.