Fine structure constant may not be uniform across time - can someone explain?

It seems that a basic universal constant only works as far back as 6 billion years. Before that, it was stronger in one direction than the other -

Can someone explain this? Which directions are they talking about and how does that affect things like electro-magnetic fields?

One of the implications, if true, is that other constants like the speed of light or gravity may also have had different values at different points in time.

Welcome to the SDMB, dzero. This question will do better in our General Questions forum, which is where we ask questions with factual answers – which I think this is, I don’t even understand the question, let alone have an answer to it.

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twickster, MPSIMS moderator

It means in different directions in the ‘fixed’ background of stars. I.e. the measurements differ from one ‘end’ of the observable universe to other opposite ‘end’.

The fine structure constant is a measure of the strength of electromagnetic interactions, so taking the observations at face value electromagnetic interactions appear to be getting stronger in one direction, but weaker in the other

I was going to put it there (did another thread there yesterday) but i got the impression it was for questions of general interest. So I guess I can use this section for any factual question. Got it. Thank you. I’ll probably make this mistake from time to time since it requires some judgment on my part - not one of my stronger points.

So would that mean as you go back in time the interaction becomes stronger or weaker? Is that the correct ‘direction’ to be thinking about?

The direction is spatial, but of course due to the finite speed of light when you look very far away you also look very far back in time too.

Maybe this question will display my ignorance of physics, but doesn’t this provide a preferred frame of reference? :eek:


This means that they’re messing around in the noise level. Give em a few years, and they may have something.
Remember, we’re moving at quite a clip with respect to the CMBR, and orbiting the sun and the galaxy and suchlike. These movements all complicate the above calculations.

Dependcs how you want to use the word ‘preferred’, but the arrangement of matter often makes one frame of reference preferable to others. This doesn’t really violate the principle of general covariance.

As I say, I’m no physicist. Maybe “privileged frame” is a better term?

Wikipedia (for whatever that’s worth) says:

Wouldn’t a variation in a physical law across the universe in one specific direction be a “variance of the form of physical laws under arbitrary differentiable coordinate transformations”? You seem to know what you’re talking about so apparently the answer is “no”, but I don’t see why.

In any case, if this pans out, wouldn’t it be a MAJOR change in physics?

I’ve been wondering about why they make such a big deal about alpha varying not just across time, but also across space – I mean, if it varies across time in some frame of reference, it varies across space in another, right?

There’s been talk about this for years, and it’s always been buried in the noise. And the researchers involved have always been honest about this, and the popular press has always way overhyped it.

The thing is, whenever you take any physical quantity that you expect to be zero (in this case, the amount of change in alpha), and measure it, your best-fit value will always be something other than zero. It’s only newsworthy if your error bars are small enough, and the deviation from zero is large enough, that zero falls outside the error bars.

At least this time around the popular press is correctly describing it as a change in alpha, rather than as a change in the speed of light.

What I mean is that a ‘preferable’ frame doesn’t violate general covariance. The variation of a physical constant across spacetime may very well do.

So this is basically unjustified hype about a measurement that’s within the margin of error. Actually, the article is pretty clear that this is far from proven.

It didn’t sound right to me.

Okay, thanks. I guess that’s what I was trying to say but I got concepts confused.

It looks like this is probably unjustified hype anyway.

Not to be picky, but SciAm is rarely (if ever) guilty of unjustified hype. In fact, I don’t think I’ve ever seen them do ordinary “hype”. If they are printing an article about this, it is because it is a significant development or is an important and usually timely topic they think their readers want to know something about. There might be one or 2 other categories you could put their articles in but I think those 2 are the big ones.

The only other science publication directed at a lay audience that I think is as low-key and reputable is Science News.

That was true about 10-20 years ago, but they’ve really gone downhill the past decade or so. After I saw a cover story about Milgrom’s MOND hypothesis, and a blurb about a device that would supposedly convert gravitational waves to electromagnetic and back at 50% efficiency, I canceled my subscription.

Science News is still pretty good, though they aim for a somewhat more educated audience than Scientific American ever did.

I’ve been a regular reader and subscriber to both for at least 20 years. I’m not the most observant person around but if they had really been humping any outlandish theories I hope I would have noticed. I’m not a physicist so I can’t judge whether or not Modified Newtonian dynamics is plausible on it’s face, but I do know it has been covered in a few documentaries I’ve seen. If it was news worthy at the time, I could see making it a cover story. I don’t recall that issue though.

I probably give them more benefit of the doubt simply because I’m not a scientist. One thing I have noticed is that they have been a lot more preachy lately, especially with their special issues. Maybe if I had wasted my time reading those articles I would have been more upset.

I’ve also noticed that while all of the articles used to be written by scientists in that particular field,that doesn’t seem to be as true any more.

Science News however I think is geared mainly to secondary school and college libraries. I think they used to say that inside the front cover in the fine print. I’ll have to check a current issue and see if they still do. All things considered though, that may in fact be a more educated audience.