Physicists Nail Down the ‘Magic Number’ That Shapes the Universe

Re:Physicists Nail Down the ‘Magic Number’ That Shapes the U... by amelius on Wednesday December 02, 2020 @05:18PM (#25282481)

Is it really a constant or can there still be a (a little) variation in the number when measured over astronomical distances, or over large timescales?

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Re:Physicists Nail Down the ‘Magic Number’ That Shapes the U... by Denvercoder9 on Wednesday December 02, 2020 @06:10PM (#25283025)

We don't know for sure, and we probably never will. It's impossible to prove that something is actually a constant over large distances and timescales. You can always go a bit further or wait a bit longer, where it might not be as constant as we expected.

However, most experimental data so far is in agreement on it actually being a constant.

Wikipedia has a section on it: https://en.wikipedia.org/wiki/Fine-structure_constant#Is_the...?

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Re:Physicists Nail Down the ‘Magic Number’ That Shapes the U... by analog31 on Wednesday December 02, 2020 @05:40PM (#25282721)

One of the potential benefits of improving the measurement of a "constant" is that you can now uncover fluctuations that were previously buried in noise. Not that I can think of a way of doing it in this case, but perhaps the spectra of distant stars might tell us something.

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Re:Physicists Nail Down the ‘Magic Number’ That Shapes the U... by l33tman on Wednesday December 02, 2020 @07:12PM (#25283602)

This PBS SpaceTime episode has a good catchup of this and ways to measure this over longer scales:

https://youtu.be/YJzoelANL_Y

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Re:Physicists Nail Down the ‘Magic Number’ That Shapes the U... by dvsfish on Wednesday December 02, 2020 @07:39PM (#25283813)

Phenomenal channel

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Re:Physicists Nail Down the ‘Magic Number’ That Shapes the U... by bsder on Wednesday December 02, 2020 @08:23PM (#25284115)

It really does appear to be a constant.

One of the things the cosmologists are always doing is looking for anomalies that might indicate that some "constant" really has changed over time or distance.

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Re:Physicists Nail Down the ‘Magic Number’ That Shapes the U... by mxcrossb on Wednesday December 02, 2020 @06:11PM (#25283040)

> Surprisingly, her new measurement differs from Müller’s 2018 result in the seventh digit, a bigger discrepancy than the margin of error of either measurement.

Apparently there can be differences based on if you measure in Paris or Berkeley? Though it’s more likely there is some other source of error. I think having the technical ability for a precise measurement may one day help us look for fluctuations.

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Re:Physicists Nail Down the ‘Magic Number’ That Shapes the U... by drran on Wednesday December 02, 2020 @06:20PM (#25283135)

When our visible Universe will drastically change, this constant will change too.

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Re:Physicists Nail Down the ‘Magic Number’ That Shapes the U... by peglasaurus on Wednesday December 02, 2020 @08:20PM (#25284089)

Not sure why you're being downvoted, as by definition, if this constant is valid for how this universe is as it is configured now then significantly changing the universe will likely result in a different constant. How you might change the universe enough to cause a variation is a bigger question. Concentrating all the stars (mass) to one place might do it. Maybe not.

The flip side of that question is the larger and generally accepted as obvious statement: a constant with value "x" determines or reflects how the universe is as of now. The duration of that "now" is likely much longer than the earths entire existence.

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