I Do Fundamental Physical Constants Truly Remain Constant Over Time?

[Serra Nova]

Why are the fundamental physical constants called "constants" when they change over time?
I've read that the constants were adjusted in 1986.

How can there even be something that is constant, when we can't even see the entire universe?

 

[lekh2003]

Why are the fundamental physical constants called "constants" when they change over time?
I've read that the constants were adjusted in 1986.

How can there even be something that is constant, when we can't even see the entire universe?

The constant are arbitrary values which we can use for our equations and our physics.

 

[Serra Nova]

The constant are arbitrary values which we can use for our equations and our physics.

But why do they have those exact numerical values?
https://physics.nist.gov/cuu/Constants/Table/allascii.txt

 

[lekh2003]

But why do they have those exact numerical values?
https://physics.nist.gov/cuu/Constants/Table/allascii.txt

They just happen to have these values. We don't know why pi happens to be 3.1415, it just is. These values can help us understand the universe but they could easily be something else.

 

[Serra Nova]

They just happen to have these values. We don't know why pi happens to be 3.1415, it just is. These values can help us understand the universe but they could easily be something else.

I hope future particle accelerators will shed some light onto this. Thank you for teaching me.

 

[Serra Nova]

They just happen to have these values. We don't know why pi happens to be 3.1415, it just is. These values can help us understand the universe but they could easily be something else.

Brian Greene said that those exact values might have different values in other universes.

 

[lekh2003]

Brian Greene said that those exact values might have different values in other universes.

Yes, that was in his book. He did outline that the specific constant we had were ideal and that it could've been anything.

 

[Dale]

I've read that the constants were adjusted in 1986.

I haven’t read that. What is your source?

 

[phyzguy]

Why are the fundamental physical constants called "constants" when they change over time?
I've read that the constants were adjusted in 1986.

There is no convincing evidence that the fundamental constants change with time In terms of why they have the values they do, nobody knows. Referring to the fine structure constant, Feynman said, "It's one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by man."

 

[f95toli]

I haven’t read that. What is your source?

I suspect the OP is referring to some CODATA update (although I can't of any major change in 1986).

Note that a bunch of fundamental constants will change (and some will be assigned exact values) later this year when the SI is redefined. This is not because something has actually changed in nature; it is just because we will will tweak our system of units somewhat to make it a bit more self-consistent.

 

[Serra Nova]

I haven’t read that. What is your source?

"The 1986 adjustment of the fundamental constants has implications with respect to the establishment of standards for electrical units".
https://link.springer.com/chapter/10.1007/978-94-009-2955-5_5

 

[Serra Nova]

I suspect the OP is referring to some CODATA update (although I can't of any major change in 1986).

Note that a bunch of fundamental constants will change (and some will be assigned exact values) later this year when the SI is redefined. This is not because something has actually changed in nature; it is just because we will will tweak our system of units somewhat to make it a bit more self-consistent.

"The 1986 adjustment of the fundamental constants has implications with respect to the establishment of standards for electrical units".
https://link.springer.com/chapter/10.1007/978-94-009-2955-5_5

 

[ISamson]

I think OP is referring to "Since they are constants, the definition of constant itself states that a constant is something that doesn't change, how can they change?". I think that is the OP's question and a question that interests me as well. Thanks.

 

[Serra Nova]

I think OP is referring to "Since they are constants, the definition of constant itself states that a constant is something that doesn't change, how can they change?". I think that is the OP's question and a question that interests me as well. Thanks.

Yes it is. Thank you for correcting it.

 

[Dale]

Note that a bunch of fundamental constants will change (and some will be assigned exact values) later this year when the SI is redefined.

Yes, that was my thought also. The dimensionful fundamental constants are a reflection of our units, not physics. But I am not aware of any change to SI in 1986.

 

[Dale]

"The 1986 adjustment of the fundamental constants has implications with respect to the establishment of standards for electrical units".
https://link.springer.com/chapter/10.1007/978-94-009-2955-5_5

That is interesting. I was unaware of this. Unfortunately, I am not so curious that I am willing to purchase the article. Does the article itself not describe the cause of the change?

 

[Dale]

"Since they are constants, the definition of constant itself states that a constant is something that doesn't change, how can they change?". I think that is the OP's question and a question that interests me as well

I don’t know this 1986 revision. However, consider the speed of light. It is 299792458 m/s and it is 6.7E8 mph. Since it is a constant, how can it change?

If this 1986 revision was motivated by a change in the SI, then it is that kind of change. Unfortunately, I don’t know if that is the case.