Would we observe a changing Planck's constant?

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In summary, the conversation discusses the possibility of Planck's constant changing and the implications this would have on the Schrödinger equation and other models. However, without a theoretical model to work with, these questions cannot be answered. The conversation also mentions the recent efforts by the BIPM to fix the value of h and the irrelevance of the number of decimals obtained for c or h measurements. The conversation ends with the understanding that the topic is off-topic and the thread is closed.
  • #1
sgphysics
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If Planck's constant is changing, how slowly would it need to change before we could observe that something was going on? And if changes were discrete, how large quanta would it take? (for us to observe the jumps)

And a follow-up question: If there was another universe here, running a different value of h(bar), would we observe it? Tunneling between them possible?
 
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  • #2
sgphysics said:
If Planck's constant is changing, how slowly would it need to change before we could observe that something was going on? And if changes were discrete, how large quanta would it take? (for us to observe the jumps)

These questions can't be answered without some sort of theoretical model. AFAIK nobody has tried to construct a model in which Planck's constant is changing.

sgphysics said:
If there was another universe here, running a different value of h(bar), would we observe it? Tunneling between them possible?

Same response: we don't have a model to work with, so there is no way to answer the questions.
 
  • #3
Planck's constant is just a number that is determined only by our definition of the units sec and eV.
What do you mean by changing Planck's constant?
If an alien has the same Planck's constant as we do, he is not an alien.
 
  • #4
... or she.
 
  • #5
PeterDonis said:
These questions can't be answered without some sort of theoretical model. AFAIK nobody has tried to construct a model in which Planck's constant is changing.
.

Well, actually the model I had in mind was the Schrödinger equation. For a simple system one could easily explore altered solutions from variations in h(bar). So if a universe existed with a different h(bar), perhaps running the same E and V as in our universe, would that be possible? - presuming that everything is described by the SE.
 
  • #6
sgphysics said:
the model I had in mind was the Schrödinger equation

That equation doesn't allow Planck's constant to change.

sgphysics said:
For a simple system one could easily explore altered solutions from variations in h(bar)

How? The equation doesn't allow ##\hbar## to vary. ##\hbar## is just a unit conversion factor in Schrodinger's equation; you can just as easily adopt units in which ##\hbar = 1## and it doesn't even appear.
 
  • #7
sgphysics said:
Well, actually the model I had in mind was the Schrödinger equation. For a simple system one could easily explore altered solutions from variations in h(bar). So if a universe existed with a different h(bar), perhaps running the same E and V as in our universe, would that be possible? - presuming that everything is described by the SE.

PF is not a place to speculate on ”What would happen if...?”. Actually, the speed of light in vacuum was fixed to 299792458 m/s in 1983. In 2018, the plan of BIPM is to sanctify h by rendering its normal experimental uncertainty to 0, just like they did for c in 1983.
 
  • #8
dextercioby said:
PF is not a place to speculate on ”What would happen if...?”. Actually, the speed of light in vacuum was fixed to 299792458 m/s in 1983. In 2018, the plan of BIPM is to sanctify h by rendering its normal experimental uncertainty to 0, just like they did for c in 1983.
I do not share your view on physics, but I shall respect that any forum may decide their own limits. It's not speculation when something can be answered from understanding of math. The number of decimals obtained for c or h measurement is certainly bright engineering, but off-topic. So also the trivial fact that h-value is unit dependent,
 
  • #9
The OP question has been sufficiently addressed. Thread closed.
 

Related to Would we observe a changing Planck's constant?

1. What is Planck's constant and why is it important?

Planck's constant, denoted as h, is a fundamental constant in quantum mechanics that relates the energy of a photon to its frequency. It is important because it is used to calculate the energy levels of atoms and molecules, which has implications in many areas of physics and technology.

2. Why would Planck's constant change?

Planck's constant is a fundamental constant of nature and is believed to be a universal constant. However, certain theories, such as string theory, suggest that it may vary in different scenarios, such as in different dimensions or at the beginning of the universe.

3. How would a change in Planck's constant be observed?

A change in Planck's constant can be observed through precision measurements of physical phenomena that are influenced by it, such as the energy levels of atoms and molecules or the quantum behavior of particles. These measurements would show discrepancies from the expected values if there was a change in Planck's constant.

4. What would be the implications of a changing Planck's constant?

The implications of a changing Planck's constant would depend on the magnitude and direction of the change. It could potentially challenge our current understanding of quantum mechanics and the fundamental laws of physics. It could also have significant impacts on technology and our ability to make precise measurements.

5. Has there been any evidence of a changing Planck's constant?

There have been some studies that suggest a possible variation in Planck's constant in certain scenarios, such as in the early universe or in the vicinity of black holes. However, these findings are still controversial and require further research and evidence to be confirmed.

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