La réponse est oui et non. Les constantes de la physique se comportent comme des constantes absolues pendant l'ère matière. Dans l'ère radiative toutes varient " conjointement" : h , G , c , e , m, mu zéro. A cela il faut impliquer les variations dd'une "jauge d'espace a et d'une "jauge de temps T. Alors les équations de la physique sont invariantes. Il n'y a alors plus de redshift et le cosmos est "Lorentz-invariant". 

J'ai publié là-dessus ans Astrophysics and Space science en 1995. Vous trouverez ça sur mon site internet www.jp-petit.org au "rayon science". Je prépare un papier plus construit pour bientôt et je boucle mon 4° papier publié depuis septembre 2014. 

The general idea that physical constants, including the Planck constant,  can change over time dates back to Dirac but apparently there is not enough experimental evidence to support it: see e.g. the link below and references therein:

http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/constants.html

I did not say that the idea is new. Of course, there cannot be experimental evidence over only a century.

I agree with both answers.

Following reference may me useful,

C. M. Will,

Theory and experiment in gravitational physics

(Cambridge University Press, Cambridge, 1993)

LPI ( Local Position Invariance)  means, see:arXiv:1203.0102 (Kentosh & Mohageg)

"In local, freely falling frames the outcome of any non gravitational experiment is independent of where and when in the universe it is performed"

In this paper  (which is published in Phys. Rev. Lett.)  the conclusion is,

"based on experimental evidence from the GPS and clock comparison experiments, they see that h satisfies local position invariance to within a limit of  0.007."

Source: http://phys.org/news68967509.html

The constants are so fundamental that it is usually impossible to detect any possible changes since the tools we use to measure these changes are also changing. For instance, if the size of the atoms would increase the atoms in the measuring device would also increase to the same extent and everything would appear normal.

But there are dimensionless constants, i.e. they are independent of units. On April 21 this year new findings were published in Physical Review Letters implying that a dimensionless constant – the ratio between the electron mass and the proton mass – has changed with time.

Read more at: http://phys.org/news68967509.html#jCp

http://phys.org/news68967509.html

The Planck constant (denoted h) is the quantum of action in quantum mechanics.

As Planck discovered, it is impossible to explain some phenomena without accepting the fact that action is quantized.

Indeed, Planck discovered that physical action could not take on an arbitrary value. Instead, the action must be some multiple of a very small quantity (later to be named the "quantum of action" and now called Planck constant).

Louis de Broglie generalized the Planck–Einstein relation by postulating that the Planck constant represents the proportionality between the momentum and the quantum wavelength of not just the photon, but the quantum wavelength of any particle. This was confirmed by experiments soon afterwards.

In many cases, such as for monochromatic light or for atoms, this quantum of action also implies that only certain energy levels are allowed, and values in between are forbidden.

So the value of the quatum action is linked with the stability of the matter this is in contrast with G :gravitational constant et and c the speed of light. So it's a real physical constant and the reduced Planck constant is the quantum of angular momentum in quantum mechanics).

@Joseph: is there a proof that the quantum of action did not evolve over time?

@Nathalie

1) From physcs point of view (fast answer) this is linked with the size changes of the atom.

2) From mathemtical point of view as proof :

In his work about Maslov's work on asymptotic methods to approximate the solutions of partial differential equations which were generalisations of the WKB method, Jean Leray wrote in the 70's an entire book titled Lagrangian Analysis and Quantum Mechanics, where he gaves his own special meaning to « Lagrangian Analysis.», MIT Press, see the nice abstract entitled « The meaning of Maslov's asymptotic method: The need of Planck's constant in mathematics.»

This is a profound motivation for why there should be some finite, small, constant such as Planck's from the standpoint that the caustics you get in geometrical optics cannot be physical, and yet geometric optics ought to be a useful approximation to wave optics. From this point of view, there ought to be some constant like Planck's constant, at least in pure mathematics.

It is, however, very advanced: inaccessible unless you already know about Fourier integral operators in Symplectic manifolds, such as in Duistermaat's book or Guillemin and Sternberg, Symplectic Techniques in Physics.

For a physicist, though, perhaps just the basics of the Hamiltonian relationship between geometrical optics and wave optics, and the basics of the WKB method, would be accessible.

I attached the pdf file of Leray paper

Dear Nathalie Olivi-Tran 

Quantum Mechanics is based on Plank Constant, therefore Planck constant is  spinal cord of Quantum Mechanics.

Planck's constant, symbolized h, relates the energy in one quantum (photon) of electromagnetic radiation to the frequency of that radiation. In the International System of units (SI), the constant is equal to approximately 6.626176 x 10-34 joule-seconds. In the centimeter-gram-second (cgs) or small-unit metric system, it is equal to approximately 6.626176 x 10-27 erg-seconds.

The energy E contained in a photon, which represents the smallest possible 'packet' of energy in an electromagnetic wave, is directly proportional to the frequency f according to the following equation:

E = hf

If E is given in joules and f is given in hertz (the unit measure of frequency), then:

E = (6.626176 x 10-34) f

and conversely:

f = E / (6.626176 x 10-34)

Also see electromagnetic field, energy, frequency, SI, and Table of Physical Units and Constants.

http://whatis.techtarget.com/definition/Plancks-constant

Planck’s constant, (symbol h), fundamental physical constant characteristic of the mathematical formulations of quantum mechanics, which describes the behaviour of particles and waves on the atomic scale, including the particle aspect of light. The German physicist Max Planck introduced the constant in 1900 in his accurate formulation of the distribution of the radiation emitted by a blackbody, or perfect absorber of radiant energy (see Planck’s radiation law). The significance of Planck’s constant in this context is that radiation, such as light, is emitted, transmitted, and absorbed in discrete energy packets, or quanta, determined by the frequency of the radiation and the value of Planck’s constant. The energy E of each quantum, or each photon, equals Planck’s constant h times the radiation frequency symbolized by the Greek letter nu, ν, or simply E = hν. A modified form of Planck’s constant called h-bar (ℏ), or the reduced Planck’s constant, in which ℏ equals h divided by 2π, is the quantization of angular momentum. For example, the angular momentum of an electron bound to an atomic nucleus is quantized and can only be a multiple of h-bar.

The dimension of Planck’s constant is the product of energy multiplied by time, a quantity called action. Planck’s constant is often defined, therefore, as the elementary quantum of action. Its value in metre-kilogram-second units is 6.62606957 × 10−34 joule∙second, with a standard uncertainty of 0.00000029 × 10−34 joule∙second.

http://www.britannica.com/EBchecked/topic/462917/Plancks-constant

One most important facts of Planck Constant.

http://abyss.uoregon.edu/~js/21st_century_science/lectures/lec12.html

http://abyss.uoregon.edu/~js/21st_century_science/lectures/lec12.html

La réponse est oui et non. Les constantes de la physique se comportent comme des constantes absolues pendant l'ère matière. Dans l'ère radiative toutes varient " conjointement" : h , G , c , e , m, mu zéro. A cela il faut impliquer les variations dd'une "jauge d'espace a et d'une "jauge de temps T. Alors les équations de la physique sont invariantes. Il n'y a alors plus de redshift et le cosmos est "Lorentz-invariant". 

J'ai publié là-dessus ans Astrophysics and Space science en 1995. Vous trouverez ça sur mon site internet www.jp-petit.org au "rayon science". Je prépare un papier plus construit pour bientôt et je boucle mon 4° papier publié depuis septembre 2014. 

There is no possibility to evidence any variation of physical constants during the matter dominated era. It occurs during the radiation dominated era, through "joint variations". The effect is that c varies like a ^( - 1/2). The effect. It ensures the homogeneity of the universe because the cosmological horizon varies like a(t). This replaces the classical explanation based on Inflation theory, due to "Inflaton". I published that in 1995 in Astrophysics and Space Science. Title : " Twin universe cosmology". I am presently preparing a more refined paper about it. 

Planck´s constant and all other related physical constants (e.g. G, the gravitational constant) are probably linked to cosmic parameters like space, age and energy of the universe (see attachment). Nevertheless, there is no hint from observation, that they are not invariant in space and time. This is only possible however, if the energy of the universe increases in the same amount like space and age.

If this is really the case, the Big Bang would no longer be a singularity, since at t=0 and r=0, E also would be zero (and with zero values, the physical constants would not be determined!). Furthermore, with increasing energy in the calculated amount, it can easily be shown, that the size of the universe would equal its Schwarzschild-radius at all times. An increase in energy of one Planck-particle / Planck-time would not only keep the values of the "pyhsical constants" constant, but would also expand the Schwarzschild-radius of the universe and therefore its size with light velocity.

If these relations are not true, it seems difficult to explain, why the Schwarzschild-radius right now equals the size of the universe, and why right now the values of physical constant can be expressed in terms of cosmic parameters. With a constant energy, these relations would not be guilty at any other time, which seems to be rather improbable.

Article Are Planck-particles the primordial particles of matter in t...

Please let me add another curiosity at last: The age of the universe is app. 10(exp61) times the Planck-time, its size app. 10(exp61) times the Planck-lenght and its energy app. 10(exp61) times the Planck-energy. Rather mysterious if time and space are increasing, but energy does not.

In a relativistic world all values have to be variant.  There is no way to get around it.  If I bend and twist time and space then everything in that time and space is twisted and bent.  In a relativistic universe all constants are not constant. 

A very good question... but to find the answer you have first to know the answer to the question: the space expands or decreases the length unit? Because the answer depends on the units. You can see the problem in the link:

https://www.researchgate.net/post/The_space_expands_or_decreases_the_unit_length

Dear Nathalie,

As to me, I am sure from the 2013 that answer is NO. Planck constant appears from the geometry of our universe and do depend on the expansion velocity. You can find details here:

http://lanl.arxiv.org/abs/1401.2404

It is very unusual, but it follows from this result that in the flat stationary universe the h=0 and there are no stable quantum systems exist. But nevertheless this fact does not affect quantum theory, because it has another nature (see http://lanl.arxiv.org/abs/1603.01642 ). So we can surely say the Planck constant is the property of photons and reflects geometry of our universe.

Every result, observation, fact, can have several meanings; for instance, a person in tears can be in pain, or very happy, or having a eye problem, etc.. We have to keep in mind the possible meanings of every result and in each moment to chose the one that best fit the whole set of evidences; as the number of evidences increases, the meaning that best fit them can change, so we must not kept fixed to the first choice.

In what concerns Planck constant, cosmic data shows that the energy of photons decreases as wavelength increases; some has explained this by considering that Planck constant varies with the expansion of the space, which classifies Planck constant as a property of space.

This explanation, however, is not acceptable because the decrease of photons's energy is a violation of energy conservation.

The careful analysis of data leads to the conclusion that is not space that expands but our length units that decreases. The expansion of space is as apparent as the motion of the Sun around Earth. This is not some hypothesis that I am making, this is a conclusion easily obtainable by deduction from cosmic data, one just have to pay due attention to it.

Now, in this framework, the wavelength of cosmic waves is longer that the one of present ones for the same phenomenon because past atoms were bigger and produced longer wavelengths with a different relationship with energy - a different Planck constant. Therefore, Planck constant appears as property of the process of light emission, therefore a property of matter, not of space.

Matter properties hold invariant in standard units because these units are defined to be so - they have to comply with the concepts of reference-body and clock. However, the invariance of matter is a priori as valid as the invariance of space to define units. 

So, in standard units, Planck constant, as all matter properties, is invariant; in comoving units, the ones that best can describe this universe, Planck constant varies with matter.

At this point, this may seem confusing but it is not; however, it is a change of paradigm and that is not easy for our minds used to think that space expands and matter is invariant. We are now as the Ptolemaic scientists when they had to face the non-geocentric ideas...

It is! Please check iSpace theory presented on my RG home to understand that can be the only (mathematically correct) answer. While the intrinsically discrete model of space-time used assumed in iSpace theory (using Golden-Ratio and the concept of a changed distance definition) is not widely known yet, it's results as presented are nothing less than stunning: over 50 constants of nature including h and others like e, alpha, R-infinity and even G are calculated by exact symbolic equations to an arbitrary digit precision in any unit system chosen (but typically SI). This is possible - and only possible - if constants are just that - *constant* - and as extremely simple typically only multiplicative iSpace equations show they cannot ever vary. As at the same time all predicted values are within full agreement (and that means 10^-9 to 10^-12 (!) and not just 5-10% which is often assumed already to be good agreement) of CODATA 1998-2014 results I really believe it is soon end of live for all theories assuming "variable" constants of nature.

In a quantum universe, how can there be constants?  Everything else is in flux and uncertain.  How can the speed of light, or plank's constant, or the mass of a proton, etc. be constant and unchanging?  This seems like a mystery to me.

Nathalie,

I have often asked this question to myself.  It is one that needs to be answered.  I have thought for some time that if there are different photons there must be differences in Plank's number.

George

In flat space h should be invariant like mass and light speed, although it might change slowly with time. The possibility of change is small and we can't measure it. These are properties of space. All of them should change with curvature.

In GR Einstein gave a way to vary light speed by putting  ( ds2 = 0 ) in metrics.

c/co = ( 1 - 2MG/rc2 )

This same form appears in integral form for distributed mass in his book "The Meaning of Relativity" starting at equation 107 where L is c/co and co is taken as one by choice of units in the book.

Adding high speed as kinetic energy competing with gravity in the stress energy,

c/co = ( 1 - 2MG/rc2 + v2/c2 )

Far from a central mass, somewhat speculative.

c/co = ( 1 + v2/c2 )

Many other choices are possible and have been proposed in various places. Most of them lead to a variable h.

Energy and momentum are applied in conventional equations completing the present  set.

E2 = (mc2)2 + (pc)2

pc = Ev/c

dE = vdp

Then ( h/ho ) should emerge in a definition of dE/df  where ( E= hf ) for each of many quantum actions. The equations are solved for mass.

(m/mo)2 =  (2-c/co)/ (c/co)3

E2/Eo2 = c/co

This is just the case of  invariant h deriving from the extension of GR.

To get a variable h requires a departure from GR at high energy as proposed in modified PV and in competing theory TGD.

The Planck length, time and mass follow the Lorentz contraction. The speed of light is different in higher dimensions. The Gravitational Constant not Really Constant.

Preprint Do the Planck length, time and mass follow the Lorentz contraction?