Planck's Constant- what would happen if it changed?

[EamFog18]

Hi, I'm a sixteen year old from the UK who is studying physics and hoping to do it at uni, recently I entered an essay competition with the topic being on physical constants, their effects on everyday life and what would happen should they be changed. I have chosen to do Planck's constant as quantum physics is something that interests me and  I have seen it mentioned recently in news due to it replacing the IPK. However I am a bit out of my depth mathematically, and with no clear answer was wondering whether I could get peoples opinions on what they think would happen should Planck's constant be changed and how it will affect everyday life. 

Thanks.

[studiot]

4 minutes ago, EamFog18 said:

Hi, I'm a sixteen year old from the UK who is studying physics and hoping to do it at uni, recently I entered an essay competition with the topic being on physical constants, their effects on everyday life and what would happen should they be changed. I have chosen to do Planck's constant as quantum physics is something that interests me and  I have seen it mentioned recently in news due to it replacing the IPK. However I am a bit out of my depth mathematically, and with no clear answer was wondering whether I could get peoples opinions on what they think would happen should Planck's constant be changed and how it will affect everyday life. 

Thanks.

The first thing to know about PC is that there are two versions.

Commonly called h and hbar, which incorporates a factor of 2Pi. (you can see about this in my link)

hbar is used in most modern QM treatments.

Then look at the units of PC and ask yourself what fundamental physical units or dimensions doe it depend upon or affect. (again look in the link).

Ask here if you don't know what 'dimensions' mean in Physics - mass (M) length (L) and time (T) etc, or have more detailed questions.

Finally take a gander at Planck units.

This should give you enough material for a rip roaring tale  of Physics.

https://en.wikipedia.org/wiki/Planck_units

Go for it.

[EamFog18]

21 minutes ago, studiot said:

The first thing to know about PC is that there are two versions.

Commonly called h and hbar, which incorporates a factor of 2Pi. (you can see about this in my link)

hbar is used in most modern QM treatments.

Then look at the units of PC and ask yourself what fundamental physical units or dimensions doe it depend upon or affect. (again look in the link).

Ask here if you don't know what 'dimensions' mean in Physics - mass (M) length (L) and time (T) etc, or have more detailed questions.

Finally take a gander at Planck units.

This should give you enough material for a rip roaring tale  of Physics.

https://en.wikipedia.org/wiki/Planck_units

Go for it.

Thanks, I've had a look. 

I was wondering if in the hypothetical situation that we consider changing Planck's constant for a photon:

with the equation E=hv, we know that h=E/v, therefore by changing h to a larger value we would be either increasing the energy or decreasing the frequency of the photon, if this is true, then if we are increasing the energy of the photon would that mean we would also be increasing the mass of the photon, as energy and mass are interchangeable? 

As well as this, does PC only apply to photons when considering it as the ratio of energy of the particle to frequency or could it apply to electrons as well? 

many thanks and sorry if this is too many questions

[studiot]

2 hours ago, EamFog18 said:

many thanks and sorry if this is too many questions

No that's what this forum is for.

 

Remember that PC is a universal constant.

So if you change it you change the result of any equation or result that you apply it to, not only photons.
Nor can you only change it for some things and not others.

However photons have zero mass, so their mass would not change, only their energy as you deduced.

You can also deduce the effect on energy by noting the units of PC, as I said.

How did you get on with that bit?
You probably have not yet come across 'dimensional analysis' - it is a really handy tool.

[LaurieAG]

12 hours ago, EamFog18 said:

with the equation E=hv, we know that h=E/v, therefore by changing h to a larger value we would be either increasing the energy or decreasing the frequency of the photon, if this is true, then if we are increasing the energy of the photon would that mean we would also be increasing the mass of the photon, as energy and mass are interchangeable? 

You should also look at the Compton wavelength equations to see the relationship between the Planck constant and photons.

https://en.wikipedia.org/wiki/Compton_wavelength#Distinction_between_reduced_and_non-reduced

[swansont]

I've never read the books, but George Gamow wrote several, all with Mr. Tompkins as part of the title, about life in a world with different physical constants. I think he does Planck's constant in Mr. Tomkins in Wonderland.

https://en.wikipedia.org/wiki/Mr_Tompkins

 

If h were big enough, people would behave as waves, and diffract as they walked though a doorway.

[EamFog18]

20 hours ago, studiot said:

No that's what this forum is for.

 

Remember that PC is a universal constant.

So if you change it you change the result of any equation or result that you apply it to, not only photons.
Nor can you only change it for some things and not others.

However photons have zero mass, so their mass would not change, only their energy as you deduced.

You can also deduce the effect on energy by noting the units of PC, as I said.

How did you get on with that bit?
You probably have not yet come across 'dimensional analysis' - it is a really handy tool.

Hi, I had a look and understand that he reduces the units to simple constants, but the actual maths goes over my head! 

I’ve decided to use two systems, a photon and a hydrogen atom and then perhaps talk about the effect this will have as a whole on the universe, extrapolating from the two simple systems. Id just need a simplified explanation on what would actually occur, if that’s okay. 

9 hours ago, swansont said:

I've never read the books, but George Gamow wrote several, all with Mr. Tompkins as part of the title, about life in a world with different physical constants. I think he does Planck's constant in Mr. Tomkins in Wonderland.

https://en.wikipedia.org/wiki/Mr_Tompkins

 

If h were big enough, people would behave as waves, and diffract as they walked though a doorway.

Thank you this is definitely worth a look, do you know the science behind this by any chance? 

11 hours ago, LaurieAG said:

You should also look at the Compton wavelength equations to see the relationship between the Planck constant and photons.

https://en.wikipedia.org/wiki/Compton_wavelength#Distinction_between_reduced_and_non-reduced

Thank you this will certainly be of use.  

[swansont]

14 hours ago, EamFog18 said:

 Thank you this is definitely worth a look, do you know the science behind this by any chance? 

I have some familiarity with it.

[EamFog18]

11 minutes ago, swansont said:

I have some familiarity with it.

If its possible do you think you would be able to explain it simply, my knowledge on quantum isn't too brilliant. I know planck's constant shows the ratio between the energy of particles and the frequency at which they vibrate, as well as an effect on the energy levels of particles, apart from that I'm not too sure on the science.

[swansont]

1 hour ago, EamFog18 said:

If its possible do you think you would be able to explain it simply, my knowledge on quantum isn't too brilliant. I know planck's constant shows the ratio between the energy of particles and the frequency at which they vibrate, as well as an effect on the energy levels of particles, apart from that I'm not too sure on the science.

Everything behaves as a wave, but we don't normally notice this, because the wavelength is h/p, where h is Planck's constant (very small) and p is momentum (very large for macroscopic objects)

But make h large, and all of the sudden we notice the wave behavior of everything. The existence of an object is spread out when it's moving, and only localized when it interacts. Do you bump into a pole, or do you just go through/past it? As I said, you diffract going through a door, so you could end up jumping to one side or the other instead of going straight. Identical twins could undergo interference. 

Hitting or kicking a moving ball becomes interesting, affecting a lot of sports. Imagine a water wave at the beach, and you try to kick it. It might look like that. You might make contact and kick it, or the wave might just go past your foot and continue on its way. A goalie might think they have the goal attempt smothered, but the wave goes past them and the ball is suddenly in the back of the net.

[EamFog18]

8 hours ago, swansont said:

Everything behaves as a wave, but we don't normally notice this, because the wavelength is h/p, where h is Planck's constant (very small) and p is momentum (very large for macroscopic objects)

But make h large, and all of the sudden we notice the wave behavior of everything. The existence of an object is spread out when it's moving, and only localized when it interacts. Do you bump into a pole, or do you just go through/past it? As I said, you diffract going through a door, so you could end up jumping to one side or the other instead of going straight. Identical twins could undergo interference. 

Hitting or kicking a moving ball becomes interesting, affecting a lot of sports. Imagine a water wave at the beach, and you try to kick it. It might look like that. You might make contact and kick it, or the wave might just go past your foot and continue on its way. A goalie might think they have the goal attempt smothered, but the wave goes past them and the ball is suddenly in the back of the net.

Ah that sounds perfect for what I need, is this De Broglie's wavelength?

[swansont]

1 hour ago, EamFog18 said:

Ah that sounds perfect for what I need, is this De Broglie's wavelength?

Yes.