# Any signs of fundamental blocks of energy?

1. Apr 19, 2015

### Puma

I would just like to ask a basic question as to whether there is any sign of there being a minimum energy block size which may hint at a fundamental particle building unit, or whether there is just a continuum of energies as far as we know so far.

2. Apr 19, 2015

### rootone

A photon has zero (rest) mass, so they are pretty much fundamental.
However photons can be more or less energetic depending on their wavelength.

String theories are an attempt to define all known particles as an assembly of smallest possible units.

3. Apr 19, 2015

### ChrisVer

No signs... just some people's research or beliefs/preferences. One thing is for sure, energies above the Planck scale need some new physics.

4. Apr 19, 2015

### Staff: Mentor

No signs, but strong exclusion limits.

The concept would be very odd and does not fit into physics at all. If photons could only exist in multiples of some specific energy, for example, what happens to Doppler shift of photons at this specific energy? You would have to find a completely new set of physical rules, and at the same time reproduce all physical effects we see. That just does not work.

5. Apr 20, 2015

### Puma

Assuming, possibly erroneously, that there are blocks, it then seems impossible to find then any discreet fundamental block value due to the fact the blocks themselves can have a continuum of energies rather than discreet levels or ideally a single level... which I should have realised.

So lets say we look at a lot of particles in terms of their mass exclusive of their general movements (if possible). Lets then say the lightest of these, we guess is NM2 where N is a whole number and M2 is a new unit of mass. If we then find that all the masses of the other particles are also can be measured in whole number values of M2 it then looks like a single M2 unit is a fundamental unit of mass assuming the values are coprime.

(Sorry if this is rubbish)

6. Apr 20, 2015

### ChrisVer

If you find a number M2 which, if you multiply it with different integers N, can reproduce the spectrum of masses of the known particles, then I could give some credit in your logic (not saying whether it's wrong or right).

Obviously if you tell me that the number N is not an integer but a real number, then you can find infinite M2's which would do the job for you....

But also in any case I think you would generate infinite numbers of particles...even at positions that they don't exist in. To make this more clear to you, let's take the electron's mass $m_e$ and the muon's mass $m_\mu$. Then approximately this holds: $m_\mu \approx 200m_e$ ... However if you take $m_e$ as your number M2, then you would also have to generate $2 m_e$, $3m_e$ etc up to 200 (which obviously is incorrect).

The task of finding a theory which can reconstruct the discrete masses of the known particles (in some way I think strings are trying to do that), should reconstruct only the masses of the known particles and maybe particles with masses at energies that we have not been able to reach yet. If these theories reproduce particles with masses at our current detection scales that don't exist, they are "trash".

Last edited: Apr 20, 2015
7. Apr 20, 2015

### Staff: Mentor

You can never experimentally rule that out - just make M2 smaller than the smallest uncertainty in particle masses and it fits. But then you also have no predictive power. You would need to see some clear step-like system, and that is not present in particle masses at the current uncertainties.

To make it worse, it is known that neutrino masses are at most ~.1 eV. Apart from those, the electron is the only stable elementary particle on its own, all other elementary particles are unstable or do not exist as individual free particles, and they all have at least 1 billion times the masses of neutrinos. Measuring the mass of unstable particles with a precision of 1 times in a billion is ... uhm.... let's call it "challenging". The muon mass is known with a precision of 3.5 eV.

There is no theoretical reason to expect such a step either. The electron cannot be made out of smaller blocks of a mass below the electron mass, that does not fit to quantum mechanics or hundreds of precision experiments done with electrons. Similar for all other particles.

8. Apr 24, 2015

### Puma

Or an electron cannot be made out of smaller blocks of a mass because you would have thought it would have been observed by now. I have googled and couldn't find anything.