# What is the smallest Quantum of Energy?

1. Jun 30, 2008

### wawenspop

I am wondering about the smallest bits of space time possible
and my musings lead me to the smallest quantum of energy.
Then I have a mental picture of the 'smallest' wave packet
possible as the building block of everthing else.

For example, is the 'smallest' photon possible a
1 Hz photon? - (near absolute zero K?)
- then E = h*1 etc? Then I can start applying
Schrodinger and/or matrix math to find out more?

Or am I on the wrong track here?

2. Jun 30, 2008

### peter0302

I'm not aware of anything that says a photon cannot have a lower frequency than 1 Hz.

In QM, everything comes in chunks, but the variables defining those chunks (position, energy, momentum) are all still continuous.

3. Jun 30, 2008

### mathman

The lowest possible frequency would be determined by the longest possible wavelength. This could be the diameter of the universe.

4. Jun 30, 2008

### peter0302

Could be but must it? The photon is always traveling at the speed of light, so a photon that starts at one edge of the universe would take 24 billion years or so to reach the other edge, at which point the universe will have expanded even more.

Moreover, the frequency is just the rate at which the EM fields mutually induce. The photon still only exists at one point in space at a time, and that point moves at c, so there's no reason that the oscillations couldn't be so slow that the photon doesn't even reach a full EM cycle from one end of the universe to another.

Now a different question is what is the largest packet of energy? Would it be a photon whose wavelength is the Planck Length?

5. Jun 30, 2008

### dst

According to wiki any photon that can probe the planck length is likely to collapse into a blackhole so I guess that places a fundamental limit on photons.