© 2019 Michael Clarage
Contents
1. fluctuations in the building electrical ground
2. voltage differences across parts of plants & soil
3. How the 60 Hz ambient power affects voltages in plants & people
Fluctuations between a shelf and wall ground
Summary: the building electrical system ground fluctuates by about 0.5 volts with a frequency of about 1 minute. The same is not seen out in the grass away from the building.
Put one side of the volt meter into the wall socket ground. Put the other end onto something in the room, like a shelf. Measure the voltage difference over 3 hours.
Top image (blue) is the voltage difference between a shelf and the wall ground socket. The large oscillations are ~0.4 vpp. Bottom image is a spectrogram of the voltage. The bright yellow wanders between 0.001 Hz and 0.05 Hz.
Very clear oscillations, the period is around 1 minute. Strange jumps in amplitude.
Are these ~ 1 minute fluctuations just the power grid? I know that the 60Hz power grid frequency actually fluctuates chaotically around 60Hz. Does the whole grid also resonate/fluctuate in potential relative to the local Earth? Is there some other oscillation, like with the ionosphere? I tried the same experiment 4 times over 2 weeks, and always saw something like this.
For the first hour the amplitude is about 0.02 volts. The amplitude jumps to about 0.2V at 2500 seconds. I think corresponds to when the first batch of students came into the room. Hmmm. will have to re-run for that.
Compare fluctuations of plant leaf and metal cabinet
Potted plant compared to metal cabinet. Both share wall socket ground.
Zoom in
1) Plant suffers smaller fluctuations
2) Why are both offset 2 Volts?
3) Phase seems not completely in synch
Fluctuations between dirt and plant leaf
Here is the plant, being a good sport, one volt probe lead in the soil, the other connected to a far away leaf.
This is kind of a "floating" measure, since the plant is in a pot that is hanging from the ceiling. These share the same ~1.0 minute fluctuations, but now centered around zero.
Decay of potential in plant
One lead in plant soil. The other lead connected to the stem or leaf. When contact is first made, there is a jump in potential. This potential then decays over a few seconds. This looks like a potential difference from soil to leaf is creating a circuit through the 1 Mohm resistor of the voltmeter, forming a discharging capacitor. There are other possible explanations. Below is three tries: when connecting the leaf the potential spikes, but then decays over a few seconds. If this were a simple RC circuit the time constant for decay is simply given by RC. My plant potential decays to 66% of the max in 3 seconds, the resistance of the voltmeter is 1 Mohm, giving a capacitance of 3 millifarads, which to me seems like a lot - - but I have no idea what to expect here.
On a rainy day, the flowering plant in my room showed the decay-like "charging and discharging" lines like a capacitor.
Bottom and Top of fish tank
Put the ground terminal into the gravel of the fish tank. Put the positive terminal into the top layer of water which is filled with plants.
The top starts at lower potential than the gravel, reaching equality at about 1,000 seconds, and continuing up, leveling off at about 0.05 volts higher than the gravel. You can see at the end of the run, after some wild data points from me pulling the probes out of the water, I connected the two probe tips to get reading of zero - - which is pretty close to zero.
If we look at the top and bottom of the tank as a capacitor, with a voltage difference between them, and look at the voltage probe as the thing that is shorting out the circuit - the probe has 1 mega ohm. Taking about 750 seconds to decay to .66 of its value, this gives a capacitance of 1.3x10-9 Farads. I don't know that these values mean much in this setting. I don't even know that the voltage probe is completing the circuit. It could be that the water itself completes the circuit between the probe tips.
Also no explanation for how the top of the water could rise to positive potential relative to gravel.
Showing that the probe tip acquires a charge being in the air
I think the decay curve is in many cases the discharge of charge collected on the probe tip by being in the air.
In the above figure you see decay curves of voltage. In each case the two probe tips were inserted into the ground several inches apart. Take the red probe out of the ground for a few seconds then insert into soil, and the voltage trace jumps negative and decays to zero. Take the black tip out of the soil, hold in air for a few seconds, put bac into soil, the voltage jumps positive and decays to zero.
Showing, I believe, that the probe tip acquires electrons from the air. When placed into the soil, the tip slowly loses those electrons.
How the 60 Hz ambient power affects voltages in plants & people
Summary: Humans resonate strongly with the ambient 60 Hz power system. A plant does not fluctuate nearly as much with the 60 Hz vibrations.
Samantha, I am happy you are "motoring through" my posts. I tried subscribing to your substack, but the UI did not have a subscribe button. Is that something that can be turned off, am I not getting to your homepage?