Lichtenberg figures

Russ Edmonds, Mon Oct 14 2019, 12:30AM

The top two that look like fireworks are from a positive discharge.
Bottom five are from a negative discharge.
This was done on the bottom of a plastic oil drainage pan using an aluminum cigar tube as the electrode.
Baking powder was used for the dusting.

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Re: Lichtenberg figures
Sulaiman, Mon Oct 14 2019, 01:33AM

Nice effects.

What did you use for your hv source ?
Re: Lichtenberg figures
Russ Edmonds, Mon Oct 14 2019, 03:01PM

I used a negative charging Van de Graff generator (VDG) and a aluminum pie tin connected to a long insulating handle. I charged the pie tin negatively by direct contact with the VDG and positively by induction. With the pie tin charged it was then discharged onto an aluminum cigar tube placed on top of the plastic oil pan. The cigar tube was then removed and baking powder was dusted onto the surface of the plastic. This is almost exactly how G. C. Lichtenberg did it in 1777 only, he used and electrophorus for charging, different powders for dusting and gum-lac, resin for the plastic surface.
Re: Lichtenberg figures
medved, Sun Feb 02 2020, 09:12PM

Wow nice !

I was also made Lichtenberg's figures, but on the water surface ... a little greater.

video: Link2

on my website: Link2

below are also comparisons of the positive and negative electrodes... and the lowest in the article also photos at the highest energy in capacitors... the last attempts were up to 800J
the diameter of the lichtenberg figure is 65cm with 800J (+33kV) of energy in caps! amazed
Re: Lichtenberg figures
Russ Edmonds, Wed Feb 05 2020, 07:17PM

A "little greater" is an understatement!
A very rough guess for the energy of my charged pie tin (6pF @ 50kV) is only 0.0075 J versus your 800 J
Nice work!

I'm now charging a 2 nF salt water cap and discharging it through the same cigar tube placed on 2 mm thick acrylic sheet. I started grounding the cigar tube before I  pick it up and discovered that this grounding was causing a smaller second discharge of opposite polarity to the first.
 These next two photos are with out grounding the cigar tube before removal. Positive on the left and negative on the right.
Link2
Link2

This photo is with grounding the cigar tube before removal.
Link2
The small inner ring of the positive discharge is the second negative discharge. 
The negative discharge on the right, has an inner positive discharge that is almost as large as it is. This is because positive figures are much larger than negative for the same voltage.


 The following two photos show positive figures over 10 cm in diameter using the 2 nF cap on a 11 x 15.5 cm acrylic block 24 mm thick. The count was about 12 seconds charging time. Assuming the VDG is a constant current source of 4.5 uA (which is only approximate because of leakage at these high voltages) the voltage is about 27 kV.
Link2
Link2

This is one of the more “artsy” figures. Positive discharge thru 48 mm diameter metal sphere resting on 2 mm thick acrylic with grounded back plane. After discharge the sphere was accidentally grounded and rolled a little toward the upper left.  Blobs of negative discharge can be seen as the sphere rolled.
click on image for larger view.
Link2
Re: Lichtenberg figures
Nik, Mon Feb 10 2020, 08:19PM

I never thought to try to make those! I work in a really dusty plant and see them a lot on trash bags Link2

Occasionally I will see them around the plastic insulators on 600v equipment. I'll have to keep my eye out.

Great work!
Re: Lichtenberg figures
Russ Edmonds, Tue Feb 11 2020, 01:28PM

That's amazing!
I wonder how they formed? They look like positive discharges.
The long dust figure is really interesting.
Thanks for posting this!