I think a similar effect is explained from about 7:16 minutes in the linked video lecture. To get the context the first part of the video must be watched as well as he was talking about Benjamin Franklin and some early history of the discoveries of electricity ect. .

Lec 01: What holds our world together? | 8.02 Electricity and Magnetism, Spring 2002 (Walter Lewin)
https://www.youtube.com/watch?v=Lx64cq0HeXY

I would also draw attention to figure 2., of the linked Patent Drawing below, from One of Tesla's patents..
Here is a section of the patent referring to the two plates.

In illustration of a particular form of apparatus which may be used in carrying out my discovery I now refer to Fig. 2. In this figure, which in the general arrangement of the elements‘ is identical to Fig. 1, the device at is shown as com posed of two very thin con ducting-plates 2ft’, placed in close proximity and very mobile, either by reason of extreme flexibility or owing to the character of their support. To improve their action, they should be inclosed in a receptacle, from which the ‘air may be exhausted. The plates 25 t’ are connected in series with a working circuit, including a suitable receiver, which in this case is shown as consisting of an electromagnet M, a movable armature a, a retractile spring I), and a ratchet-wheel 10, provided with a spring-pawl 11, which is pivoted to armature a, as illustrated. When the radiations of the sun or other radiant source fall upon plate P, a current flows into the con denser, as above explained, until the potential therein rises sufficiently to attract and bring into contact the two plates 25 t’, and thereby close the circuit connected to the two condenser-terminals. This permits a flow of current which energizes the magnet M, causing it to draw down the armature a and impart a- partial rotation to the ratchet-Wheel to. As the current ceases the armature is retracted by the spring Z), without, however, moving the wheel to. With the stoppage of the current the plates t t’ cease to be attracted and separate, thus restoring the circuit to its original condition.

https://patentimages.storage.googleapis.com/pages/US685957-0.png

Patent link.
https://www.google.com/patents/US685957

Nothing new it seems.

pomodoro,

I have also always thought that they were just generation x-rays. One end of filament is at ground and the other is at 50KV AC. That is enough voltage to pull electrons from the wire but not enough to pull the positive atoms from the wire. This creates a 50K electron accelerator that slams electron into the other end of the filament which is a very hard metal. This is how x-rays are produced in dental office.

OK the first thing I notice is the copper strip actually sticks to the glass of the bulb well after the power is shut off.

The second thing is that he is comparing 60 Hz 115 volts AC to many kHz and several thousand volts AC. He would need to compare the Tesla coil output to the output from a regular HF transformer at the same frequency and voltage to show a "special effect" different from regular HF HV AC.

Third thing is simply running the current past the copper strip is depriving the plate of a near equal area to be attracted to.

A good experiment would be to test if the bulb is needed to attract the copper strip, what could be tried is a piece of glass with a resistive conductor across the back side away from the copper strip as well as just a metallic plate made to have a similar resistance to keep the voltage about right across it or some other alternative load that takes away the vacuum bulb.

Fourth thing is that the charging of the capacitor from the light bulb failed (at least once) for no good reason.

Fifth thing is that the capacitor was charged a bit from the wire even though it has much less area than the bulb.

The transmission to the beach is nothing special either, nor is the wireless transmission of pulsed DC over a distance of a foot or so.

All in all I don't see anything special in  the video except the various power supplies, I would like to have those.

Here's a clip of my setup lighting a 25 watt bulb from the output coil of the "unpowered" transformer on the right while at the same time throwing a nice arc/spark from the top of the unpowered transformer back towards the top of the transformer that is powered. They are not identical as can be seen but simply tuned near the same resonant frequency. It screams because the resonant frequency is over 700 kHz. I rigged a break out point on the top of the unpowered transformer to let out the power and let more in at the input. hehe Still input is less than 600 Watts. Expensive and noisy way to light a bulb but fun to watch the sparks.

https://www.youtube.com/watch?v=ZVx1FzLFFXc

I don't have an area safe where I am permitted to use that transformer, it interferes with stuff and even destroys some electronic stuff if I use it too close to things. Otherwise I would fix the broken spark gap rotor and do some experiments.

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Well that wasn't a demonstration of an attempt at the Dollard experiment, just showing my transformer, it produces several hundred thousand volts at the top terminal unloaded.
If I wanted 30 + KV to do the experiment using that transformer I would need to use the second transformer to step down the HV to the desired voltage, which is just a matter of winding a different output coil for the second transformer and tuning it, then the bulb could have several thousand volts across it. But it would be safer and better to design and build transformer for the voltage desired.

As a general rule I don't follow Dollard or replicate his demonstrations.

OK the first thing I notice is the copper strip actually sticks to the glass of the bulb well after the power is shut off.
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I think the x-rays are pushing electrons out of the foil as a result of high energy collisions. This leaves the foil with a static positive charge. The foil sticks to objects just like a strip of paper with a static charge sticks to things.

Just my guess. I have not done the experiment.

I have just replicated this part of Eric's experiment successfully!!

The video will be on youtube quite soon.

I will post the link when ready.

Keep an eye out ,its a shocker !
Naughty Eric....

Very well done.  It makes perfect sense to me.  I was thinking x-rays about half way through your video...holy crap...how dangerous is that?
I hope many people watch your video.

Bill