Sounds like an attempt to tap into the quantum vacuum of space.
The amount of theoretical energy in the quantum vacuum is believed to be enormous. Some estimates have energy density of enough energy in a liter of space to vaporize all the worlds oceans. Tesla was a big believer in quantum energy he called it energy in the ether since quantum physics didn’t exist yet. He was correct that energy always flows down hill from source to sink. His idea was to create a resonator that would bring the “ether” into a self resonating oscillation where the sink would be the brief periods of reversal in the resonance waves. Basically creating a lower energy state inside the vacuum chamber that once per oscillation energy flow into to it and then dissipates into the vacuum yielding a net energy flow “downhill” it would be limitless should it have worked given that the space time vacuum is also belived to be expanding and thus growing in capacity. It violates Newton since energy would be “destroyed” flowing downhill out of the known space time universe into the quantum vacuum and lost forever. Fascinating stuff.