As you know, quantised inertia predicts that a new kind of propulsion can be extracted from charged capacitors. This is essentially the Casimir effect and charging the cathode so that electrons stream across to the anode pushing the whole thing a little bit more than expected. In 2021 (see also my 2024 book) I derived this thrust using dimensional and physical arguments to be
F = 0.00014 x IA/d^2
where I is the Fowler-Nordheim leakage current, the A is plate area and d is the plate separation. This predicts the thrust measurements from several laboratories, one in California (Becker and Bhatt), Virginia (IVO Ltd), Italy and the one I set up with Richard Arundal at Plymouth University, and the thrust has also been seen in a few high-powered 'garages' or home labs. I have recently repeated and improved the derivation of this that I had before, but recently Morgan H. Lynch suggested to me another way to derive the same formula that is more speculative, but is rather elegant and couples the down to Earth component of this with black hole physics.
Imagine a small black hole, shown above. It is emitting Hawking radiation of power P (the red arrows). The total force coming off it is P/c, where c is the speed of light. Now imagine someone extremely brave goes up to the event horizon and puts a capacitor (grey //) on it so that the cathode is just on the horizon. What would the force on the electrons be? It would be P/c times the ratio between the plate area (A) and the area of the whole black hole radius d, so
F = PA/(4pi.cd^2)
Now let us imagine that the leakage current observed in the capacitor is equivalent to Hawking radiation. The mass energy flux rate is P = (I/q)mc^2, where q and m are the charge and mass of an electron, so
F = (mcIA)/(4pi.qd^2)
Now let's just put the known numbers in here and see what happens.
F = 0.00014 x IA/d^2
Compare this with the formula I derived before. The same! In other words, in some sense, that is not entirely clear yet, the QI thrust capacitor is analogous to a black hole. In a sense it is, because, for a highly accelerated object like an electron, the Unruh waves are short enough to be damped by the plates so the area between the plates is a sub-vacuum bounded by a metal horizon. Not a million miles from the concept of a black hole.
After I told him this my son asked if there was any danger. The answer is no. It's just another horizon. They form whenever anything moves (strictly - accelerates) and based on billions of years of experience they do not swallow the universe. So you too can make a 'black hole' in your garage.
By the way, I'm now making short videos about QI and related issues. The videos are available on my YouTube channel:
https://www.youtube.com/channel/UC0LWcVMLjdw7duQRVsqzZNQ
References
McCulloch, M.E., 2021. Thrust from symmetrical capacitors using quantised inertia. Research Gate: https://www.researchgate.net/publication/353481953_Thrust_from_Symmetric_Capacitors_using_Quantised_Inertia
