The video contrasts the binary states represented by conventional digital computers with the superpositions of states in a quantum computer. It does not, and does not need to, deal with how the signals in the electronics represent the logical states and so over-simplifies the details of the mechanism of transistors in representing binary states.

Transistors do not literally turn the current all on or all off and do not need to. For reliability and speed they represent states as voltages beyond thresholds, with the bistable operation within the two extreme ends of the S-shaped nonlinear transistor characteristics. "Switching circuits" use electronics to switch representations of logical binary states in terms of signals, which does not mean or require literal on-off switching of current. It has been a long time (before WWII) since switching circuits were literal switches like shunt relays, and different kinds of bistable devices like vacuum tubes, cryotrons and magnetic devices have been used that are not transistors at all.

The circuits are also more complex than the logic gates indicated in the video (and only indicated superficially at that) because the gate logic networks must be incorporated into sequential circuits with signal delays maintaining state representations across the clock cycles -- the whole aggregate state of the machine changes very rapidly in a sequence of discrete time intervals, each interval temporarily maintaining a physical representation of the current logical state in accordance with inputs to a fixed circuit.

Typical programming does not have to deal with these detailed states at all, let alone the hardware representations. There are several more layers of software in the hierarchical structure -- from machine language to high level application languages; and program layers -- from operating systems to compilers, interpreters and linkers to various modules of application programs expressed directly in terms of mathematical formulas, high level logic abstractions independent of machine representation, and modern data structures. Commonly used mathematical languages like Matlab (and the free equivalent Octave on PC's http://sourceforge.net/projects/octav... ) are a long long way from machine language and the earliest high level languages like Fortran.

The whole system in all its layers -- from the physics of how transistors and other devices work and are manufactured at microscopic sizes, to the electronic circuits and their logical design, to representation of the logical essence of the switching circuit signals in the mathematical form of applied abstract algebras, to the nature of system and application software and advanced mathematical and logical algorithms at very high levels of abstraction -- is more than fascinating.

Like other sciences now there is more in all the branches of computer science than any one person can comprehensively know. It all comes together in an integrated system that inherently links the highest levels of abstract thought and programming through multiple layers down to the basic physical reality of a machine doing exactly what it is told to for a specific human purpose, specified by both the design of a general purpose computer and a program controlling it. The prospects of quantum computing and the continuing developments in technology and applications for ever increasing human purposes are a leap to yet another level.

Fascinating, and Thank, Dale..
So long as you avoid the comments on that site...

fascinating! , Thank You, Dale! -- j
.

I still how are they going to solve the problem of Schroedingers Cat in relatonship to this type of computer? Seccond, how are computer scientiists going to stop photons escaping the system if light is the media for information transfer?

I assume your assertion that programmers are not doing math is intended to support the concept of IP for software, which I support. Clearly there is some damn hard math going on all over the place in programs, (encryption, video, sorting, signal processing, neural networks, etc).

Quantum computers are coming.

BTW, are you familiar with entangled photons and communications faster than the speed of light?

So, is every configuration is a new machine, subject to an independent patent?