Digital Revolution

Turing machines are usually regarded as the de facto model of a computer. John D. Cook even said "For example, a Turing machine is a computer reduced to theory." There is a serious objection to this view, for it leaves no place for innovations like the transistor. If a Turing machine producing symbols on an infinite tape is a totally adequate model of a computer, why bother transistors? Yet transistors are the reason why modern CPUs are so fast and small, suitable for personal computing devices. A more balanced point of view would be that Turing machines capture the logic of computation, but are not a comprehensive model of a modern computer. Turing machines constructed as they are operate very slowly. The place of transistors is to preserve the essential logic of Turing machines while greatly speed up computation. Consequently, computational steps, or logical depth, should not be regarded as a measure of real computational time, but only as a measure of logical complexity. O

Among Apple's great line-up of products, there is a weak point that's the Apple TV. Although Apple CEO Tim Cook expressed intense interest in TV , Apple TV still fell short of revolutionary and was gradually marginalized, despite rising sales. The reason is that Apple TV lacked a viable strategy, and Apple TV+ alone won't save Apple TV. The market of smart TV is dominated by Android-based devices. Google's open source approach allowed TV makers to ship smart TVs of their own. A screen integrated with Android that doesn't require additional setup boxes proved a success. Apple TV's lack of a screen may be understandable from technological point of view, that Apple only wants the best of possible TV screen technology, but without sufficient product differentiation between tvOS and Android, Apple TV makes itself appear redundant. On another front, Apple TV is an inadequate substitute for entertainment boxes like Xbox and PlayStation. The primary shortcoming is lack