Practice question · Select all that apply
Select every genuine physical limit on computing that the lesson identifies.
Hints
- Four options are constraints imposed by physics; one is about mathematics instead.
- Ask which limit would still apply on any imaginable hardware.
Show the answer
- A. Digital signals are restored to clean levels at each stage, so noise does not accumulate.
- B. Analogue signals can be copied indefinitely without degradation.
- C. Every bit is stored in some physical state - a charge, a magnetisation, a pit.
- D. Erasing information has an unavoidable energy price, however good the hardware becomes.
Why
Heat removal, signal propagation, Landauer's erasure floor and physical embodiment are all consequences of physical law. The count of possible algorithms is a mathematical matter and no physical constraint touches it.
Practise Information, Signals, and the Physics of Computing
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