They're cheap but highly accurate and, like any electronic system, are sensitive to humidity and dust. (Digital clocks are even more sensitive, which is why almost all outdoor clocks are analog.) ...

Is it time to redefine the second? Optical clocks can reach accuracies at the level of 10-18 , “which is a number so accurate that if the clock started running at the big bang, by now it will ...

There are no true self-driving cars available today. Certain systems do, however, come somewhat close to this in limited ...