The most accurate clock in space launches within days and will begin building a highly synchronised network out of the best clocks on Earth. But the project, decades in preparation, will only operate for a few years before it burns up as the International Space Station deorbits at the end of the decade. NASA's most accurate atomic clock will be tested on a mission to Venus The Atomic Clock Ensemble in Space (ACES) is a European Space Agency (ESA) mission that will generate a time signal with unprecedented accuracy and then transmit it via laser to nine ground stations as it passes overhead at 27,000 kilometres per hour. This network of clocks will be in extremely close synchronisation and provide highly accurate timekeeping around the world. The result is that ACES will be able to test Einstein's theory of general relativity, which says that the passing of time is affected by the strength of gravity, with great accuracy.

This summer, I bought my wife a vintage watch--a model called the Big Crown Pointer Date, made by the Swiss company Oris. The watch was manufactured in 1995, and is small, elegant, and mechanical, which means that it doesn't contain a battery; instead, you wind it, and it tells the time using an ingenious system of gears. The Pointer Date takes its name from what watch people call a "complication"--an added feature beyond timekeeping. It has a fourth hand, which reaches out to the edge of its face, where the numbers one to thirty-one are arranged. At midnight, the hand ticks forward, making it possible to see one's progress through the month as a movement around a circle. Even though the watch was assembled by hand nearly twenty years ago, it still works perfectly.

"The tantalizing promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor. A fundamental challenge is to build a high-fidelity processor capable of running quantum algorithms in an exponentially large computational space. Here, we report using a processor with programmable superconducting qubits to create quantum states on 53 qubits, occupying a state space 253 1016. Measurements from repeated experiments sample the corresponding probability distribution, which we verify using classical simulations. While our processor takes about 200 seconds to sample one instance of the quantum circuit 1 million times, a state-of-the-art supercomputer would require approximately 10,000 years to perform the equivalent task. This dramatic speedup relative to all known classical algorithms provides an experimental realization of quantum supremacy on a computational task and heralds the advent of a much-anticipated computing paradigm." It is fascinating to consider what will happen next in the intersection of quantum information and artificial intelligence. It is also hard to tell where it will lead, perhaps a new computing paradigm?

"The tantalizing promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor. A fundamental challenge is to build a high-fidelity processor capable of running quantum algorithms in an exponentially large computational space. Here, we report using a processor with programmable superconducting qubits to create quantum states on 53 qubits, occupying a state space 253 1016. Measurements from repeated experiments sample the corresponding probability distribution, which we verify using classical simulations. While our processor takes about 200 seconds to sample one instance of the quantum circuit 1 million times, a state-of-the-art supercomputer would require approximately 10,000 years to perform the equivalent task. This dramatic speedup relative to all known classical algorithms provides an experimental realization of quantum supremacy on a computational task and heralds the advent of a much-anticipated computing paradigm." It is fascinating to consider what will happen next in the intersection of quantum information and artificial intelligence. It is also hard to tell where it will lead, perhaps a new computing paradigm?

After decades as laboratory curiosities, some of quantum physics' oddest effects are beginning to be put to use, says Jason Palmer PATRICK GILL, a director of the new Quantum Metrology Institute at Britain's National Physical Laboratory (NPL) in south-west London and an expert in atomic clocks, points to a large table full of lenses and mirrors, vacuum chambers and electronics. "And there's a smaller one over there," he says. NPL is part of a consortium of the planet's official timekeepers. In all its atomic-clock laboratories, each of the flagship devices--some of which are huge--is flanked by a smaller one under construction. Miniaturisation is the name of the game.

On the wall of Aaron Dollar's office is a poster for R.U.R. (Rossum's Universal Robots), the 1920 Czech play that gave us the word "robot." The story ends with the nominal robots seizing control of the factory of their origin and then wiping out nearly all of humanity. Dollar, fortunately, has something more cheerful in mind for the future of human-robot relations. He sees them as helpers in our daily lives--performing tasks like setting the table or assisting with the assembly of your new bookcase. But getting to the point where robots can work in the unstructured environment of our homes (as opposed to industrial settings) would take a major technological leap and a massive coordination of efforts from roboticists around the globe.