A novelist transforms the physicist John von Neumann into a scientific demon....

Last year, MIT computer scientists and Adobe engineers came together to try to solve a major problem that many companies face: bit-rot. A good example is Adobe’s successful Photoshop photo editor, which just celebrated its 25th birthday. Over the years Photoshop had accumulated heaps of code that had been optimized for what is now old hardware. “For high-performance code used for image-processing, you have to optimize the heck out of the software,” says Saman Amarasinghe, a professor at MIT and researcher at the Computer Science and Artificial Intelligence Laboratory (CSAIL). “The downside is that the code becomes much less effective and much more difficult to understand.” This results in what Amarasinghe describes as “a billion-dollar problem”: companies like Adobe having to devote massive manpower to going back into the code every few years and, by hand, testing out a bunch of different strategies to try to patch it. But what if there were a computer program that could automatically fix old code so that engineers can focus on more important tasks, such as actually dreaming up new software?...

MIT researchers have designed a way to generate, at room temperature, more single photons for carrying quantum information. The design, they say, holds promise for the development of practical quantum computers. Quantum emitters generate photons that can be detected one at a time. Consumer quantum computers and devices could potentially leverage certain properties of those photons as quantum bits (“qubits”) to execute computations. While classical computers process and store information in bits of either 0s or 1s, qubits can be 0 and 1 simultaneously. That means quantum computers could potentially solve problems that are intractable for classical computers. A key challenge, however, is producing single photons with identical quantum properties — known as “indistinguishable” photons. To improve the indistinguishability, emitters funnel light through an optical cavity where the photons bounce back and forth, a process that helps match their properties to the cavity. Generally, the longer photons stay in the cavity, the more they match....

A transistor, conceived of in digital terms, has two states: on and off, which can represent the 1s and 0s of binary arithmetic. But in analog terms, the transistor has an infinite number of states, which could, in principle, represent an infinite range of mathematical values. Digital computing, for all its advantages, leaves most of transistors’ informational capacity on the table. In recent years, analog computers have proven to be much more efficient at simulating biological systems than digital computers. But existing analog computers have to be programmed by hand, a complex process that would be prohibitively time consuming for large-scale simulations. Last week, at the Association for Computing Machinery’s conference on Programming Language Design and Implementation, researchers at MIT’s Computer Science and Artificial Intelligence Laboratory and Dartmouth College presented a new compiler for analog computers, a program that translates between high-level instructions written in a language intelligible to humans and the low-level specifications of circuit connections in an analog computer....