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A Self-Made Machine

RepRap, a new open-source hardware project, goes a long way toward fulfilling the dream of self-replicating machines

2 min read

More than 50 years ago, computer pioneer John von Neumann conceived of a self-reproducing machine. It would mine its own ore, smelt it into metal ingots, machine the ingots into parts, and assemble the parts into a copy of itself. During the 1980s, nanotechnology evangelists worked out the same idea on a much smaller scale, prompting critics to envision a horror scenario in which molecule-size bots reduce the entire world to a featureless mass dubbed ”gray goo.”

Today there’s RepRap. Unlike gray goo or von Neumann’s idealized machines, RepRap (short for ”replicating rapid-prototyper”) doesn’t harvest its own materials. But also unlike them, it’s entirely real. For about US $725 in parts, this self-reproducing machine, spawned by a global band of engineers and hobbyists, will squirt out complex three-dimensional patterns of molten plastic filaments that will solidify into most, if not all, of the mechanical parts for another RepRap (see sidebar, ”Self-Reproduction Is Hard; Selfâ¿¿Assembly Is Harder”).

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Why Functional Programming Should Be the Future of Software Development

It’s hard to learn, but your code will produce fewer nasty surprises

11 min read
A plate of spaghetti made from code
Shira Inbar

You’d expectthe longest and most costly phase in the lifecycle of a software product to be the initial development of the system, when all those great features are first imagined and then created. In fact, the hardest part comes later, during the maintenance phase. That’s when programmers pay the price for the shortcuts they took during development.

So why did they take shortcuts? Maybe they didn’t realize that they were cutting any corners. Only when their code was deployed and exercised by a lot of users did its hidden flaws come to light. And maybe the developers were rushed. Time-to-market pressures would almost guarantee that their software will contain more bugs than it would otherwise.

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