Replacing the sun with a supermassive black hole only to see everything from Mercury to random Kuiper Belt objects get sucked into its gargantuan mass is indeed rather satisfying, although it does remind us of Universe Sandbox's sometimes cunning methodology.

A Black Hole in this case is a huge star with enormous gravity rather than a new object with different properties. Rings around planets are simulated by weightless, collision-free particles rather than fully simulated microscopic chunks of ice.

A star is a star is a star – while you can change specific gravities and densities, there's no physical distinction between a sun-like star and a brown dwarf. But it could easily be argued that adding such things would be detrimental to the overall effect; if one can simulate a black hole by building an enormous, physics-defying star, why go through the extra computational effort required to build an accurate simulation?

"There's still lots of room for improving the algorithms, which would improve the efficiency and speed of the program," says Dixon, "but the end result isn't going to be very obvious to the end users, so it's a lower priority than other features."

One man army

Perhaps the most impressive feature of Universe Sandbox has nothing to do with the software itself; it's that such a professional chunk of code could come from just one person. It can't be an easy task, surely? Dan Dixon explains,

"I left my job as an Associate Producer in the video game industry because of my dissatisfaction with the game I was working on. Even though Universe Sandbox isn't earning enough to justify the amount of time that I dedicate to the project, it's pretty easy to work on something I love." Love is one thing; making an independent distribution model work is quite another.

"My 'pay what you think it's worth' payment model has been an interesting experiment," says Dixon. "It's worked better than I expected. I'm realising this could become my full time gig." Dixon reckons he spends anywhere from 20 to 80 hours a week on Universe Sandbox-related activities, which includes everything from coding to answering emails.

Even if it wasn't presented so professionally or it hadn't turned out to be such brilliant fun, we'd still be applauding Universe Sandbox. It's a perfect example of programming ingenuity taking precedence over painstaking high-end simulation.

One of the built-in examples shows you the devastating effect the explosion of the Death Star had on planet Endor; if that doesn't encapsulate Universe Sandbox's underground ethos, we really don't know what does.

First published in PC Plus Issue 274