Comments

The video would have been much better if we could have seen the engine work. I think many people who read PopSci are also interested in the details. How is the 'cyclone' generated in the combustion chamber? How is the steam pumped? What does it sound like? What are the 'green' implications? (It runs on 'any' fuel -- does that just mean gasoline and ethanol, or does it include diesel and wood?) He said there's no oil. Don't the pistons still need to be lubricated in some way, or is the steam a kind of lubricant? I know answers to all these questions would require a longer article, but a few of them could have been answered without much extra text or video. It's a great item however and Popsci.com is free, so I'm not really complaining. Just suggestions.

It doesn't matter how far away it is as far as the time-delay question is concerned. If it explodes "next week" as the article says is possible, that is to say the light, and the gamma rays, will reach us next week. Of course this means the damage would be immediate, but of course the time of the actual explosion -- the release of those gamma rays at the star -- would be far in the past.