So that’s how unicorns fly through space — by pooping out rainbow-colored slinkies. I’ve always wondered.
The brain-twisting image comes from a review of NASA’s “helical drive” proposal, the idea that you could get massless thrust by accelerating particles to the speed of light as they traveled forward, gaining mass, and then slowing them down as they bounce back so they’d lose mass. Presto! Net acceleration forward. Only it won’t work, because:
The problem is that, even though the author does a very nice simulation, he has left out the fields that do the accelerating. When we accelerate ions using a magnetic or electric field, the ions push back on the field. There is an equal and opposite force exerted on the electrodes and coils that produce the fields, and those just happen to be in the spaceship, too.
The concept is trivially dismissed. What’s odd about it all is that the guy who proposed it to NASA is at NASA, and even admitted in his proposal that there are a few weaknesses.
- Basic concept is unproven
- Has not been reviewed by subject-matter experts
- Math errors may exist!
His proposal is full of charts and calculations, and is obviously carefully thought out and represents a substantial investment of work, yet he never rolled his office chair out into the hallway and asked an engineer in one of the cubicles nearby for a quick reality check, before going public with a crazy idea that was going to get shot down in a few seconds by some smart guy on the internet? Is this what NASA managers do all day?
This is a good example of how communication is an essential component of science. Individual minds can get led down the garden path by a tantalizing notion, but a group of minds can ferret out the problems before you make a big splashy investment of your reputation in something with a fatal flaw.








