Star Wars is Science FICTION for a reason...
I can't believe a bunch of clever scientists wasted their time figuring this one out.
Star Wars is science FICTION, not fact, meaning that some stuff that happens in the show isn't true, and can't possibly happen.
Next they'll be coming out with a story that the Death Star couldn't possibly be made...
A lot of Sci-fi is utter rubbish according to what we know currently (of course without anyway of testing these theories at present (and highly unlikely in the future) we have no way of checking who got it right).
There have been other things in sci-fi films that aren't true and that most probably couldn't happen - a time travelling delorean (knowing how bad those things were built the car would be obliterated if it tried to go as fast is it did in the movie to jump through time), mass effect relays that can take us to the collectors, an extra train platform that can only be accessed by witches and wizards running head on into a brick wall between platforms 9 and 10, the heart of gold - a ship that can make the impossible happen, or that there is a disc shaped planet riding on the back of a giant tortoise, etc.
All this is just science fiction and isn't meant to be taken as true, if science fiction was meant to be true then it would be very boring. It's just down to imagination and where it takes you and not meant to be taken literally and investigated by science.