From Paul Bowden, Nottingham, UK
Writing in response to my letter about travelling to the TRAPPIST-1 system (6 June), Bryn Glover is, of course, completely right when he says that it would be practically impossible to get there while taking all your propellant with you in a 1 g spaceship (Letters, 27 June).
So, how about scooping it up as you go along? And accelerating it out of the back of the starship? Perhaps that could be done with the so-called dark matter that we are told fills our galaxy.
Does anyone know how to do this using weakly interacting massive particles (or whatever dark matter might be)? If someone can solve this, they will give us the key to the stars!
