I'm a physics undergraduate student who has recently finished a special relativity class, but haven't done a nuclear physics class yet, so if I'm mistaken anything about nuclear physics, please object. I was pondering about a situation while doing my special relativity class which I haven't gotten a solid answer yet. The problem is this: Two particles who are not electrically attracted but may be subjected to a nuclear force attraction are seperated, in their frame of reference where they are both immobile, by a distance longer than the minimal active distance of the strong force (thereby there is no attraction). Now a minisculle traveller (who is on a linear path) is travelling at a speed close to the speed of light, close enough so that in his frame of reference, he mesures (using the usual method of length mesurement in special relativity) the distance between both particles to be shorter than the minimal strong force distance. Paradoxally, he 'should' see a force between them, and they should be attracted and collide, but in their frame of reference they are immobile and there is no force. So my question is this: Is there a relativistic correction for the strong nuclear force, or is one(or many) of my initial assumptions false? References(books, articles, etc.) would be good, but an expert's word is just as appreciated!