Is a straight line the shortest distance between two points? Quite simply, I heard a lot of talk about how a straight line isn't necessarily the shortest distance between two points.
Is this true, and if it isn't, how would that work?
 A: Here is a very non-technical answer: If our space was Euclidean then a straight line would be the shortest distance between two points. And until Einstein, through his general theory of relativity, showed that the space can actually be bent everybody believed and treated the space as Euclidean.
But now we know that the "physical" space is not Euclidean and therefore a straight line is not necessarily the shortest distance between two points. Consider for example being on the surface of a solid (impenetrable) sphere. The shortest distance between two points on the sphere is not a straight line.
I recommend you to read about geodesics.
A: If I recall what I've seen from Neil deGrasse Tyson correctly, he said that for what we currently have observed in the universe, a straight line is the shortest distance between two points. However, something that we have very healthily theorized about is worm holes. If worm holes exist, then you can travel through the worm hole to potentially travel less distance to get to the same point.
Think about it like a piece of paper. Of course, if you draw two points on opposite ends of the piece of paper, the least distance pathway is to draw a straight line connecting the two. What wormholes would do is what he describes as folding the piece of paper. So, if you fold the piece of paper so the points are closer, the least distance pathway would be using the worm hole instead of travelling along the piece of paper.
