Cosmologists say that in theory, it should be possible to see Big Bang, with a sufficiently large telescope. The idea is that when we look at distant objects with a telescope, we see them, not as they are now, but how the were when the light from them was sent. If we could look sufficiently far away, say 13-15 billions light years, we would see Big Bang happen, since it took place 13-15 billions years ago. But I don't understand how we can see Big Bang. Because if I see Big Bang, this means that photons sent from Big Bang hit my eye. At the same time, I am made of elementary particles of which at least some might have originated at Big Bang. We thus have two events: Big Bang and me looking at Big Bang today, connected by the paths of several particles, the photons and elemetary particles mentioned above, who follow different trajectories in spacetime but with the same initial and final points. But the photons have travelled by the speed of light, and the elementary particles with slower speeds. How can they then start from the same point and end up at the same point? Seems like a contradiction to me. I once asked a well known astronomer this question, and he replied that my thinking was flawed, and that I, wrongly, believed that Big Bang took place at one particular place in space. He was wrong about that. I knew then, and I know now, that at Big Bang, all of Universe was a single point. But I don't see how this resolves the paradox. Still, we have different trajectories in spacetime (no matter which shape spacetime has) with the same initial and end points, and some are trajectories of photons travelling with the speed of light and others are trajectories of slower particles.