>The universe is expanding from the central point of the Big Bang.

There is (or rather was) no central point of the Big Bang. The BB happened EVERYWHERE - your house, my house, Mars, the Crab Nebulae and every other single point in the universe. All of it - every single place - and all at once.

Conceptually this is almost impossible for humans to picture. Our everyday experience restricts our ability to see "expansion" apart from some sort of object growing larger from around a central point (like blowing up a balloon). But that's not how the universe expands (now and during the BB). Instead of thinking of an object growing larger, think about all the parts that make up the object spreading apart from every other part at the same time. You can even have an infinitely large thing expand in this way - everything in the infinitely large thing just moves away from every other thing.

Picture an infinitely large sheet of graph paper marked with a grid. Each point that marks the intersection of lines on the paper is exactly one centimeter away from each neighboring point of intersection. Then stretch the paper until all points of intersection are now two centimeters from each neighboring point of intersection. You've expanded the infinitely large sheet by adding space between all the already existing points. The expansion happened everywhere on the sheet - it doesn't have a central point (it's actually more correct to say that every point is the central point of expansion because every point looks like the central point since an observer at each point would see the entire sheet stretch away from the observer in all directions).