Why do fireworks explode a symmetrical way?
the firework artist arranges them to go off in a particular succesion. first there is the charge that propelles them into the sky. Moments later that charge in the sky ignites to show off wonderfull colors of fire.
Fireworks are things which explode in a loud and chaotic (though pleasing of course) way. This phrase therefore is saying that the result of a particular action will be "explosive" in the sense that it will lead to trouble. It means that the consequences will often predictably be highly noticeable, unsubtle and quarrelsome (bad). For example I might say that it will result in fireworks if I forget to buy my wife a birthday present!
fireworks are usually made in china, (as a lot of things are) and they are basically gunpowder, sulfate, charcoal, nitrate, fuses, and colors (to make them appear colorful) so when they are lit, the fuse burns all the way down, hits the gunpowder, and the force blows it up into the air (also causing it to, more or less, explode into colors)
Have you ever seen fireworks before? Maybe you remember that when the fireworks explode, you see the big burst of color before you hear the bang. If you were right next to the firework, way up in the air, the flash and the sound would seem to be at almost the same time, but the farther away you are, the bigger the gap will be between the pretty light and the big boom