If you're planning on watching Macy's Fourth of July Fireworks Spectacular in person or on TV, there are some fun new fireworks this year. Pyro Spectaculars, the company that designs the fireworks, will be using nautical mines in the show.
Nautical mines are actually fired down at the water, instead of up in the air. Executive producer Robin Hall explained that they "explode on the surface of the water, where the fragments will remain illuminated for a few seconds before fading out." As for how barges are packed with fireworks, check out this Post story, which also has good photos.
Another interesting fact: Fireworks displays have been designed to take advantage of wider formats on high-definition TVs. The Macy's show's theme this year is "In Our Children's Eyes," a look at the show from a child's perspective. Here's more info.
Photograph of jellyfish fireworks from Pyro Spectaculars