Behold!

The mushroom cloud consists chiefly of very small particles of radioactive fission products and weapon residues, water droplets, and larger particles of dirt and debris carried up by the afterwinds. The color of the cloud is initially red or reddish brown, due to the presence of nitrous acid and oxides of nitrogen. As the fireball cools and condensation occurs, the color changes to white, mainly due to the water droplets as in an ordinary cloud.





If the explosion occurs above the ground, when the expanding blast wave strikes the surface of the earth, it is reflected off the ground to form a second shock wave. This reflected blast wave can merge with the incident shock wave. This merging phenomenon is called the Mach effect. The overpressure at the front of the Mach wave is generally about twice as great as that at the direct blast wave front. This footage is from a conventional explosion.