Portal:Physics/Selected picture/Week 15, 2007

Image credit: Lawrence Livermore National Laboratory A rope trick is the whimsical term given by physicist Dr. John Malik to the curious lines and spikes which emanate from the fireball of a nuclear explosion just after detonation. The image is from the Tumbler-Snapper test series of 1952.

The surface of the fireball is over 20,000 kelvins and emits huge amounts of visible light radiation. The 'rope tricks' which protrude from the bottom of the fireball are caused by the heating, rapid vaporization and then expansion of the mooring cables tethering the tower supporting the nuclear bomb at the start of the test.