1. The Gadget OR The Trinity Test by Baker Ball
This picture is of the gadget explosion, seconds after detonation.

2. The Trinity bomb tower, which did not survive the blast
The Trinity Test
The gadget was the nickname for the Trinity bomb, which was the codename for the first nuclear weapons test.
The Trinity bomb was tested on July 16, 1945 in the White Sands Proving Ground in Socorro, New Mexico.
This location, and all proving grounds, are isolated from society and are safe for testing.
It is called the "fat man type" because the Fat Man bomb, dropped on Nagasaki, Japan and was modeled after the Trinity
Scientists bet on the results of the test; bets ranged from the bomb being a complete dud to being at least the force of 18 kilotons of TNT. Some feared New Mexico would be destroyed, or the atmosphere would catch fire and incinerate the planet.

3. The Science of Trinity The bomb was a plutonium-implosion device
In a implosive nuclear reaction, the radioactive fissile material (usually uranium, but in this case plutonium) is surrounded by high explosives. These explosions compress the material, resulting in criticality.
In a critical radioactive material, the material takes much longer increases or decreases in radioactivity, resulting in an extended half-life of the material and increased fallout
 In a fission bomb (like Trinity), nuclear fuels are struck by protons of a radioactive substance, which creates extra neutrons. This reaction makes possible a self-sustaining nuclear reaction.
Plutonium was used because reactor-bred plutonium had a much higher neutron release rate.

4. Trinity Test Oppenheimer, the destroyer of worlds
Kenneth Bainbridge was in charge of planning the test
The explosives expert was George Kistiakowsky
Berlyn Brixner captured the device on film
Robert Oppenheimer was a lead developer
The gadget itself was assembled by Rudolf Peierls
Samuel Allison performed the final countdown 
Bainbridge and Oppenheimer were impressed
A pilot flying when the explosion occurred said that he thought the sun was rising from the south
The explosion created such heat that it created Trinitite (melted quartz and feldspar), a glass-like material, from the sand
Oppenheimer later said that the explosion reminded him of a verse from a Hindu scripture: "Now I am become death, the destroyer of worlds."

5. Pictures
This is a picture of the Trinity bomb right before detonation. It is surrounded by a steel casing to recover any valuable leftover plutonium.
This is the only surviving color photo of the explosion. The explosion caused extreme brightness, and then blocked out the sun.

6. This picture shows the design of the Fat Man bomb, which was technically identical to the Trinity bomb. This diagram displays the parts of the weapon and the plutonium core, which gets compressed and becomes critical. The fast and slow explosives are detonated periodically in order to compress the plutonium.