Oppenheimer and the Gadget: New Mexico at the start of the Atomic Age
- Laureta Huit
- Jul 11
- 14 min read
By Aaron Krebsbach
Los Alamos Project Main Gate during the Manhattan Project.
Los Alamos National Laboratory
A re-creation of the historic security gate is at Main Gate Park today.
National Park System
On July 16, 1945, at 5:30 AM, the early morning sky of Socorro, New Mexico lit up as if it were the middle of the day. The Gadget, as it was called, had been detonated creating the first Nuclear Explosion in the history of man. Watching from a bunker, the man behind the test and head of the Los Alamos Laboratory of the Manhattan Project, Dr J. Robert Oppenheimer watched as the mushroom cloud climbed into the air and the growl and shockwave of the explosion rolled across the desert to the bunkers that the observers where in. Reports state that he turned to his brother Frank Oppenheimer and simply said, “It worked.” In a later interview with Life magazine, Oppenheimer stated that he recalls thinking of the line from the Bhagavad Gita,
If the radiance of a thousand suns were to
burst at once into the sky, that would be like
the splendor of the mighty one ...
Oppenheimer also stated in the interview that the line that also resonated with him from the Hindu Scripture at the time was, “Now I am become death, the destroyer of worlds.” A phrase that is now forever linked to him and the Trinity Test.
The Trinity Test was the final product of the three year-long Manhattan Project, encompassing the greatest minds in the US at the time, such as Albert Einstein, and theoretical physicists and father of the Hydrogen Bomb, Edward Teller. The development of the Manhattan Project was a response to the rumored, and later validated, threat of German physicists developing their own nuclear weapon. In 1939, Einstein had signed a letter penned by friend and colleague, Hungarian-born physicist, biologist, and inventor Leo Szilard to President Franklin D. Roosevelt warning that Germany may be developing an atomic weapon, and that the US should do the same to counter the Germans. The letter caught the attention of the President and the order to form the Advisory Committee on Uranium, the S-1 Executive Committee, was given, laying the groundwork for the start of the Manhattan Project. After the Japanese attack on Pearl Harbor and the US entrance into the Second World War, the Manhattan Project was created with President Roosevelt authorizing research on the bomb on January 19, 1942.
General Leslie Groves was put in charge of the project in September 1942. His brash, get it done attitude was what the war department needed to ensure the project proceeded post haste. The project was first headquartered at 270 Broadway in Manhattan as the “Development of Substitute Materials”. General Groves felt the name would draw too much attention, and he changed the name to the Manhattan Engineering District, or MED, though this was its unofficial name and the code name was still the former. Overtime the name was shortened to the “Manhattan Project” as the unofficial name. The headquarters of the project was moved to Oak Ridge, TN in August 1943 after a change in leadership within MED in Manhattan.
As General Groves worked to obtain and construct the necessary research, enrichment, and production facilities, and other locations, such as the University of Chicago, were already testing and working on components, Groves needed a leader and location for Project Y, the test and build site for the theoretical bomb. The three prime candidates were under consideration, physical chemist Harold Urey, physicist Arthur Compton, and accelerator physicist Ernest Lawrence. All three were at the tops of their fields and were Nobel Laureates, Urey for his work on isotopes and the discovery of deuterium, Compton for his work on electromagnetic radiation and the discovery of the Compton Effect, and Lawerence for the invention of the cyclotron. But all three were already engaged in different aspects of the project. Compton recommended Oppenheimer for the position, as he had assigned Oppenheimer to project specific bomb-designs in June of 1942 while working at the Metallurgical Lab at the University of Chicago.
Though Compton’s endorsement carried some influence, Oppenheimer raised several red flags with colleagues and leaders of the project. The first was that he had little administrative experience, followed by the fact that he was not a Nobel Laurette. These two concerns focused on whether he would be an effective leader and command the respect needed to cooperate and administer the scientists he would be working with, almost all at the top of their field and headstrong. The final concern was the potential security risk he may pose. Several close associates of Oppenheimer were members of the Communist Party in the US, including his wife Kitty, his girlfriend Jean Tatlock, and his brother Frank. In October 1942, Groves, Colonel James Marshall, and Lieutenant Colonel Kenneth Nichols met with Oppenheimer after a meeting at the University of Chicago with project leaders at the University. General Groves invited Oppenheimer to join them on their return trip to New York on the 20th Century Limited direct train line to New York City. After dinner, they all squeezed into Lt Col. Nichol’s roomette and discussed the project. After the long conversation, Groves was convinced that Oppenheimer was the right choice for Director of Project Y and appointed him to the position. Groves personally waived the security requirements and issued Oppenheimer’s clearance in July 1943.
With a director chosen, the question of where to conduct the testing of a possible nuclear weapon was addressed. Several sites were scouted by Groves and Oppenheimer; each site was a viable possibility with varying security risks. Oppenheimer suggested the Sangre de Christo Mountains in New Mexico for its remoteness and the sparse population of Los Alamos as compared to the other sites he and General Groves had examined. Oppenheimer had spent time in New Mexico in his youth, at the behest of his father to gain strength through the outdoors. During his time in New Mexico, he grew to love the mountains and deserts of the region while horse packing through the Sangre de Christo and Jemez Mountain Ranges and stated later in life that his two great loves were physics and New Mexico. After an inspection by Groves and Oppenheimer, Los Alamos was chosen as the site for Project Y of the Manhattan Project. The town was depopulated of many of its residents, including the boy’s school that was founded by former Rough Rider Ashley Pond Jr., and the Army constructed houses for the families of the scientists. The need for secrecy was weighed against the unknown amount of time that it would take to develop the bomb. Asking the number of people they needed to develop the weapon to relocate for an unknown amount of time to a remote region of the country without some support was a stretch. This coupled with the town needing to look and function like a normal American town to avert suspicion, led to the moving of the scientist’s families to Los Alamos.
Los Alamos was one of 22 major sites the Manhattan Project occupied and one of the three main facilities, with the other 19 facilities and labs assisting with testing, research, and enrichment. Oak Ridge, Tennessee and Hanford, Washington were the other two main sites working in tandem with Los Alamos to develop the new devastating weapons of war. Oak Ridge was tasked with enriching Uranium while Hanford worked on Plutonium. Though their facilities were created quickly, the processes were slow, and it wasn’t until 1945 that enough Plutonium and Uranium were available for use in the bombs. There was enough for the gadget and three other device. The gadget, Fatman, and Third Shot, the bomb that was prepared but never deployed for use, used Plutonium-239 while Little Boy used Uranium-235.
In January 1944, Oppenheimer had discussed at length and garnered enough support with his team at Los Alamos that he brought up to General Groves the need to test the theoretical device and measure its effects. General Groves gave the approval, but he had several concerns. The processing plants in Oak Ridge and Hanford had turned out enough material for testing and use and General Groves was growing concerned about whether the theory would translate to applied. The process for synthesizing and creating plutonium was costly, and General Groves was concerned that the amount of money sunk into creating the element would be a waste if it did not work. Hanford had created enough plutonium to create two bombs, while Oak Ridge had created enough uranium for a single gun type bomb. It was decided that the Gadget, the bomb that was to be tested, would be an implosion plutonium device. The parts and pieces for the gun-type uranium bomb were to be shipped out untested.
A small number of individuals were chosen to scout and choose a site for the test. For safety and security and to maintain as much secrecy as possible, the site needed to be isolated and remote. The site chosen also needed to be flat to minimize secondary effects of the blast, and with little wind as possible to avoid the spread of radioactive fallout. Eight sites were examined, 4 in New Mexico, 1 in Colorado, 2 in California, and 1 in Texas. The final decision was the north end of the Alamogordo Bombing Range, now White Sands Missile Range. A construction company was contracted to create the test base camp and support structures, housing 160 personnel with barracks, officer’s quarters, mess hall, and the other needed facilities for the test. Due to the number of personnel needed, the requirements were expanded to house more people, with over 250 personnel eventually assigned to the test site.
First Lieutenant Harold C. Bush was given command of the camp and he and his twelve-man Military Police unit arrived from Los Alamos on December 30, 1944. Bush set to work right away establishing the necessary security, checkpoints, and patrols. The horses they brought with them were ill suited to the patrol distance of the site and were retired to polo horses and were replaced by jeeps and trucks. The long hours and harsh desert coupled with dangerous reptiles and insects quickly diminished the moral of the MPs. Bush worked to get better food requisitioned and accommodation improvements for his men as well as organizing games and nightly movies. Luckily, they were not alone for very long. Personnel slowly started to arrive throughout early 1945 to prepare for the test, but issues still plagued the facility. The ranch well water was not potable, and drinkable water had to be hauled in from the Socorro firehouse over 40 miles away at several hundred gallons per load and the use of US Navy saltwater soap had to be used to bathe in the local high alkaline water. Because of the remoteness of the facility, electricity was supplied by portable generators and 200 miles of phone wire were strung to reach the camp to stay in communication with the other facilities. Additional buildings had to be constructed for warehouses, workshops, weapon magazines, commissaries, and bomb shelters for the test observers, which ended up being the most expensive construction of the base. As if living in the middle of the desert wasn’t challenging enough, the base was accidentally bombed twice due to its close proximity to the range.
Because of the limited amount of material, a rehearsal test was okayed by Oppenheimer using TNT, Composition B, and with radioactive material packed into wooden boxes in a pseudo-octagonal prism. Called the 100-ton test, the test was actually equivalent to 108-tons of TNT. It was done on a twenty-foot-high platform 800 yards to the southeast of ground-zero of the Trinity test. The test was scheduled for May 5, 1945, but was postponed for two days to allow for more equipment to be installed. The resulting explosion was visible from the Alamogordo Army Air Field 60 miles away, but the shockwave wasn’t felt at the camp 10 miles away. The test revealed several scientific, technological, and logistical issues and raised several additional concerns. A town hall was built for conferences and briefings, and the mess hall upgraded for the influx of traffic as each concern was addressed, and additional personnel added. More phone and radio wires were put in place, wires buried, a teletype installed for communications with Los Alamos, more vehicles were needed for the test, better roads implemented, and 20 miles of road sealed off to reduce dust that was interfering with the reading instruments.
Two weeks before the test, 250 personnel from Los Alamos were working at the test site. Bush’s unit had grown to 125 men guarding the camp. Another 160 men under the command of Major T.O. Palmer were stationed outside the area with trucks and orders to evacuated surrounding civilians if necessary, housing them at Alamogordo Army Air Field till they could be relocated. The constructed bomb shelters were at 10,000 yards north, west, and south of the tower Zero, the tower constructed to simulate ideal detonation height dropped from an airplane. Observers were scattered at different distances with many at 20 miles. Physicist Kenneth Bainbridge, who was in charge of planning the test, asked General Groves to keep his list of VIPs to 10, to which Groves chose himself, Oppenheimer, mathematical physicist and physical chemist Richard Tolman, engineer and inventor Vannevar Bush, chemist James Conant, Brigadier General Thomas Farrell, physicist Charles Lauritsen, nuclear physicist Isidor Isaac Rabi, British physicist and mathematician Sir Geoffrey Taylor, and English nuclear physicist and Nobel Laurette Sir James Chadwick. The VIPs viewed the test from Compania Hill, 20 miles Northwest of the tower.
The Gadget slowly arrived in pieces to the test in July. A trial assembly was done in Los Alamos on July 3 and parts were slowly sent down to the test site. Assembly of the capsule started on July 13. The scientist wanted good visibility, low humidity, light winds at low altitude, and westerly winds at high altitude. Given the conditions, the ideal date was forecasted for between July 18 and 21. President Harry S Truman, who had only learned of the Manhattan Project the day after he took office following President Roosevelt’s death on April 12, 1945 and was fully briefed by General Groves and Secretary of War Harry Stimson on April 25, 1945, wanted the test completed before the start of the Potsdam Conference on July 16, 1945, July 17 in Europe. The scientist scheduled the test for the morning of July 16. The same day, the USS Indianapolis (CA-35) left San Franciso with parts to Little Boy and the enriched uranium, which was in a lead lined container bolted to the floor of Captain Charles McVay’s quarters, enroute to Pearl Harbor, setting a record for the fastest time of 74.5 hours between the two. She then made her way to Tinian Island, arriving July 26, 1945. Not only was New Mexico the center of the development and testing, her sons were aboard for the delivery and at least one was lost at sea when she was sunk on July 30, 1945.
Cillian Murphy as Oppenheimer examining the “Gadget”
Oppenheimer, 2023
Oppenheimer overseas the assembly of the “Gadget” July 1945.
US Department of Energy
The preparations were made, and the date scheduled. The test was to take place on July 16, 1945, at 4:00 AM Mountain War Time. But the weather did not cooperate, and the test was delayed. Rain and thunderstorms starting at 3:00 AM MWT raised concern of radiation spreading further than anticipated and that lightning may lead to premature detonation. A favorable weather report came in at 4:45 AM MWT allowing for the test to proceed. The final twenty-minute countdown started at 5:10 AM MWT. A rocket was fired at 5:25 to signal five minutes to detonation. At 5:29 another rocket was fired to signal imminent detonation. Seconds later, a switch in the control bunker started the detonation timer. Above the test site, two B-29 Superfortress bombers circled the test site carrying members of the Project Alberta section of the project, the men who would be responsible for assisting with the delivery and deployment of the bombs. At 5:29:21 MWT ± 15 seconds, the Gadget detonated. A flash of light color shifted from purple to green then to white. A heat wave reported to as, “being as hot as an oven” was felt as far as base camp. The roar of the explosion took 40 seconds to reach the observers and was felt over 100 miles away as the mushroom cloud climbed 7.5 miles into the sky. Zero tower no longer existed. Only parts of the feet managed to survive its vaporization and remain at the site today. The crater left was roughly 4.7 feet deep and 88 yards wide. The sands of the New Mexican desert became radioactive light green glass, later named trinitite, that spanned a radius of approximately 330 yards. The Gadget detonated with a force roughly equivalent to 24.8 kilotons of TNT.
The aftermath of the test had both immediate and long-term effects. The reactions of those observing was captured through many reports and personal accounts over the years. The reactions ranged from awe to personal regret, to how pleased some were with the result. President Truman was quickly informed in Potsdam by Secretary of War Stimson. President Truman attempted to use the success of the bomb as leverage with Premier Joseph Stalin, but because of Soviet Espionage, Stalin was already aware of the bomb project long before Truman. Theoretical Physicist Klaus Fuchs who worked at Los Alamos on many parts of the bomb, was later discovered to be a Soviet spy along with several other engineers and scientists. The success of the test and the ongoing negotiation between the allies at the Potsdam Conference, resulted in the issuing of the Potsdam Declaration to the Japanese to either surrender unconditionally or face “prompt and utter destruction.” Back in New Mexico, the scientist celebrated the success, and Oppenheimer was seen to have a new pep in his step. Rabi recalled that, “his walk was like High Noon…He had done it.” While they celebrated and collected samples and readings, General Groves had cover stories dispatched to civilian newspapers as soon as possible. The blast that was seen as far away as Amarillo, Texas, 280 miles away. The official story was that a magazine of high explosives and pyrotechnics had detonated, and no one was hurt. It wasn’t until August 12, following the destruction of Hiroshima, that the declassification of the test was released.
The long-term effects of test were not completely seen till years later. The distance effected and the amount of resulting radiation was underestimated which resulted in all future testing being done at least 150 miles from any population. Local ranches were heavily affected as the backs of cattle had discolored patches and stripes down them and ranchers and their descendants started developing effects from the radiation, including cancer. Five New Mexican counties, Guadalupe, Lincoln, San Miguel, Socorro, and Torrance, felt the effects of being down wind of the Trinity Test. Future testing and affected people were covered under the Radiation Exposure Compensation Act of 1990 (RECA) but it wouldn’t be until after much rallying by the Downwinders and the increased awareness of effects of nuclear testing that RECA was expanded to include those affect by the Trinity Test. The motion was passed in the Summer of 2024.
In 2023, Christopher Nolan’s film Oppenheimer released to critical acclamation, with Cillian Murphy as the title character. The movie sparked renewed interest in the both the man and his work. The Trinity Test was once again at the forefront of people’s minds, bringing with it heightened awareness of the power of the atom. The Trinity Test was the beginning of the Atomic Age and the start of a change in world powers. Man now had access to weapons that could level cities and poison people for generations, but at the same time give leaps and bounds in medical treatment and renewable energy. The Trinity Test led to the first and only use of atomic weapons in war, leveling Hiroshima and Nagasaki and causing lasting effects on the populace but ending World War II. But the sword was double edged, the people of New Mexico were heavily affected by the Trinity Test, other states would also suffer the effects of the heavy exposure to radiation and the extent of military testing of atomic weapons. US Nuclear Monopoly only lasted for four years. On August 29, 1949, Russia detonated its first nuclear weapon, RDS-1, that looked and worked much like the plutonium bombs that had been developed at Los Alamos. It was later discovered the nuclear secrets were being passed along by Fuchs, the Rosenbergs, and other Soviet spies implanted in the US nuclear program. The Cold War was starting to heat up, and an arms race was on. The US military worked to build the nuclear arsenal and implement practical uses of nuclear energy. Nuclear reactors were created for powering cities and Navy ships, and nuclear medicine saw advancements in health care in fields like radiology. Trinity was a pivotal moment in the history of mankind. The Los Alamos National Labs were declassified and have been at the forefront of nuclear monitoring in the US. The nuclear genie was let out of the bottle, for better or worse, and he can’t be put back.
