Science For All | What was the Manhattan Project?

The Hindu’s weekly Science for All newsletter explains all things Science, without the jargon.

Updated - July 19, 2023 03:51 pm IST

Published - July 19, 2023 03:50 pm IST

This photo shows an aerial view after the first atomic explosion at Trinity Test Site.

This photo shows an aerial view after the first atomic explosion at Trinity Test Site. | Photo Credit: AP

The release of Oppenheimer on 21 July is awaited with bated breath as Cillian Murphy takes on the role of Julius Robert Oppenheimer, also dubbed as the father of the atomic bomb. 

While the movie is based on the biography American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer and focuses on the Trinity test, this week’s newsletter will look at the Manhattan Project at large.

The Manhattan Project was a top-secret research and development program during World War II that aimed to develop an atom bomb. It was named after Manhattan, the borough of New York City where the project had its headquarters. Led by the United States with support from the United Kingdom and Canada, the project ultimately resulted in the successful creation of the world’s first atomic bomb. 

The project began in 1939 after a letter from Albert Einstein to President Franklin D. Roosevelt, warning of the potential for a new and devastating weapon based on nuclear fission. In response, the US government established the Manhattan Project under the direction of the Army Corps of Engineers, with the primary goal of developing nuclear weapons before Nazi Germany.

The project brought together some of the brightest scientific minds of the time, including physicists Robert Oppenheimer, Enrico Fermi, and Neils Bohr. It had multiple research facilities across the US, the most significant of which was Los Alamos, in New Mexico, where the bomb was designed and built.

The project’s aim was to weaponise nuclear fission. This occurs when a single atom of an unstable radioactive element, particularly uranium or plutonium, is bombarded with neutrons of a specific energy, causing the nucleus to split. If the reaction releases another neutron of similar energy, it can lead to more fission, creating a chain reaction and releasing an enormous amount of energy in a short span of time.

This is the case because the nucleus splitting breaks the action of one of the four fundamental forces of nature, and the strongest by far: the strong nuclear force. It’s the force that binds quarks together to make subatomic particles like protons and neutrons.

On July 16, 1945, the Manhattan Project conducted the Trinity test in the isolated Jornada Del Muerto Desert, about 240 km away from Los Alamos. The bomb was dropped from a 30-metre-tall steel tower named ‘Zero’. The explosion has been described as a ball of fire that rose rapidly, followed by a mushroom cloud reaching a height of 12,200 metres. The explosion was equivalent to blowing up 15,000-20,000 tonnes of trinitrotoluene (TNT).

The following month, the US dropped the infamous Little Boy and Fat Man bombs, fuelled by the radioactive isotopes uranium-235 and plutonium-239 respectively, on Japan’s Hiroshima and Nagasaki cities.

Despite being used to create the most destructive weapon known to humans, the project also paved the way for nuclear energy and nuclear reactors, and shed considerable light on understanding how atoms work. It also contributed to nuclear medicine, especially the use of radioactive materials for imaging, diagnosis, and treatment.

From the Science pages

Question Corner

Is there a link between air pollution and a drop in global insect numbers? Read the answer here.

Flora and Fauna

0 / 0
Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in


Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.