Trinity 75th

Watch a message from the Lab Director

It was 75 years ago on July 16, 1945, that the Atomic Age was born. Los Alamos scientists changed the world forever with the successful detonation of an implosion-type plutonium weapon in the New Mexico desert. The Trinity Test is considered today as one of the most significant scientific achievements ever. Watch, read and learn why.

Featured Videos

Trinity and the British Mission

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The Science of Trinity

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Featured Article

The Road to Trinity

With a brilliant hot flash and a loud boom, the giant mushroom cloud with its fiery core filled the sky. The nuclear age had begun.

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Trinity Reactions

Ranging from vividly descriptive to deeply profound to a little comical, those who witnessed the Trinity Test had their own impressions of what they had just seen.

Oppenheimer portrait

“We knew the world would not be the same. A few people laughed, a few people cried, most people were silent.”

– Lab Director J. Robert Oppenheimer

Bradbury portrait

“Some people claim to have wondered at the time about the future of mankind. I didn’t. We were at war, and the damned thing worked.”

– Physicist Norris Bradbury

McMillan portrait

“I am sure that all who witnessed this test went away with a profound feeling that they had seen one of the great events of history.”

– Physicist Edwin McMillan

More stories

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    Must-read, must-watch books and movies about Lab history
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    Witnessing Trinity
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    The Mission that Changed the World
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    Q and A with the grandson of the man who piloted Little Boy to Japan
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Additional Resources

A selection of notable and valuable resources chosen by Alan Carr, the Lab’s Senior Historian.

  • Ferenc Szasz’s “ The Day the Sun Rose Twice” is more than 35 years old, but this book remains a subject-matter authority today.

  • Jim Eckles’ book “ Trinity” addresses questions he received on staff at the White Sands Missile Range and also includes anecdotes found nowhere else.

  • Office of National Security & International Studies
  • Science, Technology and Engineering
  • Office of Nuclear & Military Affairs