What are the shadows of people and objects on the sidewalk left by the Hiroshima atomic bomb?

After the US dropped atomic bombs on Hiroshima and Nagasaki, two of Japan's largest cities, on August 6 and 9, 1945 respectively, dark shadows of people and objects appeared, scattered on the sidewalks and buildings there.

In fact, shadows may have encapsulated each person's final moments. So how did these shadows form?

According to Dr. Michael Hartshorne, an expert at the National Museum of Nuclear History and Science in New Mexico, when each bomb exploded, intense heat and light radiated from the blast site, a result of nuclear fission. People and objects absorbed the light and energy, shielding the structures behind them. The light bleached the surrounding concrete or stone into black shadows.

The tremendous energy released in an atomic bomb explosion travels in the form of photon waves of various wavelengths, including long waves such as radio waves and short waves such as X-rays and gamma rays.

Between long waves and short waves there are visible wavelengths containing energy that the human eye perceives as colors.

Meanwhile, gamma radiation can penetrate clothing and skin, causing ionization or loss of electrons, damaging tissue and DNA, and harming the human body.

The gamma radiation released by an atomic bomb is transmitted as thermal energy, which can reach temperatures of more than 5,500 degrees Celsius. When this thermal energy hits an object such as a bicycle or a person, it is absorbed, creating a shadow effect in the bleached area around it.

Due to weathering and erosion by wind and water, many of the shadows cast on the stone have disappeared. Today, some of the shadowed parts are separated and preserved in the Hiroshima Peace Memorial Museum for future generations to observe and reflect upon.