Human Shadow Etched in Stone
At the Hiroshima Peace Memorial Museum, a silent, haunting image captures a moment of unimaginable devastation: the "Human Shadow Etched in Stone." This indelible mark, believed to be the imprint of a person at the instant the atomic bomb detonated, offers a profound and sobering glimpse into the immense power unleashed. It stands as a stark, permanent memorial, beckoning us to understand the science behind its formation and the human story it represents. The 'Human Shadow' is an actual impression on stone, formed by the intense thermal radiation of the atomic bomb, not by vaporization. It acts as a tangible, poignant memorial, marking the instantaneous loss of life at a precise moment in history. Beyond its emotional impact, the shadow provides scientific evidence of the bomb's unique 'flash burn' effect and its immediate, localized destruction.
AI Summary
At the Hiroshima Peace Memorial Museum, a silent, haunting image captures a moment of unimaginable devastation: the "Human Shadow Etched in Stone." This indelible mark, believed to be the imprint of a person at the instant the atomic bomb detonated, offers a profound and sobering glimpse into the immense power unleashed. It stands as a stark, permanent memorial, beckoning us to understand the science behind its formation and the human story it represents.
- The 'Human Shadow' is an actual impression on stone, formed by the intense thermal radiation of the atomic bomb, not by vaporization.
- It acts as a tangible, poignant memorial, marking the instantaneous loss of life at a precise moment in history.
- Beyond its emotional impact, the shadow provides scientific evidence of the bomb's unique 'flash burn' effect and its immediate, localized destruction.
A Silent Witness to History
Today, at the Hiroshima Peace Memorial Museum, you can stand before a piece of stone known as the "Human Shadow Etched in Stone." It's a powerful and somber exhibit, believed to be the shadow of a person who was sitting at the entrance of the Sumitomo Bank when the atomic bomb exploded. Often called the 'Human Shadow of Death' or simply the 'Blast Shadow,' it's a permanent scar from a day that changed the world.
That Fateful Morning
On August 6, 1945, the world witnessed a new kind of warfare. The 'Little Boy' atomic bomb detonated high above the city of Hiroshima, unleashing an unprecedented wave of destruction. Its immediate impact wasn't just a physical blast—it was also a sudden, intense burst of heat.
For just a few seconds, the ground directly beneath the explosion was subjected to temperatures exceeding 1,800 degrees Celsius (3,270 degrees Fahrenheit). To put that into perspective, that's hot enough to melt steel! But crucially, this extreme heat was incredibly brief.
The Flash Burn Effect
This short, intense thermal radiation created what scientists later termed the 'flash burn effect.' Because the heat exposure was so brief, it didn't have time to soak deeply into materials. Instead, it intensely scorched only the very surface of objects, leaving the underlying material largely unaffected.
This phenomenon created stark 'shadows.' Imagine a painted wall where an object stood in front of it: the exposed paint might ignite or bleach, while the paint shielded by the object remained untouched. Similarly, smooth granite surfaces became roughened by the heat, but any areas protected by an intervening object retained their original polish.
The Human Shadow's Origin
The 'Human Shadow' itself was found approximately 260 meters (about 850 feet) from the bomb's hypocenter. It's believed a person was waiting for the Sumitomo Bank to open, sitting on the stone steps. The bomb's heat intensely burned the surrounding stone, effectively 'bleaching' it, while the person's body shielded the area beneath them.
This left a darkened, un-scorched outline—the person's 'shadow'—on the now-lighter stone. It's a common misconception that the person was 'vaporized' into the stone, but science tells us this isn't possible given the temperatures and exposure time. The temperatures required for human vaporization are far higher than even Hiroshima's extreme heat.
Instead, the shadow signifies that the person absorbed the bomb's radiant heat, shielding the stone beneath. The individual themselves would have suffered horrific burns and been instantly subjected to the blast and radiation effects. Witnesses corroborated seeing a person at the bank entrance just before the explosion, and a soldier later testified to recovering the body.
While the museum once claimed the shadow belonged to a 42-year-old woman named Mitsuno Ochi, conclusive proof has never been found. The identity of the person who cast this poignant shadow remains officially unknown, adding another layer of quiet tragedy to the artifact.
Journey to the Museum
The 'Human Shadow' wasn't always within the museum's walls. For decades, it remained on the original stone steps of the Sumitomo Bank building. But by January 1971, a 3.3-meter-wide by 2-meter-high section of the stone, containing the shadow, was carefully cut from its original location and moved to the Hiroshima Peace Memorial Museum.
Over time, the delicate shadow began to degrade due to weathering. To protect this vital piece of history, the museum initiated research into preservation methods in April 1975. By 1991, serious conservation efforts were underway, and today, the stone is carefully enclosed in glass to safeguard it for future generations.
The Sumitomo Bank: Ground Zero's Witness
The 'Human Shadow Etched in Stone' began its life as part of the entrance steps to the Hiroshima Branch of Sumitomo Bank. Located a mere 260 meters from the hypocenter, this building bore the brunt of the atomic blast, making it a powerful witness to the destruction.
Constructed in 1928, the bank was a substantial reinforced concrete building, featuring four floors above ground and one below. Designed in a Romanesque style with a distinctive large arch on its facade, it was an imposing structure in the city's commercial district.
The building was severely damaged in the bombing; most of its interior was utterly destroyed. Yet, remarkably, certain areas like the coin room, cash, and even passbooks remained intact, a testament to its robust construction. Papers from inside, however, were scattered miles away by the sheer force of the blast.
On that fateful morning, the bank was set to open as usual. While many employees were still on their way, 29 lost their lives instantly, and 40 were injured. Many passersby, caught near ground zero, sought refuge in the building, and a large number of bodies were later recovered from within its ruins.
After the war, the Hiroshima Branch courageously reopened, becoming a symbol of resilience. Both the 'Human Shadow of Death' and the nearby Atomic Bomb Dome quickly became iconic landmarks, embodying the devastating power of the bomb and the immense loss of life.
To protect the shadow from further deterioration while it was still at the bank, Sumitomo Bank took early steps. In 1959, they erected a fence around the stone, and by 1967, it was covered with tempered glass to shield it from the elements and human touch.
Ultimately, when the Hiroshima Branch was rebuilt in 1971, the decision was made to permanently remove the stone steps bearing the shadow. They were then generously donated to the Hiroshima Peace Memorial Museum, ensuring this powerful artifact could be preserved and shared with the world, forever telling its silent story.
Article
Human Shadow Etched in Stone
Human Shadow Etched in Stone (人影の石, hitokage no ishi) is an exhibition at the Hiroshima Peace Memorial Museum. It is thought to be the shadow of a person who was sitting at the entrance of Hiroshima Branch of Sumitomo Bank when Little Boy was exploded over the city. It is also known as Human Shadow of Death or simply the Blast Shadow.
Background
Human Shadow Etched in Stone
In this example of a flash burn 1.33 miles (2.14 km) from ground zero at Hiroshima, the paint on a gas holder was scorched and rendered lighter than it originally was by the thermal radiation, except for the places where the valve handle blocked the radiation, which retained the original (darker) color.
A Japanese man recreating (in 1946) the probable position that the person on the steps of the Sumitomo Bank which would have created the flash burn "shadow" when the atomic bomb detonated nearby on the morning of August 6, 1945
On the morning of August 6, 1945, the Little Boy atomic bomb was detonated at an altitude of 1,968 ± 50 feet (600 ± 15 m) over the city of Hiroshima, near the Hiroshima Prefectural Industrial Promotion Hall. Among its other effects, it subjected the ground area to extremely high radiant temperatures for several seconds (higher than 1800 °C/3270 °F for less than 4 seconds). Because the duration of this high-temperature burn was so short, it did not have time to diffuse or be dissipated by thermal diffusion. This meant that the immediate surfaces of affected objects were raised to a very high temperature while very little temperature rise occurred beneath their surfaces. After the war, investigators named this the flash burn effect. The angles of the burns, and the specific changes to the surfaces, were closely studied, as they could be used to precisely determine explosion parameters such as the exact altitude, height of burst, and size of fireball.
Throughout Hiroshima (and Nagasaki), "shadows" were found where an intervening object had shielded some part of a surface that was otherwise scorched by direct, line-of-sight heat radiation. For example, the paint on a building might ignite, except in the areas in which it was shielded. Polished stone became rough where it was exposed to the heat (which caused crystals within it to expand), while shadowed areas remained smooth. The British mission to Hiroshima and Nagasaki noted in 1946 that the surfaces of asphalt roads "retained the 'shadows' of those who had walked there at the instant of the explosion," and judged them "objects of macabre interest and pilgrimage for visitors".
The "human shadow" at the entrance of the Sumitomo Bank was approximately 260 metres (850 ft) from the hypocenter of the atomic bomb explosion at Hiroshima. It is thought that the person had been sitting on the stone step waiting for the bank to open when the heat from the bomb burned the surrounding stone white and left the person's shadow visible as a darkened area.
While the belief has persisted that it shows the remnant of a "vaporized" person, this has been shown to be scientifically impossible: the temperatures required to vaporize a human body in such a short amount of time exceed even the high temperatures experienced on the ground at Hiroshima. If the shadow is of a human being, it indicates that the person absorbed sufficient heat to significantly burn or alter the surface of the steps they were obscuring. Rather than vaporized or reduced to ash, the person would have any of their clothing or skin exposed to very high temperatures, and likely have been extremely burned, as well as subjected to the blast and radiation effects.
The person who cast the shadow almost certainly died immediately in the flash of the bomb. Witnesses reported seeing a person sitting at the entrance just before the explosion, and a soldier testified he had recovered the person's body. The museum exhibit claimed the shadow belonged to a 42-year-old woman named Mitsuno Ochi (越智ミツノ, Ochi Mitsuno), but conclusive proof of this claim cannot be determined and the victim's identity remains unknown.
In January 1971, part of the stone containing the artifact (3.3 meters wide by 2 meters high) was cut from the original location and moved to the museum. As the shadow had been degraded due to weathering, in April 1975, the museum began research into preserving the shadow. In 1991, the museum reported that earnest investigation of preservation methods had commenced. At present, the stone is surrounded by glass.
History
Hiroshima Branch of Sumitomo Bank
• The black x-mark indicates ground zero, while the red circle is the Hiroshima Branch of Sumitomo Bank (now Sumitomo Mitsui Bank) • Aerial photograph on July 25, 1945, before the bombing • Aerial photograph on August 8, 1945, two days after the bombing
Hiroshima Branch of Sumitomo Bank after the bombing. The Human Shadow Etched in Stone was at the steps, near the person standing at the entrance.
The view toward the east from Hiroshima Chamber of Commerce and Industry. The white building in the center is the main office of Geibi Bank, and the building on the right is the Hiroshima Branch of Sumitomo Bank.
Photograph by U.S. armed forces on November 20, 1945
The stone in exhibition in Hiroshima Peace Museum
Human Shadow Etched in Stone was originally part of the stone steps at the entrance of the Hiroshima Branch of Sumitomo Bank, located 260 meters (850 ft) from ground zero. The current location of the Sumitomo Mitsui Banking Corporation, Hiroshima Branch is Kamiya-cho 1 Chome.
The bank was built in 1928. It was designed by Kenzō Takekoshi (竹腰健造) at the department of engineering of Sumitomo Group (now Nikken Sekkei), and was constructed by the Obayashi Corporation. The building was constructed out of reinforced concrete, with four floors above ground and one below with an open ceiling up to the third floor. The rooms for business, reception and coinage were on the first floor, the meeting rooms and cafeteria on the fourth floor, and the boiler room in the basement. It was built south of the head office of Geibi Bank (now head office of Hiroshima Bank), which had been built the year before and was almost the same size. It was designed in a general Romanesque architectural style, and was characterized by a large arch with molding on its front façade.
The building was severely damaged in the bombing of August 6, 1945. Although most of the building's interior was destroyed, the coin room, cash, and passbooks were undamaged. Papers from inside the building were blown as far away as Numata-cho by the blast.
On the morning of the bombing, the bank was to be open as usual. Most of the employees were on their way to the office when the bomb was dropped. There were 29 employees killed immediately (including those in the branch and those on their way to work), 40 were injured and none missing. Some of the survivors died within a few days from radiation sickness, while others worked until retirement. Passersby took refuge in the building as it was close to ground zero, and a large number of bodies were recovered.
After the war, the Hiroshima Branch reopened. "The Human Shadow of Death" and the Atomic Bomb Dome quickly became landmarks for the bomb's destructive power and the loss of life. To preserve the shadow, in 1959 Sumitomo Bank built a fence surrounding the stone, and in 1967 the stone was covered with tempered glass to prevent its deterioration.
The Hiroshima Branch was rebuilt in 1971. The stone steps with the shadow were removed and donated to the Hiroshima Peace Memorial Museum.