64年前（1945.8.6）被原子彈夷為平地的日本廣島（組圖）

 Hiroshima, 64 years ago

Tomorrow, August 6th, marks 64 years since the atomic bombing of Hiroshima, Japan by the United States at the end of World War II. Targeted for military reasons and for its terrain (flat for easier assessment of the aftermath), Hiroshima was home to approximately 250,000 people at the time of the bombing. The U.S. B-29 Super fortress bomber "Enola Gay"took off from Tinian Island very early on the morning of August 6th,carrying a single 4,000 kg (8,900 lb) uranium bomb code named "Little Boy". At 8:15 am, Little Boy was dropped from 9,400 m (31,000 ft) above the city, free falling for 57 seconds while a complicated series of fuse triggers looked for a target height of 600 m (2,000 ft) above the ground. At the moment of detonation, a small explosive initiated a super-critical mass in 64 kg (141 lbs) of uranium. Of that 64 kg, only.7 kg (1.5 lbs) underwent fission, and of that mass, only 600 milligrams was converted into energy - an explosive energy that seared everything within a few miles, flattened the city below with a massive shock wave, set off a raging firestorm and bathed every living thing in deadly radiation. Nearly 70,000 people are believed to have been killed immediately, with possibly another 70,000 survivors dying of injuries and radiation exposure by 1950. Today, Hiroshima houses a Hiroshima Peace Memorial Museum near ground zero, promoting a hope to end the existence of all nuclear weapons. (34 photos total)

A Japanese soldier walks through a leveled area in Hiroshima, Japan in September of 1945, one month after the detonation of a nuclear bomb above the city. From a series of U.S. Navy photographs depicting the suffering and ruins that resulted from the blast. (U.S. Department of Navy)

2

Anaerial view of Hiroshima, viewed some time shortly before the bomb was dropped on it in August of 1945. The scene shows a very densely built-up area of the city on the Motoyasu River looking upstream.(Hiroshima: The United States Strategic Bombing Survey Archive,International Center of Photography, Purchase, with funds provided by the ICP Acquisitions Committee, 2006) #

3

A nearly photograph of Hiroshima, before August 1945, looking upstream on the Motoyasu River toward what would become the most famous of all Hiroshima landmarks - the domed Hiroshima Prefectural Industrial Promotion Hall, immediately adjacent to ground zero. The building was originally designed by Czech architect Jan Letzel and completed in April 1915. (Hiroshima: The United States Strategic Bombing Survey Archive, International Center of Photography, Purchase, with funds provided by the ICP Acquisitions Committee, 2006) #

4

Detail from a U.S. Air Force map of Hiroshima, pre-bombing, circles drawn at 1,000 foot intervals radiating out from ground zero, the site directly under the explosion. (U.S. National Archives and Records Administration) #

5

Commander A.F. Birch (left), shown numbering the bomb code named "Little Boy" unit L-11, before loading it on trailer in Assembly Bldg. #1, prior to it being loaded aboard the B-29 Super fortress bomber "Enola Gay", on the base of the 509th Composite Group at Tinian Island in the Marianas Islands in 1945. Physicist Dr. Norman Ramsey stands at right - he would later go on to win the Nobel Prize in Physics in 1989. (U.S. National Archives) #

6

"Little Boy" unit rests on a trailer cradle in a pit below the open bomb bay doors of the B-29 Super fortress bomber "Enola Gay" on the 509thComposite Group base at Tinian Island in the Marianas Islands in 1945.Little Boy was 3 m (10 ft) long, and weighed 4,000 kg (8,900 lb), butonly carried contained 64 kg (141 lbs) of uranium which would be usedto create a nuclear chain reaction, and resulting explosion. (U.S.National Archives) #

7

Shortly after 8:15 am, August 5, 1945, looking down on the rising smoke from the atomic explosion above the city of Hiroshima from one of two U.S.Air Force bombers from the 509th Composite Group. By the time this photo was taken, the flash of light and intense heat from a fireball370 m (1,200 ft) diameter had already taken place, and an intense shock wave radiating out faster than the speed of sound was dissipating,having done most of its damage to ground structures and people in a circle 3.2 km (2 mi) in diameter. (U.S. National Archives) #

8

Shortly after 8:15 am, August 5, 1945, looking back at the growing "mushroom"cloud above Hiroshima. When a portion of the uranium in the bomb underwent fission, and was transformed instantly into an energy of about 15 kilotons of TNT (about 6.3 × 10¹³ joules), heating a massive fireball to a temperature of 3,980 C (7,200 F). The superheated air and smoke rapidly rose through the atmosphere like a giant bubble, dragging a column of smoke up with it. By the time this photo was made, smoke had billowed 20,000 feet above Hiroshima while smoke from the burst of the first atomic bomb had spread over 10,000feet on the target at the base of the column. (U.S. National Archives) #

9

A view of destruction in Hiroshima, in the autumn of 1945, across one of the branches of the river that cut across the delta the city is centered on. (Hiroshima: The United States Strategic Bombing Survey Archive, International Center of Photography, Purchase, with funds provided by the ICP Acquisitions Committee, 2006) #

10

A View Of ground zero in Hiroshima in the autumn of 1945, showing total destruction resulting from dropping of the first atomic bomb. The hypo center (point directly below the bomb explosion) is visible in this photograph, approximately above the Y-shaped intersection at center-left. (U.S. National Archives) #

GMapImgCutter CASA - Terms of Use

11

Click, drag and zoom above to better view this panoramic view of a destroyed Hiroshima, made up of five photographs taken from the roof of the Chamber Of Commerce And Industry Building on October 6th, 1945, only 2months after the bombing. At far left are the ruins of the Geibi Bank Building and Shima Hospital. At center is the ruined structure of the Prefectural Industrial Promotion Hall, beyond it a bridge across the Matoyasu River, just about at the hypo center of the explosion. At lower right is the still-standing structure of the Red Cross building, its roof depressed from the shock wave. At far right is the T Bridge at the meeting of the Matayashu River and the Ota River. To view the full panorama image (10,000 pixels wide), click here. To see the original five component photos at 2,500px, click 1, 2, 3, 4, 5. (U.S. National Archives) #

12

Bridge across the Ota river, 880 meters from the hypo center of the bomb burst above Hiroshima. Note where roadway is burned and the ghostly shadow imprints left where the surface was shielded by cement pillars. (U.S.National Archives) #

13

Color photograph showing damage in Hiroshima in March of 1946. (U.S. National Archives) #

14

Bomb damage to Okita Iron Works, Hiroshima, Japan. November 7th, 1945. (U.S. National Archives) #

15

A street scene showing atomic bomb damage in Hiroshima. Note how the sidewalk has been pushed up, and a drain pipe has punched through the bridge. Scientists say this phenomenon is due to a vacuum created by pressure of the atomic blast. (U.S. National Archives) #

16

This patient (photographed by Japanese forces on October 2nd, 1945) was about 6,500 feet from ground zero when the rays struck him from the left. His cap was sufficient to protect the top of his head against flash burns. (U.S. National Archives) #

17

A view of the densely packed houses of Hiroshima weeks after the bombing,at the edge of the severely damaged area (note the flattened building sat bottom). (U.S. National Archives) #

18

Twisted iron girders are all that remain of this theatre building located about 800 meters from ground zero. (U.S. National Archives) #

19

The Hiroshima Fire Department lost its only ladder truck when its West Side main fire station was destroyed by the blast and fire of the atomic bomb, 1,200 m (4,000 ft) from ground zero. (U.S. National Archives) #

20

An aerial overview of Hiroshima in autumn of 1945. The hypo center and Atom Bomb Dome are visible at top center. (U.S. National Archives) #

21

Color photograph of the ruins of central Hiroshima in autumn of 1945. (U.S. National Archives) #

22

A"shadow" of a hand valve wheel on the painted wall of a gas storage tank after the atomic bombing of Hiroshima. Radiant heat instantly burned paint where the heat rays were not obstructed, 1,920 m (6,300ft) from ground zero. (U.S. National Archives) #

23

A victim of the bombing in Hiroshima lies in a make shift hospital located in one of the remaining in bank buildings in September of 1945. (U.S.Department of Navy) #

24

From the caption provided with this photo of a victim from Hiroshima: "The patient's skin is burned in a pattern corresponding to the dark portions of a kimono worn at the time of the explosion". (U.S. National Archives) #

25

Blast victims shown in a fly-infested makeshift hospital in a bank building in Hiroshima on September 15th, 1945. (U.S. Department of Navy) #

26

Formation of keloidal scars on the back and shoulder of a victim of the Hiroshima blast. The scars have formed where the victim's skin was directly exposed to the heat of the explosion's initial flash. (U.S. National Archives) #

27

Anaerial view of ground zero and the now-famous Atom Bomb Dome in Hiroshima, weeks after the bombing of August 6, 1945. (U.S. National Archives) #

28

A man looks over the expanse of ruins left by the explosion of the atomic bomb on in Hiroshima, Japan. (AP Photo) #

29

An aerial view of the destruction in an industrial section of Hiroshima, seen in the autumn of 1945. (U.S. National Archives) #

30

A view of Hiroshima and outlying hills, seen in the autumn of 1945, from the ruins of the Red Cross building, less than one mile from the hypo center. (U.S. National Archives) #

31

Members of the U.S. Army examine the area around ground zero in Hiroshima, Japan in the autumn of 1945. (U.S. National Archives) #

32

Visitors view a panorama showing the aftermath of the atomic bomb attack, at a museum at the Hiroshima Peace Memorial Park on July 27, 2005 in Hiroshima. Japan. (Photo by Junko Kimura/Getty Images) #

33

The Peace Flame has burned for the atomic bomb victims at the Memorial Cenotaph at Hiroshima Peace Memorial Park in Hiroshima, western Japan,Tuesday, Aug. 4, 2009. The flame has burned continuously since it was lit on August 1, 1964. It symbolizes the anti-nuclear resolve to burn the flame "until the day when all such weapons shall have disappeared from the earth." (AP Photo/Shizuo Kambayashi) #

34

Hiroshima today - detail from a panoramic view of Hiroshima Peace Memorial seen on April 14, 2008. Full panorama available here. (Dean S. Pemberton / CC BY-SA)#