Actual work was begun in the US in 1942 and it was finished in 1945, therefor about 3 years.
To assemble the early bombs from a kit in the field took about 3 days with an assembly crew of 40 to 50 men working around the clock.
Because it was the right time for it:All the natural phenomena needed to make it had been discovered.All the materials needed to make it had been discovered and characterized.A war was in progress.A significant fear existed that the enemy was already working on it and might get there first.
Defense against the possibility that Nazi Germany might make one first.
Pakistan, though apparently they gained the ability to make nuclear explosions in 1987. http://www.fas.org/nuke/guide/pakistan/nuke/
You can not be really very sure how many are left, because when there is war, they will just make more atom bombs if they need some more.--------------------------------------------------------------------------------------------------------------------------------------Completely wrong. If the U.S. and Russia fought a nuclear war, the war would be over in a couple of hours at most and it takes months to manufacture a nuclear weapon. Also the war damage to the nuclear weapons production system would take years to repair before any manufacturing could begin again. There would be no chance to make any more.If the nuclear war was fought by other countries, perhaps they could make more but all the other countries nuclear weapons put together are less than 1/4 of those that either the U.S. or Russia have.
Sticks and stones have always been available for use as weapons. Either one could have been the first, but the stick may make more sense.
Nobody, the US was the first country to work out how to actually make nuclear weapons.
first new clear weapon made is 1996
plutonium + weapon
5
It took about 5 years to make a proper nuclear weapon.
Although the Germans during World War II were the first to come up with both the concept it never came to light. America was the first nation to make a nuclear weapon.
Science---Nature Animals---Science l l Physics Biology--- Bacteria l Steel---Tool Reaction --- Physics l l Weapon Nuclear Reaction --- Weapon l Nuclear Weapon
weapon + plutonian = nuke
nuclear bomb = plutonium + weapon
US
Uranium makes for an excellent element for nuclear fission. Hydrogen is most commonly used for nuclear fusion.
you are either macgyver or its not possible :P