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The first man-made nuclear explosion (
in the Alamogordo desert in New Mexico on 16 July 1945 5:30
During the explosion equivalent to 20
kg TNT not 50 or 10 gram, but less than one gram of matter was converted to energy in according to the equation E=mc².
Desert sand was sucked up in the mushroom cloud mixed with fission products
and molten to form a crust with a diameter of 600 meter.
This glassy radioactive mass is called 'Trinitite', in Dutch 'Trinitiet'. Analogous to 'Granite' and 'Graniet' (
I bought this specimen on the international
where you can also buy meteorites, like these from the
Campo del Cielo
After 68 years Trinitite is still radioactive.
The the ionizing radiation is more intense than the cosmic radiation
background radiation, discovered by Victor Franz Hess in 1913, but
much less than than the radiation from the
in the dial of my grandfather's wristwatch.
Before the use of uranium
for nuclear fission was known, demand was very low.
Uraniumcompounds were mainly used to colour glass and ceramics.
In 1939 worldconsumption was
≈ 100 ton
with a price to match: 0.83 $/pound.
Exploration for uranium ore was very limited and
80% came from the
In 1939 this mine was closed because extraction of the strategically important
metals copper and tungsten was considered more important.
The Manhattan Project required about 6600 ton uraniumoxide or 5595 ton pure
uranium (Helmreich p. 47).
The first consignment came in september 1942 from 1200 tons high-grade
) Congolese uranium ore that happened to be stored in Staten Island, New York.
Some 60 tons uraniumoxide were bought from Canada and more followed.
Currently the worldconsumption is
≈ 70000 ton/yr
mainly used in nuclear reactors.
For non-nuclear application depleted uranium is used, because that emits
less radiation and is widely available as wasteprocuct of the nuclear industry.
Most of these applications take advantage of the high specific density of uranium
of 18.7 g/cm³.
Uraniumglass under incandescent light Uraniumglass under ultraviolet light
The use of uraniumcompounds to colour glass was already known in antiquity.
Around 1900 uraniumglass was very fashionable for its eerie green
fluorescence under ultraviolet light (black light).
The glass contains around 2% uranium and its radioactivity is harmless.
However safety measures must be taken during its production.
The use of uranium in the glass industry predates the discovery of
radioactivty. Initially the risks of handling (powdered) uranium were
Natural uranium consists of 99.7% U238 and 0.3% U235. Uranium has to be
enriched in U235 to be useful for a nuclear reactor or bomb.
There is of course no chemical way to enrich uranium.
The Manhattan Project relied on
both are very energy inefficient and have a low yield.
Now enrichment is done with specially designed
Otto Frisch gives a graphic account of the discovery of uranium fission
by Lise Meitner, Otto Hahn and Fritz Strassmann
in his memoirs
In his 2 April 1939 letter to president Franklin D. Roosevelt
Albert Einstein wrote only about uranium ore.
Both the Trinity test as the bomb that was dropped near Nagaski
on 9 augustus 1945 were nuclear implosion bombs with 6.4 kilogram plutonium
Plutonium was used in almost all of the over 2000 nuclear test-explosions
that were performed in the twentieth century, also in the thermonuclear
bombs (H-bomb) which are a thousand times more powerful than the first
Plutonium is found in nature only in trace amounts. As an artificial
element it was discovered by Glenn Seaborg in 1941
It is produced in a nuclear reactor from uranium-239 and has to be separated
from the reaction products by chemical means.
Pu-239 is radioactive with a
of 24360 years.
It is extremely poisonous. An inhaled dust particle of 0.6 µgram can
Another isotope of plutonium, Pu-238, with t½ of 86 years can not be used for nuclear explosions.
It was used as (heat)
in the Pioneer-10, 11 and other spacecrafts.
Research on the chemical properties of plutonium were done when micrograms
In March 1944 the first gram of plutonium metal was produced in the USA
and its physical properties could be determined for the first time.
Read an excerpt form Berstein's
The current worldinventory of Pu-239 is
kilogram, 2500 ton, of which 155 ton in nuclear warheads.
To cite the International Atomic Energy Agengy:
The dual challenge is that plutonium is a valuable energy source and a matter of global concern because of its potential health hazards and possible use for the production of nuclear weapons.
Becquerel's discovery of spontaneous radioactivity is a famous example of serendipity, of how chance favors the prepared mind.
There followed a period of intense research into radioactivity, including the discovery of additional radioactive elements thorium, polonium and radium, the latter two by Becquerel's doctoral student Marie Curie and her husband Pierre Curie.
Uitgebreide engelstalige wikipedia pagina.
The Manhattan Project began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US$2 billion (about $26 billion in 2014 dollars). Over 90% of the cost was for building factories and producing the fissionable materials, with less than 10% for development and production of the weapons.
Operation Crossroads was a series of two nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. They were the first nuclear weapon tests since Trinity in July 1945, and the first detonations of nuclear devices since the atomic bombing of Nagasaki on August 9, 1945.
Tsar Bomba is the nickname for the AN602 hydrogen bomb, the most powerful nuclear weapon ever detonated.
The claim that you can see the curvature of the earth on the accompaning photo implausible.
Other relevant URLs
In 2005, the world commemorated the 60th anniversary of the first nuclear explosion in the New Mexico desert. This website was created for students, educators, and the general public to provide an easy to use collection of resources to better understand that milestone of human history.
- 1896 discovery of radioactivity of uranium by Henri Becquerel.
- 1911 discovery of the atomic nucleus by Rutherford, Geiger and Marsden.
- 1911-1913 discovery of Cosmic Rays by Victor Franz Hess.
- 1938 discovery of nuclear fission by Lise Meitner en Otto Hahn.
- 2 augustus 1939 Albert Einstein signs his letter to Franklin D. Roosevelt.
- 2 december 1942 first chainreaction in an experimental nuclear reactor involving a large number of people led by Enrico Fermi.
- 24 maart 1944 first gram of plutonium metal reducted by Ted Magel.
- 16 juli 1945 5:30 MWT Trinity test as part of the Manhattan Project.
- 6 augustus 1945 8:15 Nuclear bomb dropped on Hiroshima
, 64 kg U235, 16 kiloton.
See diagram ⇑
- 9 augustus 1945 11:02 Nuclear bomb dropped near Nagaski
, 6,4 kg Pu239, 20 kiloton.
See diagram ⇑
- 1 maart 1954 Bikini test (15 Megaton H-bomb, codename Castle Bravo).
- 30 october 1961 11:32 (Moscow time) AN602, Nova Zembla (58 Megaton H-bomb, Tsar bomba).
- 26 april 1986 Tsjernobyl diaster (reason to buy a Geiger-Müller counter).