A nuclear explosion is an explosion that occurs
as a result of the rapid release of energy
from a high-speed nuclear reaction.
The driving reaction may be nuclear fission,
nuclear fusion or a multistage cascading combination
of the two, though to date all fusion based
weapons have used a fission device to initiate
fusion, and a pure fusion weapon remains a
hypothetical device.
Atmospheric nuclear explosions are associated
with mushroom clouds, although mushroom clouds
can occur with large chemical explosions,
and it is possible to have an air-burst nuclear
explosion without these clouds.
Nuclear explosions produce radiation and radioactive
debris.
History
In 1963, the United States, Soviet Union,
and United Kingdom signed the Limited Test
Ban Treaty, pledging to refrain from testing
nuclear weapons in the atmosphere, underwater,
or in outer space.
The treaty permitted underground tests.
Many other non-nuclear nations acceded to
the Treaty following its entry into force;
however, three nuclear weapons states have
not acceded: France, China, and North Korea.
The primary application to date has been military.
However, there are other potential applications,
which have not yet been explored, or have
been considered but abandoned.
They include
Nuclear pulse propulsion, including using
a nuclear explosion as asteroid deflection
strategy.
Power generation; see PACER
Peaceful nuclear explosions
Nuclear weapons are largely seen as a 'deterrent'
by most governments; the sheer scale of the
destruction caused by a nuclear weapon has
prevented much serious consideration of their
use in warfare.
Nuclear weapons
In the history of warfare, two nuclear weapons
have been detonated—both by the United States
in World War II.
The first event occurred on the morning of
6 August 1945, when the United States dropped
a uranium gun-type device code-named "Little
Boy" on the Japanese city of Hiroshima.
The second event occurred three days later
when, again, the United States dropped a plutonium
implosion-type device code-named "Fat Man"
on the city of Nagasaki.
These bombings resulted in the immediate deaths
of around 120,000 people and more over time,
because of the nuclear radiation.
The use of these weapons was and remains controversial..
Nuclear testing
Since the Trinity shot, mankind has detonated
roughly 1700 nuclear explosions, all but 8
as tests.
Of these, two were used in warfare, and six
were peaceful nuclear explosions.
Nuclear tests are experiments carried out
to determine the effectiveness, yield and
explosive capability of nuclear weapons.
Throughout the twentieth century, most nations
that have developed nuclear weapons have staged
tests of them.
Testing nuclear weapons can yield information
about how the weapons work, as well as how
the weapons behave under various conditions
and how structures behave when subjected to
nuclear explosions.
Additionally, nuclear testing has often been
used as an indicator of scientific and military
strength, and many tests have been overtly
political in their intention; most nuclear
weapons states publicly declared their nuclear
status by means of a nuclear test.
Effects of nuclear explosions
The dominant effects of a nuclear weapon are
the same physical damage mechanisms as conventional
explosives, but the energy produced by a nuclear
explosive is millions of times more per gram
and the temperatures reached are in the tens
of megakelvins.
Nuclear weapons are quite different from regular
weapons because of the huge amount of explosive
energy they can put out and the different
kinds of effects they make, like high temperatures
and nuclear radiation.
The devastating impact of the explosion does
not stop after the initial blast, as with
regular explosives.
A cloud of nuclear radiation travels from
the epicenter of the explosion, causing an
impact to life forms even after the heat waves
have ceased.
The radiation can cause genetic mutation,
radiation poisoning, and death.
See also
Lists of nuclear disasters and radioactive
incidents
Soviet nuclear well collapses
Visual depictions of nuclear explosions in
fiction
References
