What does 'ground zero' mean?

I’m from Sweden, and would like to know…

Traditionally, it means the point at which a nuclear bomb is detonated.

Or any bomb, for that matter. It’s also used to describe an area/entity that is affected most by a phenomenon/occurence.


A minor nit pick, for the literal minded:

Ground Zero is the point on the ground, or surface directly below the detonation point of a nuclear weapon. A difference, which is trivial to someone standing there, but important to the total effective blast produced.


" It is when I struggle to be brief that I become obscure." ~ Horace

Nuclear weapons are set either to “ground burst” or “air burst”. Ground burst weapons explode on impact with the ground and ground zero in this case is the point of impact.
Air burst weapons do far more damage. They are set to explode above the target. Height is dependant on the relative strength of the weapon. Ground zero is the point directly below the point of explosion.

“Vapour central”

I thought it was the end product after Olentzero fell into a big mortar and pestle.

On that subject, did you hear what happened to the sausage maker who backed into his meat grinder?
He got a little behind in his work.

Or the optometrist who fell into his lens grinder and made a spectacle of himself?

(ducks and covers.)

Drawing upon my remote college days studying international relations, with an emphasis on nuclear policy and such recent developments as the SALT treaty (yes, I AM that old!):

I believe ground and air burst serve different purposes. Ground burst would be best at destroying hardened targets such as silos and command centers. Necessary in a first strike.

Air bursts spread their heat, pulse, and radioactivity over a greater area, resulting in a larger immediate area of damage. Such as over a city, or massed troops.

But back in the favor of ground burst, they spew more radioactive dirt and crap into the air, providing the gift of death that keeps on giving as the wind blows.

Now why couldn’t I have chosen something happier and more useful to study?

If you’re curious, have a decent 'net connection and are somewhat morbid, there’s a whole hell of a lot of atomic test footage available for download at http://archive.org.

It’s interesting that this question was asked just a couple of weeks before the World Trade Center attack. Time to investigate Sweden.

To get back to the OP, why is it called ‘ground zero’?

Is there a ‘ground 4’ (presumably further away from the blast) ?

“Ground” because it’s on the ground. “Zero” because it’s zero distance from the blast center.

“Ground Four” could mean four miles, kilometers, furlongs, light-years, microns. Since they’re not definitive, the term “Ground” plus a non-zero number isn’t used.

Ground zero, according to Cassell’s Dictionary of Slang, is also defined as the basic position, the start, the essentials, and dates from the 1950’s.

This is a UK publication.