# Space is big, and magnetism is strong

#### andrewmm

Joined Feb 25, 2011
1,131
I woke again with a question

The earth has a magnetic field that shields us from nasty radiation,

It does not seem that strong at the surface

two questions,

a) I wonder how much power / magnetism would be needed to protect enough of a space ship to enable the crew to be protected ?
say 3m by 3m by 3m

b) inside a magnet, is there a north south ? i.e. if the space ship was "magnetised" some how, would all the ferrous bits inside get magnetised ?

Last edited:

#### BobTPH

Joined Jun 5, 2013
3,002
Simple explanation:

The earth’s field is weak, but extends over a large distance, so there is plenty of time for an incoming particle to be deflected.

You could not create such a large field around a spaceship, because it depends on the distance between the poles.

More details:

Magnets create a dipole field, which is a result of the two poles, (get it? Di-pole.) Dipole fields fall off at the cube of the distance for distances large compared to the distance between the poles.

Bob

#### andrewmm

Joined Feb 25, 2011
1,131
Simple explanation:

The earth’s field is weak, but extends over a large distance, so there is plenty of time for an incoming particle to be deflected.

You could not create such a large field around a spaceship, because it depends on the distance between the poles.

More details:

Magnets create a dipole field, which is a result of the two poles, (get it? Di-pole.) Dipole fields fall off at the cube of the distance for distances large compared to the distance between the poles.

Bob
Does the strength of the magnetism affect the amount the particles would be deflected ?

So even of poles were only m apart, not Km,
I wonder how strong they would have to be to deflect "sufficient" what ever that is the particles.