Electromagnetic field

[methane]

Coming from a non scientific background I have trouble understanding the concept of fields in general. I know it represents the strength of a force at points in space, but if space is empty then what physically is a field, or is it purely a mathematical idea?

[Loosehead]

The agents of the forces, the bosons, enable them to act across space using bosons, eg the boson for gravity is the graviton. The presence of these bosons can be demontsrated but they have yet to be observed themselves. The forces are effected by matter but matter is not necessary for the transmission of the forces. The forces are not merely mathematical they are very real and can be shown to exist in simple experiments and indeed in not so simple experiments!.

[fo3nix]

A field itself is a kind of concept, yes. However, they're certainly real -- it's just a way of thinking about things.

Imagine a real field, in the countryside somewhere.

It's empty at the moment, just soil. You want to sew some seed, and so get a few seeds and drop them in one place somewhere. You then do this every foot or so, so that if you were looking at the field from the air, you'd see a kind of grid of clumps of seed.

The 'strength' of this field at a certain point is simply the number of seeds at that point. You can think of EM fields the same way -- the strength of it can be different in different places.

Make more sense?