Re: Big magnetic fields

In article <pan.2005.07.07.11.57.10.289822@xxxxxxxxxxxxxxxxxxxx>, David Mitchell <david@xxxxxxxxxxxxxxxxxxxx> writes 
My actual question still remains though: is is possible to create a
magnetic field such that it acts as a barrier, and/or a means of
manipulating magnetic objects; and if so, what would be the
characteristics of the mechanisms required to generate such a field.

I'd try magnetic mono poles.


I have in mind some sort of enclosing field (presumably spherical-ish)
which would act as a layer of attraction to anything magnetic passing
through it (the resulting deceleration, hopefully, slowing it down or
turning it into plasma which successive spheres would stop completely),
Read E.E."Doc"Smith's "Skylark" series. They had some pretty cool shields there.


In addition, would it possible to create a "confinement layer" of some
sort, which you could fill with plasma (ignoring the problem of
radiative losses :-) or, for example, iron filings, to act as a
self-healing barrier to energy weapons and non-magnetic objects.
"Polarise the hull plating!" said Capt. Archer. (Sorry, couldn't resist).

You'd have to have 2 different kinds of field that didn't interact with each other, but did interact with plasma/iron fillings - difficult to handwave that one.

Try putting a shell of deep frozen mercury around your ship. If it gets hit by something it gets hot, then it melts... and turns mirror coloured, reflecting a laser. It also vaporizes, carrying away the heat of the weapon. Repair is simple - add more mercury.

Also, charge your ship *and* the shell up to umpteen million volts. Anything that gets through the shell will acquire an electric charge and be repelled by the charge on the ship. Use multiple shells on the bigger ships and increase the voltage the further in you get.


I realise that such a field would have to be improbably strong - are there
ways round that?


If so, what would be plausible sphere diameters, metres? kilometres?
Depends on the size of your power source, but the inverse square law is really going to start to bite when the size gets big.


With regard to manipulating objects, again: what would be a plausible
range for this, and what would be plausible parameters for things like
the force it could exert and the precision it work to (could you use it
for cargo-handling, for example, or EVA's) ?
Polarised gravity sounds much more like what you need. Remember, some things simply aren't affected by magnetic fields.

--
Steve Charlton                  | You may have trouble getting
steve@xxxxxxxxxxxxxxxxxxxxxxxxx | permission to aerobrake or
hint: ^^^^^^^^^                 | lithobrake asteroids on Earth!
      reverse this              |   - James D Nicoll

.

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