Sid,

you could do yourself some big  favours by quietly thinking out your questions before putting them into words. You give me the impression that you are too impatient; you talk while thinking instead of thinking before you talk. I must sympathise, but if you first write out what you want to say, then put it aside and get someone else to read it to you and tell you what he thinks you meant,  you would be badly surprised and would hurry to write something very different.

The bad news is that you would do better to write the new version slowly!

Now, about your super magnet...

>wiil not the piece attach to the maget only after eight years i.e. 4 light years for the energy to reach the iron and 4 light years to come back.<

Yes and no. assume that you start by making the magnet, say having wrapped a massive solenoid around a core, and at time X you start up the current.

Your iron at Alpha Centauri would only begin to react to the field after 4 years. It would take you another four years (eight in all) to see the iron react. The first light to carry that information back to your telescope would only have started four years after the generator of the electric power for your magnet had begun to chug. 

But, "... the piece attach to the maget......"? The iron could only reach your magnet long, long after, millions of years after, if at all. Your magnetic impulse could travel at the speed of light, having no mass, but the iron does have mass and would take huge amounts of time to travel four light years!

Its more like never!

Energy function between a dipole and a induced dipole is

inversely   proportional to ( r up 6 )  ; force hence is the same 

at ( r up 7)  !

For that reason, the force of gravity ( r² ) between that electromagnet,

however small, will be much higher at 4 light years than themagnetic force.

In practice, at an distance of about 100 times the distance between the poles,

You will need extremely good instruments to "see" some magnetic field.

And last not least: such small magnetic fields do not induce ferromegnetism.

To move domain boundaries in a ferromagnetic material You need some 

minimum field strength. Below that, the piece of iron will behave as a

paramagnetic material.

Georg

 PS why doesnt this editor allow exponentials?) They appear

as I want in the editor , but after saving only some question mark shines up.

For 2 it works, for 6 or 7 it does not