I'm working on something of a writing project and while I'm a layperson as far as most forms of science goes, I've had my head in science and astronomy since I was very young and I'm familiar with many concepts and such. Yet, when I came to writing about a magnetic field, I've found that I know far less than I thought I have, so I've come here to ask a few questions of the people here. First, I need to explain a bit about my 'writing project' which is a science fiction writing project in which a spacecraft generates a very powerful magnetic field of a very particular kind, but all my searches and inquieries have proven to be quite fruitless when attempting to figure out how much energy that a very powerful magnetic field requires. As such, my first question is just how much energy is in a magnetic field or how much energy in joules does a magnetic field require to operate per tesla of field strength? The purpose of the question is essentially to answer how much power from the space craft's generator would the field would require to effectively operate. While I may have found some sources that could have helped me, my lack of understanding of the subject prevents me from understanding what I need to know to properly utilize these equations. Any help in this regard would be tremendously helpful. My second question is what effect do extremely powerful magnetic fields have on space-time or the fabric of space? When I say 'extremely powerful' I generally mean the equivelent strength of a magnetar's magnetic field and greater. Any help in these matters would be greatly appreciated.