Space drive (part 2)
Posted on Wednesday, 16 May, 2012 | 5 comments
Columnist: William B Stoecker
Some time ago I posted an article on so-called reactionless space drives, which appear to violate the tried and proven law of conservation of momentum. If such a drive could be made to work, it would need only an energy source (nuclear, solar, or beamed microwave energy, for example) to propel space craft all over our Solar System and perhaps beyond. If a high enough thrust to weight ratio could be achieved, it could propel craft from Earth’s surface into space; if not, it might at least take them from Earth orbit into deep space. The immense loads of dangerously explosive propellant required by conventional rockets would no longer be needed. Understand that “space drive” does not refer to gravity control, which is an entirely different concept, nor to ion rockets. Unfortunately, that little matter of the law of conservation of momentum seems to get in the way.
In my previous article I described my own idea for such a space drive, and pointed out that no less than three physicists, including well known UFO researcher Stanton Friedman, had been unable to find the specific flaw in my reasoning. They were reasonably sure that my idea could not work, since the law of conservation of momentum requires that forces balance, but they were unable to point out where the forces would balance. And there matters seemed to rest, until I went back and took another look at my idea and realized that the forces do balance, and it violates no laws. It merely seems to, if thought of as a closed system…but it is not a closed system. To explain all of this, let me propose a simple thought experiment.
Imagine an electromagnet, hooked up to some energy source. Attached to it by a frame is a piece of iron, at some distance from the magnet. The electromagnet is switched on for a fleeting instant, and then switched off again. Its magnetic field travels out in all directions as a wave, propagating through space at light speed, about 300,000 kilometers per second. When it reaches the piece of iron, the iron is pulled toward the electromagnet, and its own magnetic wave travels back to the electromagnet. But by the time the wave reaches it, the electromagnet has been switched off…so it is not attracted toward the iron. The forces within the system are unbalanced, and there is an “impossible” net momentum in one direction. The entire apparatus, including the piece of iron, is accelerated in that direction.
Yet forces do balance…outside the system. To understand how, let us modify our thought experiment. Imagine just the electromagnet and its energy source, floating out in space somewhere, without the iron. When it is switched on, its field travels outward more or less forever, getting weaker and more diffuse as the distance increases, until it is so weak that no instrument could detect it…yet it still exists. It affects every magnetic particle it encounters, including, for example, minute traces of iron in the incredibly thin dust between the stars. These iron particles are (very, very weakly) pulled toward the electromagnet from every direction, and all these forces ultimately balance. But if the aforementioned piece of iron is restored to the system, it absorbs some of the field in one direction. The sum of the force on the piece of iron and the remaining force on everything else in that direction is the same (ultimately) as the force on everything without the iron. Meanwhile, in the opposite, or “forward” direction, the total force on everything exactly balances the force to the “rear.” It may not be readily apparent to an observer, and it may take a very long time indeed, but everything balances. So the drive will work.
But to make it efficient and give it a high thrust is another matter. In an actual space drive (as opposed to a thought experiment), the iron would probably not degauss, or lose its magnetism, quickly enough. It would have to be replaced by another electromagnet, which would be briefly switched on at the exact instant that the magnetic wave from the first electromagnet struck it. The device could be made with an electromagnet to the rear repelling one to the front, or one in front attracting one in the rear. But the magnets would probably have to be built without iron cores, which greatly increase field strength but which probably would not degauss quickly enough. This would limit thrust. And there is another complicating factor, one more difficult to visualize. The current in the electromagnets would travel as an electron wave; typically, in a copper wire, at about eighty percent of light speed. It would be desirable for the current in one electromagnet to be completely off when struck by the magnetic wave from the second one; this would necessitate a delay, so the drive might actually be producing a thrust for, say, a third of the time. This greatly reduces a thrust that might be very weak to begin with. I am not an electrical engineer, but I suspect that someone trained in that field could take my basic idea and improve on it.
And from Earth orbit even a very weak thrust can make deep space exploration cheap and routine. Ion rockets, for example, are now beginning to be used, and they also have a very weak thrust. And they do require propellant, which eventually is exhausted…the space drive, powered by solar energy, could be used over and over. And any fair comparison of power to weight ratios with, say, an ion rocket, must take into account the weight of the ion rocket’s propellant and its tank and fuel pump. And even very low rates of acceleration can build up enormous speeds in relatively short times. A craft accelerating from Earth orbit at only one hundredth of “g” or Earth gravity would exceed our planet’s escape velocity in about eight hours (remember, it is already travelling at nearly 18,000 miles per hour in low Earth orbit). In another week it would be moving at about 175,000 miles per hour.
If the device can be improved to the point where it can accelerate a useful payload at just over one sixth of a “g” spaceships could shuttle back and forth between low Earth orbit and the Moon, landing and taking off over and over. And if (I am not very optimistic about this) the thrust to weight ratio can be increased enough and a suitable power source (perhaps beamed microwave energy) can be developed, the craft could take off from Earth’s surface, and spaceflight would become relatively cheap and relatively safe. Quite literally, the sky would be no limit.Article Copyright© William B Stoecker - reproduced with permission.