Chapter 6 - Moving bodies by internal force

The basic design approach for the major component of an internal force engine (that part that moves without externally applied force) has been already discussed: a heavy moving body contained in a relatively light body collides internally the resulting impact moves both bodies. Following the laws of conservation of linear momentum for elastic bodies, and the law of conservation of energy (which is true for bodies incapable of self-movement), the resulting velocity for the Internal Force Moved Component can be found out from the masses of the inner and outer bodies, and the speed with which the inner body hits the outer body. The mathematics involved is only of high school level. They are given in Appendix B.

In the lunch box experiment we had a car which moved up a ramp, hit the wall of the lunch box, slid down the ramp due to gravity or slight reversing, taking care not to hit the rear wall at all, or at least not too hard. As a result of the hit, the lunch box moved forward, but stopped. We had assumed that if there had been no friction it would have kept on moving.

Unfortunately, we (or rather, I) had been mistaken. It was friction that allowed the lunch box to move forward in the first place. What actually happened was that as the toy car accelerated, it pushed the lunch box back. But the lunch box did not slide back because of friction. On the other hand, the friction was not high enough to stop the forward motion due to the sudden internal impact, but eventually it did stop the movement of the lunch box.

So if the experiment had been done in outer space, what would have happened? As the toy car accelerated, the same force causing the acceleration, by Newton's third law of motion (to every action there is an equal and opposite reaction) would have an equal and opposite counterpart pushing back the lunch box. Yes, the lunch box would definitely move with respect to a static object after the acceleration. But if would stop after the collision - the momentum of the toy car and the lunch box would be exactly equal. So the lunch box could only move forward in a series of hops - there would be no velocity addition, thus no possibility of infinite speed, nor even breaking the law of conservation of energy. While Newton's first law of motion would have been broken, no practical use would be served.

Look at it from a slightly different manner. Let there be a light container in outer space, and a human being running in it. As he increases speed, the container moves in the direction opposite to his motion. To avoid hitting the other end, he decreases his speed (he decelerates). This will involve a force on the container in the reverse direction, bringing the speed of the container to zero when the human being stops at the other end. So the container will move a little bit, then stop. If the human bangs himself at full speed against the wall at the other end, the overall effect would be exactly the same - the container will come to an abrupt halt, after having moved some distance.

Quite infuriating.

I checked the above scenario by constructing a "faster than light ship" made of cheap pine planks and a heavy steel post. It looked like a boat without a bottom. I flopped in it, in the waters of an inlet near Tooradin. My idea was to hit the bow of the ship with the post, making the whole thing move forward, and let it carry me with it, strapped to it that I was. I soon found that I was only travelling forwards and backwards, making very little forward progress, if at all. (Perhaps the current took me along!)

But my family members, stern critics all, did allow that Newton's first law of motion had been shaken, if not broken.

How could I really break Newton's first law of motion, get velocity addition?

What does happen to all the kinetic energy (that is, energy of a body in motion) when the impact happens between the inner mass and the outer body's wall? The net momentum becomes zero, so there is no resulting velocity with respect to the initial reference frame. But what really happened due to the process of collision? The atoms or molecules on either side got compressed by the huge force of collision, and then regained their original shape - if the collision was within the elastic limits of the materials involved. The sudden squeezing of the atoms or molecules resulted in heat, which was dissipated to outer space. So all the kinetic energy just became heat energy. (Heat is the quantity of flow of energy between bodies of different temperatures, and temperature relates to the rapidity of motion of the atoms or molecules in the body.)

Was it possible to translate the kinetic energy of the inner and outer masses into some other form of energy, say kinetic energy, in a more useful direction?

I thought of hydraulic systems. In such systems, which are interconnected by fluids in pipes, if you squeeze down on some pedal, you could raise up something.

Let us put a hydraulic system of E-shaped cross-section between the inner mass and the outer wall of our container in outer space. It is fixed to the container. The inner mass accelerates and is hurled towards the opposite wall but this time it is met by a plunger that pushes back the hydraulic fluid as a result of the impact. The speed of the container becomes zero, as the forced back fluid will ultimately impact upon the rear wall of the container, slowing down its forward motion to a halt. But instead of so much heat being generated through the kinetic energies involved in collision, the fluid molecules are squeezed. The squeezed fluid molecules are forced through the outer horizontal arms. The plungers in the outer horizontal arms of the E-system now can now fling back with nearly the same kinetic energy (squeezing the fluid molecules will involve some kinetic energy loss) two bodies in the direction opposite to that of the motion of the inner mass that hit the central arm of the E-system. These two bodies can collide with the wall at the other end, giving a net motion to the entire container. This is half the cycle. The other half would involve the two bodies accelerating back, colliding with their corresponding plungers, and forcing the central inner body back against the wall from where it began the cycle. This process would also involve a velocity addition for the container.

In the cycle described earlier, at first the acceleration to the whole system would come from the forces required to move the masses backwards. This would have been completely negated by the backward collision process; now the hydraulic system would make the kinetic energies involved be channeled such that they eventually gives an incremental velocity to the entire system, instead of dissipation as heat. There can be no upper limit to the velocity that can be reached by this system, in outer space. The law of conservation of energy will thus be violated, following from the equations given in Appendix A. Our internal force moved body would use the electrical force involved in moving masses internal to a body, as the life force to accelerate the body to a certain velocity! The internal energy for the body would be converted to kinetic energy for the body. Effectively, it would act as any life form.

Let us now try to design an internal force moved body.

Consider a heavy bar, composed of iron with many partitioning insulations for large parallel currents, resting on a non-magnetic surface, carry a great deal of current. The direction of the current is perpendicular to the magnetic field created by electromagnets that sit on the top and bottom sides of the heavy bar. The result will be that this bar will be subjected to a large force, which will accelerate it causing it to hit the inner wall of the outer container. However the outer container will be subjected to the same force, acting in the opposite direction. So, on the whole, the system will not move very much the backward movement of the outer container will be stopped by the internal collision in the forward direction.

Now place a hydraulic system in the rear. When the bar hits the plunger, it compresses and so acts upon the hydraulic system instead of dissipating heat as a result of the collision. The two outer arms of the E-shaped hydraulic system, as a result of the extra fluid suddenly squeezed into them, will fling forward two masses similar to the heavy bar discussed. (That is, these masses corresponding to the outer arms are also composed of iron with many partitioning insulations for large parallel currents, and they too can be pushed back by electromagnets). These masses will hit the inner wall at the other end, impart their momentum to the whole system now at rest, and thus give a net constant velocity to the system. Once that is done, the electromagnets will push them back hard on to the corresponding plungers of the hydraulic system. This will push back the heavy bar which will hit the same inner wall, adding to the velocity obtained by the earlier forward collision. This will be one complete cycle. In the next cycle the velocity will be increased by the same amount, for the same application of energy.

The above gives the rough idea for the design. It is cheap, reliable and energy-efficient. The main material involved is iron, so plentifully available. The fluid in the hydraulic system could be a gas.

Some back-of-the-envelope calculations, now. Assuming 50% losses, a 1000 watt energy input would increase the velocity of a 10 kilogram mass by 10 meters per second every second. In one minute, the body would reach the speed of 600 meters per second!

I wish I could have made one such part, to completely convince myself. But the technical difficulties, not to mention the cost, are too great; furthermore my wife does not approve of my using our hallway and dining table for mechanical activities. There are limits to her indulgence, and words as follow do not help!

Call me fool, idiot, absolute ass.

Call me all names, all sounds, crass.

Yea, say them again and again, lass.

I'll only gleam brighter than brass.

My meaning youll never know, girl.

You'll always think me worthless churl

Who'll never cars or minks furl,

Never bestow thick strands of pearl.

A secret I'll tell you now.

I infuriate you to see just how

Magnificent form the lines on your brow.

Hey, let me go, don't bite, ow!

"Minks! Who wants minks!" was the spontaneous criticism.

A small experiment, now. Place some marbles along a concavely curved solid edge, so that they touch each other, and ultimately form two parallel rows. (There is a diagram showing that in this book.) Use the last marble to hit the marble in one of the rows with some force - and see how this force gets communicated through the chain of marbles, and makes the last marble pop out in the direction opposite to that of the hit! Thus the energy of the hitting marble is not totally lost to the curved surface - it is given to another marble, in the useful direction. This proves the fundamental principle by which we may violate Newton's first law of motion.