Introduction

I state that it is possible to accelerate a closed system (box on frictionless surface Fig 0a, or a spaceship) by accelerating a interior mass M1 (fig 0b) so that it travels “forward” until it collides with the box’s interior wall (Fig 0c) pushing the box forward.

I also state that the cycle can be repeated with the box gaining acceleration with every collision.

When I affirm we can make a closed system (in this example a airtight box) gain acceleration by means of some “clever mechanism” inside the box without expelling mass from the box, you are correct in being mistrustful because every engineer and/or scientist to whom the idea is presented will initially state very forcefully that:

1- It is not possible because it contradicts the laws of Newton, conservation of linear momentum and others.

2- Many inventors have previously proposed systems that never worked when/if tested.

Therefore a “I’ll believe when I see it ” skeptical attitude is quite appropriate, a scientist has the right (duty) to be skeptical of any proposition that apparently contradicts a physical principle/law, but when a proposal can be demonstrated in a experiment that is both valid and reliable, it cannot be dismissed no mater how “fundamental” a idea/principle/method/law it is in apparent conflict with.

If the idea/principle/method/law disagrees with the experiment it’s wrong, that all there is to it (Richard Feynman describing what science is)

Designing a Valid Experiment.

Ideally any proposal of a propellantless propulsion system should be tested in a micro gravity environment, as the international space station is not available (for me) I have constructed the test assembly setup as described in the following illustrations.

First a “closed system” where we can put the mechanisms we wish to test, in this case a transparent airtight box, transparent so we can observe what is happening inside and airtight so there is no interaction with the air outside the system (any small orifice could create an invisible jet that may produce a false positive).

Fig 1

Simple Dynamic Tests Rig I (simplified for clarity)

The transparent airtight box must be able to move with minimal friction, to that end we balance the box from a tall ceiling, when the test rig is balanced (with the apparatus to test inside the box) and at rest (Fig 2a) we turn on the apparatus to be tested, if a force is generated the test assembly will rotate around its rotation axis, said force can be estimated by the change in the box’s position after n seconds (Fig 2b)

See note 1.

Fig 2a Fig 2b

Important

It is not sufficient for the test assembly to gain some rotational velocity after the apparatus to be tested is turned on, a small change in velocity can be possibly be created by vibrations inside the box and maintained by inertia for a little while.

In order to deduce the apparatus being tested is in effect creating a useful force against the box’s internal wall the acceleration must be constant, gaining velocity until air resistance or/and the rotation of the test assemble twists the cord (string to the roof) tensing it.

We shall find it is not easy for a tested mechanism to pass this test.

Simple Dynamic Tests Rig II

Figs 2a and 2b are simplified illustrations of a balancing test assembly, in order to minimize oscillations that may distort results, Fig 3 illustrates a test assembly with superior stability.

(If you wish greater details for construction of described test bed contact me)

Fig 3

A square aluminum frame (2m) is attached by 4 cables to a long cord hung from the ceiling; this setup permits the frame to rotate on its central axis with minimal friction.

On one end of the aluminum frame we have the transparent airtight box (Fig 1) that will serve as our closed system, at the opposite side a ballast (counter weight) for balance. The assembly has freedom to rotate around the rotation axis (fig 3).

Test 1 (car in box)

Fig 4

To illustrate the effect a mass interacting inside a closed system (the transparent box), we will first use a toy R/C car (Fig 4), when the toy car (internal mass) is turned on it gains acceleration by directly interacting with the transparent box (fig 7).

Figs 5 and 6 show the toy car’s initial position at rest, at this moment all the elements on the test bed are at rest.

Fig 5

Fig 6

If we turn on the car’s wheels in a counter clockwise direction, the car will move in the –X direction and the transparent box moves in the +X direction making the frame rotate in the counter clockwise or +X direction, fig 7 shows a side view of the described actions, fig 8 shows a top view of the actions portrayed.

Fig 7

Fig 8

The frame will continue to rotate in the +X direction until the car collides with the transparent box’s inner –X surface (fig 9) excreting a force (F1), that cancels the frame’s rotation.

Fig 9

If we reverse the toy car’s direction the objects will return to their original position. It is not possible to give the frame a constant angular acceleration by any combination of movements we command the toy car to perform, at most we can obtain a cyclical clockwise/anticlockwise oscillation, but the frame will not gain rotational velocity.

The toy car’s motor is attached to the wheels in such a manner that any intent of acceleration the car in any direction will push the transparent box in the opposite direction, we can replace the toy car with a little cart (box on wheels) that has NO MOTOR and the wheels axis are as frictionless as possible, so it is free to accelerate in any direction WHEN A FORCE IS APPLIED ON IT.

Fig 10

We can try various methods to accelerate the little cart.

If we accelerate the little cart with a “pushing arm” (fig 10 A) or a spring (fig 10 A) pushing against a bar attached to the transparent box’s inner surface no final acceleration to the transparent box is obtained no matter how many times we try.

We can accelerate the little cart without directly pushing against the transparent box if by a mechanism we expel a ball (fig 10 C) or a series of balls (fig 10 D) from the cart, we will succeed in momentarily accelerating the little cart without affecting the box, but the instant the cart and ball (or balls) collide with the boxes opposite walls all forces inside the box equalize and no motion is obtained.

(A more detailed presentation of methods A, B, C and D can be seen here see figs 2, 3, 4, 5 and 6)

We can try to accelerate the little cart INDEPENDENTLY of the box by other methods that have previously been proposed like a pendulum drive (fig 10 E)

We can also try various counter rotating masses devices (Fig 20 F), we tried complex mechanisms with the rotating masses parallel to the horizontal (like the well known Dean Drive), and with the masses inclined (as the double pendulum drive), various rotation velocities both constant and/or varying rotations were tested and the result was always the same, the little cart just vibrated back and forth and was not able to “push” the transparent box in any direction.

This so far confirms (AGAIN) that a closed system (spacecraft or other) cannot accelerate by interaction/movements of masses inside the spacecraft if no mass is expelled from the system.

Let’s do something different

Fig 11

If we replace the toy car with a propeller car (Fig 11), the wheels of the propeller car are “free moving” and as frictionless as possible. If the propellers are turned on the “car” is set in motion by the collision of air molecules and propeller.

Fig 12

Fig 13

Figs 12 and 13 illustrate the test bed’s elements in their initial position at the start of the experiment, the propeller car is positioned against the transparent box’s inner +X side.

Fig 14

We will use the R/C control to create a 3 part cycle (1-blow air in the +X direction, 2-blow air in the –X direction, 3-collition of car and box’s inner +X wall)

Part 1: We turn on the propellers so they blow air in the +X direction against the transparent box’s inner +X side, this results in two actions: (Figs 14 and 15)

1-The propellers collision with surrounding air molecules propel the propeller car in the –X direction (fig 14 ∆2)

2-Collisions of air molecules against the transparent box’s inner +X wall give the box a slight acceleration in the +X direction (fig 14 ∆1) and the frame rotates counter clock wise (fig 15).

Fig 15

Part 2: As soon as the propeller car moves a few centimeters in the –X direction, the propellers direction is inverted so that air is blown in the –X direction, this makes the car change direction and accelerate in the +X direction (figs 15 ∆3 and fig 16).

We observe that although the frame’s counter clock wise rotation slows slightly it does not stop (fig 17).

Fig 16

Fig 17

Fig 18

Fig 19

Part 3: the propeller car collides with the transparent box’s inner +X (figs 18 and 19) giving a hard “bump” that increments the frame’s counter clock wise rotation velocity.

When we repeat the cycle, we will see an increment in the frame’s counter clock wise rotation with every collision.

CONCLUSION

After repeating the experiment numerous times we can:

Confirm that it is not possible to increase the frame’s rotation by acceleration of a contained mass by any means that requires direct contact with the transparent box (various other mechanisms were tried but not shown in the document)

It is possible to increase the frame’s rotation if the contained mass is made to accelerate with no direct contact with the cylinder by means of air currents (figs 11 to 19).

This experiment can be easily replicated.

The same results have been obtained by placing the transparent box on dry ice plucks (minimal fiction), floating on water and other attempts of optioning a low friction surface for the test bed.

Video of a “quick and dirty” setup.

Why does this work (or what happened to Newton’s third law?)

We must remember that the propeller car in not the only object inside the box, there are also billions and billions of very small fast moving gas (air) particles that are constantly colliding against each other and the container’s wall (Fig 20).

Fig 20

The “average” distances between said particles may be 40 times the “size” of the gas particle yet as they constantly move at very high velocity (dependent on the temperature) they are constantly colliding with one another (fig 20). For every collision there is an equal and opposite force, but the direction (vector) of each particle changes depending on the exact condition of the collision.

The total kinetic energy is maintained but the direction of the molecules tends to randomize therefore filling the container.

When we activate the propellers (fig 21), the spinning blades will collide with air particles (Fig 21), every collision will result in two opposite forces, F1 pushes against the propeller blade and F2 that propels the colliding particle a in the opposite direction.

Fig 21

Every collision transfers momentum to the “propeller car” that accelerates in the “forward” direction, for every collision a particle is propelled in the opposite (backwards) direction, Newton’s third law is maintained.

As the particles travel in the “backwards” direction they have a strong chance of colliding multiple times with the billions of air particles, and every collision obeys Newton’s law (equal and opposite forces) but the particle’s vector tend to randomize therefore the resulting force against the box’s rear wall is inversely proportional to the distance between the source of the breeze and the rear surface.

There are those that state that the sum total of particles colliding with the opposite wall must remain the same regardless of distance traveled or number of random collisions, but if that were the case the results observed in the experiment would be different

This document is a work in progress

No insights on apparent conflicts with the conservation of linear momentum law are offered in this particular document.

More Information:

Greater detail of proposal (in a micro gravity environment)

Video explaining the proposal and applications

Short presentation describing the proposal and experiments (Prezi).

Applications (trip to mars and asteroid defection)

Main page (more info than you want)

Note 1

Using balancing masses behavior to deduce the force on an objet has been done previously on many occasions, Henry Cavendish used similar methodology in 1798 to determine the gravitational constant G and demonstrate Newton’s Inverse-square law of gravitation (see fig 22).

Fig 22

Note 2

To control the propeller motor (on-off-left spin-right spin) it is best to use a RC controller so that no external cables protrude from the assembly. (use same method to activate any mechanism to be tested)

Suggested method:

Obtain an inexpensive toy RC car or other toy

Remove the RC circuit (generally includes the battery compartment) (fig 23)

Fig 23

Connect the control wires of one of the toys motors (most have two or more) to the propeller motor, in this example a normal LEGO motor (fig 24)

This setup will control the propellers direction remotely.

Fig 24