Milković's inertial propulsion cart + some improvements.

[broli]

For the people who don't know what I'm talking about check this video out:

http://www.youtube.com/watch?v=4foY5r2TMOo

In a nutshell the cart moves forward due to the centrifugal force caused by the pendulum. But that's not the only force involved.

As the weight drops and essentially moves forward it pushes the cart backward. The opposite happens when the weight rises up again, it pushes the cart forward. This is simply newtons third law. Since the mass moves forward the cart has to move backward to keep the Center of Mass constant.

You can see the cart starting to move backwards just when the weight is dropped but as its still falling something mysterious happens. The cart suddenly jerks forward in contradiction to newtons third law as it should still be moving backwards. When the weight rises again the cart inheritable wants to move forward so no comment there.

I agree that a controlled experiment would include an air track but I have no such lab.

Now as for the improvements.

1) Removing the forward/backward jerking motion due to newtons third law.

Basically this means that if the mass is dropped and moves forward the cart doesn't move backward slightly due to newton 3. This can be easily done by having two pendulums each 90° out of phase. When one mass is at the bottom ready to go up the other is at the top ready to go down. This interplay will leave the Center of Mass unchanged while the cart doesn't get jerked around.

2) Removing the sideways jolts due to the centrifugal force.

When the pendulums swing let to right they also drag the cart sideways. It would be best if this sideways force was canceled. The method to do this is taking the system from 1) and mirroring it. Thus the whole system will end up with 4 pendulums now. Whenever one pendulum is going down on one side its mirror image is going down on the other side. This will thus cancel the side way forces.

3) Removing gravity as the prime force.

This can be simply done by either magnetic attraction or by a spring attached to each pendulum and the base of the cart. The latter would be some engineering feat as the spring has to follow the pendulum around on some guiding rail. This last suggestion allows the system to work in space.

I'll probably add some visual aids later on.

[TinselKoala]

1) The video is incorrect in its claim that this system has not been used before. Unless, that is, the video was made before 1999.

2) The cart moves by pushing against the surface that it is on, completely in accord with Newton's laws. This can be tested very simply and no air table is needed. All one needs is a flat level surface (the glass table top shown in the video will be fine); some smooth even-sized balls, like glass marbles or steel bearing balls, or even mouse balls; and another flat and smooth piece of glass that is perhaps two or three times as long as the cart, that is ballasted with modelling clay to have the same mass as the cart.
Put the marbles on the table, put the ballasted glass on top of the marbles, put the cart on the top of the glass. Start it up and observe.

If the cart is not pushing on the glass the glass will remain stationary. If the cart is pushing on the glass the glass will move backwards as the cart moves forwards and vice versa. If Newton's laws hold and the mass of the glass is the same as the mass of the cart, both items will move equal (and opposite) distances.

Since I have already done this experiment with several substantially identical devices to those shown in the above video, I won't be doing it again.

But I encourage all interested to try the experiment I outlined above. Including the creator of the device pictured in the video.


(No one imagines that an ice skater violates Newton's laws, because they understand that 1) the skater, like the pendulum, stores energy which can be released over time to do work; and 2) the ice skates, like the cart's wheels, are only "frictionless" along a line. If the skater, or the pendulum, produces a force vector that is NOT along the frictionless line...Newton prevails, the skater or cart moves forward, and the floating slab of ice or piece of glass moves backwards.)


EDIT to add this item of interest:
http://physlab.net/pendulum_cart.html

[broli]

TinselKoala, I agree with your controlled experiment. But I would like to add suggestion #1 in there. With that this can then be clearly proven or disproven as the glass bottom shouldn't move at all if the idea works. Or vice versa. If it doesn't work the cart will not move at all.

If you ever perform such experiment please let me know  .

[Merg]

1) The video is incorrect in its claim that this system has not been used before. Unless, that is, the video was made before 1999.

The video was made in 1996 - watch 06:28 min. of the video:
"An excerpt from the TV show "Svet ideja", Radio Television of Novi Sad (Serbia), filmed in 1996."

[Merg]

This belongs here:

Superiority of Pendulum Drive - Potential Energy to Kinetic Energy
http://www.youtube.com/watch?v=GuTMYgQDUzs

Veljko Milkovic demonstrates a simple experiment showing the change of potential energy to kinetic energy and proving the energy excess is possible with the pendulum drive.

Experiment Description:

The change of potential energy to kinetic energy of a metal ball in two cases: (1) a metal ball is rolling down on the inclined plane of the pendulum cart from upper edge and crashes at the lower edge of the cart resulting in 11 cm path traveled by the cart (2) The same metal ball is attached to the pendulum rod on the same pendulum cart and it is realized to swing from the same starting point as in the case (1). The path traveled by the cart is now 30 cm, almost 3 times longer; showing and proving in that way the superiority of pendulum drive and confirming the energy excess is possible with the pendulum drive.