Mechanical propulsion

[Alchemist]

if it's something as simple as mass, then mass could be fed into one sphere at a time, through say a dense liquid, then drained and alternated between movements. then you will have the larger mass object, pulling on the lower mass object.

The question is about how mass transfer works. when the fuel enters the duct it accelerates, therefore the craft gets small acceleration in another direction. When the fuel reaches the second tank it decelerates giving the craft acceleration in another direction. during steady flow of the fuel these forces compensate, but when you start transfer you get some brief uncompensated momentum that will be canceled only when you stop the fuel transfer. So, while the fuel moves forward, your craft slowly drifts backwards and the center of mass is still where it was.

Now if you could teleport the fuel without applying force in such way... wouldn't it be easier to teleport the entire craft

[Yasmy]

<snip> Unless of course I'm neglecting some fundamental principle.

You're ignoring or misunderstanding Newton's laws of motion. If you had to pick one topic in physics, learn Newton's laws.

Your device would have to break Newton's first and third law to work the way you describe it.

[Red Iron Crown]

Ah, is it perpetual motion month already?

It does seem to be.

[Sirrobert]

Watch this if you're confused

[Ravenchant]

Ah, is it perpetual motion month already?

Yeah. It could be worse, though. Remember that Espinoza guy?

[Roastduck]

Newton's Laws, man. Every time one of those balls moves, you have an equal force going in the opposite direction. Not only will your speed not change, if your weights aren't balanced, you'll just end up putting your probe into a spin

[Red Iron Crown]

Newton's Laws, man. Every time one of those balls moves, you have an equal force going in the opposite direction. Not only will your speed not change, if your weights aren't balanced, you'll just end up putting your probe into a spin

Not possible. Angular momentum is conserved just like regular momentum. You can rotate it but can't impart a spin.

[Roastduck]

Not possible. Angular momentum is conserved just like regular momentum. You can rotate it but can't impart a spin.

Is there a difference in mechanics between rotation and spin? I genuinely do not know. I just figured that if the weights are unbalanced, there would be a net reaction force favoring one side, cause motion around at least one axis

[Red Iron Crown]

Is there a difference in mechanics between rotation and spin? I genuinely do not know. I just figured that if the weights are unbalanced, there would be a net reaction force favoring one side, cause motion around at least one axis

You can rotate it to a new orientation by moving parts, but you cannot impart a spin that continues when parts stop moving.

[TheGatesofLogic]

this doesn't work, the objects moment of inertia might change as the process progresses, but only in such a way as to conserve momentum through the repetition of the cycle, and the center of mass will never move