Recent content by Bob not Alice

Hi mfb, Good stuff. :oldsmile: The rocket concept isn't really what I was looking for as it involves a permanent mass loss to the system. Neither was the "bounce", hence my stipulation the "the only force acting between them is their mutual gravitational attraction". That was meant in reference...

Hi folks, A system of two masses, stationary with respect two each other, is the starting point. For convenience I'll specify one mass as being much larger than the other. The only force acting between them is their mutual gravitational attraction. At time zero they are an arbitrary distance...

Hi DEvans, Thanks for chipping in. Your point about springs is well taken as they are, after all, just another expression of electrostatic forces, as is magnetism when one factors in special relativity. I agree that there isn't a problem except, perhaps, my struggle to visualise the physical...

Hi folks, There are a number of statements out there on the web to the effect that 'canonical momentum is simply “the quantity that is conserved” in electromagnetic interactions, while the kinetic momentum is just the product of mass and velocity'. Fair enough. There must also be a presumption...

Yes, that was why I dusted off my old idea. But I'm not sure whether the operating principles involved are quite the same. Maybe they are but I'm really hoping that someone with a deep knowledge of electrodynamics can point out what's wrong with the simple assumptions in my opening post. Bob.

Hi nasu, Mechanically Bob.

. Thanks for the prompt response: my childhood hero was Eric Laithwaite. But the effect I'm describing and seeking help with is the apparent, and hence rather unlikely, violation of conservation of momentum as all that's needed for the "motor" described above is that the electromagnets are held...

Hi folks, This is such a simple idea that I know I can't be the first to think of it so there has to be a "gotcha". Maybe an induced electric field working in the opposite sense? Is there a kind soul out there who can spare a few moments to educate me after reading what follows? Thanks About...