Mach Effect Thrusters: Humanity to the Stars

[K^2]

I don't know if that's what we're getting, though. In video I've linked above, authors of the paper appear claim that their rough estimates on thrust experienced by loop of wire is roughly what they're getting. Now, I have not run these numbers, nor have I read the paper, so I'm going purely from the claim as reported in the video, but that sounds like tether is exactly what they got. Don't get me wrong, I'm not about to knock tethers, but I don't see an indication of a path to a more compact design. It's still a wire carrying current. You either increase its length, or you increase the current to get the thrust you need.

[sevenperforce]

59 minutes ago, K^2 said:

I don't know if that's what we're getting, though. In video I've linked above, authors of the paper appear claim that their rough estimates on thrust experienced by loop of wire is roughly what they're getting. Now, I have not run these numbers, nor have I read the paper, so I'm going purely from the claim as reported in the video, but that sounds like tether is exactly what they got. Don't get me wrong, I'm not about to knock tethers, but I don't see an indication of a path to a more compact design. It's still a wire carrying current. You either increase its length, or you increase the current to get the thrust you need.

Right. I haven't read the paper either, but from Manley's video it sounds like the effect is a coupling between the circuit powering the resonance chamber and the magnetic field of the Earth. 

If the effect was actually located inside the resonance chamber, then we'd have a path to a more compact tether design. But so far there has been no indication of this.

Current tether designs (no pun intended) use electrical current. I wonder if a physically rotating object with an electrostatic charge (think two loops of wire forming a capacitor) could be more compact/efficient.

[wumpus]

1 hour ago, sevenperforce said:

Right. I haven't read the paper either, but from Manley's video it sounds like the effect is a coupling between the circuit powering the resonance chamber and the magnetic field of the Earth. 

If the effect was actually located inside the resonance chamber, then we'd have a path to a more compact tether design. But so far there has been no indication of this.

Current tether designs (no pun intended) use electrical current. I wonder if a physically rotating object with an electrostatic charge (think two loops of wire forming a capacitor) could be more compact/efficient.

Wire doesn't form a capacitor, but perhaps two high resistance wires (megaohms or such) keeping two capacitors apart might be what you are thinking.  I still doubt that such a design makes sense outside the Earth's magnetic field.

Do probes to Jupiter's moons us electromagnetic propulsion?  It is said to have a beast of a field, although you'd presumably need plenty of non-magnetic propulsion to get there.  I know Mars doesn't have such a field, does Venus?  It would at least allow a slingshot between Venus and Earth using only electromagnetic propulsion.

[sevenperforce]

6 minutes ago, wumpus said:

Wire doesn't form a capacitor, but perhaps two high resistance wires (megaohms or such) keeping two capacitors apart might be what you are thinking.  I still doubt that such a design makes sense outside the Earth's magnetic field.

Do probes to Jupiter's moons us electromagnetic propulsion?  It is said to have a beast of a field, although you'd presumably need plenty of non-magnetic propulsion to get there.  I know Mars doesn't have such a field, does Venus?  It would at least allow a slingshot between Venus and Earth using only electromagnetic propulsion.

You could pack positive and negative charge on two separated wires.

Difficulty with electromagnetic propulsion in the Jovian system is power; solar power is in short supply out there.

Venus has no meaningful magnetic field.

[wumpus]

4 minutes ago, sevenperforce said:

You could pack positive and negative charge on two separated wires.

Difficulty with electromagnetic propulsion in the Jovian system is power; solar power is in short supply out there.

Venus has no meaningful magnetic field.

Wires don't like to store charge (which is why they are good at moving it around, it doesn't stick to them).  Plates like charge.  You'd only manage to cover the silhouette of the wire with charge, which doesn't have much point.  Wires *will* store current (and have measurable inductance), but I've never heard of anyone worrying about the capacitance of a wire (although it has to exist in transmission lines, but has no real effect other than establishing an impedance to go with the inductance).

[sevenperforce]

26 minutes ago, wumpus said:

Wires don't like to store charge (which is why they are good at moving it around, it doesn't stick to them).  Plates like charge.  You'd only manage to cover the silhouette of the wire with charge, which doesn't have much point.  Wires *will* store current (and have measurable inductance), but I've never heard of anyone worrying about the capacitance of a wire (although it has to exist in transmission lines, but has no real effect other than establishing an impedance to go with the inductance).

Yeah, I get that. Was thinking of something more like a ribbon. Trying to figure out if there is a geometry wherein counter-rotating helical ribbon capacitors would couple linearly to the Earth's magnetic field lines.

[K^2]

I'm having trouble looking up at what voltage capacitors will start to leak due to field electron emission, as that's going to be limiting factor on charge. Second limiting factor is mechanical strength. That one's easier. You can get steel wire loop going at about 500m/s regardless of loop radius and wire diameter. That isn't much. Gut feeling is that you'll get stronger current with superconducting wire.

[MaverickSawyer]

Heh. Just saw the reports on the latest tests... Turns out that the w.t.f. in "w.t.f. Thruster" actually stands for "Well, that failed". 

EDIT: ... Seriously? That's censored?

*sigh* *tries different tack*

YAY! Works.

Edited May 27, 2018 by MaverickSawyer