Woodward Effect - Thread 2

[dustinthewind]

You stimulate a thought: you don't need a propellantless thruster if you can persuade the vacuum to spit out propellant.

Can that be better than a photon rocket, I wonder....

Sadly, but not unexpectedly, no. If you create particles of mass m and velocity v, their momentum is γmv and total energy
γmc^2. If you used (only) that energy to create photons, they have momentum γmc^2/c = γmc. So a photon rocket is better unless v>c 

edit: sorry, looking back at this I realize what you're saying is that it's inefficient to create the matter and then just shove it away. and I agree with this. What I was trying to get at was how increasing the mass of your propellant does increase effeciency (his suggestion has merrit in increasing effeciency by increasing mass) and that it may not be necessary to make the mass if we can push off the vacuum.

I could prove pushing off a more massive particle is more effecient for propulsion via an analytical argument. If you want to show it in mathematics you have to use momentum conservation and energy conservation and work out the math. I'll just explain that via the argument however right now.  Probably a colossal waste of energy to make matter to push off though.

The argument goes if you have two equal masses and stored potential energy and the energy is released and converted to kinetic energy then the energy is distributed 50/50 between the two masses. 

Now take the mass of a photon and the mass of a ship and you have stored potential energy and it's released as kinetic energy.  For the photon you can assume it's mass is it's energy divided by the speed of light squared. Working out momentum conservation and energy conservation equations and solving What you find is that almost all the energy is imparted to the photon and almost no energy is imparted to the ship. If I remember correctly the ratio of energy distributed to the ship is something like the mass of the photon divided by their total mass.  I do the energy exchanged during a kinetic collision here math line 8 and 9. 
https://www.researchgate.net/publication/311406776_Is_the_frustum_EM_Drive_4_decelerating_light_for_propellantless_propulsion

This is the reason why Photon propulsion is inefficient. Only with recycled Photon propulsion can they recycle those photons many times and each time the photon is recycled it imparts a small percentage of energy to the ship again but essentially it's pushing off the other mirror.

I'll make what I have to say short is that I believe you don't even really need to create real particles and you can just push off virtual particles. Some might argue you can't but by virtue of the electric field those virtual particles can exist for longer periods of time and gain Mass via the energy stored in them eventually becoming real particles. If you push off those that energy distributed to them doesn't just disappear. I suspect there's a possibility it may relate to gravitomagnetism or simply SpaceTime manipulation.

The last thing I'll say is that I believe this is probably the negative Mass that they are measuring.  I believe energy imparted to this field is actually (repulsive/speeds up coordinate time, light, and radioactive decay, effective Mass reduction) but this is my educated speculation and for reasons that I'm not going into right now but this relates to the mach effect thruster.  There's a possibility it may relate to the EM drive too

[aceshigh]

Years ago, someone (I think QuantumG?) made a profound suggestion:

“Chuck it out of an airlock”.

If it accelerates, then…

Ric

if Starship makes access to orbit REALLY ship (like $20 per kilogram that might end either
1 - validating a propellantless propulsion scheme (the ones using new physics, not stuff like magnetic sails)
2 - being the nail in the coffin of 99.9999% of propellantless propulsion schemes, which live like zombies because it's so difficult to eliminate noise from stuff at micronewtons of force.


That said, and speaking more seriously, chucking stuff like that out of airlocks would increase space junk... and when I say junk, let's remember most propellantless propulsion (not necessarily Woodward Effect, there is at least more physics behind it than most other schemes) are junk even before being put into space.

Also, I suppose at LEO orbit the drag is still intense enough, plus other factors, that it would still be difficult to discount noise, when the force is only micronewtons?