Starship Particle Accelerator Propulsion

[gamowin]

Recently I had a dream where I was on board some kind of star ship. Upon asking about the propulsion method, I was told that the ship used massive particle accelerators to generate matter-antimatter pairs which actually had more mass in total than the starting matter. Enough of this new matter was collected to sustain the particle accelerators, while the rest would be electromagnetically propelled away. I don't pretend to understand anything about quantum physics, but is something akin to this technically possible?

[Sampa]

That is a truly incredible story. In fact, I remember having a similar dream, only I was a tactical officer on board a ship that was under attack.

[DundraL]

Yes it's possible. Just as rockets use chemical energy to fling mass out the back, you can also use magnetic fields to fling charged particles out the back.

[0111narwhalz]

However, I'm sure you realised that the "matter-antimatter pairs with greater mass than the original matter" would constitute a perpetual motion machine. This particular facet is a fallacy.

The rest is fine.

[YNM]

More mass than at start ? How ? I know that relativistic mass is larger than rest mass, but you lose considerable energy in that process. I mean, can anyone tell me the efficiency of particle accelerators ?

[Nuke]

when the particle gets close to c, it becomes harder to accelerate it, the energy has to go somewhere and ends up increasing the relativistic mass of the particle. so if you eject the particle out the tail pipe it gives more thrust than a low energy particle. you end up with isp near c.

not sure what the accelerator size or power supply requirements for this are, i assume both will be huge. as a result overall ship mass will be high, and and thrust will be very low. might work out for a generation ship.

[PB666]

However, I'm sure you realised that the "matter-antimatter pairs with greater mass than the original matter" would constitute a perpetual motion machine. This particular facet is a fallacy.

The rest is fine.

yes, assumming thes were virtual particles, you might be able to accelerate them, not withstandin the consevation argument, but they could never supply the energy to accelerate them.

In theory once the quantum pair is generated, you put energy in to stabilize them and separate them. The you put more energy into accelerate them. With out the energy input they vanished back into vacuum space. you would have to be very fast though, because these appear at 10E-43 second and are gone just as fast. The pair are actually not free, the energy you put into capture them is minimally two photons of high energy. you only get that energy back if they annihilate.

I should add that this is theoretically possible because it is possible to create high energy photons without using antimatter as the source, and you coukd calculate the minimum hv require for pair production, but if you are dreaming, why not create a proton anti-proton, as these have more momentum your push off mass will be be greater. in this dream you

calculate the spectrum and perfect incident angles

you create two photon sources, you incrase hv a little over desired

you scatter the frequency a little therefore creating a perfect beam

the collision happens every time, followed by two massive EM fields that project the charge to contaiment field.

They are kept only momentarily and fed into the particle accelerator, the ship is very long and the charges are accelerated GeV energy.

There is only one problem with the dream. We don't know how to make the proton making photons by any conventional method, the photons themselves are highly coorosive and prefer to interact with matter, so. The other problem is high a accelerators are heavy abd need alot of cooling which means alot of mass.

Edited September 10, 2015 by PB666