7 Faster Than Light Travel Under Ritzian Physics
Using interacting electric fields, it is impossible to accelerate anything faster than the speed of light. Using rocket propulsion, it is possible to accelerate to an arbitrary speed. A rocket can, after all, accelerate to a speed faster than the speed of its own exhaust.
However, any spaceship travelling at speeds approaching that of light will experience increased apparent momentum of the gaseous particles in space striking its hull. This corresponds to the increased heating of targets through high speed particles striking them.
In relativistic terms, the apparent momentum increases exponentially to infinity as we approach the speed of light. In Ritzian terms, the apparent momentum increases until the particle's nuclei actually physically collide when other forces come into play - I'm not sure on the details of what will happen here.
We are talking about a new regime, where different principles operate. It may well be that the particles the spaceship collides with will blast the nuclei of its hull to pieces, and very quickly erode the hull. There are a lot fewer particles in space compared to the atmosphere that we breathe, but the much higher apparent momentum will more than make up for this.
If there are no "new forces", but we can travel ftl, then borrowing some concepts from Relativity, perhaps we'll generate a tiny black hole with each collision. However, I do not feel black holes can actually exist (take or leave that comment for the moment), and a new force regieme will come into operation, so this should not be a problem.
However, there are a few factors which may allow us to nevertheless fly a spacecraft at faster than light speeds.
First, most of the particles in space are hydrogen and helium atoms/molecules. If we make the ship's hull out of material with large nuclei (Einsteinium, with an atomic mass of 254, may be a good choice :-) ), it is possible that the gaseous particles may strike the nuclei of the ship's hull without blasting them apart, and the structural integrity of the ships hull may be retained. It seems likely that the ships hull will become radioactive in this process, but if it stays together, this will be something. I don't know just how likely this will be, or what chance the hull's nuclei will have of staying together - I don't know enough nuclear physics.
If we construct our spaceship "aerodynamically", we may find that while some particles strike the ship, they then pass their momentum onto other particles in space so that they then travel "around" the ship, and the number of particles striking the ship is much reduced. This situation is somewhat analogous to what happens to an aircraft travelling faster than the speed of sound. We don't get the aircraft crashing into every molecule in its path - a few do, but most make their way "around" the aircraft.
And, of course, the atmosphere of space will cause drag, slowing the spaceship down. Through "aerodynamic" design, we will be able to reduce this drag, but we may nevertheless require continuous thrust to maintain our speed. And the drag will make the ships hull heat up - which would have to be dissipated.
We can make an analogy to supersonic travel. When aircraft travel at speeds below that of sound, particles keep their distance from each other and disturbances propagate at the speed of sound. At speeds faster than sound, the particles "crowd together" - they almost form into a fluid. When this occurs, the particles "roll over each other" rather than "whacking into each other" as they would normally do at subsonic speeds.
Because the particles "roll over each other", the air is able to move around the aircraft at supersonic speed, while air motion is normally limited to less than the speed of sound.
This could be similar to what could happen on board a spacecraft. Assuming the incoming particles do not blast the nuclei in the hull to pieces, we could imagine them "rolling over each other" at speeds faster than that of light, meaning that particles *do* move around the ship at speeds faster than that of light, and do not transmit the excessive amounts of energy we would otherwise expect.
Navigation may be very difficult. Just what happens to incoming light beams when we are ourselves travelling FTL is a difficult question, now that we have decided not to sweep it under the carpet. It will be impossible to see behind the spacecraft, in the same way that a jet pilot travelling above Mach 1 cannot hear an explosion behind them. And what about the light coming in front ? We'll probably be able to see that, but I'm not sure.
Obviously, there are a few unknowns here. I don't know how dense the vacuum of space is, or what will happen when high speed gaseous particles strike heavy nuclei.
Now that we can get to the speed of light, the next question is : what's involved ? Assume we had an accelerating force of 20g. The crew could be in hibernation, breathing liquid or whatever to tolerate this acceleration. After 17 days, we would reach the speed of light. After 70 days, we would reach 4 times the speed of light. Hence, it would take us in the order of a year to travel four light years to the nearest star. Intersolar travel could be performed over a human timescale.
But how do we get the sustained 20g acceleration ? I think it would be fair to say that it would not be feasible to use rocket propulsion, though it would be possible in principle. Perhaps we could get a very small payload (nanotechnology ?) up to past the speed of light by conventional means.
But there is * one * form of rocket propulsion that might just do the job. Atomic bombs. On this basis, a rocket puts a string of small atomic explosions behind it, which generate thrust.
Chemical rockets depend on the release of energy in chemical bonds to generate thrust. They are not very efficient in terms of thrust/propellant mass. However, atomic bomb based rockets can achieve much higher efficiencies - perhaps enough to make the movement of a worthwhile mass at FTL speeds feasible.
It is not possible to have forces act between objects which are travelling FTL. It's just like the difficulty we have with propelling shells at high speeds - we can't accelerate them to more than the speed of sound in the gas behind them, because the gas cannot keep up.
This means we cannot use a ramjet to travel FTL. It could, however, accelerate us up to close to the speed of light, after which we could use stored propellant to get over the lightspeed barrier. But we would still need sustained thrust as the drag from the vacuum of space would probably be substantial.
Lastly, there are photon drives. There are many difficulties with their use. Could we get 20g acceleration from one ? How much energy will a given sized fission/fusion reactor give us ?
The notion of a "photon drive" opens the can of worms of "photon momentum". Sure, Ritzian electrodynamics has not yet gotten grips on this concept, but remember that photon momentum has been the source of much trouble in physics, and it has been the efforts of an army of physicists that have given us quantum electrodynamics, searching long and hard for *some* way of fitting incompatible concepts together.
I believe that the notions of photon momentum, and even mass/energy equivalence can exist independently of SR, and would be compatible with an enhanced Ritzian theory. To say more than this more speculation than is warranted. What I say now is more an attempt to capture the imagination than say anything with a sound backing in physics. I will borrow notions of mass-energy equivalence as necessary, but I make no claim to a consistent framework.
The advantage of photon drives is that the "mass" thrown overboard is ejected from the ship at the speed of light. Any rocket can travel faster than its own exhaust, but the faster the exhaust, the more efficient the rocket is in term of thrust generated for the mass thrown out the rear.
As a nuclear reaction progresses, this releases "mass-energy" which is ejected from the rear of the ship. A given amount of reactor fuel releases a certain amount of "mass-energy". We must compare the mass energy released to the remaining mass of the ship and consider what the highest speed we could accelerate it to based on a certain amount of propellant.
If we want to be simple, we could use the known characteristics of nuclear reactors, calculate how much energy they put out, and translate this directly into a velocity increase of the spacecraft, assuming that the energy is converted to kinetic energy of the spacecraft.
Hypothetically, if we could get some force acting between object travelling at speeds close to that of light and beyond we could get FTL travel.
Say, we had a planetoid with a force generator on it which pushed a spacecraft away from it. If the planetiod was much bigger than the spaceship, we could accelerate the spaceship well past the speed of light, and (assuming conservation of momentum) not mess up the planetoid's orbit too much. Of course, there would have to be a 'decelerating field' at the spacecraft's destination.
It may just be possible to accelerate to the speed of light and beyond.
Next : 8. A letter on the subject of black holes and alternatives to Dr. Narayan