=LSF= Operational Data Network

[The.Rolling.Stoned]

ENCRYPTION: High
PRIORITY:Medium
COMM ID: Charles Manson
SUBJECT:Knowing the limits

*secure transmission established*

So recently I have discovered (from numeros experiments and research) the possibility of developing and mounting a Reactionless Drive Core on our various Crafts.

Let's say the idea of a spaceship carying 10 times its empty weight in fuel sickens you. You want the space aboard your space ship to house your colorful crew mates, dazzling weapons, holodecks, and other fun and excitement — not deck after deck full of boring old propellant. And you want to allow for long patrols without having to refuel at every destination. So, you elect to go the route and equip your spaceship with a gravity-manipulation Reactionless Drive that allows her to accelerate without throwing material out of her tailpipe. Problem solved, right?

But hold on. You've also opened up a can of worms.

First, if we allow them to accelerate without pushing anything, they are now violating one of the most basic laws known to physics: the conservation of momentum. In other words, you can't apply a force to an object in one direction without causing an equal-and-opposite force on some other object. Ships fly up because their exhaust flies down. Jumping up pushes the Planet ever-so-slightly downward; falling back to the ground afterward pulls the Planet ever-so-slightly up. By letting our space ships violate this basic law, we're saying that momentum is not always conserved. What other circumstances in our universe will cause momentum not to be conserved?

Second, are you also violating the conservation of energy? A 1000 tonne spaceship traveling 1/10 of the speed of light has a kinetic energy of 450 quintillion Joules, equal to 100,000 megatons of TNT. That energy had to come from somewhere. Did it come from burning some sort of fuel on board your space ship, to power the generators? If you used the thermonuclear fusion of hydrogen into helium as your fuel source, and you managed to hand have a fusion reactor technology that's nearly 100% efficient, you'd have to burn at least 350 tonnes of hydrogen to obtain that much energy, which is a third of your spaceship's own mass. (This isn't as bad a mass-ratio situation as if you'd used a plain-old momentum-conserving fusion rocket, but it's still pretty significant.) And you'll have to burn just as much again to slow your space ship back down at the end of your trip. If this is too much for you, and you decide your reactionless gravity drive simply works by tapping into the magical gravity waves of the universe and surfing along them with only minimal power requirements, then your space ship's kinetic energy is being created ex nihilo. You've got yourself a free energy machine! Just strap your space ship to one end of a long lever, strap the other end to a huge electric generator, and fly in circles. You can generate enough energy to power our entire civilization this way, with no cost in natural resources. This will play absolute havoc with our economy.

Third, if any 1000 tonne space ship can easily accelerate to a tenth of light speed, then every two-bit spaceship owner has in his possession a weapon of mass destruction. Those 100,000 megatons of TNT-equivalent kinetic energy will act like 100,000 megatons of actual TNT if they strike a planet. Want a future populated by plucky tramp space-freighters and sneaky space pirates? It ain't gonna happen if every ship is a Mega Nova Torpedo-on-steroids waiting to happen. Every spacecraft captain will be on too short a leash. Any spacecraft that even looks suspicious will be killed before it can become a threat. (And, yes, all fast-moving spacecraft, and even stationary spacecraft, will eventually be detected — there ain't no Stealth In Space.) Any civilization that doesn't take these precautions won t be a civilization for very long. This might work as a setting for your future totalitarian dystopia, but is hardly the right world for romantic swashbuckling adventures.

The potential damage done to our story by a reactionless drive is just one example of the broader principle. Any technological marvel that sidesteps the real life roadblocks facing space travel has the potential for unintended consequences. Thermonuclear torchships? They've got the same "spaceship = weapon of mass destruction" problem that reactionless drives do, albeit on a more manageable scale.

So what do we do when we need our pilots to be able to move between the stars faster-than-light, or teleport, or do any of the other myriad things that our current best guesses at the law of nature say are impossible? You set the technology up in such a way as to limit the damage to our civilization . Maybe your Deflector Shields are magnetic, and can only affect charged particles and ferromagnetic metals — and your spaceship needs to open up holes in its shields to shoot iron slugs or particle beams at an enemy. Maybe the high speeds needed to traverse interplanetary distances in days or hours are imparted not by our space freighter's own engines, but by planetside pushers that will only push it onto a predictable course, thereby eliminating the threat of rogue spaceship commanders turning their vehicles into WMDs. Maybe the violations of the Laws of Thermodynamics needed to make stealth In space work are curtailed in some way that prevents us from getting useful energy out of any warm object.

I'm scraping everything and moving on.

Manson Out...