Comm. buoys & relays (interpretation 2)
BLAH BLAH BLAH, WORMHOLES, HUGE POWER USAGE, RELAYS NEED TO HAVE AN ENERGY OUTPUT SEVERAL ORDERS OF MAGNITUDE HIGHER THAN AN ENTIRE GALAXY!
Medigel: the first step on the road to immortality
Now, this is a slight departure from my normal fare, as it doesn't involve eezo. However, I think it is worth paying attention to. Medigel is a substance that, in universe allows the complete healing of a gunshot wound in perhaps 15 minutes. It is also stated to be a product of genetic engineering. It would therefore make sense for humans to have developed an artificial symbiotic bacterium that constantly excretes medigel. This would lead to humans having an almost krogan-level healing factor.
Also, if there's a symbiotic bacterium that makes magic regen sauce (medigel), it would be trivial to produce one that excretes telomerase. What's telomerase you ask? You see, on the ends of our DNA are these things called telomeres that prevent genetic corruption when a cell divides. Over the course of your life, your telomeres get shorter and shorter, until your cells eventually lose the ability to divide. What telomerase does is extend your telomeres. Normally, telomerase only exists in your reproductive organs, but if it could be made to exist in all your regular cells, you would be effectively immune to old age.
Finally, hunter-killer bacteria could be designed to murder cancer cells and pathogens. This would lead to humans in this universe having an immune system strong enough to shrug off just about anything, as well as making human tissue incredibly toxic to eat for any non-human. In addition, these hunter-killer bacteria would be a perfect biological weapon for use against non-humans.
FTL (revisited): There is no speed limit
I've already discussed how an FTL drive can easily be used to destroy a planet. That's not what I'm talking about at the moment. Back in chapter 1, I determined that the council races could reduce mass to the degree that c was 3,000,000 times greater than its normal value, bu that they didn't normally go faster than a few thousand c to save fuel. However, the particle beam turbines I discussed in chapter 2 have no such limits as 'fuel' for either energy or thrust. This means, that if the ship normally accelerates at 1 g, it instead accelerates at 3,000,000 gs. The reduced mass of the passengers, however, prevents them from being liquefied by this, and the ship breaks the light barrier in about 10 seconds. Bear in mind, this ship could keep up said acceleration forever (theoretically), meaning that there is only 1 excuse for the Council races not cruising around at 1,000,000 c as a matter of course. Indoctrination. In addition, the Reapers could move at multiple trillions of c, as the relays can move a ship at least 100,000,000 c, and they only add the energy equivalent of accelerating the ship by 3 km/s.
Mass accelerators: a slight adjustment
Back in chapter 2, I made the foolish mistake of assuming that muzzle velocity to barrel length had a linear relationship, which is not the case. Instead, a mass accelerator accelerates its projectile at a constant rate until it exits the barrel. If we had a rather wimpy coilgun 100 meters long that accelerated its projectile at 2,000 m/s/s, the bullet will remain within the barrel for 0.23 seconds and have a muzzle velocity of 447 m/s. Now we mass lighten the gun's interior by 1,000. The bullet is now accelerating at 2,000,000 m/s/s, remaining within the barrel for 0.007 seconds with a muzzle velocity of 14,142 m/s. As you can clearly see, this is NOT a linear relationship, with a severe case of diminishing returns.
In the case of the navy's planned railgun I mentioned back in chapter 2, it has a relatively short barrel I'll estimate at 10 meters for the purposes of this thought exercise. It also has a muzzle velocity of 5,800 m/s. this means it accelerates its bullets at 3,364,000 m/s/s and remains in the gun for 0.0018 seconds if you want to be generous. Mass lighten that by 1,000 now. At this point the bullet is accelerating at 3,364,000,000 m/s/s (~11.2 c/s/s) and exits the barrel at 183,412 m/s after spending roughly 0.0000545 seconds in the gun.
We now scale up our theoretical gun that accelerates its projectile at 3,364,000,000 m/s/s to 1 kilometer in length and find that the bullet only comes out at 1,834,121 m/s after spending roughly 0.000545 seconds in the gun. This indicates that for 10 times the firepower you either need a gun 100 times the length, or a gun that accelerates the bullet faster. Well, we know how to accelerate the bullet faster don't we? Just intensify the mass effect field.
As determined in chapter 1, the council races have the capability to reduce mass to 1/3,000,000 of its normal amount. Therefore, if we multiply the non mass-lightened acceleration for that near future railgun I described by 3,000,000 we find that it accelerates its bullets at 100,920,000,000,000 m/s/s (~33,640 c/s). For the 10 meter gun this results in a muzzle velocity of 31,767,908 m/s (~0.1 c) with 0.0000003 seconds being spent in the gun. The 1 km gun results in a muzzle velocity of 317,679,083 m/s (which is actually slightly above c, and thus causes a low-level FTL field collapse event upon exiting the gun) with 0.000003 seconds being spent in the gun. A theoretical 1 meter gun (some sort of bull-pup rifle) would have a muzzle velocity of 10,045,895 m/s with 0.00000007 seconds spent in the gun (assuming the bullet being used is identical to those in the ship-mounted guns, which I highly doubt)