Quote (brmv @ 10 Jan 2014 01:45)
if they would attack, you would have tears in your eyes
if they have the technology to travel here within a reasonable time, they can wipe out humanity if they want to
Just for fun, it would be fun to put some numbers and see if that's actually realistic. I'll try to bring realistic numbers, and put it relative to real world uses. Anyone feel free to challenge my math, as i'm using wikipedia to do some of this calculation and reference, and am not familiar with all of the subject matter.
Now, as a basis here, let's estimate how much energy they would need to travel here. They are currently building a proof of concept of a warp engine. Since someone managed to optimize the theoretical design, the theoretical energy need to go to alpha centauri was reduced, from the previous estimate of the mass-energy equivalent of the planet jupiter, to that of voyager 1 (722 kilos). What that means is, according to a calculator i found, 6.4890e+19 joules, or 180 250 000 000 000e kwh, or 180.25 petawatt hour of energy/power to get from here to alpha centauri in a small ship. The entire world put together produces 143, mind you, and they'd need to travel distances millions of times larger, on crafts that would likely be thousands of time heavier.
Industrial lasers get up to a few kilowatts, they can slice solid steel from nearly any distance. Let's assume they do produce more energy in one ship, than we do in the entire world, imagine the power of a laser 1% of that power, a laser of 1.8 terawatt, run for an hour, accounting for 1% of the energy spent getting here even in a small ship from a neighborhing system, i think it's safe to say that laser would be able to wipe up any city off the map, from orbit too, whatever we tried to do. That's not even taking into account the insane bacteriological weapons they might have at their disposition too.
Honestly, with these kinds of figures, we'd have as much chance of survival as ants do when we try to carpet bomb them. But these kinds of numbers are giving me another thought. These civilisations, if they have access to these kinds of terrifying weapons, if they were warlike, they would likely have wiped each other off the map far before reaching any other world. If they had come close, one could imagine that the survivors would have learned one hell of a lesson, lasting the rest of that race's history.
Secondly, to start a war, they have to either hate us, fear us, or covet what we have. They'd have no reason to hate us, nor fear us, and what could they possibly find on earth, that they cannot get just as easily elsewhere? If they did visit us, something tells me that they'd more likely to be some kind of alien national geographic than some overlord conquerors here to kill and enslave us.