First of all, dfjchem, I am sorry that I went asleep when you sent the link to this thread in my messages.
I don't think that aliens are gonna attack us. I mean, they should have some reason behind attacking us. Resources? Nah, there are many planets and asteroids hovering in the universe, I don't think that Earth has something what so many other asteroids and planets don't have and also, why will they bear the trouble of attacking us when there are so many resources just flying around. Labour? I don't think so. If an alien world is really capable of interstellar travel, they should have hundreds of robots working for them all around. So, we can take that assumption out of account. Just for fun? A big LOL, I mean, why will they even try to attack us just for fun? That's a laughable assumption.
And also, what will be their mode of transport? I mean, even if they travel extremely close to the speed of light, why will they even bear the brunt of travelling a hundred lightyears when they can just look at us? If they want to just observe us, they will just launch a big telescope into space and just look at us. Or, if they want to get our news. They can just adjust their radio telescopes and listen to the radios, it's that simple, I guess.
Well, even if they can do a warp or something like that. Maybe, they know how to do an Alcubierre Drive. But there, how can they get so much energy!? As far as I know, to do an Alcubierre, we need a mass equivalent to the mass of Jupiter. And, oh E = mc², it is ridiculous to get that much amount of energy! And also, how can they make negative mass? It seems ridiculous to me. I mean, that will be just a degree less than impossible.
Not if they can suck energy out of a black hole.
I am going to talk some Philosophy now. What is the secret behind the success of human species? Our thirst for knowledge. It's because of our thirst for knowledge, we have reached this far. It's because of our thirst for knowledge, we first ventured into the seas. It's because of our thirst for knowledge, we first discovered how to control fire. It's because of our thirst for knowledge, we first made religions to define things we don't know. It's because of our thirst for knowledge, we first made spaceships to travel into the unknown.
Well, now, if an alien species really has the same thirst for knowledge, then, I won't be surprised if they really take the risk of going into the unknown to find us. Tell me, if humans become as developed as them, won't we at least, send interstellar satellites? Of course, we will. But, it will take time for the satellite to reach another solar system, even if it reaches. But, there, we don't know how rare is life in the universe. And also, we don't know how old the oldest intelligent species are. Let's say the nearest intelligent life is 100 lightyears far. We, humans, are just 30,000 years old, and if we take the hominins into account, we are almost 2 or 3 million years old. Now, say, the nearest intelligent life is 100 million years old. Then, of course, they are far, far, far more advanced than us. Well, if they are really that old, then, I won't be surprised if they are here on Earth already. Maybe, who knows, they look just like humans or are wearing a suit pretending they are humans. Who knows?
Well, there have been many conspiracy theories that aliens control the Earth. And, they are the ones who made us, helped us develop and blah blah. Um, I don't know about them, but I believe that aliens have visited us at least once.
It's really easy. We won't even know that they even saw us. There are so many interstellar comets flying around. Who knows that the aliens didn't build their bases on one of them and have visited hundreds of solar system, maybe even ours.
Well, you all have already thought about wars between aliens. Er, if they are like us, I won't be surprised if they are battling each other. But, I guess, a peaceful environment is important for space travel.
So, here we stand, at least I stand, we don't know anything. We have just started to swim in the never-ending ocean of the Universe.