This kid is wrong on soo many levels.
If we wanted to, we could literally make all of the human weapons that the UNSC used(Including the Spartan Laser, but that's something different here.). The weapons we currently have right now could be science fiction to another world. Our minds work in special ways that in which we could turn what ever we want into a reality(to some degree of course

).
This kid has to lay off the Minecraft for a bit and watch a couple of hours of the Science Channel or something to learn what can and can't happen.
He mentioned that we can't jump 50 feet in the air. I'll give him that, but that's becuase our bodies weren't built to jump that high.
Now that thing that ticked me off was that he said aliens don't exsist. He seriously needs to go outside for a bit and look around. How can he see all the life around him and say that life doesn't exsist somewhere out their in the cosmos? Alot of the creatures that are alive right now look like things that science fictions writers can't even begin to imagine in their noggins. Sure we may not see a Covenant-Style culture out there, but we could be wrong.
Now, the thing that made me laugh was that he was whining on how games need to be real when he's playing Minecraft.