Portals and Aliens

Around 10-20 years ago, people realized that a bunch of aliens exist & that we can build portals which can summon them.The bigger the portal you make, the bigger the alien it can admit.These portals and aliens have several characteristics:We can't go through the portals into the aliens’ side. We can only learn about the aliens by studying the ones we’ve summoned.This relationship is not symmetrical. The aliens know a lot about our world.You can't specify exactly which alien will walk through you...