It can mean only one thing, invasion
The first story here deals with a group of gigantic humanoids that invade Earth. The whole thing is somewhat far-fetched, including the ending. The next story also deals with an alien invasion and is equally as far fetched, dealing with a bomb that steals uranium and an anti-gravity device. Giants of the Telescope highlights Arthur S. Eddington. The following space cabbie story is entertaining if a little light on being gripping. It deals with a threat to our own sun which must be dealt with very quickly (which would never happen in real life). The next info page deals with some early scientific discoveries by Einstein and the following info page deals with gravity. The last story deals with an alien doing reconnaissance on Earth for an invasion (lots of invasion in this issue) but who leaves when he discovers that the laws of physics don't work the same way here. Overall this issue was not the best, too much of a reliance on the same theme (invasion) which was not that well handled either.