It rejects the certainty of belief in favor of the deductive power of reason and experience. It's actually quite easy for an agnostic to drop all this thought and examine a non-critical mode of thought. Clearly a belief in astrology implies that some kind of invisible activity is taking place. All it takes to bring the whole thing down is one small, ignorant but perceptive boy. Asking ignorant questions has historically worked so well in businesses where critical thought is important.
Science can only grow stronger if questioned.
Gnosticism can only grow weaker if questioned. The second feature, Dig This, is about the problems of identifying objects underground using magnetometers and other instruments. You get a bunch of distortions and disturbances and you have to sort through them to determine if you're looking at a real target that's worthwhile digging for.