It's more than just measuring outcomes. There's also a very strong belief among the scientifically minded that there should be a valid causal chain between one event and another. Astrology, even if it succeeded, would fail this test because there is no causal chain acceptable to science that explains why astrology was correct.
Another test that must be met (and which many conspiracy theories fail miserably at) is the implication test: e.g., if that is true, then what else could be true? For example, if you believe Bush engineered 9/11, then surely he could have planted WMD evidence in Iraq (a far simpler conspiracy!) We never found WMD in Iraq, planted or otherwise, so the idea that Bush did anything special around 9/11 is just silly.
One conspiracy which I think is particularly potent is the moon landing deniers. This conspiracy is tough to argue against because ultimately it really is unlikely that humans ever made it to the moon, and only a very few people were actually involved, and indirect video evidence is indeed capable of being faked. The best reason I can think of to argue against this is that far too many people would have had to be in on it for it to work, but really that's not very satisfying.
(Next moon landing I hope the mission lays down an enormous silver blanket that can be seen by amateur astronomers and ordinary people are encouraged to come out and look through a 'scope for themselves!)
Another test that must be met (and which many conspiracy theories fail miserably at) is the implication test: e.g., if that is true, then what else could be true? For example, if you believe Bush engineered 9/11, then surely he could have planted WMD evidence in Iraq (a far simpler conspiracy!) We never found WMD in Iraq, planted or otherwise, so the idea that Bush did anything special around 9/11 is just silly.
One conspiracy which I think is particularly potent is the moon landing deniers. This conspiracy is tough to argue against because ultimately it really is unlikely that humans ever made it to the moon, and only a very few people were actually involved, and indirect video evidence is indeed capable of being faked. The best reason I can think of to argue against this is that far too many people would have had to be in on it for it to work, but really that's not very satisfying.
(Next moon landing I hope the mission lays down an enormous silver blanket that can be seen by amateur astronomers and ordinary people are encouraged to come out and look through a 'scope for themselves!)