Belief in the supernatural can take many forms, all of which imply some degree of irrational thought. What do you believe, and how do you measure up?
According to Wikipedia, a supernatural phenomenon is "anything above or beyond what one holds to be natural or exists outside natural law and the observable universe." Which is to say it is not subject to the laws of physics and/or not detectable by observation. Astral projection, for example, allows one to retain consciousness outside of the constraints of the physical body. A god can exist outside of space and time.
A ghost never has to go to the bathroom.
Angels. Ghosts. Resurrection. Speaking with the dead. Telekinesis. Precognition. All involve serious violations of the laws of gravity, motion, and thermodynamics; other charges may be filed later. As we understand the universe scientifically, none of these things are possible. None has been reliably demonstrated under conditions controlled for the countless number of variables that could be involved, and none has been posited with any sort of plausible mechanism behind it. Of course, a "plausible mechanism" would likely render it not supernatural. After all, if a miracle could actually happen, it wouldn't be much of a miracle.
"It's a miracle!"
As for "outside the observable universe," what does this mean? Obviously, being not directly observable would not necessarily place anything outside the universe; science often has to observe phenomena indirectly, by measuring its effect on something that can be observed directly. Our five senses only sample a small amount of the information available, after all. No, this phrase could only mean "does not affect the physical universe in any detectable fashion." Which means it is indistinguishable from something that does not exist.
So, a more concise definition: a supernatural phenomenon is "anything impossible caused by beings or forces that don't exist."
Because they want to.
If you're good at it, they might give you a hat.
The brain, you see, is very prone to certain types of mistakes and biases that can seemingly confirm the most unlikely beliefs. Foremost among these is the tendency to see patterns in random noise; whether it's seeing the Virgin Mary on your grilled-cheese sandwich, or believing that "celebrities always die in threes," it's all about connecting random dots in one particular way and ignoring millions of other ways to connect those dots. The human brain is a pattern-seeking engine, it will find meaning in randomness, and it will often see just what it wants to see.
Should have called him "The Douchebag."
Of course, the power of telekinesis requires out-and-out deception. Convincing people that they have seen something move without apparent cause usually involves a bit of distracting patter and sleight-of-hand to prevent the audience from seeing the actual cause. Most "magicians" don't seriously claim to have real, honest-to-goodness supernatural powers; you know it will be an illusion. Interestingly, the up-front illusionists will be the ones who do the big, spectacular tricks, while the people who really want you to believe they have special abilities will most often perform smaller, less exceptional feats like bending spoons.
But again, if you can't demonstrate these powers under conditions controlled for the variables (such as luck, cheating or other perfectly natural phenomena) then you have demonstrated nothing. Not that I don't believe you, understand, but you need to eliminate the possibility that you're simply a lucky bastard, or, just maybe, lying like a sack of shit. Then we can talk.
The world of astrology has been shaken in the last few years, what with Pluto being demoted from planet to one of many objects in the Kuiper Belt and Ophiuchus being gerrymandered into the Zodiac more recently. This has caused some upheaval among astrologers and necessitated some rethinking of some of the details (some are very upset at this new sign being tossed into the mix), but the facts remain: the constellation Ophiuchus has been in our sky essentially unchanged for thousands of years. Nothing has changed; astrologers just weren't paying attention to the actual sky, that's all. No biggie. As for Pluto, it was never a real planet to begin with and just needs to STFU.
Then again, accounting for new information regarding appearances in the heavens has never been astrology's strong suit.
Yes, it's true: if you believe in God, be it Yahweh, Allah, Ganeesh, Thor, Zeus, or any one of the thousands of deities that humans have worshipped throughout history, you believe in the supernatural. You may disagree with that; perhaps your "god" is a more sophisticated concept, a natural, creative force, not a being who interferes with the physical world. That's fine; no one will be able to prove you wrong. Of course, if that's your belief, your god is indistinguishable from one that does not exist.
Oh, don't even get me started.
Really, kids, we gave grandpa to a nice farm family.
If you believe in the supernatural despite the lack of evidence for such things, exactly what is your criteria for believing in something? If empirical evidence is not required, how do you differentiate between one claim and another? Critical thinking requires some means of testing claims against reality, because claims often contradict and compete with one another. Some turn out to be utter horseshit. What is your basis for evaluation? Why believe one thing and not another? If you have no consistent basis for doing so, you're liable to believe just about anything, aren't you?