What is Astrology and why is it nonsense?

Astrology is a belief that astronomical events directly influence human beings. While astrological beliefs have existed for more than 2,000 years in almost every civilization, modern Western cultures have developed the belief that star constellations influence or predict a person's personality and beyond that can predict daily, weekly, monthly, and yearly happenings in that personality type's life due to other cosmic events.

"Okay, but I like to read my horoscope every day... it is sooo me!"

Try an experiment, have a friend buy a newspaper and cut out all of the daily horoscope readings without the signs attached to them. Have your friend keep track of which ones are which and not tell you. Then mix them all up and read them one by one. After reading them, try to pick the one that's yours. You will most likely not pick your own star sign. Let's say you do pick yours, to make sure it's true... you must be able to demonstrate the same results every time. Try the experiment every day for a week. You will not pick yours every time.

(For teachers) Classroom experiment:
Pick any daily horoscope and read it aloud to the class, ask "Raise your hand if you think this is your horoscope." 2/3 of the class will on average raise their hand. If it were a science, 1/12 would raise their hands.

"Astrology is a science!"

Astrology is NOT a science, it perpetuates itself as if it were. Tricking and lying to people about superstition and projecting it to "sound" scientific. If it were a science there would be evidence that astrological claims were true. There is no evidence. In fact there is plenty of evidence that supports that it is false. Making Astrology a very powerful and popular pseudoscience.

"I just read it for fun, how could it be bad?"

It's bad because its a lie. If you know it's not true yet you still "read it for fun", I suppose it cannot hurt you but it is a silly waste of time. If you are interested in space there is a really cool REAL science called Astronomy that can help! Since reality is so much cooler than any make belief crap we've been able to conjure up, you'll be entertained forever.

The reason it is bad for believers is that if you were to be going through an issue in your life and you turn to your horoscope for answers, since it isn't based on fact you might be taking really horrible advice and make poor decisions that can hurt other people.

It is also bad because believing in astrology makes you scientifically illiterate and not very smart. It's always better to be intelligent, otherwise you'll just let yourself be fooled by harmful lies your whole life.

"I usually base my relationships on horoscopes, is that bad?"

It's only as bad as racism. So depending on how you feel about judging other people's personalities by the conditions in which they were born with no control... then... yeah.

 Taking advice that isn't true is pretty unfair to your and your almost loved one. You might just pass up a really awesome relationship with someone whom might actually value you because your sun signs weren't "compatible". 

Hilarious Fact: Your "Sign" is not actually "Your Sign"

If astrology believers spent a little more time learning astronomy (real science), they might learn that all the sun signs you're supposedly born under... is actually not the same anymore. Oh, and there's actually 14, technically. Due to Earth's precession of the equinox, how the Earth actually rotates, the sun sign you were actually born under is off by one sign. So.... I suppose astrologers could fix that easily but that would mean assigning billions of believers new signs... and that would be admitting they made a mistake which if it were a real science you'd probably want to correct a mistake you know is there. Astrologers prefer to ignore those pesky details.

"Why is it important to know the facts?"

The interest in astrology seems to be the psychological or emotional need to feel personally connected with the cosmos. It's important to know real science instead of this pseudoscience because that inherent interest you have that drew you to it in the first place is so essential to the existence of our species. The reality of your connection with the cosmos is by far more complex, exciting, and more significant that any pseudo-scientific explanation could derive.

90% of you is made up of 90% of the stuff in the cosmos. 

You are literally the remnant of a supernova star that exploded. 

See? SCIENCE IS WAY BETTER.