 Greetings and welcome to the Introduction to Astronomy! In this lecture we are going to talk about astronomy and astrology, which you may be surprised or may be not that these things are often confused, and I'll often get students excited to take my astrology course when in reality we are covering astronomy. But let's look a little bit about how these two are related and how they are different. And what we find with astronomy and astrology, well, astrology's beginnings were quite different than what we think of today. There were seven special objects that wandered through the sky, and these were given a special significance, and that was our sun, our moon, and the planets known at the time which were Mercury, Venus, Mars, Jupiter, and Saturn. These were special, they wandered through the heavens, whereas all the stars remained fixed relative to one another. These objects changed their positions, and could they have an impact on people's lives? And that was the question, and that's the basis of astrology. So let's look at some of these constellations, and you may be familiar with these. These are the constellations of the zodiac, and you may be very familiar with them by name, but they are not very prominent constellations. Many of them do not have a really bright star within them. Some do, Taurus has a bright star, Gemini has a couple, Leo has a bright star, so does Virgo, and Scorpius. So less than half of them actually have relatively bright stars in them. The others are prominent constellations because, and all of them are because the sun, the moon, and the planets move through these constellations. So they're not prominent because they're unusually bright, some of them can be very difficult to locate. However, we can then find the areas of them where the planets are passing through. Now let's look at them here a little bit differently. Here we see the sun at the center, and the earth moving around it. And here the earth moving from June through August through the summer months. And starting out pointing with the sun in the direction of the constellation of Taurus in June, and then toward the constellation of Cancer in August. Now, how do we know what position is, how the sun is in one of these constellations since we can't see the stars? Well, we don't, but we do know what constellations we can see. So in June, that means that Scorpius would be a relatively prominent constellation. And in August, maybe Sagittarius would be more prominent. And that, again, is because those are the ones that would be the most prominent constellations in the night sky. So what we see is that why do all of these objects pass through these constellations, and that is a consequence of the solar system being flat. If the solar system were more spherical, then we would not see that. But here the planets follow the same path as the sun, and we'll go through this same grouping of constellations. So what does this mean for astrology? Well, astrology is, and in fact, natal astrology specifically, is looking at where the sun, the moon, and the planets were at the moment of your birth. So here we see for Queen Elizabeth I of England and her birthday and birth time, and you also need to know locations as to where all of these things are, and the various symbols will tell you where these planets were, the planets were, and what things were rising or setting at the time. And these were all very important. Now, astrology's been around for a long time and was developed by the early Greek astronomers, including Tolmi, who we talked about previously, who also gave us a similar treatise on astrology. We talked about his Almagest in astronomy, but here we have a similar work on astrology. So one thing that we're seeing is that there was not a big difference very early on between astronomy and astrology. They were very closely tied together. So when we see a horoscope, what do we see? Well, the common horoscopes that are used, this guy is divided into 12 sections, and these are those constellations of the zodiac that you are familiar with. The sun will spend approximately one month in each constellation. However, this is not always the case. Sometimes it'll be a little more or a little bit less. The zodiac, for astrological purposes, is kind of splitting this up a little more evenly than it actually is. And in fact, the sun passes very quickly through some constellations like Scorpius and actually passes through the constellation of Ophiuchus, which is not one of the zodiacal constellations. Now, we also talked about Hipparchus and Procession. Well, this is constantly changing the coordinate system. So what does this do? It's changing the positioning. When does the sun pass through each of these constellations? And we are now one zodiac sign off from what your zodiacal chart would say. So if you just use the standard horoscopes that you find, you would find that on May 6th, the sun would be in Aries. However, the horoscope would say that someone on May 6th would be a Taurus. So because of Procession and all the time since the original horoscopes were developed, this has changed, and we're now off by one constellation. And that will continue to get further and further off as the Procession continues. So here we see, again, how the equinox is moving. And this is the equinox in around the year 2000. And then by 2500, we're here, so we're moving from Pisces, the location. And here it was over on the other side of Pisces in 500 BC. So in 1500 years, the vernal equinox had changed by position that much. So this is where the equinox was 2500 years ago. And here it will be another 500 years from now heading off into the constellation of Aquarius. And that will continue making things even further and further off as time goes on. So when we look at the horoscope in the newspaper or the internet, you're looking at just one part of this. You're looking at the sun sign. So what was the constellation was the sun in when you were born. And that means that about 8% of the population has exactly the same horoscope prediction. Now, if you really want to look at a complete horoscope, you want to only look at the sun, but the moon, and the planets, where were they? And whether they were rising or setting or where they were located, where was one of them in retrograde motion at the time. Those all had very specific meanings. There are some rules specific, but there's also a judgment involved in horoscopes, which really sets them apart from astronomy as a science. Then when you have too much on judgment, then you're having far less of a science and becoming what we'd call a pseudoscience. So it's something that is based on science and may use terminology of science, but is actually not science. So when we look at these, again, for a long time, from the Greeks through the time of the Renaissance, some of the astronomers that we'll be talking about in the coming lessons, Tycho Kepler and Galileo, were astrologers and astronomers at the same time. And in fact, this is a horoscope cast by Johannes Kepler in 1608. So we have all of the different areas as to where each constellation, where the planets, where the sun and moon were located at that instant of birth. Now by the 1700s, they were separating. Astronomy was becoming the study of the sky, and astrology became the perceived impact of objects in the sky on our lives here on Earth. So in reality, as I've kind of mentioned already, astrology has become a pseudoscience, and that is something that purports to be scientific and uses scientific terminology so you can use some of the things like retrograde motion or something being in conjunction as being very important for an astrological prediction. However, it is not based on rigorous testing like a true science. And in fact, studies have shown that there is no relationship between a horoscope and people's lives. So there is nothing here in terms of a relationship between them. And the horoscopes are simply vague enough that you can really, people will find some truth in them. So let's go ahead and finish up with our summary here. And what we talked about is astrology really is looking at the study of the position of the sun, moon, and planets and their perceived impact on our lives, whereas astronomy is the detailed study of the celestial objects. In the past, they were essentially interchangeable. Up till about 400, 400, 500 years ago, they were the same. However, more modern studies, they've separated, and we found that there really is no scientific basis or truth to astrology. So that concludes this lecture on astronomy and astrology. We'll be back again next time for another topic in astronomy. So until then, have a great day, everyone, and I will see you in class.