light and telescopes/Solar system


Consider these discussion questions based on chapters 3 – 4 (SEE ATTACHEMENT FILES)  and answer at least TWO of them, and reply to at least four other students (2ND PAGE)’ answers or questions with answers of your own or pose questions for them to reply to.  You could also add your own questions to any of the topics within each question; if you don’t understand something, ask others to answer your question.  In other words be actively engaged with not only my questions but the answers and questions others provide.

1) Comment on the contributions of the Mayans, Aztecs, Celtic Druids, Chinese and other people to Astronomy and our understanding of the universe.  What did they invent and think of that surprises and amazes you?  What other cultures do you know about and what did they do and invent that inspires and amazes you?  How about other ancient Astronomers such as Ptolemy, Eratosthenes and Aristarchus.  What did you learn in this section that was new for you and what did you already know?  Do you now understand the Geocentric model better?  If not, what questions do you have about it?  What other ancient Astronomers do you know about and what did they accomplish that surprises and inspires you?

2) Discuss the findings of Renaissance Astronomy starting with the Heliocentric theory of Copernicus.  What was his motivation to put forth a new model of the solar system?  What were the contributions of Galileo, Kepler, Brahe and Newton?  What surprises you about their findings and theory, what inspires you?  Can you add any other people to this list of people that added to our understanding of the Universe such as Francis Bacon, Robert Hooke, Michael Faraday, Henrietta Leavitt, Marie Curie, etc, etc?    Is there anything that you still don’t understand in this section?  Do you understand what Inferior Conjunction, Superior Conjunction and Opposition mean?  Why are Venus and Mercury always visible close to the sun?

3) Discuss the reason for seasons in your own words?  What causes us to have four seasons?  How would you answer someone that believes we have seasons because sometimes the Earth is close to the sun and sometime it is far away?  What else did you learn about seasons and the tilts of planets that was new to you?  What don’t you still understand about seasons?  Do you understand what we mean about the Tropic of Cancer, Tropic of Capricorn, Arctic Circle and Antarctic Circle and what is their meaning and where they arise from?

4) How about the section on Phases of the Moon, Eclipses and Tides?  What was new to you or surprising that you did not know before?  What did you already know?  Is there something you still don’t understand about any of the topics like phases, why we see only 1 side of the moon, why and when do eclipses take place or why and when do tides occur?  What do Spring Tides and Neap Tides mean?  Why are eclipses not visible every month?  What is the meaning of annular solar eclipse?  What is a partial or umbral lunar eclipse?  Why are lunar eclipses visible to more people and for a longer duration?


Did you know that some of the first Chinese records about  astronomy are from about 3000 BC and that they used the circumpolar stars as their reference point for the heavens.  They also discovered why the moon shines and why solar eclipses happen.  They also used the seismograph to detech earthquakes and they used the compass to know where they were going and where they were.

Who was Francis Bacon, lived 1561-1626 Francis Bacon is credited for the scientific method , whereby laws of science are discovered by gathering  and analyzing data from experiments and observation, he made the rules and procedures for the gathering and analyzing the data.  Rather than using logic based arguments.

The Mayans, Chinese, Aztecs and Celtic Druids contributed in many ways to Astronomy like the Mayans r4ecorded and interpreted all aspects of the sky, they also believed that the will and actions of the gods could be read in the stars, moon, and planets. The Chinese used the circumpolar stars as their reference point for the heavens. The Celtic Druids built a place called Stonehenge used to worship the sun.  What really caught my attention was learning how the American Indians carved out shapes in caves to track the path of the sun to predict the time and seasons. It really shows how time has changed and how advanced the methods of obtaining such information have developed.

I think that the reason why we have seasons is because the earth is tilted as it moves through its journey every year around the sun. Since the earth’s axis is tilted at an angle of 23.5 degrees, this means that the earth is always pointing to one side as it goes around the sun. In the lecture it did mention most people would say that seasons are due to Earth’s distance from the sun, yet Earth is closest to the sun around January 3rd and farthest from it around July 4th. I found really interesting that different portions of the earth receive different amounts of sunlight at different seasons. I really thought the amount of sunlight was always the same amount every year.

Aztecs and Mayans were a brilliant civilization, these people definitely knew their astronomy. Did you know an English man that did research on these civilizations  almost 100 years dubbed the Aztecs and Mayans “savages”, and that word doesn’t really go with them yes they has sacrifices but so did other civilizations, point being if the Mayans and Aztecs were savages then how did these quote on quote savages know so much about the stars, how did they know when an eclipse was going to happen, and they had temples dedicated to things that were related to astronomy, they even had maps of the stars, they knew what they were doing clearly, and in the modern day we have learned from them. Along with the Celtics they knew when the summer solstice was near and when it would be because of Stonehenge and for people from ancient times they were rather intelligent, and contributed to what we know today.  Also the  Mayans and their calendar, they had things that were similar to what we know as the modern day zodiac they may have not have had the same animals on their but the calendar let them know what time of year it was and what sign they were born under.

My question is just how these civilizations found out about this, I mean they didn’t have the technology or advanced tools to do a lot of things to but to know when certain events will happen and be right about.

I want to start off with, I did not know that the Earth tilts to be brutally honest I just though it gets hot because it just does,  or something like maybe the sun is just hotter around a certain time, I did not know that the way seasons work is because  the earth is tilting at a certain angle either away from the sun or towards it. If someone were to tell me that seasons happen because the sun is sometimes close and sometimes a little far away, I would say well yes but actually no, its the earth it tilts towards or away from the sun, when its leaning toward the sun it could mean spring and summer and coming and when it tilts away well that means fall and winter are coming.  Like I said when first starting this the tilting of planets is new to me I didn’t know they did that, I never gave it any thought on how it worked, but all of it was new to me and I finally learned how the change of seasons work.  For the different circles and tropics what I understand is that they all have different amounts of sunlight and on certain days some get more, some get less, and one which is the arctic circle on Dec 21 gets no sunlight.

Something that was new to me was that a Solar Eclipse happens when the moon covers the sun. The Angular diameter of the sun and the moon are about the same which is why the moon can cover the sun. A solar eclipse lasst no more than 7 minutes. .I also learned that the New Moon happens when the moon is between the Sun and the Earth. The full moon happens when the Earth is between the Sun and the Moon.  I also learned that Galileo Galili was the 1st person to use the newly invented telescope (1605). He made crucial observations. He observed the irregularities on the Moon. He observed the Sun spots, (which showed that the heavenly objects were not as perfect as once thought to be).

Spring Tides are two phases which occur every month during the New Moon and Full Moon phases. The sun and moon are lined up so their tidal forces add up. Therefore, you will get higher than usual high tides and lower than usual low tides. For someone who likes to surf it is best to go to the beach during the New Moon or the Full Moon phase when it is a high tide, around noon. If you do not like waves go during sunrise or sunset when it is a low tide. Neap Tides occur twice every month during the 1st Quarter and 3rd Quarter phases. The sun and moon are at perpendicular angles to each other so the tidal forces cancel. During these phases there is a blend of tides. Tides are due to the differential force of the Moon and the Sun on the two sides of the Earth. The Moon’s tidal force on the Earth is about twice the Sun’s tidal force.