Introduction to Astronomy - Lecture 1

Lecture 1 of an Introduction to Astronomy is the history of Astronomy. Settle down with a hot drink and come on a journey through time....

[teramasz]

A million years ago as a kid I took my 30x magnification refractor (cheap but decent quality Russian made lenses) and pointed it at a bright object in the Sky. It was Jupiter and four it's moons. I was so excited, goose bumps allover me. I remember waking up my mum to show her what I saw. It was amazing! Never forget that feeling and each time I look at Jupiter it brings me this memory. Thank you Dan for these lectures.

[CraigKostelecky]

I never liked the idea of giving Copernicus so much credit for our model of the solar system. The only thing "right" in his model was the order of the planets. But he still had perfect circles and epicycles to explain retrograde motion. Also, there were other astronomers who proposed a heliocentric model (most notably Aristarchus of Samos), but their writings never made it to the European's hands (or were destroyed in the fire at the library at Alexandria) and all we ever really saw was other people writing about their ideas (mostly critical articles).

Kepler really is the hero we should give most of the credit to. He took all of those precise measurements of Mars (by far the best and most complete naked eye measurements ever recorded). He took observable reality and crunched the numbers with every single shape until he found out that ellipses fit the data almost perfectly. He had no idea why any of this worked, he just knew that his math could explain all of the data he had and most importantly predict where the planets would be in the future.

Galileo was able to confirm many of the theories that came out of Kepler's model with his telescopic observations. These observations could not be explained with a geocentric model.

Newton then gave us the why with his universal gravity theory (which isn't 100% correct, but it's close enough for almost all of the data we see within the solar system. Einstein would later redefine gravity in the early 20th century). Kepler's model and the math behind it only really worked with our specific solar system and the planets. Newton was also able to explain the motions of all of the planets, moons, stars, and comets without having to rely on our sun.

[daniel-lhuz]

so didn't realize this wasn't live. I just sat through 5 minutes of a countdown. :(

[Jehannum]

You'd never get "Gallileo was a bit of a knob" on a BBC documentary!

[SkunkapeProductions]

Ive decided to block all flat earthers im sick of thier lies. I will die knowing I saw the curvature of the earth at 60000 in the military.

[PaulDredge]

Sir Issac Newton said something that seems to explain the flat earth issue: "A man may imagine things that are false, but he can only understand things that are true, for if the things be false, the apprehension of them is not understanding". A man of singular vision and understanding - much like you, Dan!

[davidadams]

Great timing I just got my first telescope! Orion star blast 4.5,

[darnhard]

Dan if u r doing a lecture leave the comments section alone as it makes us lose focus on the lecture, thank everyone at the start for their support, and then focus on the lecture

[davidbrisbane]

Johann Kepler discovered in 1596 that the ratios of the orbits of the six planets known in his day were the same as the ratios between nested Platonic solids. Kepler was understandably quite impressed with this discovery and called it the *Mysterium Cosmographicum* .

It just shows you, that although Kepler did great work with his planetary motion laws, he was still a man of his time and not beyond dabbling is mysterious things far removed from science as we know it today.

[michaelwalsh]

Thing is I've met quite a few astronauts and have had annual live calls with people on the ISS thanks to a camp organised by esa. Some of these come back every year and I've gotten to know quite well and the fact that some people disregard these people as fake or actors really annoys me.

[frelonvert]

Thank you for explaining to people who may not know, that religion and science were closely intertwined (and kind of still are). I certainly learnt a great deal about quantum theory, and studied Dawkins, Krauss and Sagan during my Religious Studies degree (seriously). It frustrates me when the science deniers blame their ignorance on their religious beliefs... when no such religious belief limits access to science... in fact, with various grant schemes, Churches may offer MORE access to science :)

[carolinelabbott]

I missed this live, dang it. Oh well, I'll catch it next time. 🙂

A good lecture. Thank you.

[scottgibson]

I took astronomy101 in college as an elective, because it interested me, and because it gave us supervised access to the school’s equatorial mount 14” Celestron telescope.The instrument had a clock drive, but no computer seek.You found objects by setting their a
Titude, and azimuth, and then looking for them in the finderscope.I enjoyed that class so much, that I bought myself a Celestronsuper C8+ for my own use, and because Halley’s comet was just coming into view.

[charlesculpepper]

I m so glad I watched this lecture. Although I knew 98% of what you presented it was well worth the time to learn more about our past.
You are indeed a good teacher. Kept it short and sweet enough to make me read more about these great men. Thanks again Si Man Dan.

[UncleDan]

Saw the Andromeda galaxy last year from my backyard, just the fact of seeing something millions of light years away was awesome!!!!

[bromixsr]

I got my degrees in the fields of astronomy and aerospace engineering, so I may have seen a DSO or two. Aimed at beginners or not, this was in no way boring. Keep up the good work.

[yoghurt]

For anybody interested in the work of the mentioned protagonists I recommend “On The Shoulders of Giants”, ISBN 076241698X

[Sickofit]

Finally just watched this, glad I did. Always been fascinated by the sky's especially at night. Failed school massively and now I'm am adult this is exactly what I need, a easy
Listening crash course !! Great work Dan 👍

[Jason-jecr]

That was fantastic mate really can’t wait for the next lessons it was very informative and made a lot of sense 👍

[dhvsheabdh]

A point worth noting. When it came to the Tychonic model over the Copernican model, of which Kepler was fond, there was no proper, genuine reason for Tycho Brahe to *not* be believed. After all, the Tychonic model is simply the heliocentric model viewed from a different frame. It is only when we realise the Earth is definitely moving from things like stellar aberration that we can finally throw the Tychonic model away.