16th November 2023. Look at it there threatening to kill our very distant descendants, BOOOOO!!!
So, it looks like your very, very distant descendants are in for a very, very bad time. Because the Andromeda Galaxy and the Milky Way Galaxy are going to collide in 4 billion years time. So unless they have the technology to travel to some other galaxy by then, or unless technology has evolved to the point where they have invented some sort of, I don’t know, Andromeda Galaxy resistant shielding, then they are all going to be killed in a horrible…..
Wait no, let me just check that.
False alarm. It won’t be a collision. It’ll be more like the Andromeda Galaxy got lonely and decided it needed a new roommate, but don’t worry, it promises it’s going to be a good houseguest and won’t knock over any of our stuff. So don’t worry, your children’s children’s, children’s, children’s……..
(Who knows how long later.)
children’s, children’s, children have nothing to worry about!:
That sketch at the top of this blogpost I did only a few days ago. I’m doing a lot of astronomy these days, some days, Earth makes me sad, because we still haven’t achieved a perfect utopia where everything is wonderful. Also some days Earth bores me, it’s just one planet, sure, we’d die if we went literally anywhere else, but still, some days, BORING!!!!!
13th July 2019. I decided to include this sketch of Andromeda because different sketches look different, you never sketch the same object twice, and this one looks really fluffy. Awe isn’t it cute!!!!!!
Hubble, no not the one in space! The other Hubble! Edwin Hubble observed a star within the Andromeda Galaxy called a Cepheid Variable, he made this observation about one hundred years ago in fact. It was one of the most important observations ever made in astronomy. Let me explain.
In the beginning of the twentieth century, it was believed by many that the Milky Way galaxy was the only thing that existed, or that the Milky Way was the entire universe. Many astronomers questioned this assumption, such as Heber Curtis, and in 1920 he engaged in a debate, called “The Great Debate”, in fact, with Harlow Shapley, with Shapley arguing that the Milky Way was the entire universe, and Curtis arguing that the Milky Way was just one galaxy among many in a universe that was incomprehensibly massive. But, how could there have been any doubt that Curtis was right? After all, if I were to take my telescope out the back tonight (assuming no clouds) I would be able to see the Andromeda Galaxy (2.5 million light years away), and Bode’s Galaxy and the Cigar Galaxy (12 million light years away). And this is just what can be seen from this cesspit of light pollution, I’ve seen Caldwell 30 (40 million light years away.) And both Curtis and Shapley had access to much bigger telescopes than my tiny little ten inch telescope awww isn’t it cute! So, why didn’t everyone agree with Curtis?
Think of it like this. Imagine you live in Ireland (unless you live in Ireland in which case you don’t need to imagine), and with a telescope you are able to see England, France, Germany, the U.S.A, and Australia. Yes this is physically impossible blah blah blah but this will help me explain why people thought the Milky Way was the entire universe! So with this telescope, you can see Germany sure, but you don’t realize that it’s “somewhere else”. You are under the impression that Germany isn’t another country, but is just a city located in Ireland. Same when you see France, you think the Eiffel Tower (no that one’s overused), you think the Bois de Boulogne is a place you can visit without ever leaving Ireland. You spot a kangaroo and think the fellow isn’t in a very different country but is somewhere out by Youghal!
So that’s an oversimplification, but hopefully a helpful oversimplification, of what people thought at that time. They could see the Whirlpool Galaxy and the Pinwheel Galaxy sure, but they thought they were relatively near, and were part of this galaxy, they did not realize that they were extremely far away and were entirely separate galaxies.
Cepheid Variables are stars who’s precise distance can be calculated. (I don’t know how, and I’ve tried to understand how but it was a bit tricky for me to understand, but just take my word for it!) So, when Edwin Hubble saw a Cepheid Variable in the Andromeda Galaxy, he knew that it was so incredibly far away, that it could not be a part of the Milky Way, so he knew that the Andromeda Galaxy wasn’t a part of this galaxy, but was a separate galaxy that was incredibly far away. And by extension it was realized that Bode’s Galaxy, Caldwell 30 and all the other galaxies weren’t a part of this galaxy, but were extremely far away and completely separate from the Milky Way. With this observation, the world realized that the universe was much, much, (how many muches should I use? I think 3 is sufficient to emphasize the point but 4 just gets a bit silly, I’ll go with 3). Anyway, with this observation, the world realized that the universe was much, much, much bigger than anyone had ever imagined.
So, thanks to Edwin Hubble, we know that…. Hang on. Am I forgetting somebody? Yes, I think I am! It’s time for you to learn about one of the unsung heroes of astronomy, Henrietta Swan Leavitt.
Henrietta Swan Leavitt is from a time when misogyny was so open and accepted that women weren’t even allowed to use Harvard’s Telescope. But despite the limitation of, not being allowed to use a telescope, she came up with a method of measuring the distance to Cepheid Variable stars. So it’s not just Edwin Hubble that deserves credit for proving that the universe was inconceivably massive, without Henrietta Swan Leavitt, this monumental development in astronomy would not have happened. And I often wonder, what if women were allowed to use telescopes and be respected as full astronomers back then? Would she have gotten there first, before Hubble? Would everyone’s favourite space observatory be called the Leavitt space telescope? I think it’s incredibly likely that that would be the case.
The Andromeda Galaxy was the first galaxy I ever saw with my telescope. And weirdly enough, I was disappointed at first. It just looked like, well, a smudge. In fact, I thought that’s what it was, but I found when I moved the telescope right, it moved left, if I moved the telescope down, it moved up, and so on and so forth, so I knew this was just what the Andromeda galaxy looked like. At first I thought, this is just what it looked like in a light pollution heavy area, but I later found out, deep sky objects do kind of look like that. Later I found more galaxies, such as the Cigar Galaxy and Bode’s Galaxy, that I found to be more visually impressive, but they still look, kind of smudgy:
But for me half of the joy of astronomy is, not what things look like, but what you are looking at. When you are looking at the Andromeda Galaxy, you are looking at a galaxy that contains at least a trillion stars. A trillion! My brain starts to explode at a billion, a billion is my upper limit, and yet it contains a trillion stars! It’s incredible.
But, when I got into astronomy sketching, I found the act of drawing what I see made all of the galaxies in our universe look to be more than just a smudge. Sure, they still don’t look as amazing as Hubble images, not even close, but the act of drawing forces my eye to work its hardest, so now I don’t see a smudge anymore. I don’t see an amazing, breathtaking James Webb quality imagine either, but I do see a galaxy, and that’s the wonderful gift that astronomy sketching has given me.
Ponderings Of An Autist 