Seismology: A Lesson in Curiosity

Back in high school--cause I can talk about high school now, like it's in the past--I had this teacher. He is crazy, terrifying and wonderful in many ways, and I love him and am terrified of him at the same time. He is a good teacher in many ways, to spite how frightening he can be. However, I'm going to tell you a story that has nothing to do with either of those opposing qualities. 
One of the classes I had this guy for was Geographie Planetaire (Global Geography), in the last semester of grade twelve. One afternoon--or morning, I don't remember--we were learning about the layers of the earth. I had adopted a pesky habit the previous school year of constantly questioning supposedly absolute knowledge, which often involved playing devil's advocate, not to mention annoying a lot of people. 

So, suddenly as I sat there listening to him teach, I thought 'Wait a minute!'. My hand shot into the air, and when he eventually turned away from the board where he had been illustrating as he spoke, he answered my hand. I asked him how we could know what was on the inside of the earth. After a few moments of silence, during which he looked at me with a familiar expression of irritation, he uttered dismissively "Well, it's a scientific fact." Then he went back to drawing.


It's a scientific fact.


As mentioned, this blog is an extra credit assignment for a university Astronomy course. This past week we were on the unit pertaining to earth and the moon, and I found out the answer to my question.

The answer is seismology. "Seismology is  is the study of earthquakes and seismic waves that move through and around the earth." according the Michigan Technology University. Basically seismologists measure the seismic waves from earthquakes and things (So, the energy that they give off) when they occur on one part of the planet and then measure them at various other places on the globe. They observe how the waves have been changed or distorted and that can tell them about the density and amount of matter they've had to travel through. It makes sense, doesn't it?

SOURCES

Professor Edward's Lecture on The Earth and the Moon for Solar System Astronomy at Mount Allison University

http://www.geo.mtu.edu/UPSeis/waves.html

We're Doomed. What Now?

Disclaimer: I want to be clear that this post does not look at the arrival of the year 2012 as a possible way that the world could end, because as far as i know there isn't any specific scientific reason why it would happen simply due to that exact date. However if one were operating under that assumption, the thoughts and opinions expressed in this entry would still apply, so please continue reading.

The One We've All Been Waiting For: Is There Life On Other Planets?

Let us get the junk out of the way first, shall we? Crop circles: easily fabricated. U.F.O sightings: U.F.O doesn't mean space ship, it means Unidentified Fly Object, meaning an object that is in the sky, and that you can't be sure what it exactly it is. It's just not enough for me. Alien abductions: -insert list of hallucinogenic drugs and appropriate disorders here-.
Next, I'm going to briefly discuss my general theory about the existence of life on other planets, which does not include any research, but does however, include common sense and a lot of thought. The universe is... enormous. More so than we can possibly conceive of. I can't see how we  could be the only planet in the entire universe with any form of live. I feel as though the assumption that we are the only life forms in the universe would be the equivalent to the Europeans, knowing that the world was roughly as large as it is and still maintaining--without many excursions outside of Europe--that they were the only people on the planet.

Now for some actual evidence. It just so happens that there has been some further discovery in this area by NASA as of late. 54 of the 1,200 planets recently discovered orbiting distant stars are both relatively the same size as earth and are "habitable zones from their suns", which of course means they aren't so close that life forms would burn to death, nor so far away that they would freeze. I think that's the biggest (and most reliable) evidence I found about extraterrestrial life existing in general, but there are many other smaller pieces of evidence that I came a cross, mostly on this website. Upon reading a few of the articles I decided they were too controversial to spend a lot of time on here. Especially since I'm not super educated on this stuff  and I'm also very gullible, so I don't trust my own judgement on the legitimacy of such things, but feel free to check it out and draw your own conclusions.
As for those out there who live in fear of Aliens taking over our planet, here is some more of my general theorizing: Even the controversial evidence that I glanced at mostly involved microbes, bacteria, plant life and other things like that. Plus, even if there were beings out there of the same level or more intelligence than average humans, I actually paranoia about an Alien take over is probably based off of the same (figurative) geocentric view of the universe. If there are such societies out there among the stars, what makes us think they would be spending all there time, energy, and alien currency figuring out the technology and planning that would be necessarily for that? Don't they have their own alien world issues to worry about? This is even more unlikely when we consider how much we've damaged our planet and used up it's natural resources. We should probably stop flattering ourselves and quit worrying so much about it.

SOURCES

http://www.telegraph.co.uk/science/space/8337518/Life-on-other-planets-latest-discovery-comes-after-string-of-recent-signs-of-extraterrestrials.html 

Black Holes

Now, the subject for this week's blog is fairly straight forward compared to my previous entries. Along with my original mandate, there are also a few questions about astronomy that have just been nagging at me for years, so every once in a while I might differ from my usual more exploratory approach and just go straight for the answer. This, my friends, is one of those times.

Black holes. Does anyone really know what they are? As a kid I remember hearing two things about back holes: One was that if you got too close to one, you would split apart into a million pieces, and the other was that if yo got sucked into one you would be spit back out, having aged like 90 years. We never really talked about them when we touched on black holes in astronomy in elementary school, and I always assumed that this was due to the fact that the administration had deemed them much too menacing to introduce into our curriculum. I mean just listen to the sound of it in your head: BLLAAACK HOOOLE! It just gives you shivers, doesn't it? Especially for those of us with trypophobia (don't look it up). Well, I'm a big girl now, and I want to know the scoop.
So, here's the scoop: "We're talking about something that is so dense, it is made out of pure gravity," says Justice Jones, my best friend in the whole wide world, to summarize his explanation of black holes. He speculated that the first theory I had heard about black holes as a child was legitimate, since the pull of the gravity of a black hole on the atoms of one's body would be greater than that of the atoms on each other, thus drawing them all separately into the center of the black hole. Now, you're probably thinking 'Come one, this girls BFF is not a scholarly source for scientific information'. Well, I will have you know that A: He practically is, and B: I did do some actual research. 

So, a star that is at least 10 to 15 times larger than the sun goes supernova, it leaves behind a huge mess of dust and gas and things. If there isn't any forces outside this former star, opposing the gravitational pull of that stuff, then it all just collapses in on itself...and it just keeps collapsing until it has zero volume and infinite density. I'm not kidding. I got this from the NASA site and everything. So, the gravity of this thing is so strong that even light can't escape it. That's why it is called a black hole. 
Are you any less scared of black holes now? Yeah, me neither.
But don't worry! You actually have to be pretty close to a black hole to get sucked into it. Specifically, you'd have to cross into the Shwarzchild radius. Say, for example, that our sun was a black hole, we would have to be 3km away from it to get sucked in, and the nearest black hole is many, many light years away. Relax.
Will the universe eventually get entirely consumed by black holes? In this unscientific, uneducated bloggers humble and un-researched opinion: Yes. And then we'll have another big bang and then it happen all over again, and so on, and so forth.
So, that's the story on black holes.

SOURCES

http://imagine.gsfc.nasa.gov/docs/science/know_l2/black_holes.html

http://hubblesite.org/explore_astronomy/black_holes/home.html

http://www.daviddarling.info/encyclopedia/B/blackhole.html
http://scinewsblog.blogspot.com/2010/11/simulated-black-holes.html

Meanings of Ursa Major

Another celestial object that Father Bear saw fit to point out to his son (for obvious reasons) was Ursa Major, also called "Great Bear" and  a couple of other names which  I hope to explore a little. Many ancient cultures are known to have seen the image of a bear in this collection of stars, the most well known of which would probably be the Greeks, but Native American tribes such as Blackfoot and Algonquin also associated  it with a bear.The entire image of the bear is a bit hard to make out, especially taking into account the light pollution from today's cities, but it's pretty easy to see a certain very well known grouping of seven stars inside of the constellation, which brings us to...

The Big Dipper. The Big Dipper--or "plough" as it is called in the UK and Ireland is often referred to as a constellation, but it is in fact an asterism inside of the constellation, Ursa Major. An asterism is a  simple pattern of stars. It can form part of a constellation, or can be made up of stars from more than one. So, there you go. If you draw a line straight up through the outside two stars of the bowl of the big dipper it'll point you right to Polaris.

So, let's look at another cool meaning for Ursa Major's most famous asterism. See, I didn't just watch TV when I was little, I also loved to be read to. And I had many favorite books, but one of them was a beautifully illustrated book by Jeanette Winter called "Follow the Drinking Gourd" about the harrowing journey of African slaves through the underground railroad and on to freedom. "The Drinking Gourd" (which refers to the big dipper) was one of the aids that these people used to find there way to where they had to go, and the folk song "Follow the Drinking Gourd" is said to have lyrics that are secretly detailed instructions about how to get there. I think that's the coolest thing about Ursa Major and The Big Dipper. I mean how many constellations --or asterisms. Sorry-- can boast helping so many people out like that? 

SOURCES

http://en.wikipedia.org/wiki/Ursa_Major

http://en.wikipedia.org/wiki/Asterism_(astronomy)
http://www.astro.wisc.edu/~dolan/constellations/constellations/Ursa_Major.html
http://starryskies.com/The_sky/constellations/ursa_major.html
http://wiki.answers.com/Q/How_many_stars_are_in_the_ursa_major
http://www.mallorcaweb.net/masm/UMa1.htm
http://www.astropix.com/HTML/C_SPRING/BIGDIP.HTM