xkcd (Part 3 of 3)

Certainly some of the most intricate here:

































(I must say this is honestly the best explanation I've ever seen of gravity wells.)

xkcd (Part 2 of 3)

Some of these may be hard to see, but I only posted these specific comics because they are some of my favorites. Again, if you like any of these or find them interesting (as I do), visit: www.xkcd.com

About how this site got started (by Randall):

I was going through old math/sketching graph paper notebooks and didn't want to lose some of the work in them, so I started scanning pages. I took the more comic-y ones and put them up on a server I was testing out, and got a bunch of readers when BoingBoing linked to me. I started drawing more seriously, gained a lot more readers, started selling t-shirts on the site, and am currently shipping t-shirts and drawing this comic full-time. It's immensely fun and I really appreciate y'all's support.

xkcd (Part 1 of 3)

All of this comes from a website called: www.xkcd.com

About Randall Munroe (in his own words):

I'm just this guy, you know? I'm a CNU graduate with a degree in physics. Before starting xkcd, I worked on robots at NASA's Langley Research Center in Virginia. As of June 2007 I live in Massachusetts. In my spare time I climb things, open strange doors, and go to goth clubs dressed as a frat guy so I can stand around and look terribly uncomfortable. At frat parties I do the same thing, but the other way around.

Mitochondria and their Origin

Mitochondria are organelles located in the cells of eukaryotic species. They provide these cells with most of their supply of cellular energy (which is derived from dephosphorylation of the chemical ATP [adenosine triphosphate]). They have many other purposes as well, but to delve into them would stray too far from the point I'm trying to show. While the human genome has been largely the more popularized aspect of genomics (for good reasons), each mitochondrion within a cell has it's own genome. The DNA sequences within these mitochondrial genomes are very similar to the genomes of many bacteria. As a result, it has been postulated (and is now largely accepted) that the mitochondria in our cells were once endosymbiotic prokaryotes. Endocytosis allowed these ancient prokaryotes to become "embedded" within the eukaryotes without killing them. This hypothesis is also supported by the size of ribosomes within the mitochondria and the membrane of the mitochondria. This endosymbiotic hypothesis is also accepted for plastids within plant and algae cells.

This site is the coolest mitochondrial genome site I have ever seen. It is the reason I posted about this topic:

http://mitowheel.org/mitowheel.html

Read what wikipedia has to say about mitochondria:

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

General Information on M13 (Messier 13) Cluster:

Alternative Designation: NGC 6205
Distance from Earth: 25,100 light-years
Radius: 84 light-years
Mass: 10^36 kilograms
Age: 1.4*10^10 years

The following passage was taken from NASA's main website, http://www.nasa.gov/:

"Like a whirl of shiny flakes sparkling in a snow globe, Hubble caught this glimpse of many hundreds of thousands of stars moving about in the globular cluster M13, one of the brightest and best-known globular clusters in the northern sky. This glittering metropolis of stars is easily found in the winter sky in the constellation Hercules and can even be glimpsed with the unaided eye under dark skies.

M13 is home to over 100,000 stars and located at a distance of 25,000 light-years. These stars are packed so closely together in a ball, approximately 150 light-years across, that they will spend their entire lives whirling around in the cluster.

Near the core of this cluster, the density of stars is about a hundred times greater than the density in the neighborhood of our sun. These stars are so crowded that they can, at times, slam into each other and even form a new star, called a "blue straggler."

The brightest reddish stars in the cluster are ancient red giants. These aging stars have expanded to many times their original diameters and cooled. The blue-white stars are the hottest in the cluster.

Globular clusters can be found spread largely in a vast halo around our galaxy. M13 is one of nearly 150 known globular clusters surrounding our Milky Way galaxy.

Globular clusters have some of the oldest stars in the universe. They likely formed before the disk of our Milky Way, so they are older than nearly all other stars in our galaxy. Studying globular clusters therefore tells us about the history of our galaxy."

This site is a fascinating catalog of all the Messier Objects:

http://seds.org/messier/objects.html#cluster