galaxy
Tag archives for galaxy
Is Dark Energy the same as Acceleration?
Posted by Ethan on April 10, 2008 In a comment on my last post, What is Dark Energy, Kendall asks the following, which is such a good one I think it deserves its own post: I thought the expansion was accelerating? Aren’t you saying that it is on its way down to 85% of its current rate? Sounds like expansion is slowing,…
Somethin’ Neat about our Galaxy
Posted by Ethan on March 26, 2008 So last week I was up at Pacific University in Portland, OR for a job interview. As part of a faculty interview, you have to lecture on a topic for undergraduates, but they give you the topic just a couple of days before. My topic was Gauss’ Law, which talks about the relationship between an…
How much better are cameras?
Posted by Ethan on March 24, 2008 Cameras, CCDs, prisms, grisms, etc., are all some of the instruments that can go on top of telescopes to help us see things better. We haven’t really increased the size of telescopes so much as we have the quality and ability of the apparatus that go atop them. Take a look at various pictures I’ve…
Bring him to me!
Posted by Ethan on February 29, 2008 The Milky Way galaxy is a relatively big spiral galaxy. So is Andromeda. There are about 20 dwarf galaxies that are gravitationally bound to us; combined with us, all of this makes up the local group. But Andromeda is moving towards us, and eventually, it’s going to merge with us. I’ll once again show you…
How old is the Sun in Galactic years?
Posted by Ethan on February 27, 2008 The Moon goes around the Earth, the Earth goes around the Sun, and the Sun goes around the center of the Milky Way. We know the Moon takes about 4 weeks to make its trip around the Earth, and that causes the Moon phases: We also know that the Earth takes one year to go…
Pulsars, Dark Matter, and the Size of our Galaxy
Posted by Ethan on February 20, 2008 Alright, startswithabang-ers, Ben, my most avid commenter, saw me online while I was eating breakfast this morning, and pointed me to this new press release. Now, before you get started clicking on everything, the guy who the release is about is Brian Gaensler, who’s a really nice guy, lives in Australia, whom I met at…
Why we need Dark Matter in the Universe.
Posted by Ethan on February 19, 2008 Last week, Pamela Gay over at Star Stryder pointed me to a press release which claimed that, among other things, perhaps dark matter wasn’t necessary. So I wrote a guest post on her blog explaining why it was. Apparently, some people still aren’t convinced. So I will lay out for you all the reasons I…
Galaxies are made exactly how, now?
Posted by Ethan on February 13, 2008 Last week, Jamie (my significant other) came home from work and told me about a conversation she had with her coworker, Chris. This week she asked another one, Miguel, whether he had any questions about Astronomy, Physics, space, etc. This week’s question comes from Miguel: What is a galaxy, anyway? Why does it look like…
Dark Matter: Is it right in front of us?
Posted by Ethan on January 31, 2008 Last year, I had just finished my Ph.D. studies, and had moved to Madison, WI to teach introductory physics at the University of Wisconsin. I was working on this paper, and when I submitted it, I got a phone call from New Scientist magazine’s space division. Fast-forward two weeks, and I find this article online,…
Question: The Milky Way to an outsider…?
Posted by Ethan on January 25, 2008 I got a great question earlier today from my buddy Zrinka, and decided to figure out the answer for her, and also for myself. She asks: Ethan, is it possible to know, or better to say to imagine somehow how our galaxy looks from outside? What a simple-sounding question! After all, we know what the…
