Archive for: April, 2007

Dark Energy Considered Harmful

Apr 19 2007 Published by under The Business of Astronomy

Simon White has written a treatise published on astro-ph (arXiv:0704.2291v1) where he argues that Dark Energy, or, more specifically, the current bandwagon of interest in Dark Energy, is potentially harmful for astronomy.

Despite the fact that I'm deeply interested in cosmology and Dark Energy, despite the fact that those subjects are my favorite topics for public-outreach lectures, and despite the fact that I was there as one of the major contributors tot he 1998 discovery of the acceleration of the Universe's expansion and hence Dark Energy, I agree with almost everything Simon White has to say. There's one point I vehemently disagree with, and one meta-point I think is worth discussing, but I will save both of those for different posts.

Continue Reading »

16 responses so far

Popular Video Game Covers & the Tennesse Titans

Apr 18 2007 Published by under Video Games

As a Nashville resident, and somebody who's really a 49ers fan but one who is developing some hometown interest in the Tennessee Titans, I was happy to see that last year's rookie quarterback Vince Young has been selected to be on the cover of the video game Madden '08.

So the only question that remains is: will cornerback Pacman Jones make it on the cover of "Grand Theft Auto IV"?

4 responses so far

The Authoritarian Response? (Reacting too fast to tragedy) (v2.0)

Apr 17 2007 Published by under Politics

This is an edited version of an earlier post. I came to realize from the response to it that I had inadvertently pulled out a canard that colored the post into something that was different from what I intended. The post is almost entirely intact, but I've deleted (and replaced) the last paragraph, which is what changed the post from what I really wanted to say into something that had a lot of people reacting to what wasn't my main point, and which ultimately gave an impression that I was arguing something different from what I was.

It's terrible and tragic news, what has happened at Virginia Tech. Given that, this entry is probably coming at an extremely insensitive time, given what I'm going to say-- but on the other hand, I really believe that it is at times like this that we need to think about these things. Before I say any more, I just want to make it clear that I'm horrified by what has happened, and that my heart goes out to the family and friends of the victims.

I'm down in Chile observing at the moment. I woke up to get lunch. The TV is always running here, even if nobody is watching. (It kind of drives me nuts.) Well, today, the news is awful: at least 21 people killed in a shooting rampage in a college in Virginia.

Another astronomer, not an American, watching, says, "They need gun control."

Isn't that always the response? There's a horrible tragedy with guns, and our first instinct is to further restrict the legality of guns. Now, I know that most of the science bloggers here are firmly in favor of gun control, and indeed that most of the world thinks America is nutty in terms of how legal guns are already. But I think that this "we need more gun control!" that is cried whenever there is a highly publicized gun tragedy is part of a larger, and dangerous, pattern.

Something bad happens. It horrifies us. It scares us. We want to feel protected, we want to feel that others are safe and protected. We go to what is practically a feudal response: put the government, put our feudal masters, in more control over us, so that people can't go and do terrible things like that. When we think of feudalism, we generally think of the oppression of the serfs, and the fact that a very few (the lords) benefited from the labors of many (the serfs). But we must also remember that part of the theory behind feudalism was that fealty went both ways; the serfs worked for the lords, but then the lords had a responsibility to protect the serfs. As we turn more and more to government or large corporate entities to look out for our interests, to protect us, we are asking them more and more to act as feudal lords. And, in so doing, we must keep in mind the oppression that the serfs suffered.

I can tell already that I've lost 90% of the readers; "he's talking about oppression because we think that dangerous weapons should be controlled!" Please, bear with me.

Continue Reading »

26 responses so far

Two interacting galaxies

Apr 16 2007 Published by under Astronomy & Physics, Pretty Pictures

Here are images of two more galaxies. These weren't taken during the current run, but in a previous run. Last November, I was also down at CTIO with some students. I was doing blazar work on the 1.0m telescope (not to be confused with the 0.9m telescope I'm using right now), and shot off some images of the galaxies that Katie was observing spectroscopically. The two galaxies below are those galaxies.

The first is NGC 1614:

ngc1614.png

This galaxy has what we in the biz call a "disturbed morphology." It's not just a clean spiral galaxy, and it's certainly not an elliptical galaxy. Sticking off down and to the left (to the southwest— yes, i got that right) is a big ol' tidal tail, the smoking gun that tells me that this galaxy is in fact an interacting galaxy. Indeed, this is a major interaction that is well on its way to being a major merger.

The second galaxy, also imaged last November, is ESO 420-G013:

eso420-g013.png

When I show these color images, there has already been some handwaving. I've done a nonlinear conversion of the flux measured into a brightness, and have chosen that conversion in each of the red, green, and blue channels primarily for artistic purposes. In this case, though, in order to highlight the features of interest, I used the Gimp to further process the image to make two additional versions:

eso420-g013-lowlevel.png eso420-g013-sat.png

In the image on the left, I cranked up the nonlinearity to bring out the low-level features. Notice the ringing or banding structure? The galaxy seems to have a "terraced" light distribution. That's another thing that tells me that this galaxy is in fact likely to be an advanced merger of two other galaxies.

On the right, I've cranked up the saturation to enhance the color contrast. There are a number of things to notice here, but the one I want to highlight is right at the nucleus. Notice how the nucleus is a bright red spot, and the brightest spot in blue light is acutally offset to the southwest (down and to the right)? What's going on here is that there is a lot of dust and gas right at the nucleus. Dust blocks light, but it lets through more redder light than bluer light. This is why the sky is always so red right at sunset. Because there's so much dust right at the nucleus of this galaxy, it shows up a lot redder than the other parts around it.

5 responses so far

Phil Plait on the move

Apr 16 2007 Published by under The Business of Astronomy

Anybody who reads this blog is probably familiar with Bad Astronomy. If you're not— if you know my blog and not his— then you live in a really bizarre alternate Earth. Just in case that's you, go and read it. He's probably the web's most popular astronomy blogger, but he's been a blogger longer than he's been a blogger. (Huh?) His "Bad Astronomy" site is loaded with all sorts of goodness. The names comes from the fact that he's long dedicated himself to debunking bad astronomy in the popular media. Indeed, he has a book of the same title. If anybody ever gives you crap about the Moon Landings, Phil's pages on the topic and his book are the places you should point them to.

In any event, Phil has been on the faculty at Cal State Sonoma. But he's quitting! He's going to become a writer full time! This sort of boggles me; as another academic type, it sounds a little to me like Phil is going to stop cutting his hair (which he probably doesn't need to do anyway) and run off to join the circus.

I wish him the best! I hope this really works out for him. I hope that he's successful as a writer. I know he's successful as a blogger, but that doesn't pay the rent... so I hope that whatever happens, he and the Bad Family have a way to support themselves.

Phil is also going to be the guest at an informal chit-chat in Second Life next Saturday (April 21), hosted by Slacker Astronomy. Read more about it on that website. (And I'm gonna write a lot more about Second Life sometime soon.)

4 responses so far

The Authoritarian Reseponse (More Gun Control?)

Apr 16 2007 Published by under Politics

NOTE added 04/17: from the response I've seen, and from the all-out assault Chad directed at me and others, it's clear to me that I made some mistakes in my original post, undermining what was my main by inadvertently pushing a hot button or two. I leave this post here in the interest of honesty, but please read the updated version of this post instead of this one!

Continue Reading »

45 responses so far

Real-Time Galaxy Image

Apr 14 2007 Published by under Astronomy & Physics, Pretty Pictures

I apologize for my silence of the last few weeks; real life gets busy at times. This time, I was in a crunch finishing up things before running off to an observing run at the CTIO Observatory in Chile. That's where I am right now. I'm at the 0.9 meter telescope doing imaging of "blazars," a class of active galactic nuclei that sometimes vary on timescale of minutes (which is surprising if you know how big galaxies are). My graduate student Katie Chynoweth is observing on the 1.5 meter telescope, doing spectroscopy of infrared-luminous galaxies.

Below is an image — really, a composite of 27 images taken over the course of about 2 hours through red, green, and blue filters — i took with the 0.9m telescope:

eso264-g057-full-sm.jpg

The target I'm interested in is the galaxy that's right at the center:

eso264-g057.png

This galaxy goes by the romantic name ESO 264-G057, and is in fact one of the infrared luminous galaxies that is a part of Katie's project. She's been observing that galaxy and one other (whose picture will probably show up here in a day or two!) this week, and I took this image in support of that project.

So this is an image of the galaxy that's only two days old! Well, plus the 230 million years it took the light to reach Earth....

18 responses so far

« Newer posts