Galactic Interactions

*Horrible* service from Sprint; receive text messages, risk getting signed up for additional billing.

Posted on October 31st, 2009 — permalink

I noticed on my Sprint cellphone bill that there was an additional $10/month charge for some mobile alert thingy. I believe it’s been there for a few months. This happened before, a year or so ago, and it lingered then; a different thing.

I called the Sprint service folks to get this removed and figure out what happened. Well, it turns out that if you receive a text message from one of these services, and you open it up, you might automatically get signed up for the service. Yes! That’s just ridiculous. I asked if that could be blocked, and the guy told me he could block all text messages. It turns out that there is no way to receive text messages without risking being signed up for random third party services just by opening that text message. He tried to disclaim any responsibility for Sprint for this, because it’s a third party, but of course Sprint is doing the billing for it (and I’m sure Sprint gets some cut for doing the billing). It’s just crazy that Sprint isn’t able to block this kind of crap without blocking out all text messages.

My wife and I hardly ever use text messages; our plan doesn’t even include any free ones, as we only send a couple a month. Now, we’ll be sending (and receiving) none….

This may be enough to make me eat the $400 fee it will take to terminate my Sprint service early, if I figure out that there’s another cellphone service provider that doesn’t have something stupid like this. Sprint did refund me for the last three months of billing for this service; I’ll give them that much. But a service that lets you receive text messages which can get you signed up for additional billing just by opening that text message is an insecure service; I don’t care how helpful any given customer service representative is, that’s a broken company and a broken service.

ADDENDUM: Can you tell I don’t use text messaging much? So there is this thing called “Premium Text Messaging”, which is the cellphone equivalent of 1-900 numbers. Some legit, probably, the vast majority probably scams like the one we had. It seems that some mobile providers can block just premium text messages without blocking all text messages (i.e. messages from your friends). I cannot figure out if you can do that with Sprint, as they’re very unclear on their website. The customer service guy I talked to certainly wasn’t clear; he said he was blocking all text messages. When I asked if there was a way to avoid getting signed up for services without having to block all text messages, he said no. That implies to me, in retrospect, that there’s no way to block all premium text messages without blocking text messages altogether; you’d think he’d have said something about it when I asked that question. My next task will be to figure out which companies are able to block all premium SMS without blocking all SMS.

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The Moon in “Heroes” is VERY different from our Moon.

Posted on October 25th, 2009 — permalink

My wife and I tend to watch TV shows a year after they come out; we rent the DVDs from Netflix and watch them then. We’re right now working our way through the third seasons of Heroes. If you’ve watched even the first season of Heroes, you know that Eclipses are a Big Deal and somehow cause or affect superpowers in humans. Well, there’s another total solar eclipse coming in Season 3. Here’s a screenshot (also showing a vapor ring left behind as Nathan Patrelli took off flying at high speed) of the moon about to eclipse the Sun:

OK, first, the good. Yes, the Moon is apparently about the same size as the Sun in the sky. (Yeah, the Sun looks a little bigger, but that’s probably because of the glare. There’s about to be a total eclipse, so they’ve got to have about the same apparent size. In any event, the size is close.)

Now, the bad. When the moon is that close to the Sun in the sky, it is a tiny, tiny, tiny, very thin crescent, basically a new moon. You will not see it at all, until it starts to actively block out the Sun. The reason for this is that since they’re so close to each other in a sky, it’s almost a straight line from the Earth to the Moon to the Sun. The distance to the Moon is much less, so the Moon is between us and the Sun. Thus, the side lit up by the Sun is the far side of the Moon from us.

Yet, here, instead of an almost-new moon, we see an almost-half-full moon! For half of the moon to be lit by the Sun when we see the two right next to each other in the sky, the moon would have to be at about the same distance from us as the Sun…. Well, it’s not quite half, so it’s a little closer, but we’re talking inside the orbit of Mercury here. And, for the Moon to look as big as as the Sun when it’s that far away, it will have to be physically almost as big as the Sun!

In our Universe, the Moon is a satellite of the Earth, about 1/4 the diameter of the Earth, and orbiting the Earth. The Sun is about 100 times the diameter of the Earth. The reason they look about the same size in the sky is because the Moon is so much closer.

From the evidence in the image above, however, the Earth of the Heroes Universe is very, very strange. They orbit a binary “star” system, including the Sun and the Moon… although the Moon is not a satellite of the Earth at all, but a binary partner to the Sun. However, the Heroes Universe Moon is an extremely bizarre object, for despite being so large, it does not shed any light of its own in the optical. It’s clearly not a large gas cloud, for you can see by looking at it that it’s a solid object with “seas” and craters and all of that. So, it’s something that has somehow managed to be as big as the Sun without triggering fusion inside to make it glow.

Wow.

Well, given that all these superpowers work, we already knew they were operating under different laws of Physics, so I guess we shouldn’t be surprised.

My only fear is that people watching the show don’t realize that the producers are being very clever here in showing us that the Moon is a gigantic object that is nearly as far away as the Sun, very different from the case in our own world. I fear that some people watching might either think that the producers of the show have done the typical Hollywood thing and made a boner of a mistake, or may think that it’s entirely reasonable to see a near-half Moon right next to the Sun in the sky. I hope in upcoming episodes there will be dialog between the characters that more clearly reveals the nature of their Moon as a star-sized object close to the Sun.

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Howard Barker’s 13 Objects — global performance October 20 and 21

Posted on October 15th, 2009 — permalink

Howard Barker is a celebrated British playwright. On October 21st, there will be an international celebration of his works entitled 21 for 21. Participating in this celebration will be Avatar Repertory Theater, the virtual theater company of which I am a part. We’ll be putting up a production of his play 13 Objects: Studies in Servitude.

This is one of those things that makes it very clear that virtual worlds are not just computer games. These 13 short plays are all interesting and challenging, and vary all over the place in tone. Some of them are funny, some of them are grim, some of them are surreal, and all of them give you various different things to think about. It’s being directed by Joff Chafer, a faculty member at Coventry University. The cast is a sundry group of people from all of the USA, the UK, Austrailia, and New Zealand. It includes at least three former professors (two of whom were English professors, one of whom was perversely a professor of physics & astronomy…), a former Opera singer, and a couple of people who have performed and continue to perform professional theater in real life.

The design of the sets for all 13 plays follows a run-down, semi-post-apocalyptic theme. The objects in the sets were all constructed by famed former Second Life builder Arcadia Asylum, famous for her “hobo” type builds. Near the stage, there will also be “installations” for each of the 13 short plays, present through October 20 and 21 (and probably available even before then). You’ll see the sets, and hear recordings of the voices of the actors who will be performing on those sets.

This play will be free to attend. If you have a Second Life account, drop by; the show will at this spot in the Coventry University sim, at 4PM PDT (23:00 UT) on Tuesday October 20, and 2PM PDT (21:00 UT) on Wednesday, October 21. If you don’t have a Second Life account, consider getting one! They’re free; visit www.secondlife.com, ignore the gratuitously flash-heavy front page, and click on the big orange “Join Now” button to create an account.

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First impressions of Leiden

Posted on October 4th, 2009 — permalink

I’m out in Leiden for the next three days for the AMUSE Workshop. AMUSE is an evolution of MUSE, a software framework for integrating various different modules of stellar modeling together. So-called “N-body models” model the orbits of lots (”N” being a large number) of stars orbiting around each other as a result of their mutual gravity. They’re great as far as they go, but they aren’t all of the physics. If the timescale of your simulation goes on long enough, eventually you’re going to have to take into account stellar evolution– the fact that more massive stars live shorter lives and go supernova, spewing most of their mass out into interstellar gas. If you’re dealing with dense systems (think the Galactic core, or globular clusters), you have to take into account “strong interactions” between stars, which most N-body codes don’t handle by themselves. And, if the systems are really dense, you may have to take into account mergers of stars, which involves hydrodynamics. Additionally, there is gas in galaxies, which also involves hydrodynamics.

Traditionally, all of these different areas are modeled separately. Sure, there is definitely some overlap between N-body codes and few-body strong-interaction codes. However, the goal of MUSE was to make it possible for people who write disparate simulations to link them together for a more realistic simulation that needs to take into account multiple systems.

All of which is why I’m here. But the real reason I want to write this is to just dump my first impressions of Leiden:

• This is a very bike friendly city! There are paths for bikes and motorized scooters, bike lanes, and massive bike parking lots all over the place. And you see huge numbers of bikers riding around. But very few of them are wearing helmets.
• The Dutch language is much more mystifying to me as an American than either French or Spanish. Now, yes, I did study French all the way through junior high and high school, so I’m not coming at French as a complete ignorant. But I certainly find Spanish names easier to wrap my brain around than Dutch names. However, it’s not as hard as Sweden, where the collection of letters that form street names just would not stick in my brain with the linguistic substructure I’ve built in there all my life.
• Trash! There is litter, and there are piles of trash, all over the streets.

Update 2009/10/06: It turns out that the trash was a transient thing. October 3 is an annual festival that Leiden celebrates for its liberation from Spain a few hundred years ago. That festival can go on for days and culminates on October 3. I was seeing the aftermath of Saturday night’s festivities when I arrived on Sunday, October 4. I happened to arrive on exactly the worst day for trash in the streets…!

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“Other Peoples’ Liberals”

Posted on October 2nd, 2009 — permalink

As I listen to the Hollywood Elite fall all over themselves defending Roman Polanski, saying how awful it is that he’s been apprehended for the 30-year-old crime of rape of a 13 year old (perhaps not involving physical force, but certainly involving drugs and coercion), I’m reminded of a term I use, “Other Peoples’ Liberals”. This is related to the term “Limousine Liberal” (or even, at times, “Marin County Liberal” if you happen to live in the right place, although that’s too broad a brush).

These are the folks who drive SUVs because they have a “legitimate” reason, but decry the fact that so many people drive cars with low gas mileage and destroy the environment. This is Dianne Feinstein, a staunch gun control advocate but who had a concealed carry permit; when confronted, she said she needed it for her protection. This is parents of a friend of mine who was one of the most out gay people I knew. He said that they were all for gay rights in the abstract, but were not happy to find out their son was gay. This was the father of a women I knew in high school, who was all for racial equality, but who expressed some objections when she was dating a black man.

These are people who are all for tolerance and environmentalism, as long as it doesn’t require them to disturb their own back yard.

In a word, hypocrites.

To be sure, it’s not at all an exclusively liberal thing. It seems that a few months can’t go by without our finding out about the extreme illicit sexual adventures of an extreme outspoken conservative “family values” politician. Rush Limbaugh was all no-tolerance on drugs, until all of a sudden he’s up on drug charges. Excessively wealthy executives are for the unregulated free market and treat “socialism” as the dirtiest word ever, until all of a sudden their bank is failing and they need government bailouts to survive.

High standards of behavior that everybody else must be held to, but which are clearly too strict when applied to you.

Hypocrisy is universal. As is the ability for people to be able to overcome cognitive dissonance and justify their own bad behavior, and to come to the defense of the people they have chosen to celebrate, even when they themselves or those they celebrate have violated things they would otherwise speak out against vociferously.

We just need to recognize it for what it is, even when the subject is somebody who’s produced challenging art and that has been celebrated for that art.

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Astronomy talk in Second Life : Solving the 3-Body Problem

Posted on September 18th, 2009 — permalink

I’ll be giving a talk in Second Life on Saturday at 10AM SLT (Noon CDT, 17:00 UT). This is part of the regular series Dr. Knop Talks Astronomy.

Double and Triple Stars: Solving the 3-Body Problem

If you look at the stars in the night sky, you discover that a very large fraction of them are not isolated, but are in fact in binary star systems, or even in larger groups. Using Newton’s gravity, we are able to perfectly solve for the orbits of a system involving just two bodies, but it’s impossible to analytically solve it for more. In this talk, I’ll describe why we care– not only in trinary star systems, but three-body interactions also matter in rich clusters. I’ll describe how we’re able to solve the 3-Body problem and figure out the orbits of stars in such system, and give a demonstration of a working computer that actually solves the system in Second Life, right before your eyes….

The talk will be at the MICA Large Amphitheater in Second Life. Remember, a Second Life account is free!

In related news, I’ve now uploaded the slides to all of my previous talks to the MICA website.

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The other horrors of 9/11

Posted on September 11th, 2009 — permalink

Many people will consider this post to be in extremely poor taste.

But there are things that I think that we really need to keep in mind as we’re remembering the lessons that we learned, the tragedies and the horrors of 9/11. (And, this won’t be the first time I made a post that many considered in poor taste….)

To frame the whole thing, let’s start with what I call George W. Bush’s most egregious untruth— not a lie, for I don’t doubt that he meant it when he addressed the nation on the evening of 9/11, but what in retrospect turned out not to be true:

None of us will ever forget this day, yet we go forward to defend freedom and all that is good and just in our world.

What was the legaciy of this moving forward to defend freedom, justice, and goodness?

• The passage of the PATRIOT Act, rushed through in less than two months, voted on so fast in a political climate where legislators would be viewed in a light similar to how this blog post will be viewed if they voted against it. It was a massive piece of legislation that incorporated all sorts of expansion of powers for law enforcement and limitations in the checks and balances. Many of the things in there would have been the subject of vigorous debate and public scrutiny if they had been proposed individually. Yet, in the climate of “We MUST do something” after 9/11, it was rammed through, and public opinion would have had it no other way.

  And, yet, despite how controversial the authoritanrian tenets of this act should have been in the “land of the free”, one senator and only 15% of the House of Representatives voted against it. Many (all?) of those who voted for it hadn’t read the act, and I wouldn’t be surprised of most of them didn’t really know what was in the act they were voting for.

  This kind of “must do something” response is the legacy of 9/11 that I hope we learn the most from. We open ourselves to manipulation from people who would love to pass all kinds of authoritarian laws when we respond in haste and in fear to a horrific event such as the 9/11 terrorist attacks.

• The Iraq war. Bush & co. were going to go into Iraq anyway. 9/11 made it easy for them. They could frame the whole war in terms of terrorism and defending America. A large proportion of American citizens were led into believing that Saddam Hussein was connected to the 9/11 terrorist attacks, even though there is absolutely no evidence for that. (The USA Today article I link to cites 70%; other numbers I’ve seen are closer to 1/3 or 40%. In any event, a significant fraction of Americans believed the lie.). 3,000 people died on 9/11. In Iraq, 4,200 Americans and something like 100,000 Iraqis have died as a result of the war. (And we won’t even talk about the cost of this war, rushed into, in compraison to, say, any potential cost of a much-reviled universal health care plan.)

  Was Saddam Hussein evil, and did his regime need to go away? Yes. Did the US make a complete mess out of the war, as a result of disastrous misplanning and lack of understanding about rebuilding after Saddam was ousted? Absolutely. I will say that over the last year or so, I’ve actually been almost optimistic that Iraq may be able to get back on its feet; I had not been for years before that. And, heck, the war in Afghanistan is looking scary now… I can’t help but wonder if much of that results from our redirection of focus from that war (which had broad international support) to Iraq long before the Afghanistan war was anywhere near complete.

• Many US citizens and many US politicians have started to speak out in favor of torture. Why? Fear. Because 9/11 has convinced us that we have to do whatever it takes to fight back against those who would do those sorts of things. Never mind that torture doesn’t work and generates bad intelligence. Never mind that it sullies the image of America internationally, gives those who hate America a great reason to hate America, and will only make things harder on Americans who get captured by terrorists. Never mind that it makes us evil that we do it. We want us our revenge. We suffered from the horrors of 9/11, so we want to make sure somebody else suffers in kind. We have seen it be effective week after week in the TV show 24, so we think we’re being courageous and doing the hard thing to support it. It makes me sick. I have some hope that perhaps we’re going to hold those at the top accountible for the decisions they’ve made, but for the most part, we’re probably going to throw some lower-level scape goats to the dogs as a way of pretending “accountability” while we still debate whether or not we should continue this barbarous and ineffective tactic.

• The end of due process. OK, that’s overstating it; due process still exists. And, as the link at the bottom of this paragraph shows, finally, years later, we’re reevaluating what we did and realizing that it was wrong. But there remain lots of ways for the government to work around it when they want to. Hoards of people picked up for the slightest suspicion have wasted away years of their lives in Guantanamo Bay as they are held without trial, without hearing. Yeah, they may not be American citizens, and thus not subject to protection from our authorities by our Constitution, but what of our ideals? What happened to defending freedom and justice? And, indeed, being an American citizen doesn’t stop you from being held without due process if the right part of the executive branch declares that you’re a material witness, without any proof whatsoever.

There are other things. The general paranoia we have about photography of public places, and how cops and security guards come down with unreasonable suspicion against those who are just taking pictures. The UK’s institution of universal surveillance and a lack of law enforcement oversight. The fact that anybody is still paying any attention to Dick Cheney as he tells us we should be torturing away as his administration always did. Folks’ laptops being seized, searched, and (effectively) confiscated at national borders without reasonable suspicion, in blatant violation of the spirit of the fourth amendment to the Constitution. The complete squandering of the sympathy and goodwill that the US had in the international community after 9/11 as a result of our aggressive and self-righteous posturing.

I believe it’s just a matter of time before some nutcase— be it a terrorist of the 9/11 variety, or a homegrown white guy of the Oklahoma City bombing variety— is able to get his hand on a “weapon of mass destruction” and blow it off in some highly populated area. And, I’m talking something nuclear here (be it a “dirty bomb” or a small nuke or some such), not just an airplane full of jet fuel— because the N-word makes everything so much scarier. And, I have to admit, I despair in the authoritarian rules that will be passed by widespread popular demand, quickly, in response to that.

We should never forget the horrors of 9/11. But we should also never forget the terrible mistakes we made in response to 9/11.

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“The Stars in a Galaxy” — talk Saturday at 10AM PDT / 17:00 UT in Second Life

Posted on September 4th, 2009 — permalink

I’ll be giving the latest installment of my the regular talk series “Dr. Knop Talks Astronomy” (usually, but not always, given by me) in Second Life tomorrow (Saturday) morning. This time I’ll be talking about the stars that make up a galaxy:

We now know that most of the mass of a typical galaxy is Dark Matter. But, when you look at an image of a galaxy in optical or near-infrared light, the light you’re seeing comes from the stars. It turns out, however, that the stars that are responsible for most of the light you see are not representative! Most of the stars in a galaxy, and indeed most of the stellar mass of a galaxy, aren’t the ones emitting the light that you see in a typical image. In this talk, I’ll describe what we know about the kinds of stars that one finds in a typical galaxy. How typical is the Sun? What are the stars that we’re mostly seeing when we look at a galaxy? And what makes up most of the stars in a galaxy?

Drop by and see us in the StellaNova Large Amphitheater in Second Life. Second Life accounts are free; you can join at the registration portal offered by the SciLands.

This talk will use Second Life Voice.

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Physics GRE Considered Harmful

Posted on September 3rd, 2009 — permalink

“As presently constituted, it’s quite possible that the GRE physics subject test does more harm than good, and we should either fix it, or seriously consider getting rid of it altogether,”

A quote from Jennifer Siders in this article at aps.org, that really we ought to take seriously. I doubt we will, though, because the Physics GRE is well entrenched at most graduate programs across the country, and making changes like that is always tough. Indeed, the article I linked to (as a result of seeing it in Pamela Gay’s Facebook status) was written 13 years ago, and yet the Physics GRE is still going strong.

I’ve been grouchy about standardized tests for some time. When it comes to things like the general GREs and the SATs, I believe that it does correlate with overall academic performance. Whether or not it’s testing the right stuff, there seems to be some correlation between what it tests and what we’d really want to test. But, it’s not perfect. That is, for (say– I’m making this number up) 80% of students, the SAT and general GRE might a good indicator of how successful they’ll be in college. As such, from a mercenary college admissions’ point of view, it’s worth keeping using them. Most of the time, they get the right students, and damn but it’s really easy to cut down on the number of applications you actually have to put work into thinking about by sorting on a simple number. Of course, from an individual fairness and a humanity point of view, it’s pretty sad to think that the other 20% (or whatever) who would have thrived at a certain college aren’t even considered because of a bad test….

The Physics GRE, however, has bothered me since I started as an assistant professor. Now, mind you, this is not personal sour grapes. My Physics GRE score back in 1990 was 89th percentile. At the time, I felt a little bad about that; I was one of those geeks who always did well on standardized tests, and thought that I should get over 90% on anything math/science related. Much later, I realized that 89th percentile is damn good for the Physics GRE. I did not personally suffer as a result of the Physics GRE, so I’m not posting this out of bitterness.

But, there is evidence that the Physics GRE does not correlate very well with how you do in Physics grad school. It seems completely unsurprising. In grad school, you do well by doing well at research. Yeah, you have to pass your classes, but even there it’s very different from what the Physics GRE tests. The Physics GRE tests your ability to think uberfast (which may be relevant in conference arguments, but is not terribly relevant for most research), your ability to recall things you’ve memorized, and your ability to quickly go through canned problems about basic physics. It’s not completely irrelevant, but it’s not testing what is most important about graduate school.

Of course, all the hand-wavy justifications for why it’s the wrong test only mean so much. As I said, there is evidence that the Physics GRE does not correlate very well with how you do in Physics grad school. What’s more, there’s evidence that women who do just as well as men in grad school on average score lower on the Physics GRE. In other words, either because of societal conditioning or because of intrinsic differences, the Physics GRE is more unfair for women, on average, than it is for men. Given that we’ve got a recruiting and retention problem for women in Physics, we should take this very seriously.

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Sedalia, MI makes Christians look bad

Posted on August 31st, 2009 — permalink

You’ve probably seen this if you follow the science blogosphere at all. The Smith-Cotton High School in Sedalia, MI has done a forced recall on T-shirts made for their band. Why? Because the T-shirt riffed on the classic “primate turning into human” motif used as a symbol for evolution.

Parents got all upset about this— the shirt didn’t even promote evolution, it just referred to it. I can’t help but wonder if parents in similarly backward and ignorant communities might object to iconography of Greek mythology on shirts related to sports teams named appropriately? Or, are they smart enough there to recognize that just because somebody used a very recognizable image, it doesn’t mean that it’s true? Asserting that the Greek gods are real is, of course, anathema to a strict interpretation of Fundamentalist Christianity, just like evolution.

And, of course, there’s also the fact that evolution is real. That there was such an uproar that the school had to repossess the shirts really just makes Christians in America look backward, ignorant, and in denial of reality. It gives fuel to the fire of those who would argue that being religious is inconsistent with accepting modern science— for, assuredly, religion is the reason why many Americans refuse to accept modern science. Those who are small-minded and knee-jerk in their reactions to things that challenge their interpretation of their religion go nuts when a school “associates itself” with Evolution. And, in so doing, it makes it harder for those of us who are trying to remind the world that religion doesn’t necessarily lead to bad science. It’s just extreme wingnut religion that does.

The principal of the school repossessed the shirts claiming that the law required the school to remain neutral on the subject of religion. This is, of course, complete bullshit, because the shirt didn’t say anything about religion at all. There is a difference between saying anything about religion, and doing something that might offend some religious sensibilities. This argument he makes is essentially the “politically correct” argument. Yes, usually one associates “politically correct oversensitivity” with political forces on the left, but the truth is that this behavior can come from either side of the political spectrum; it’s just a matter of which sensibilities they are oversensitive to.

Rejection of Evolution is just as obsolete a religious concept as is the geocentric Solar System. That something like half of the USA doesn’t agree with this doesn’t make it any less true. If we’re going to object to iconography associated with Evolution, we really ought also to reject to any iconography that suggests the planets orbit the Sun.

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