Thursday, December 29, 2011

How Long is a Sunset? How Long for the Moon?

Monday night I got to see the lovely sight of Venus and the thin crescent Moon shining close to each other in the dusk after sunset. I was somewhat surprised when I saw them again half an hour later, only a little closer to the western horizon. And then yet again, some fifteen minutes after that. Living in the tropics as I do, I'm used to things setting (and rising) very quickly. If you see something close to the horizon, you'd better look quick, because it'll be gone before too much longer. Here in California, further from the equator, things hang around longer before dropping belong the horizon.

The reason has to do with the fact that the Earth is a sphere (to a good first approximation). If you're in the tropics (between \(\pm\)23.5\(^\circ\)), the Sun appears to set very nearly perpendicularly to the horizon.  Not only that, but your tangential speed \(-\) the speed you travel around the circle you proscribe on the surface of the Earth each day \(-\) is higher than it is further north or south, since you're further from the rotational axis of the Earth. As you travel away from the equator, celestial objects appear to set at more of an angle, and your tangential speed is lower as well, leading to objects taking longer to set (or rise).

Some simple mathematical calculations show that the Sun, about half a degree on the sky, would take about two minutes to set if you were located on the equator and it was either the spring or fall equinox. As you travel further from the equator that time increases until you reach the Arctic or Antarctic circles, where upon the time to set ends up being longer than 24 hours, and the Sun simply travels around the sky. Above the Arctic circle (or below the Antarctic one) you are, in theory, guaranteed at least one, 24-hour period in which the Sun is above the horizon the whole time, and one 24-period in which the Sun is below the horizon the entire time. In theory, these would occur on the summer and winter solstices for the norther hemisphere, vice-versa in the southern. (In practice this depends on other factors such as clarity of the atmosphere, height of the observer above sea level, and the fact that the Sun is a disk on the sky and not a point.)

If you're wondering about similar considerations for the Moon, the picture is fairly similar, albeit modified by two important considerations: one, the Moon's orbit is inclined from the plane of the Earth's equator; and two, the Moon orbits the Earth, and so has a motion of its own that slows down its rising and setting (since it appears to move eastward across the sky, opposite the apparent direction given it by the rotation of the Earth). The Moon is nearly the same size as the Sun on the sky so a naïve calculation would give it about two minutes to set as a minimum time, but in practice the combination of all the factors mentioned above means it will always take longer than that. (Of course, since the full Moon sets at dawn, I doubt too many people are interested in how long it takes to set.)

A hui hou kākou!

Tuesday, December 27, 2011

Adventures in Malware Removal

Yesterday -- Christmas day -- my sister's computer contracted a rather serious case of malware that took me over an hour to neutralize. It's a nasty little program that goes by various names depending on your operating system, usually some combination of "XP/Vista/Win 7 Antispyware/Antivirus/Security 2012". This program is very well designed to look like the official Microsoft Security panel (at least on XP, which my sister has), so much so that when it first appeared even I, naturally suspicious as I am, was almost fooled. Ironically, it was the program's own strenuous self-preservation efforts that alerted me, as it will block any browser you open from accessing the Internet. (At least, it will block Internet Explorer and Firefox, which were the only ones I was able to test, though I suspect it would block others as well.)

Like many malware programs out there, XP Security 2012 (the name that appeared for my sister, and which I'll use for simplicity) poses as a virus scanner, then pretends to scan your computer and locate a bunch of bad stuff, which it promises to remove upon upgrading to the paid version. At best, such programs simply take your money; at worst, they can actually infect you with the very viruses they claim to remove. These programs work by looking very official, and XP Security 2012 takes it up a notch by blocking your Internet access, making it hard for you to check online for a solution.

Luckily, one solution is simply to restore your computer to an earlier backup point. By going to System Restore (found under Start Menu --> Programs --> Accessories), you can restore you computer to an earlier point (after which I would recommend clearing your browser cache of temporary downloads; the file seems to get onto your computer by posing as some sort of legitimate download. In this case I think it may have been a phony Adobe update.). This method may not work if your restore point doesn't go back far enough, although since the program seems to activate immediately on installation (or at least very soon), you would likely need a restore point just a few days ago to work.

I actually found and used a program from the anti-virus group Malwarebytes Anti-malware, although given the rigamarole I had to go through to get it working I wish I'd found the restore point solution earlier (XP Security 2012 can block programs with the .exe extension that it feels are a threat, so you need to change the extension on the Malwarebytes installer to .com, run it to install the anti-virus program, then change its extension to .com in order to run it and remove the malware. Luckily, it works very well)

Here's hoping that your own Christmas was less eventful! Merry Christmas everyone! Mele Kalikimaka kākou!

Thursday, December 22, 2011

Astronomical Perspective

Flying to or from the island of Hawaiʻi is made much more interesting on days with moderate cloud cover by the sight of one or more of the volcanoes that make up the island rearing its massive bulk above the clouds. I've been walking, climbing, and driving on Mauna Kea for over two years now, and I'm still staggered by its gargantuan size every time I see it from the air.

The first time I saw it like that, I gained a measure of insight into Hawaiian culture; I like felt I could better understand the thought processes of people whose ancestors had for centuries lived on and around these voluminous volcanoes. This time, however, I was struck by an entirely different kind of realization.

You see, for all their bulk, Mauna Kea and Mauna Loa are absolutely minuscule when compared to the size of the Earth. If the Earth were the size of a basketball, you wouldn't even be able to feel them with your fingers. In fact, not even the Andes or the Himalayas would protrude enough to be tactile. One concept that astronomers and physicists have to handle, perhaps more than any other people, is a sense of scale for things that are inconceivably beyond our human experience, both incredibly tiny and fantastically large. It's one of the reasons I created my picture showing the relative sizes of the Sun and planets. Seeing those volcanoes provides me an invaluable opportunity to refresh and recalibrate my sense of scale. If you ever have the pleasure of traveling to Hawaiʻi and the ability to see those beautiful mountains, take a moment to reflect on their size in the grand scheme of things. The act of gaining an increased sense of perspective never, in my experience, fails to bring amazement and a heightened sense of wonder at our amazing universe.

Monday, December 19, 2011

Gradu-ma-cated!

Well, as of December 17 I am officially graduated from UH Hilo, and entertain fully the rights, privileges, and responsibilities thereof. I'm now a proud Vulcan alumnus with a bachelor's degree in both astronomy and physics, with a minor in math.

...I'm also extremely tired from a very busy week spent with my family, and I'm flying back to California tomorrow for a few weeks during which time I hope to rest and recover. I've got several blog post ideas just waiting to be set free so you'll probably hear from me soon, but until then, ke Akua pū, a hui hou kākou!

Monday, December 12, 2011

Imaging with Large Telescopes

Last week I posted an image of the Sculptor galaxy taken with the Faulkes 2-meter telescope on Haleakalā while we had some free time as my group was gathering data for our Observational Astronomy final project. Today, I have a picture of our original target, the open cluster Messier 52. It's a moderately rich open cluster located in the constellation Cassiopeia. Unusually, its distance is not well known, with estimates ranging from 3,000 to 7,000 light-years.

Messier 52, in Cassiopeia.

I had to cheat a bit more than usual to get this picture, because it doesn't actually have any red data. All we needed for our project was blue and green data, so I simply duplicated the green data and used it as red to get this picture. I think it came out all right, according to the data we got most of the stars are fairly neutral or white anyway, so the missing red data wasn't really that important for this cluster.

If you're wondering about the ratio of the picture, it's actually two different fields that I combined which we took in order to ensure we got the entire cluster.

Saturday, December 10, 2011

The Power of Calculus

Recently a classmate of mine asked for some help with a physics problem falling under the purview of classical mechanics, and I, not having had a chance to use the ol' calculus for a while, eagerly proffered it.

Start by imagining a jet fighter flying along at a supersonic speed, leaving a hyperbolic shock wave (the famous "sonic boom") behind it.

(Pretend the red dot is a jet fighter.)

Now, the only two pieces of information we have about this problem is that the angle the shock wave makes with the horizontal is 30\(^\circ\), and that the speed of sound in the surrounding air is 330 meters/second. Can we figure out the plane's speed using just this information? You're probably not too surprised to hear that, indeed, we can, through the power of calculus.

Calculus is, at its heart, a study of how things change in relation to each other. And what is speed, but a measure of how position is changing with time? In the language of calculus, we can represent this using differentials, which give rise to differential equations. Differentials themselves are odd mathematical beasts, whose existence has been hotly debated over the centuries since Leibniz first proposed them, but like good physicists we can ignore that aspect of their nature for this post and focus instead on how we can use them.

Let's assume the jet is moving in the positive \(x\) direction, so that we can represent the jet's position by \(x\). This is simply a function of time (we're assuming the jet moves at constant speed), so \(x=f(t)\). We don't know what \(f(t)\) is yet, but if we find it out, we can then differentiate \(x\) to get the speed. I'm going to gloss over how exactly we accomplish that (it's not too difficult, it just takes a while to explain), but it involves taking a differential of the variable on each side of the equation \((dx=f\,'(t)dt)\), then dividing one by the other to get a derivative,
\[\frac{dx}{dt}=f\,'(t)\tag{1}\]
Such a cavalier treatment of differentials is likely to drive any mathematician reading this crazy, but it works well enough for physicists. The prime (\('\)) on the \(f\,'(t)\) simply says that the function it represents (which we also don't know) is simply the first derivative of \(f(t)\). We could continue to take derivatives, but there's no need for this problem (a second derivative would tell us about the jet's acceleration, for example).

Equation \((1)\) can be thought of as the instantaneous change in the jet's position divided by an instantaneous amount of time. Since we can't attack this equation directly with the information we have, let's look at it from another angle. We know information about the shock wave the jet is leaving that could be helpful to us. To see how so, let's briefly review how a sonic boom forms.

When a jet is traveling at sub-sonic speeds, any noise emitted by the jet will be able to expand out from it in a circle. If the jet had a system that emitted brief "pings" several times a second, it might look something like this if you could see the pressure front of the sounds waves:


Note how the sounds waves are closer together in front, and farther apart in back. If you keep increasing the jet's speed, the wave fronts will get closer and closer to each other, until:


BAM! the jet exceeds the speed of sound, meaning that it is now leaving those expanding circles of sound behind as it out-races them. The expanding wave fronts naturally create a hyperbolic shape behind the jet, leading to a huge buildup of sound that all hits at once as the shock wave passes a point, leading to a sonic boom.

Now, from the problem, we know one piece of information about these circles: namely, that they expand at the speed of sound, 330 m/s. In the picture above I've drawn in a radius of the largest circle, call its length \(r\). How fast the length of \(r\) changes can be represented mathematically as
\[\frac{dr}{dt}=330\tag{2}\]
where the units are implicitly recognized to be m/s (although it is important to keep units in mind to make sure the answer we eventually get makes sense). If we want to know the length of \(r\) as a function of time, we can antidifferentiate it in a manner analogous to how we differentiated \(x\) a while ago. Although in more complicated case antidifferentiation is more an art than a science when done by hand, it's fairly simple for this simple equation. First we multiply by \(dt\) on both sides (again, making mathematicians wince), then antidifferentiate (which we denote with the special symbol \(\int\) ). Antidifferentiation "undoes" the action of differentiation in the same way that multiplication "undoes" division, and that fact is so important it's one of the Fundamental Theorems of Calculus.
\[\begin{align}
dr&=330\,dt\\
\int dr&=\int330\,dt\\
\int dr&=330\int dt\\
r&=330t\tag{3}\end{align}\]
Now, what this equation tells us is that the length of \(r\) is equal to the time (from some specified starting point) times 330. We could re-write it in a manner equivalent to equation \((1)\), \(r=g(t)\), except that in this case we know that \(g(t)=330t\).

So, we know how fast the shock fronts from the sound waves expand. How does this help us? Well, note that the radius creates a right angle to the shock wave surface (i.e., the circle is tangent to the shock wave where they meet). This means that we have a right triangle, and we know from the information provided that the smaller angle is 30\(^\circ\).

In the figure below I've redrawn this triangle with just the essential information. We have the two known angles (and by extension the third), \(r\), and \(x\). We know how \(r\) is changing with time (\(dr/dt=330\)); can we determine how \(x\) is changing?


We can, if we can figure out a relation between \(r\) and \(x\). From basic trigonometry we know that \(r=x\sin30^\circ\) (Strictly speaking this wouldn't be an actual triangle because the hyperbolic nature of the shock wave would mean that the right corner of the triangle would be rounded instead of pointy, but it's close enough to reality to be useful for this simple problem.). But from equation \((3)\) above, we also know that \(r=330t\). If we combine those two equations, and do a little algebra, we can figure out how \(x\) depends on \(t\), i.e., what \(f(t)\) is in equation \((1)\):
\[\begin{align}
330t&=x\sin30^\circ\\
x&=\frac{330t}{\sin30^\circ}=f(t)\tag{4}\\
\end{align}\]
Remembering our discussion from above, we know that we can find the speed of the plane simply by differentiating equation \((4)\). When we do that, we get
\[\begin{align}
x&=\frac{330t}{\sin30^\circ}\\
dx&=\frac{330}{\sin30^\circ}dt\\
\frac{dx}{dt}&=\frac{330}{\sin30^\circ}=f\,'(t)\tag{5}
\end{align}\]
(again setting mathematicians' teeth on edge). So the speed of the jet turns out to be \(330/\sin30^\circ=660\) m/s. We can sanity check our work by noting that this is greater than the speed of sound (by twice), as it should be since the plane is supposedly flying supersonically. We could also generalize this into a formula for any angle that the shock wave makes by replacing the 30\(^\circ\) by a variable (say, \(\theta\)). Then we would have
\[\frac{dx}{dt}=\frac{330}{\sin\theta}\tag{6}\]
which would allow us to calculate the plane's speed for any (valid) angle we could measure.

Now, you may be looking at that last equation and thinking to yourself that it's putting the cart before the horse, so to speak. After all, the angle of the shock wave is dependent on the speed of the jet, not the other way 'round \(-\) yet that's exactly what the equation seems to be saying. This is part of the beauty and power of calculus, that we can ascertain relationships among variables from unconventional directions. It all depends on what you're solving for. You could invert the equation to find the angle as a function of the speed like so,
\[\theta=\csc^{-1}\left(\frac{1}{330}\frac{dx}{dt}\right)\]
and it would be just as valid as equation \((6)\), and would  better reflect what's physically happening to boot, but as we've just seen that doesn't mean that equation \((6)\) can't be useful too.

So the lesson to take home is that calculus is an immensely powerful tool, precisely because it allows us to see the world in a different way, and one that allows us to unleash the full power of mathematics upon it. Calculus is, in my opinion, one of the seminal works of Western civilization, and one, moreover, that richly rewards its studiers. We could all, I think, stand to know a little more calculus.

Thursday, December 8, 2011

Adventures in Image Reduction and Composition

Today I have an image of the Sculptor galaxy, NGC 253 (also known as the Silver Coin or Silver Dollar galaxy for its appearance in small telescopes). This dusty galaxy is fairly nearby by cosmic standards, only about 11 million light years away in the direction of the constellation Sculptor. Unlike most of the images I put up here, this one was not taken at the Vis. Instead, it was taken by the 2-meter Faulkes North telescope on Haleakalā. Last week my group in our Observational Astronomy lab were using the Faulkes telescope to get data for our project, and it wound up that we had a free hour, so on the advice of our teacher we used it to image this galaxy.

The Sculptor galaxy, NGC 253.

This image is by far the hardest one I've ever put together. To begin with, when I got the data from the telescope it had no easy identifying information as to which picture was what, so by trial and error I had to work out which pictures had been taken through the red, green, blue, and H\(\alpha\) channels. Once I'd done that, I had to figure out how to get the images to stack, because Deep Sky Stacker couldn't find enough stars (don't ask me why) for it automatically stack them. Once that was accomplished, I had to figure out how to play with the stretch of the final image to capture a good dynamic range -- no easy feat. All of that meant that I ended up re-reducing the data at least five or six times, and that was before I even began assembling the various pictures into the final image. I put together at least three versions of this picture, playing with the light curves of the different colors to try to get something that captured the beauty of the galaxy without either blowing out the bright parts or losing detail in the darker regions of the arms. This version is fairly close to true color, whatever that means in astronomy. I only took one (conscious) liberty: in addition to the standard RGB filters, we got some images with a hydrogen-alpha (H\(\alpha\)) filter, which is a filter that lets only one particular wavelength of light through (in this case the light emitted when an electron drops from the third to the second orbital in a hydrogen atom, which appears red). But whenever I tried mapping the information from that filter to red, I ended up with a galaxy that looked much too red, so I left it as simple luminance data. It's not "correct", but I think it gives a more aesthetically pleasing picture, so I left it. Perhaps in the future I'll go back and see if I can't get it to look better and at the same time more chromatically correct, but for now I'm moderately satisfied with it.

Sunday, December 4, 2011

Mathematics and MathJax

You know how I'm always saying \(\LaTeX\) makes math look beautiful? Well, yesterday I stumbled upon a way to get that same look in HTML. It's called MathJax, and it's really quite neat. All you have to do is link a JavaScript script in the header of your webpage (accomplished by editing my Blogger template), and the script will go through and convert any \(\LaTeX\) formatting into proper HTML that should be able to be rendered by any browser.

With MathJax, you can have inline equations like \(a^2+b^2=c^2\), or equations displayed with their own focus, like this:
\[ x = {-b\pm\sqrt{b^2-4ac}\over2a}\tag{1}\]
\[e^{i\pi}+1=0 \tag{2}\]
((1) is the quadratic formula; (2) is Euler's Identity)

This happens to be extremely fortuitous, because I was just thinking of writing a post with some calculus in it, and was pondering how to get the equations in. Now with MathJax, I'll be able to write a lot more about math in the future.

Edit (12/4/11): In case anyone would like to use MathJax in their own blog (or other website), here's how to do it. You need to put a line linking to the MathJax script in the header of your site. To accomplish that with Blogger, you need to access your blog's template (the easiest way to do that is to click on the "Design" link at the top right of the screen). Once there, click on the "Edit HTML" button. It'll bring up a dialog reminding you that can seriously mess up your blog if you don't don't know what you're doing. Click "Proceed", whereupon you'll be able to see the code underlying you blog. Once there just paste the following code somewhere in the header of your template; I'd suggest putting right before the line with "<b:skin><![CDATA[/*".
<script type="text/x-mathjax-config">
  MathJax.Hub.Config({ TeX: { extensions: ["autobold.js"] }});
</script>
<script type="text/javascript"
    src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS_HTML">
</script>
Note that by default this script doesn't process AMS (American Mathematical Society) symbols or commands. Since the AMS packages are very helpful, there's an easy way to include them. Simply add the following options to the "extensions" list, right after "autobold.js".
"AMSmath.js", "AMSsymbols.js"
That should be it! Try writing some \(\LaTeX\) expressions enclosed in either
\(...\)
or
\[...\]
for inline and displayed math, respectively. Check out the MathJax webpage if you need more help or information.

Thursday, December 1, 2011

English, Entropy, and Assignments

Tonight I've been writing a paper for my linguistics class on the historical development of Hawaiian Pidgin English into Hawaiian Creole English as it exists in the present day. This is an important, if subtle, distinction: a pidgin is a simplified language that is used as a second-language lingua franca between two or more groups of people who cannot otherwise communicate with each other, while a creole is an actual language used by a group of people as their primary language. Pidgins can be created between any two (or more) languages, and oftentimes throughout history have developed into full-fledged creole languages. The “Pidgin” spoken in Hawai‘i is a true creole, no longer a pidgin (and hasn't been for quite a few decades). (It draws mainly upon English and Hawaiian, but also upon languages such as Japanese, Chinese, Tagalog, and Portuguese, from the various people groups that were brought in to work on the plantations after the overthrow of the monarchy in 1893.)

The interesting part in this is that, while pidgins are simplified forms of language used only for specific purposes (such as business transactions) and not spoken otherwise, the creoles they develop into are complex languages capable of dealing with all aspects of life that their speakers encounter. This flies in the face of the established linguistic wisdom that languages tend to simplify over time, which is why it got me interested. For instance, in the Middle Ages English used to have special verb forms for present singular verbs, namely -e for first person (“I speake”), -(e)st for second person (“thou speakest”), and -eth for third (“he speaketh”). These have now been dropped completely, and first, second, and third all use the same form of the verb now (the bare verb stem itself, “speak” in this example). Middle English itself is a simplification of Old English, for instance having dropped the nearly one dozen forms of the word “the” that used to exist. Many other examples from other languages could be given as well.

Given this general trend, what are we to make of the fact that a full-fledged creole language seemingly arises from a simplified pidgin? There are several things to keep in mind. First, we must remember where this complexity comes from: it does not arise from nowhere, but rather comes from the languages that originally combined to create the pidgin. Speakers of a pidgin borrow syntax, grammar, and vocabulary from their native tongue and weave it into the collective pidgin language, increasing its complexity. Second, we must remember that there are intelligent agents at work. The observation that languages tend to decrease in complexity is a result of the fact that people like ease and simplicity. If everyone understands you when you take shortcuts in your speech, leave out a conjugation here, a declension there, pretty soon everyone's doing it and shortly thereafter those conjugational and declinational forms no longer exist. However, if people can't understand what you're saying, or you can't figure out a way to say what you want to in the pidgin you're using, you will add (or more likely borrow from your native tongue) ways of speaking that will allow you to express what you want.

In a way, it's similar to the loophole in the Second Law of Thermodynamics that allows life to exist. Technically, it's not quite as iron-clad as that law, because people could, if we chose, increase the complexity of our language; however, it's overwhelmingly unlikely. Also, the decrease of entropy in one portion of a system requires an equal or larger increase in another, while the increase in complexity of a pidgin turning into a creole requires no such corresponding simplification in the parent languages, but the general idea is similar. It's possible to mathematically quantify the entropy of a particular message in information theory, and it would be interesting to see how the entropy of a language changes as it develops from a pidgin into a creole.

(There are slight differences between how languages and physical systems change. Physical systems tend towards states of high entropy, because those are more likely, and thus simpler. Think of the number of ways in which the parts of a clock can be assembled such that the clock will work. Now compare that with the enormous number of ways that you could arrange those same parts without the clock working, and you'll see why over time, without repair, the clock would tend toward one of those numerous simpler states [since a non-working clock is simpler than a working one]. Languages, on the other hand, tend towards states of low entropy, because for languages those are simpler. Think about having 12 different ways to say “the” compared to one. One way is simpler in this case, which is one of the reasons English no longer has 11 other ways. This apparent inversion [physical states tend towards high entropy, languages towards low] comes about because of the way entropy is defined in information theory, but regardless of the semantics, the basic idea is that both physical systems and languages tend to change into less complex forms, even if the way of measuring such complexity is different.)

Friday, November 25, 2011

Celestial Owls

Today I have a picture of NGC 457, an open cluster known by two more-evocative names: the ET Cluster, or the Owl Cluster.

NGC 457, the Owl Cluster in Cassiopeia.
Personally I prefer the Owl Cluster because to my eyes I can see the shape of an owl pretty well. Two bright stars fit as eyes, the main body of the cluster serves as its body, while slight concentrations of stars to the sides form the wings.

One interesting fact about owls is that in  many different cultures worldwide owls are considered to be harbingers of ill omen or bad luck. However, the Greeks associated owls with wisdom, so much so that Athena, goddess of wisdom, had the owl as a symbol. Given the classical roots of Western Civilization this idea carried over, and may be part of the reason that the technical term for a group of owls is a parliament.

Monday, November 21, 2011

Superluminosity...Impossibility?

Saturday I had my first day of work up at the Vis. It was kind of strange -- I've been volunteering there for over two years now, so it was a little odd being staff instead. Everything went swimmingly, however, and I enjoyed it quite a bit (although I was exhausted by the end of the day! Working 14 hours in a row is a bit tiring).

I also had some time during the day when it wasn't too busy to mull over the report of superluminal neutrinos from back in September. By chance, a report came out the next day (today) by a group of scientists from Italy that puts forward a possible proof that the neutrinos are not traveling faster than c. According to the paper, which builds on work from two American physicists, neutrinos traveling faster than light should emit gamma rays and electron-positron pairs, in a sort of weak-force analog to Cherenkov radiation.

(For those who don't know, Cherenkov radiation is produced when particles with electric charge move faster than the local speed of light in medium. For instance, light travels only about 75% as fast in water as it does in vacuum, so it's quite possible for a particle to move faster through water than light can. When one does, however, it emits a special kind of radiation known as Cherenkov radiation [assuming that the particle is electrically charged, such as an electron]. This effect is visible as the characteristic blue glow of nuclear reactors.)

Neutrinos are not electrically charged, so they don't produce Cherenkov radiation. In fact, they interact through only two of the four fundamental forces, and they happen to be the weakest two: the weak nuclear force, and gravity (this is why they're so hard to detect). However, the paper argues that in analogy with electromagnetism, uncharged, superluminal neutrinos should emit gamma rays and electron-positron pairs through weak interactions.

Now this is all well and good theoretically, but it has practical implications too: by emitting this sort of radiation the particle's own energy is drastically modified (in fact, calculations suggest that each emission would remove more than 3/4 of the neutrinos' energy). This ought to be dramatically visible in a graph of the energy of the arriving neutrinos. And to make a long story short, it's not. The neutrinos' power spectrum looks unaffected, making it virtually impossible for them to have exceeded the speed of light by the amount claimed.

This experimental test is brilliant, because instead of trying to better measure the distance or time (both of which are fraught with difficulty) it attacks the problem from another direction, that of energy. I suggested just such an experiment to measure the neutrinos' energy in one of my first posts on this subject back in October, although I admit I wasn't thinking about this particular test (I wish I'd thought of the weak-force analog to Cherenkov radiation, because it's a neat little idea). Anyway, it's nice to see the scientific method in action here, and I'll try to keep you up to date on this topic in the future.

Friday, November 18, 2011

Further Adventures with Avocados

Today I was experimenting with new sandwich fillings, and may have stumbled across the world's tastiest concoction. Tastes are subjective, I know, but this delectable delicacy left me idly licking every last bit off my taste-testing spoon while zoned out in blissful rapture for several seconds. It also happens to be incredibly easy to make: simply combine 1 medium or small ripe avocado, 2 big spoonfuls of mayonnaise, and 1 can of tuna. The resulting flavor is, well, you need to try it for yourself.

The taste by itself is sensational, but I'm sure it would also go well as a base, or could have other things added to it. Ironically, it didn't do so well as a sandwich filling because it kept spilling out, but it might serve as a dip, as a sort of enhanced guacamole.

If anyone out there tries it, let me know how it turned out!

Wednesday, November 16, 2011

Our Star

Have you stopped to ponder just how mind-blowingly huge the Sun is lately?

Last week while volunteering up at the Vis I took a picture of the Sun through the solar telescope on a whim. I noticed a large sunspot group on it, but didn't think anything else of it until this week when I learned that said sunspot group (called Active Region 1339) is one of the larger ones on record. I'd also heard somewhere along the line that it was larger than Earth, so I decided to do some visual comparing of my own. After seeing how Earth and Jupiter looked against the Sun, I decided to go all the way and add the rest of the planets. This image is the result. It shows the 8 planets of our Solar System against the Sun with AR 1339, all of them correctly sized relative to each other. (The distances between the planets are not to scale, due to the way I set up the picture.)

Our Solar System.
Look at this image, and let it sink in for bit. The Sun accounts for a whopping 99.86% of all matter in the Solar System. It's big. For fun, see how many other sunspots you can spot in this picture that are larger than Earth.

Edit (11/25/11): One other thing I like about this picture that I forgot to mention the first time is the sense of security it gives, when you really think about it. Stable orbits, despite their ubiquity in nature, are still nothing to take for granted, and it's sort of comforting seeing just how huge the Sun is compared to the Earth, and just how firmly we're caught in its gravitational embrace.

“Tremble before Him, all the Earth; indeed, the world is firmly established, it will not be moved. Let the heavens be glad, and let the Earth rejoice” -- 1 Chronicles 16:30-31a

Tuesday, November 15, 2011

Globular Cluster Photo Series (Part 14): M71

Today's picture is of the globular cluster Messier 71 in the tiny constellation Sagitta, the Arrow (not to be confused with the much larger and more familiar constellation Sagittarius, the Archer). M71 is an unusual globular cluster between 12-13,000 light-years away with a diameter of about 27 light years, fairly small for a globular cluster. It has a small apparent diameter of only 7.2 arcminutes (less than a third the width of the full Moon).

Messier 71 in Sagitta.
Sagitta is located in the plane of the Milky Way from our point of view, which explains the high stellar density in the background of this image. M71 was for a long time (up until the 1970's, in fact) thought to be a dense open cluster rather than what it actually is, a loose globular cluster. One reason was that the stars in M71 are younger than is typical for globular clusters, although that fact simply turned out to mean that M71 is a relatively young globular cluster. M71 also lacks a particular kind of variable star called RR Lyrae stars (after the prototype RR Lyrae) that are common in globular clusters, which turned out to be related to its age: its stars are too young to have become RR Lyrae-type variables yet. In fact, M71 contains only 8 known variable stars, though one of them is an interesting irregular variable.

This lack of RR Lyrae stars is one reason the distance to M71 is known to no better than a thousand light-years. RR Lyrae stars make good standard candles within our Galaxy, as the relation between their periods and their luminosities is well-known. They are also much more common than the other type of variable star commonly used as standard candles, Cepheid variables. RR Lyrae stars can be found at all angles in the sky (in contrast to Cepheids which is are strongly associated with the galactic plane), and consequently make up 90% of the variable stars found in globular clusters.

Anyway, that's it for tonight, I need to get some sleep. A hui hou!

Monday, November 14, 2011

Moon rocks!

Saturday I went up for a summit tour and stayed to volunteer because it was the University Astrophysics Club night, and the sky was actually clear after a week of clouds and rain. And I'm glad I did, because not only was I able to image four different objects (while instructing a fellow student in the operation of the imager), but some people from NASA who were there running some tests showed up with a real moon rock in a box, and a real astronaut too!

To say that the crowd was excited was be a gross understatement. (And of course they brought the moon rock on the day I decided not to bring my camera.) A lot of the students from the UAC got to talk to the astronaut too, which from what I heard was the highlight of their evening. I'd write more about it, but I'm rather tired tonight, and was actually outside taking care of things for a good portion of the time they were there.

One reason I'm tired is that I just finished an 18-page, multi-megabyte document going over the data reduction process to create pictures from the images captured by the imaging telescope (yes, collecting the data is only about half the work). I've learned a bit about data reduction over the months, so I'd like to be able to pass on my knowledge to anyone else interested in learning to use the imager who comes after me.

Anyway, I should really get to bed now.

Saturday, November 12, 2011

Avocado Adventures

Recently I read a very interesting book called In Defense of Food: An Eater's Manifesto by Michael Pollan. It's about how many of the "diseases" associated with a Western lifestyle appear to be directly linked to the Western diet. (I put diseases in quotes because these are not, strictly speaking, caused by any sort of pathogen: I'm talking about things like heart disease, cancer, late-onset diabetes, obesity, and other similar ailments. And by Western diet I don't mean "someone who lives on Big Macs and milkshakes", but "pretty much anyone in America who buys food from the grocery store and isn't eating some unusual diet".) In Defense of Food  also talks about "nutritionism", the belief that food can be thought of as merely human fuel and reduced to its constituent chemicals. In this mindset it's easy to make food healthier -- simply remove the "bad" nutrients and replace them with "good" ones. This mindset has been the guiding policy of the American food industry for nearly the entire past century.

Now, on the face of it, this position appears reasonable. It has, in fact, had some dramatic victories, such as the discovery of vitamins. The near-eradication of such "diseases" as beriberi and scurvy stands as a monument to its success. Pollan is not saying that nutritionism is necessarily wrong, just incomplete. He makes a good point when he argues that while modern science may be able to identify all the components in a type of food, it is much less able to figure out how all those components work together in the digestive tract. There may very well be important interactions we don't know about between the nutrients in food during the digestive process that help make it healthy, in which case manually tinkering with the balance of those nutrients may not be effective or helpful. Evidence that simply knowing the nutrient value of foods is not enough is not hard to come by. For starters, there's what's known as the French Paradox: the French eat a diet that by nutritionism's standards is wildly unhealth, yet they enjoy far better health on the whole than Americans. And that's not just because Americans are an unhealthily eating lot: according to studies, Americans are the most health-conscious people on the planet, while paradoxically also suffering from some of the highest rates of the aforementioned Western diseases.

The evidence points to the typical Western diet (even of health-conscious people) being the culprit. Again, evidence for this is easy to find: time and again, scientists during the 1900's noticed that when indigenous people switched from their native diets to the Western diet, invariably Western diseases (or "diseases of civilization") soon followed. In a dramatic demonstration of how these effects can be reversed, a group of middle-aged Aborigines in Australia suffering from ailments such as obesity and type 2 diabetes went "back to the bush" for a few months and experienced dramatic improvements to their health. (You can find a link to a quotation from the book detailing this experiment here.)

Now, some of you may be thinking to yourselves, "If the price to pay for the luxuries of modern living is being a bit obese and a higher risk of cancer and heart disease in old age, I think I can live with that." And indeed, I would be inclined to agree with you. Neither Pollan nor I are advocating a return to pre-Industrial Revolution-style conditions in order to escape diseases that, while nothing to sneeze at, are nothing compared to what mankind struggled with prior to modern medicine and agriculture. However, the question is whether there are only two alternatives: live a healthy life without modern conveniences or an unhealthy one with them. According to Pollan there is a third option, namely, living a healthy life by taking advantage of the conveniences of modern life.

Doing so, however, will require a bit a rethink of our approach to food. According to Pollan, more and more of the food found on grocery store shelves isn't so much food as it is "edible foodlike substances". While preserving food (such as by drying, salting, smoking, etc) has been around pretty much forever, much of the processing done to food on the shelves today is much, much, younger, and Pollan argues that we haven't had enough time yet to fully understand what we're doing with out diet. Prior to industrialization every culture on Earth had some sort of traditional diet that they ate and had been eating for hundreds if not thousands of years, and those diets obviously worked, else the culture wouldn't be around to be eating them. In contrast, industrialization and the accompanying changes to our food supply (and they have been dramatic changes) have only been around for 150-200 years, at most. Of interest is the wide variety in those pre-Industrial diets, many of which would not be thought at all healthy according to modern nutritional science. For instance, people have survived and thrived on diets consisting almost entirely of plants, and almost entirely of meat, and ones everywhere in between, often with large amounts of nutrients that are considered extremely dangerous today (various kinds of fat, etc.). This suggests that we ought not be too dogmatic about what we think we know about food.

There are many other things I could expand upon, such as the fact that the majority of nutrients in the Western diet now come from just four species: corn, soybeans, wheat and rice, while the number of species in the world's collective cookbook stands at over eight thousand. Or that the higher incidence of Western diseases is not simply a matter of more people living to older age, but a demonstrable effect based on diet (and lifestyle. Pollan reminds us that the two cannot really be separated). But this post is already long enough, and I'd just be poorly parroting the book, which is well-written and an interesting read. Pollan's advice boils down to seven words: "Eat food. Not too much. Mostly plants" and while I have never been one to pay too much attention to my diet before, I was so intrigued by the ideas in this book that I've decided to try to eat a healthier diet by a) paying even less attention to health claims by food than before, and b) just attempting to eat a balanced diet of real food that has withstood the test of time.

Basically, I decided to start trying out new recipes and such, so the last time I went shopping I got some avocados at the store (so THAT'S what the title is about!). I don't remember eating avocados much as a child, so I decided I'd be bold and try to make something with them. I created some guacamole, and was instantly hooked (I also learned that unripe avocados are not to be trifled with, but that's another story). In fact, I could definitely see this becoming a new favorite food in the very near future. See, Mom, I may still be a picky eater, but I do try new things from time to time. And sometimes I even like them.

Anyway, it occurs to me that I just wrote a two-page essay to describe a new food foray, but I was planning to write something about In Defense of Food anyway, so I killed two birds with one stone there. If you have any other favorite recipes involving avocados, feel free to leave me a comment! (For some reason, I've spent this entire post wanting to write "avocados" as "avodacos".)

Friday, November 11, 2011

Asteroid Fly-By Redux

Well, I've been busy getting things paperwork done for my new job, but I'd be remiss if I didn't tell you how things went Tuesday. Simply put, not much happened. There was an all-staff meeting that morning so I was shown how to use the register and ended up being left to watch the First Light Bookstore for two and a half hours, so I didn't have time to attempt to see the asteroid while minding the store. Then clouds rolled in around lunch time when I was relieved, and stayed there for the rest of the afternoon.

From the information I gleaned, I don't think it would have been possible to see the asteroid at closest approach (at 1:28 PM here) anyway. I may make an attempt to see it Saturday night when I'm up there for the UAC night as it may still be visible, but we'll see.

And boy, I'd heard that the First Light Bookstore had one of the highest profit-to-square-footage ratios of any store in Hawaiʻi, but it wasn't till I was tending the register that I really realized just how much people often spend of souvenirs.

Tuesday, November 8, 2011

Asteroid Fly-By

Just a quick post today to let y'all know that I'm going up to volunteer at the Vis on Tuesday for the first time as a daytime volunteer. This is because there's an asteroid fly-by happening tomorrow, and we're going to determine if we have any chance to see it. I need to get to bed soon so this post will be short, but basically it's a little asteroid called 2005 YU55 which is about a quarter-mile wide. It'll approach to about 198,000 miles at its closest, a bit closer that the orbit of the moon, at 1:28 PM Hawaiian time (that's 3:28 Pacific, and 6:28 Eastern time). It's only going to be about magnitude 11 even at closest approach, so more than ten times too faint to be seen with the naked eye, plus the fact that the sun will be up won't be helping at all. However, it may be possible to see in the days to come as it appears to move slower as it get further away in a direction almost opposite the sun.

Anyway, need to get some shut-eye now, so I'll write a longer post later with a bit more detail, along with any results we might possibly get.

Sunday, November 6, 2011

Telescopes and Snow

This past Thursday my Observational Astronomy class got to go on a field trip to Mauna Kea, where we were treated to tours of three of the observatories up there: the Gemini North facility, the NASA Infrared Telescope Facility, and Hōkū Kea, the telescope that will eventually be for undergraduate students at UH Hilo when they finish fixing it.

We've had quite the storm system washing over the island this past week, so there was actually snow on Mauna Kea when we went up -- and not just "small piles in places the sun hasn't melted yet", but "a pretty good covering". Since I could probably count the number of times I've been around snow on my fingers and toes, it was pretty impressive to me.

Puʻu Hau Kea (Cinder Cone of White Snow)

Looking back whence we came.

Puʻu Makanaka (the large one. I don't know what Makanaka means, perhaps a proper name)

From left to right: Canada-France-Hawaii telescope, Gemini North, the UH 88-inch, the United Kingdom Infrared Telescope, and Hōkū Kea. All looking very cold.

Part of the Sub-Millimeter Array, standing staunchly amidst the cold.

Having gotten all those distracting pictures of frozen water out of the way, I can proceed to describe the actual objects of our tour. Our first stop was the Gemini North telescope, one of two identical 8.1-meter (that's 27 feet) telescopes built and operated by a consortium of countries. The other, Gemini south, resides in Chili, so that between them the two observatories cover almost the entire night sky. The two domes are identical, and are an imposing sight close up:

The Frederick C. Gillett Gemini Telescope dome, up close.

It's hard to capture the sheer size of a telescope that has more area than the floor of my room in one shot, but I tried. The Gemini telescope is similar in many ways to the Subaru telescope, which is almost the same size. For some reason, they're even painted suspiciously similar shades of blue. I did my best here:

The Gemini North telescope. It is huge.

Since it can be hard to appreciate something when you have nothing mentally to compare it to, have another shot with some crew members working in it (that big box they're standing around is an instrument they're about to put on telescope, and yes, it's so big that they're standing on it):

Removing one instrument and swapping in another.

From Gemini we moved to the NASA Infrared Telescope Facility, a 3-meter (9.8 feet) telescope built exclusively for infrared viewing (many of the optical telescopes on Mauna Kea such as the Keck twins, Gemini, Subaru, etc. have the capability to do some limited infrared observing, but IRTF is one of the two telescopes built exclusively for it). IRTF was originally built to support the Voyager missions and to this day at least half of its observing time is taken up by planetary research. Because of this it has a somewhat unusual mount called an English yoke equatorial mount. It's something like two tuning fork stuck with their open ends together, with the telescope free to rotate in between. The advantage of this design is that it is much easier to observer objects that are very near the zenith than would be possible on a regular alt-az mount such as most of the large telescopes on Mauna Kea have.

The NASA Infrared Telescope. Note that same shade of blue paint at the bottom.

Here's another shot from below showing the telescope nestled between the two arms of its yoke:

Showing off the telescope's unusual mount design.

Finally, we ended our time on the summit with a brief tour of Hōkū Kea. It's a mere 0.9 meters, and the entire dome area is probably smaller than Gemini's mirror. It's also apart for maintenance at the moment with the mirror being down for some work, so I didn't get any interesting pictures. There wasn't much to see besides the empty tube, although it too was painted that same shade of blue. I actually asked people at each telescope if there was a reason for the color, but all I got were blank stares so I still don't know. Maybe it was just cheap.

Anyway, after our frosty tour we left to return to the warmth of Hilo, but not before I captured one more snowy landscape in memory:

Looking to the south-west, Hualālai is visible off in the distance through the clouds.

Addendum: If you've read this far you must like pictures, so you may like to check out the post directly before this one. I re-reduced my Andromeda Galaxy picture, and I think it came out a lot nicer. I added it to the post, so you can see both of them and compare. A hui hou!

Tuesday, November 1, 2011

The Great Galaxy in Andromeda

Saturday night while I was up at the Vis I decided to take a break from imaging globular clusters to try my hand at what probably pretty much every astrophotagrapher ever has broken their teeth on: Messier 31, the Great Galaxy in Andromeda.

The Andromeda Galaxy is located in the direction of the constellation Andromeda, about 2.5 million light years away. It's not the closest galaxy to our own Milky Way, but it's the closest spiral galaxy and the one closest in size to the Milky Way in our Local Group of about 30 galaxies. (Intriguingly, although Andromeda is larger in size than the Milky Way, recent studies indicate that the Milky Way may have more mass. It also has a higher star formation rate, and a higher rate of supernovae.)

The Great Galaxy in Andromeda, Messier 31. Technically, only the innermost part of it. M32 (at top) and M110 (at lower left) are also visible.

While Andromeda may or may not be the most massive galaxy in our Local Group, there is no doubt that it's the brightest galaxy in the northern hemisphere. It's also the largest on the sky. In fact, if we could see it all, it would appear as wide as six full moons on the sky! Its huge size, however, is paradoxically what makes it so hard to see. All that light is spread over a large area, making it exceedingly faint. What you're seeing in this picture is no more than the central third of the galaxy; it stretches out on both sides almost as far again as seen in this picture (mostly because I didn't have a lot of time to image it, so I took the longest exposures I did in the time available).

Being as it is the largest on the sky and brightest in the northern hemisphere, Andromeda was the first galaxy to have its spectra taken (by Vesto Slipher in 1912) and the first galaxy to be confirmed as such (i.e. a system of star not materially associated with the Milky Way), by Edwin Hubble in 1922-23. This discovery increased the size of the known universe by several times, and was instrumental in the development of our current picture of the universe.

The Andromeda Galaxy is a fascinating star system, and I could write pages more on its various interesting features, but it's getting late here and I ought to get some sleep. After seeing how this picture came out, I'm tempted to try again and get a longer exposure to show fainter details, so perhaps I'll write more about it if I do.

Edit (11/5/11): Due to a suggestion from a master imager, I went back and re-reduced the data for this picture, stretching the light curve in a different manner to get better results. DeepSkyStacker, the program I use to do the data reduction, lets you apply different light curves to your photo after it does all the work to reduce the noise in the image. Basically, different light curves are better for bringing out different features. The one I chose (called "cube root") helped show the faint nebulosity better without simultaneously blowing out the the bright, dense core. So, here's the same picture, version 2:

The Andromeda Galaxy, Messier 31. Now much prettier!
If you compare the two pictures, you can see that the second one shows a lot more detail. I'm glad I learned how to apply different light curves, as my typical globular cluster shots didn't usually change much when I played around with them before so I wasn't quite sure what it did. But as you can see, it works wonders with nebulous subjects! (And since there aren't as many globular clusters to image during the winter, I'll probably be taking a little break from them to image some of the other cool objects in the night sky...)

Sunday, October 30, 2011

Reflections

Writing FluxClassify this semester has been a rewarding and interesting experience for me. I've learned a lot about how computer graphics and graphical user interfaces work and how to design a program that is easy and fun to use -- in short, a good program. It's also been a bit of a relief.

To understand why you need to know that I consider my hunger for knowledge to be a very integral part of myself, to the point that when I began to suspect I was losing it last year it was cause for much distress. Coming to college for knowledge is rather like satisfying your thirst by drinking from a fire hose, and after three years I found that I just wasn't as interested in my classes as much. A lot of people think I'm really smart (and I suppose having a good memory helps), but the truth is that I'm just motivated to put effort into finding out about things that interest me. When I became less interested in my classes I put less effort in, and that led directly to my first non-A grade in college. I began to fear that perhaps my innate curiosity had been satisfied, which is what drives physicists in the first place. Overall the last two semesters have had a semi-constant background of worry about whether I was really suited for the lot in life I've always wanted.

However, over the summer and fall I've come to realize that my hunger for knowledge never really left me -- my appetites just changed! Looking back over the last two semesters I see that I was still interested in learning thing. They may not always have been related to what I was learning in class, but I was still as voracious as ever in my pursuit of knowledge. Working with Dr. Takamiya helped because it introduced me to a latent desire to learn more about computer programming that's been a steady background of my life for over a year and half now.

My research experience has been helpful as well because what I learn from working on it mimics more closely how I learn naturally in life than learning in a classroom. My Observational Astronomy Lab this semester pleasantly surprised me in this respect, because our final project (for the remainder of the semester) involves going out, taking actual data, and writing a report about it, and I'm actually really interested in it. In short, all my changing knowledge appetite means is that I'm a little bored of classroom learning for the moment and ready to apply it (which is good news for grad school!). I suppose it's no big ground-breaking realization, but it has been a slow process of discovery for me, and I'm very relieved to see that while my curiosity may be satisfied on one subject for a while, it'll just find something else to investigate. Because, really, a physicist without curiosity is an oxymoron.

And now I need to finish this long-winded post and leave for a day of volunteering on Mauna Kea. A hui hou!

Wednesday, October 26, 2011

Victory! Vindication! Version 0.4.0!

Success! I'm very excited this evening because the newest version of FluxClassify, my spectra-categorizing program, is now functional. The three weeks I spent learning new code and racking my brain over how to do things was not in vain. It's already a huge step up from the previous version, and much, much, easier to use. It's not quite ready to release to my eager group of spectra-classifiers due to some details I intend to implement to make it even easier, but I hope to have it out with a bare minimum of extra features by this weekend. I'm even more excited about this, my first program written with Pygame, than I am with its predecessor, written in wxPython (and my first GUI), because Pygame is much lower-level than wxPython so I had to learn how to do a lot of things the hard way or re-invent the wheel in various places. The flip side is that I have extremely fine control over everything, so if I can figure out how to do something, I can do it exactly the way I want it. Ah, the sweet taste of victory.


See this? This is a shot of FluxClassify's main menu. It may not look like much, but that list of observations to choose from is auto-generated. That's right, it automatically takes stock of the data you give it to dynamically create a clickable menu on start-up. Also? Everything you see there is relatively placed based on the size of the screen, so it should work just fine on differently-sized screens.

Although, it is a bit sparse right now...I may add a better background in the future. I do plan to add some "Options" buttons later this week, such as the ability to mute the sound.

...Oh, I didn't mention it has sound effects? That's another nice thing about Pygame, it allows easy integration and playback of sounds. It's amazing how much a simple "click" sound when you mouse over a menu option  adds to the experience. In essence, I'm designing a program that I would enjoy using, to make sure that other people enjoy using it too. And I won't stop improving it till it's nice and polished. It doesn't hurt that I have fairly high standards in program usability and quality.


The entire reason I spent three weeks learning and writing new code was for what you see before you here. This here is a shot of FluxClassify in action. As I mentioned before, one observation comes in two parts, one taken through a blue filter, one taken through a red one. Up until today, people have had to classify those two parts separately, by manually flipping through pictures and switching between them and FluxClassify to record their results. It's time consuming, inefficient, somewhat boring, and obscures the big picture of the observation. This program is designed to do away with all that, by displaying both the blue spectrum (on the left) and the red spectrum (on the right) together in one place, something I couldn't figure out how to do in wxPython (I couldn't get it show any pictures, period). I chose this picture, incidentally, because of the strong flux seen in both spectra - a good hydrogen-beta emission line on the left, and an even nicer hydrogen-alpha line on the right.

If you're wondering how exactly to use this program, well, that's why I said it's not quite ready to release yet. Currently you can classify spectra with a few key presses (and I plan to keep that), but I also plan to include mouse clicking, and buttons to show people their options and what they picked. Once I have that stuff down, and a few other odds and ends I've thought of, it'll be ready to release for beta testing! A hui hou!

Tuesday, October 25, 2011

Globular Cluster Photo Series (Part 13): M92

Today I have an image of the globular cluster Messier 92 for your viewing pleasure. M92 is one of the more spectacular globulars in the sky, but is unfortunately outshone by the slightly more spectacular M13 with which it shares the constellation Hercules. M92 is smaller than M13 at 109 light-years across compared to its 170, but is at roughly the same distance, about 26,700 light years away (M13 is about 25,000). These two factors combine to give it an apparent diameter on the sky of 14.0 arcminutes, a bit smaller than M13's 20.

Messier 92 in Hercules.
M92 is a nice looking globular cluster, still large enough on the sky to look interesting, and fairly concentrated. M92 boasts one of the few eclipsing binary systems known in globular clusters. It has another, more interesting claim to fame, however. The Earth's spin axis slowly precesses over time, taking about 26,000 years to describe a large circle on the sky. (Think of a top slowly wobbling in a circle as it spins. It's the same physical principle.) Precession is the reason that Thuban (a star in Draco) was the North Star for the ancient Egyptians rather than Polaris like it is today. Anyway, in about 14,000 years precession would point the Earth's axis less than a degree away from M92, leading to M92 being a sort of North Cluster. For comparison, M92 is about a fourth of a degree across, so you can see just how close that would be. Polaris itself is about a degree from the North Celestial Pole, which is small enough that it doesn't matter for everyday navigation aiding.

Pretty interesting, no? A hui hou!

Sunday, October 23, 2011

A (Nobel) Prize Winning-Performance

Wednesday night I had the privilege of hearing a talk by Brian Schmidt, one of the three winners of this year's Nobel Prize in physics for his work as the leader of one of the two teams who independently discovered the acceleration of the expansion of the universe. This was his first public talk since being announced as one of the winners, and he even turned down an invitation to meet queen Elizabeth to give it! Despite the talk only having a week's notice, it was packed. Quite literally standing room only, as I and many other stood the entire time. There must have been easily two or three hundred people in attendance, many from the local community.

The talk was very informative, and given at a level that non-scientists could understand. As a result he didn't cover too much material that was new to me, but what he did cover he discussed in an engaging and knowledgeable manner. All in all it was a great experience, and I'm glad so many people from Hilo got to come and see some of what astronomers do up on top of the mountain. Positive PR is always a good thing for us!

Sunday, October 16, 2011

Project Orion

Today I came across what is certainly one of the most intriguing and arguably one of the best ideas the human mind has ever come up with: Project Orion.

Project Orion was a serious research program in the late 40's and 50's dedicated to achieving rocket propulsion in a...slightly unorthodox manner. In essence, it boiled down to chucking atomic bombs out the back of the rocket and detonating them to provide thrust. Mull on that for a few seconds. This was a dead-serious project by some top physicists. The explosion from the bomb would push on a large pusher plate at the back of the vehicle that would be attached with some heavy-duty inertial dampeners causing the whole thing to act like a spring, bouncing back after each explosion only to be greeted with a fresh one for the maximum impulse. Serious calculations showed that it would take about the same about of bombs to get a wide range of payload masses, from 2,000 tons (on the order of the size of the Saturn V rockets that went to the moon) all the way up to 8,000,000 tons (on the order of the size of a small city[!]) into orbit, meaning you could launch much greater masses with the same amount of "fuel" than you could using conventional measures. How many bombs does it take to launch a spaceship into orbit, you ask? The guys in charge of the project have you covered. It would take about 800 nukes at the rate of about one per second to launch something into orbit in a manner akin to "an atomic pogo stick."

Imagine that, if you will.

Imagine being among the first crew to experience one of these. The whole point of the inertial dampener is to decrease the acceleration when the bomb goes off from a lethal 100g to a more human-survivable 2 to 4g, but that's still some significant shock. And every second for over ten minutes you'd get another one. Another interesting fact: the guys in charge of the project were worried that the random nature of the explosive fireballs might send a spacecraft off course, but were reassured when they found that the effects tended to cancel out. Well, that sounds nice in theory, but in reality it means that in addition to the jerky forward motion you'd be feeling, there'd be tiny, random, deviations each time which you know aren't going to knock you off course, but which I'm sure would be pretty unsettling anyway.

Plans for launching such space vehicles included -- I am not kidding here -- covering the landing pad in a layer of conventional explosives and literally blowing the ship far enough up into the sky that it could drop its first nuclear charge without risk of shrapnel from the nuke interacting with the landing pad damaging the ship itself. I mean, how cool is that?? The project ended up being shelved not because of the extreme amounts of fallout it would generate (the idea was never actually flight tested), but because no one at the time could think of a need to launch thousands of tons of payload into space (the signing of the 1963 Partial Test Ban Treaty also made it impossible to test. The U.S. tried to get an exemption for nuclear propulsion into the treaty, but the Russians were [understandably] reluctant).

In the aftermath of bans on open-air nuclear explosions, some people have proposed a similar idea, but one where the spaceship would be launched by more conventional means (or assembled in space) before igniting its nuke drive far enough away from Earth to be non-hazardous. It was calculated that a mission to Pluto and back could be completed in a single year using such a drive. In contrast, New Horizons, the probe currently heading to Pluto, is the fastest man-made object ever, and it's still going to require nearly 15 years to get to Pluto.

And now, perhaps, you can begin to see why I find this idea so fascinating, so captivating, so wonderfully and uniquely "out there" that I could not sleep without writing this post about it. Because when you get right down to it, really, all worries aside, who wouldn't want to ride a nuclear-powered rocket? ("Prime the nuke drive, Scotty!")

Monday, October 10, 2011

Art and Awards

Saturday night was the annual Volunteer Appreciation Banquet up at Hale Pōhaku for all the Mauna Kea volunteers. Although I've been to two before this (indeed, my first time ever volunteering was on the night of the banquet in 2009), this is the first time I've been able to stay for the entire banquet (the banquet runs longer than the time the volunteers who are actually volunteering that night need to be down at the Vis by).

I enjoyed the banquet immensely, especially getting to see various people I knew recognized for their outstanding contributions as volunteers. There were 11 “major” awards given out, things such as “Most Dedicated Volunteer,” “Most Enthusiastic,” and “Stellar Spirit.” And then, in a totally unexpected turn of events,  I heard my name called out associated with the last one, “Best Images of the Year.”

Close-up of the amazing fleece jacket I got as part of it!

Of course such an award needed some examples, and I found it mildly amusing (even as I was blushing up a storm) that two of my pieces of artwork were shown while only one image made using the imaging telescope was. (Although, since it was the image in the post directly preceding this one, I suppose you could argue that it was equivalent to showing 16 images.)

Needless to say, I was touched, and truly honored. One of the nicest things an artist can hear is that someone enjoyed their work and as you can imagine I was pretty pleased. In fact, coming off of that, this seems as good a time as any reveal my latest piece of work. It's based off the recent announcement of the discovery of Kepler-16b, one of only five planets known to orbit two stars, and the first one whose parent suns are close to being Sun-like (though both are still smaller than our Sun). This image is of a completely fictitious solar system, although the two stars in it have fairly realistic coloration and relative size.


I'm not really happy with the spiral arm running through this picture, but I really, really like how the stars and planet came out, enough to make this my background picture (that's why it has the dimensions it does). They are the main focus, after all. I tried to give an impression of the stars' mutual gravitational pull from their close obit distorting them somewhat away from a purely spherical shape, and for some reason I find the tiny starspots on their surfaces adorable. Ah, well, I should probably get to bed now after being up late last night. A hui hou!

Saturday, October 8, 2011

Messier Globular Cluster Collage

How's that for a noun cluster? This picture is a collage of all the pictures of globular clusters I've taken so far, all nicely labeled.

My housemate Jonathan told me the title immediately made him think of ‘assorted candies.’

These are all at the original size as they appeared in the images I took, they haven't been scaled relative to each other (well, they're original size when you click on the image to see the full version). When you look at them like this it's easy to see why Omega Centauri is one of the best ones to see visually. For comparison, Omega Centauri is about the size of the full moon on the sky. They're arranged in no particular order. They're also not at the same quality level, and I might end up re-doing some of them such as M107 if I get the chance. I've submitted this picture for the slideshow at the annual Volunteer Appreciation Banquet for Mauna Kea volunteers tomorrow, which I'm really looking forward to!

Thursday, October 6, 2011

Pygame to the rescue!

I don't think I've mentioned this before, but in the project Dr. Takamiya and I have been working on we came to the conclusion (after many attempts to stave it off) that the analysis of spectra could not be done reliably by computer (too many false positives), but would need to be done by a human. And when I mention we have a total of 33,525 spectra, you'll appreciate that it's going to take some time.

Because of that, I decided to implement Project Spectra Zoo, modeled after the much more famous and polished Galaxy Zoo. Basically, it involves volunteers from the large number of incoming freshmen this semester doing the analysis for me (in return for getting their names in the paper and some valuable experience). Now, in the spectra to be analyzed, there are a lot that are not entirely clear as to how they should be classified even for someone like myself, so the idea is to have every spectrum analyzed by at least two people and then compare the results, paying attention to those cases where people disagreed. Since having some sort of standardized results would facilitate that happening, I decided to write a program to help people with the analysis.

(Now, I'd just like to say that writing this program shows just how much I have learned and grown over the past year. I used a Python package called wxPython for writing graphical user interfaces [GUI's], and it would have been completely impossible for me to have written something in it at the end of last summer. I know, because I tried for a few days, and got nowhere. Only after learning a bunch more about Python, including the concept of classes, was I able to understand how to use wxPython.)

wxPython is good at what it does, which is created programs with a native feel to them for whatever OS you're using. Using it I was able to create FluxClassify, seen below in version 0.3.0.

FluxClassify.py, V0.3.0
Briefly, each numbered checkbox represents a spectrum in the 15-by-15 array format we're working with. Users can check boxes to represent the presence of a spectral line in an image (or even activate a third state for an "I don't know" answer), save their classifications for both the red and the blue filters (each picture comes in two parts of 225 spectra each), and output a file containing all the classifications they made in an easy computer-readable format.

It's perfectly usable as it is, but it requires users to manually flip between the spectra and the program which gets distracting and slows the process down considerably. I dreamed of a new program, one more similar to Galaxy Zoo: one that would display a single spectrum, wait for the user to classify it, then move on to the next one.  With this grand vision in mind, I set about learning how to place graphics in wxPython (the spectra are all saved as JPEG files).

This turned out to be a surprisingly difficult and daunting task. It turns out that the wxPython documentation is awful. I've always found the (plain) Python documentation to be an amazingly helpful and useful resource, and never realized just how above-par it was. After a two days of bumbling around with confusing and complicated wxPython tutorials, I was ready to—well, not give up, but to look around for other options. It was looking for other options after my first tangle with wxPython that led me to the much-more-useful-for-my-purposes Python Imaging Library last summer, after all.

So a few days ago, I was considering the problem of getting graphics—images—into a program with a GUI. And then the idea came to me: what programs, out of all computer programs, tend to make the heaviest use of graphics? The answer is games. Games, more than any other program, use the most and most complicated graphics. This line of thought came to me because I had recently downloaded the Pygame package when I discovered it had a version for Python 3.2, intending to check it out later. Now, I've spent several hours over the last two days checking out Pygame's documentation, and it turns out to be much simpler getting graphics on-screen. I haven't begun writing FluxClassify's successor yet, but I'm sure it will be a lot easier. It may not look quite as polished, but it'll be more efficient and easier to use, and that's what counts.

And who knows, considering I'll have used a package intended for making games to write it, maybe I'll throw a gaming element or two in there as motivation for my volunteers to classify spectra. It doesn't hurt to make scientific research fun, after all!

Monday, October 3, 2011

Even More Superluminal Musings

In my last post I promised the next one would have some stuff about quantum mechanics and the apparently superluminal neutrinos. Well, here it is a week later, and still no post. This is mostly because my ideas that I mentioned turned out to be of little interest after I thought about them some more, and then I got kind of busy with school and stuff. But since I promised a post, I might as well share what I was thinking about.

To start off with, relativity does not actually say that nothing can travel faster than the speed of light, c. It just says that no information can travel faster than that speed (and also nothing with mass, but since anything with mass carries information, that's almost a sub-case). In fact, in a beam of light composed of multiple 'wave-packets', you can measure the speed in several different ways, and some of those ways will give you speeds greater than c. They can't be used to carry any information, though. Spacetime itself is also thought to be able to expand faster than c (you just can't move faster than c through spacetime...which always leaves me feeling a bit confused).

You're probably asking yourself at this point, what does this have to do with quantum mechanics? A lot, as it turns out, because moving faster than the speed of light is not unknown in QM. One example has to do with the phenomenon known as entanglement. In the right circumstance, two particles can be created together such that they become entangled. What this means is that if one is measured to have a certain attribute, the other will have the exact opposite attribute. The usual example is that if one is measured to have 'spin up', the other will be measured to have 'spin down'. Spin up and spin down are extremely complicated to explain, and don't mean exactly what you would expect in classical mechanics. Just accept that the particles, when measured, can be either one or the other, but not both, and not anything in between, and which state it is is completely 50/50. The "when measured" part is important, because according to QM the particles aren't actually in either state before you measure them. Your act of measurement causes one to take on one state, and the other to take on the other. The interesting thing is that it happens, as far as we can tell, instantaneously.

Say you take one particle (without measuring it) and give the other one to a friend (again without measuring it), and you both take them far apart from each other. Then, at an agreed-upon time, you both measure your particles. Despite them not having a fixed orientation (spin up or spin down) before measurement, measuring one will instantly "collapse" the other into having the other orientation, so that they always have opposites. What's interesting is that you can have the two particles far enough apart that there's no way the second one could "know" the value measured for the first one utilizing any sort of subluminal communication. I.e, if you measure the two particles 20 nanoseconds apart, but it would take light 100 nanoseconds to move between them, there's no way for information to be exchanged according to relativity, and no way for the second particle to know what value to give when measured. And yet it happens. Always when the experiment is performed, the two particle have opposite spins, and the only conclusion is that they are "communicating" instantly. The reason this doesn't violate relativity is because no information can be exchanged this way -- you don't know what the value of your particle will be before you measure it, so there's no way to send a signal to your friend measuring the second particle, because he simply gets the opposite of what you have. If he measures a +1 every time you measure a -1 and vice versa, it does no good if you measure a random set of plus and minus ones.

Anyway, the other way that QM allows for faster-than-light travel is called tunneling. Tunneling is strange and a bit freaky, because there's no analog for it in classical mechanics or our everyday experiences. Imagine a particle trapped at the bottom of a potential well, by which I mean that the particle is repulsed from the sides, and doesn't have enough energy to escape. If the particle is unobserved, it exists as a sort of probability wave, and this wave can sort of leak through the sides of the well if there are areas of lower energy on the other side (think a well dug into the top of hill. The area at the bottom of the hill is of lower potential energy than the bottom of the well). This leakage is highly dependent on several factors, and almost always extremely small -- but what it says is that if the particle is suddenly measured, it has a chance of being found outside the potential well despite not having enough energy to get out. Again, this happens instantaneously, as far as we can tell, but again it can't be used to send information because it all depends on measuring the particle in the first place, and it may or may not be in the well when you do.

After that extremely long roundabout explanation, my initial thought was that the neutrinos were somehow tunneling as they made their way through the Earth's crust, causing them to appear to travel faster than light. After some thought, I decided this wasn't feasible for several reasons.

1. Tunneling depends on repulsion, and neutrinos aren't electrically charged (their name means "little neutral one" in Italian). They only interact via the weak nuclear force and gravity. Gravity doesn't repulse, and the weak force, as its name suggests, is much, much weaker than electromagnetism, which is where all known tunneling comes from. I'm not even sure it would be possible to induce tunneling with the weak force. It also depends on the particle being confined -- if it's just flying through space and meets an obstacle, it can simply ricochet off and never bother with tunneling.

2. Neutrinos hardly ever interact with matter. Whether or not they can tunnel is a moot point if they can pass through the Earth without interacting with a single atom of it, and billions do every second. So even if they could (which they probably can't), they probably wouldn't.

3. Tunneling is by its nature extremely rare for any single particle. Given that the scientists at OPERA have made multiple measurements (thousands, in fact) of the neutrinos that appear to be superluminal, it's extremely improbable that they were all tunneling, especially in light of the above two points.

What will most likely happen is that some measurement or combination thereof will be found to be in error, although it might require improvements to our measuring technology first. I haven't heard anything about the experiment since the initial buzz, but I'll keep an eye out for news, and keep you guys updated on the eventual conclusion of this (although if it does turn out to be superluminal motion, I hardly think you'll need me to tell you about it). A hui hou!