The Eternal Universe

I Am Going To Graduate! (And Possibly Going To Back To Los Alamos.)

2012-01-24T13:36:00.000-08:00

As some of you may have noticed, I have been neglecting the blog for several months. The biggest reason is I have frantically been playing the game of both doing research and applying for jobs; a combination that is stressful enough that it is nearly impossible to maintain any side hobbies.

One glance at the Astro Rumor Mill, where the state of the cosmology/astrophysics jobs are being discussed, you will see that there are several hundred applicants applying for a lesser number of positions. (Which alone is stressful) Now add the fact that you start seeing other people's names get entered onto that page having received offers or being shortlisted while you are receiving rejection letters starting in December and you can get an understanding why come the end of January you might start feeling as stressed as you ever were awaiting the decision of whether you passed or failed the comprehensive exam.

I plan on making a couple blog posts on this as many of you will go through this yourself and I want you to be well prepared. :)

With all that out of the way, a quick glance at that rumor mill and you will find I was offered a Director's Fellowship at the Los Alamos National Laboratory. This is a good offer and it means, among other things: I will be able to graduate this year for sure!!! Graduate school is going to actually come to an end in the coming months!

Now, there is still time to receive other offers, for example the Hubble Fellowships have not yet been named which among many circles are considered a bit more prestigious, so it isn't 100% I will take this offer yet. However, I am very happy to have received this offer as the Director's Fellowship is a great offer and Los Alamos is a great institution to do research at. (And am happy and excited you know what offers you all will have in the coming years.)

On Barbed Wire Fences and Internet Freedom

2012-01-18T20:19:00.000-08:00

When I was in High School I had an excellent American History teacher. One of the things he taught us about was the role of the frontier in the development of the American psyche. He was of course introducing us to Frederick Jackson Turner's Frontier Thesis which emphasizes the role of the American frontier in the development of American ideas of freedom, liberty, and property. Because of the availability of seemingly endless amounts of open land and resources Americans developed a strong rugged individualism and seemingly boundless optimism than was not present in European societies.

All this began to change when in 1874 Joseph Glidden was granted a patent for wrapping a small wire in between two longer intertwined wires. This short, sharp wire, called a barb, would become the critical part of what is now called barbed wire. This simple invention would radically revolutionize the shape and character of the American West (and would go on to change warfare, fortifications, security and crowd control). Over the next few years barbed wire would divide up the historically open range land and would restrict the free and open movement of people and cattle.

The change was not immediate, but over the next several decades the change came in fits and spurts. In some cases the changing dynamic was manifest in the Range Wars of the late 1800's. The open range cowboys and ranchers fought the fences and farmers for access to water and grazing land. This type of conflict became so typical that it would later be immortalized in the many Westerns made in the 50's and 60's. Perhaps one of the most famous movies in this genre was The Man Who Shot Liberty Valance.

Despite all this it was not until 1893 that Frederick Jackson Turner declared the closing of the American frontier, and wondered how the closing would change American society. Even though we "ran out of new land" to populate, Americans were able to find new frontiers. We moved into new technologies. We were inspired to go into space and even reached the moon. For a while space became our final frontier.

Due to some minor issues with space travel it seemed that that frontier would have to wait. This is when the frontier of cyber space opened up to us. Again we had before us a seemingly endless and uncharted territory where we could go and range free. Just as in the 1800's the frontier is being populated and is playing a significant role in the shaping of our society. But just as history repeats itself (or at least rhymes) we are again faced with the barbed wire of our age. It is coming in many forms, and most recently it has made an appearance in the form of two bills before the American Congress.

Some people are staunchly opposed to these bills (or any form of control, for that matter), while others are concerned about the apparent lawlessness of the Internet and think that something must be done. I have seen some comments about how people are just over reacting and that this will not actually change the face of the Internet since the same powers that be that are pushing these bill have an interest in keeping it the way it is. It is hard to say how these bills, or any other approach would change the Internet, but if history is any clue then we are in the midst of a modern day electronic range war. The question is, will the Internet remain open range land or will we accept and keep some form of electronic barbed wire. The are benefits to both, but it is debatable if the American psyche will allow the barbed wire to happen or if it will force the frontier to remain how it is.

Now I must admit that there important differences between the range wars and barbed wire of the 1800's and the issues of Internet freedom but as I mentioned before, even if history does not repeat itself it will at least rhyme. Still, we are perhaps in a pivotal moment in history where our last immediately available frontier may be closing and we are left to wonder how that will affect our lives, our society and our future. Or this may not be the pivotal moment in history, but we won't know until the history books are written.

What I Meant to Say...(aka Cultures for Quals)

2012-01-18T12:55:00.000-08:00

Not long ago I posted about passing the PhD qualifying exam. Hooray! I provided a rather informational view of the prelim process (what you'd find on our Aerospace Dept. web page at the University of Michigan), and then a recapitulation of some of the culture surrounding the process.

As every student can attest, the culture surrounding professors, exams, and classes is usually fairly loaded with tradition, and reputation for the class itself, the tests, and the professors teaching. The culture surrounding the PhD qualifying exam is even more encumbered with these traits because of the gravity associated with arguably the most important test in a student's career. In our dept. the PhD qualifying exam was recently changed (as I mentioned in the first post), and unsurprisingly the culture surrounding the exam changed alongside it.

In years past (so I'm told) students got together many months in advance and began studying. Practice sessions were numerous with plenty of example problems. Those practice sessions were often conducted by students who previously passed the exam. A camaraderie was established between those students that lasted far beyond the exam. Despite the individual nature of the exam, the students made a group effort, and there was strength in numbers. Celebration afterwards consisted of a night of binge drinking followed by a solid month of surfing the web in lieu of research (well that's what I've been led to believe ;-) ).

Today's culture is a bit different. The group camaraderie isn't quite as strong, the celebration shorter, the preparation more individual, and to my knowledge few students having passed the exam are willing to donate their time to the cause of future quals takers. Perhaps this is good to some extent. At least one important upshot of the change is the large number of practice sessions generously conducted by the faculty. Those practice sessions, without doubt, for me, were the most important part of preparation for the PhD qualifying exam. Were they tortuous as one professor regularly joked about? Yes. Were some professors hard on us? Yes. Did they bring out a slew of tricky problems not covered in class? Yes. But I don't believe for a second that any of us who took the exam would deny the importance of being instructed, especially in such a small group setting, by admittedly some of the world's best experts in our area of education. Let me be crystal clear here: despite whatever "torture" was inflicted, despite being pushed to the limits, and feeling that self-destruction was inevitable for being forced to derive the EOMs of a glider (which I of course learned how to do after the fact, which I think is the point of all this education anyway), the benefits far outweighed the costs, and I sincerely doubt my ability to pass that exam without the help I received in this regard. My feeling is that these practice sessions (a far cry from merely being a chance to torture pathetic grad students) really represent the desire of faculty to help promising researchers be successful and appropriately represent the institution they know and love.

This is one aspect of the culture of our quals that I really hope sticks around. The binge drinking can go (I don't drink anyway), and I'd get bored after about a week of surfing the web. But the instruction provided here in our dept. from top-notch faculty really is unparalleled and I would be sad to see those faculty conducted practice sessions stopped, especially if faculty felt it was unappreciated.

For my own part, I think it is important to show that former quals takers recognize the importance of and are willing to conduct practice sessions with the next gen quals takers. Rekindling that camaraderie, the passing of the torch, and the support from generations past creates the potential for developing strong relationships, increase academic prowess, and represent the university even better.

...and that's what I really meant to say.

Dorigo: Firm Evidence Of A Higgs Boson At Last!

2011-12-13T07:32:00.000-08:00

This post is designed partly to send to to Dorigo's blog for more information as I am quoting his post and because, unlike the "mainstream" media, he actually is a professional particle experimental physicist and so gives the story a little closer to the truth then you will find other places.

That said, it looks like the search for the Higgs Boson, undoubtedly one of the most promenant searches in physics of our generation, may be nearing an end. Just some quotes:

I believe this is firm evidence of the existence of a SM Higgs at 124-126 GeV.

First of all, we expected it to be around there...

Second, three-point-six standard deviations above background expectations from one experiment would not be enough ... But the two experiments are providing a very coherent picture.

Third, the evidence is coming from different search channels, and they all appear to be coherent with the Standard Model expected cross section.

Fourth, I do not believe we need to worry anymore too much about the look-elsewhere effect.

As you know, I have always said "half of three-sigma results are false" since there is just so often an unknown systematic skewing your statistics. However, in this case two different experiments using different channels arrived at the same answer. One at 3.6 sigma and the other at 2.4 sigma. Now I would say the risk of something being off by an unknown systematic is pretty minimal and thus I think we have reason to believe there is a high probability we are finally uncovering the Higgs: A boson at 124-126 GeV. (Though it isn't official yet I should remind you!)

But still: Congratulations particle physicists!

Three Kinds of Lies: Statistics on BYU Football

2011-12-07T11:14:00.001-08:00

I have been fascinated with the quarterback controversy that plagued BYU this season between the hyped phenom Jake Heaps and the grizzly "gamer" Riley Nelson. While Nelson had much better traditional statistics than Heaps, Heaps played against a tougher schedule. The author of a the BYU sports blog LoyalCougars.com asked me if it were possible to statistically correct for the difficulty of the defenses Heaps and Nelson played to compare them on level ground. Being a football fan and a math nerd, I dove right in. The results are written up in a post over at LoyalCougars.com, so if you feel like delving into the statistical rabbit hole, go check it out.

Kepler Finds A Possibly Live One

2011-12-05T09:53:00.001-08:00

The Kepler mission has been looking for planets that might have liquid water (and therefore life as we know it) and it looks like they have their first confirmed candidate - the oh-so-memorably-named Kepler 22b. Kepler 22b, or just 22b for short, has a radius 2.4 times as big as the Earth's and orbits a star that has roughly 2% less mass than the Sun every 289 days. That places it right at the inner edge of that star's habitable zone (the range of distances from their star where planets might have liquid water), as illustrated by this lovely NASA graphic.

If you assume an Earth-like greenhouse effect for 22b (which is a big assumption considering Venus and Mars have drastically different atmospheres than Earth), the mean surface temperature (assuming it has a surface) would be a balmy but not unreasonable 22 degrees Celsius compared to Earth's mean surface temperature of about 14 degrees Celsius.

NASA likes to call this type of planet a "Super-Earth", however that's something of a misnomer as planets with more than twice the radius of Earth probably aren't primarily rocky planets like Earth, Venus, and Mars but rather more like smaller, defrosted versions of our solar system's ice giants, Neptune and Uranus. Using planetary structure models, one can map out the range of possible compositions for a planet of a given radius (remember with Kepler's transit data they know the planet's size but not it's mass).

As you can see, 22b likely has a composition with significant amounts of hydrogen and helium, which means it may have a very thick, deep atmosphere. Alternatively it could have very large amounts of water, but at this point there's just no way to tell what it's made of as the planet is too far from it's star to be detected using the radial velocity technique, which can determine a planet's mass. It's possible that space telescopes like Hubble and Spitzer might be able to get some information on the composition of the planet's atmosphere, but most likely this one is going to have to wait for new telescopes and instruments to be characterized more fully.

The best part is that 22b is not alone. The Kepler team only officially announces a planet as discovered when they can confirm it using another telescope (here they used Spitzer to verify a transit), but the list of "planet candidates" in habitable zones is growing. As of the now, there are about a half-dozen planet candidates in habitable zones that are smaller than 22b.

As Kepler approaches it's third anniversary, expect those numbers to increase dramatically. You can already see the trend by comparing the numbers of planets from the June 2010 (in blue), February 2011 (in red), and December 2011 (in yellow) data releases.

You can find the official NASA press release here and the slides from that press release (which are the source of these lovely images) here.

Yahoo! Makes Black Holes Hip

2011-11-30T20:35:00.001-08:00

Disclaimer: As a certified nerd in high school, I never really knew what the kids were saying even when I was one of them, so "hip" may not be the right word. Whatever the appropriate vernacular, Yahoo! is doing it for news about black holes - complete with pop culture analogies. You can see the video here (curse you Yahoo! and your lack of embedding options). The specific "discovery" they reference was an observation of a peculiar gamma ray burst by the SWIFT satellite, which is a pretty amazing bit of science and certainly worthy of mention. Besides, everybody likes black holes due to their position on the top of the cosmic sexiness ladder.

As someone who once hoped to model almost exactly what was observed, I have to say that Yahoo! did a decent job with the science. Sure, they make it sound like we have close-up video of the event rather than a brief gamma ray point source and they think astrophysicists wear lab-coats and write "science" on glass plates, but those are forgivable mistakes in my book. My only two questions are how can we get more videos like this and why for the love of everything holy don't they have an embed option?

You WIll Not Be Unemployed If You Go Into Astrophysics!

2011-11-09T11:43:00.000-08:00

The Wall Street Journal has compiled a list showing the average salary and percent unemployment for people who major in various fields. To my surprise, the unemployment for people who major in an Astronomy or Astrophysis is zero percent!

Here is the breakdown: (major,unemployment, 25% earnings, 50% earnings, 75% earnings)
ASTRONOMY AND ASTROPHYSICS 0.0% $56,000 $62,000 $101,000

Compare that with physics science in general:
PHYSICAL SCIENCES 2.5% $36,000 $51,000 $68,000

And a few other majors:
NURSING   2.2% $48,000 $60,000 $80,000
MATHEMATICS   5.0% $42,000 $63,000 $95,000
ACCOUNTING 5.4% $41,000 $61,000 $94,000
COMPUTER SCIENCE 5.6% $50,000 $77,000 $102,000
GENERAL ENGINEERING   5.9% $47,000 $73,000 $101,000
PRE-MED PROGRAMS 5.2% $40,000 $60,000 $86,000
BUSINESS MANAGEMENT 6.0% $38,000 $56,000 $85,000
ECONOMICS 6.3% $42,000 $69,000 $108,000
HISTORY 6.5% $34,000 $50,000 $81,000
ENGLISH LANGUAGE AND LITERATURE 6.7% $32,000 $48,000 $75,000
PHILOSOPHY AND RELIGIOUS STUDIES 7.2% $30,000 $42,000 $65,000
PRE-LAW AND LEGAL STUDIES 7.9% $32,000 $45,000 $69,000

And... the worst is clinical physcology:
CLINICAL PSYCHOLOGY 19.5% $25,000 $40,000 $61,000

But seriously why?!?!
Look, as cool as it is to look at stars, galaxies, the CMB and other stuff related to the cosmos all day, why in the world do people who do so find themselves with zero unemployment? It's not like we put bread on the table for anyone in any direct way or anything of such practical value. And yet there seems to be plenty of jobs to go around. But why? And it is more then just zero unemployment. We seem to make more money then most on top of it.

But I'm not complaining. I am happy to find a high paying job waiting for me. I guess the occupy Wall Street people need to start occupying the planetariums. :)

Why I haven't been blogging a lot lately

2011-11-03T10:34:00.000-07:00

I have a long list of potential posts I want to write and other posts I want to respond to but unfortunately a lot of my focus is taken up in research and teaching. So to give you an idea of what I am doing I will present this graphic:

Graph showing the number of processors being used on the Kure supercomputer. y-axis shows number of processors, x-axis shows time. The blue line shows how many processors are currently being used.

That bump on the right hand side of the graph is me submitting a job to the supercomputer. There aren't a lot of people using the supercomputer at this time, so I am taking advantage of that and submitting my large jobs that take 300+ processors to do. The supercomputer that I am using is named Kure after Kure Beach in North Carolina (all our supercomputers are named after beaches, nice huh?). Kure has 1856 processors, of which my research group have exclusive use (priority access) to 320 of them.

When I get a good video of what I am doing I will post it here, but for now I am dealing with stuff like this:

Your LSF job listed below died because of a network problem with 2 of the nodes it was running on. We are working with networking to fix the network problem. You can resubmit the job at your convenience. Sorry for any trouble this may have caused you.

Job <84297>, User , Project , Status , Queue , Command <#BSUB -n 128;#BSUB -q patrons;#BSUB -R "span[ptile=8]";#BSUB -e err.%J;#BSUB -o out.%J;mpirun ./athena -i starburst.athinput -d ./frac_cloud >starburst_frac.log>, Share group charged

Thu Oct 27 13:22:14: Submitted from host , CWD , Output File , Error File ;

Thu Oct 27 13:22:25: Dispatched to 128 Hosts/Processors <8*n-6-14> <8*n-6-10> <8*n-11-6> <8*n-9-3> <8*n-9-4> <8*n-6-13> <8*n-4-9> <8*n-9-6> <8*n-9-2> <8*n-9-8> <8*n-9-7> <8*n-9-5> <8*n-6-15> <8*n-10-12> <8*n-10-11> <8*n-11-5>;

Wed Nov 2 17:03:22: Completed ; TERM_EXTERNAL_SIGNAL: job killed by a signal external to LSF.

Copernican Versus Tychonic Solar System Models.

2011-11-03T09:09:00.000-07:00

There was a time not long ago where scientists believed the earth was the center of the universe, like Tycho. However, after Copernicus had his revolutionary discoveries we learned that we, and the rest of the solar system, in fact orbit the sun.

This website has a cool demonstration of how the solar-sytem would look under both models. Of course, Copernicus was right, but it is still cool to see what the solar system would look like if Tycho was. Use the faint buttons in the lower right corner to change between models.

The other cool thing I like about this animation is that you can see the relative length of orbits for each planet.

Do Cars and Construction Equipment Discourage Women in Physics?

2011-11-02T09:00:00.000-07:00

Physics has a gender problem and to see an example you need look no further than the list of this blog's authors to your left. You'll note that all of us are male. A broader look into this problem yields what is known as the "scissors diagram".

Here the black lines show the fraction of men and women at various stages of physics careers while the red lines show the expected fraction from historical trends (because when current full professors were in high school there were far fewer women taking physics than there are today). It appears that for some reason men and women both take high school physics in nearly equal numbers, but that for some reason women are far less likely to study physics in college. Physics is not alone in this problem, as I've written about previously, but we are having a much harder time fixing it than fields like math or chemistry.

There are a lot of ideas as to why this might be the case but here's one from a Physics Today article that I hadn't considered before - problem sets based on cars and construction equipment. I recommend reading the whole article as it is well-written and insightful, but allow me to over-simplify the basic argument: homework problems in introductory physics courses generally use examples from topics like cars and construction work that are more likely for men to be familiar with than women.

My initial reaction was skepticism - how much difference can using terms like "pile driver" instead of "a machine that drops a heavy weight on [a metal rod], lifts the weight, and drops it again" possibly make? But the more I think about it, the more I start to think that maybe the authors have a point. I don't think that the real issue is that men are more familiar with pile drivers than women - I think the issue is that when textbook problems appeal more to men than women, a subtle message is sent that women are out of place in physics, and no one wants to feel out of place.

Now don't get me wrong - I'm not arguing that physics problems should avoid real-world examples or that women can't understand problems talking about cars going around banked turns - but I do think it would be wise for physics faculty to try to use more examples from fields that have a higher concentration of women - like health care or preforming arts. Instead of asking questions about baseball and football only, mix in some questions about ballet. Ask more questions about blood pressure and less about pneumatic nail guns. I'm sure this single step won't fix the larger problem, but I think it's generally a good idea to do everything we can to attract the best people to our field and not just the best men.

How The Universe Changes At Every Wavelength.

2011-11-01T09:10:00.000-07:00

I found a very interesting website that shows what the universe looks like at every wavelength and it is really cool. I encourage you all to check it out.

Now, I am not an expert on the physics that dominates each wavelength but I will mention a few I know a thing or two about. First, are the familiar visible wavelengths are shown in the top image. Pretty cool. Nice shot of the galactic plane of the Milky Way. The visible bands of course are much of the stars in the Milky Way themselves.

Above is the far-infraed and that means dust! That's right, the light coming from dust is brightest in the far infrared, and so what you are seeing is the wispy dust structures surrounding the Milky Way.

Next: the above is the microwave regime and what should that immediately bring to mind?.... The Cosmic Microwave Background (CMB) of course! And you can see it well in the corners of the image with the tell tale fluctuation patterns. That glow my friends dates back to just after the big bang itself. Unfortunately you also see how hard life can be for CMB physicists as they have to extract the CMB with all that other "foreground" garbage (garbage to CMB people at least) in the way that has to be carefully subtracted out.

Lastly: Gamma ray bursts. This is what the universe looks like in gamma rays. You will note some strong bright dots bursting with gamma rays. These are cool because they are often very energetic events like supernova or formation of black holes.

So you can learn a lot from looking at the same sky in different wavelengths. So go to that site, play around and have fun. The differences you see at each wavelength underscore different physical processes happening across the universe.

Could The First Stars In The Universe Really Be Annihilating Dark Matter?

2011-10-31T09:33:00.000-07:00

Stars today burn bright through the interactions of elements like hydrogen and helium. But was that the same story for the first stars in the universe, or was their light dominated by the annihilation of dark matter? Recently, Ili et al. took up the challenge of finding out what astronomers should be looking for if this is the cas.

Some background: If dark matter really is a weakly interacting particle, then shortly after the big bang, when the universe was very hot and dense, dark matter particles should have been rapidly annihilating. But what if, after gravitational collapse, the original dark matter halos (think giant globs of dark matter being pulled together by gravity) became so dense that it re-triggered the annihilation of dark matter? If this happened, the light from the first stars would not be mainly from elements like hydrogen and helium interacting, but instead be from dark matter annihilations themselves.

Well how could we detect such a thing? Well start by looking at the plot below:

Here we see the predicted "star formation rate" versus redshift predicted by their numerical simulations. What this shows is that the peak star formation of these "dark stars", as they are called, happened at a redshift of around ~12, or ~13 billion years ago, just after the big bang. (Remember, the higher the redshift the farther back in time.)

When an object emits a lot of light a long time ago, two things happen:

The light becomes redshifted due to the expansion of the universe so that what once was visible light becomes infrared.
They lose a lot of signal at certain wavelengths due to the Lyman alpha forest. (See plot below).

The plot above shows what happens when you have the combination of 1 and 2, and is the predicted "SED" for these objects meaning, this is how bright the objects are supposed to be at each wavelength. As you can see, one one hand, since these objects are at high redshift, the light they emit at the ultra-violet and visible wavelengths has been redshifted to the infrared. Second, because of the Lyman alpha-forest, you see a drop of below certain wavelengths of light. (If you don't understand all this it's fine, just know there are predictions for how bright these objects should be at each wavelength so we can now go look for something with that pattern.)

Unfortunately, we can stare at these objects at every wavelength. Instead, we have to use powerful telescopes and stare at them at the specific wavelengths of those telescopes and hope for the best. For example, this is a prediction of what Hubble could see in the 1.25 and 1.6 micrometer wavelength bands it has:

The solid red and blue curves are the predictions of the "magnitudes" of these objects in the 1.6 (red) and 1.25 (blue) micrometer bands of Hubble. (Magnitude is a measure of brightness and the smaller the magnitude the brighter the object... not a typo, astronomers do everything backwards...) So if you could find an object at redshift 10 with Hubble with a magnitude of ~28 in the 1.6 micrometer band and ~30 in the 1.25 micrometer band, that could be a good hint.

The next step would be to rule out such an object being a normal star. To do this you use spectroscopy:

Diﬀerentiating ﬁrst galaxies at z>10 from [dark stars] would be possible with spectroscopy: the [dark stars] (which are too cool produce signiﬁcant nebular emission) will have only absorption lines while the galaxies are likely to produce emission lines as well. .Of particular interest would be the HeII emission lines at λ ∼ 1.6µ as well as Hα lines which would be signatures of early galaxies rather than [dark stars].

So there you go: find a high redshift object with the right drop-off in brightness in the right wavelength bands with the right spectroscopy properties and you make have a star, not powered by the interactions of hydrogen and helium like stars today, but may in fact be light from dark matter annihilation similar to the theoretical dark matter annihilation that may have been given off just after the big bang.
Cosmin Ilie, Katherine Freese, Monica Valluri, Ilian T. Iliev, & Paul Shapiro (2011). Observing Dark Stars with JWST e-print arXiv: 1110.6202v1

The Real Money In College Football

2011-10-28T09:35:00.000-07:00

Every wondered how much money goes into college football? Apparently, Paula Lavigne, an analysist for ESPN has a website devoted to exactly how much money is going through the hands of college football teams:

The information comes from detailed financial disclosure forms that athletic departments submit annually to the NCAA. These are for the fiscal year ending in 2008. ESPN requested the forms from all 120 Division I colleges in the Football Bowl Subdivision under state and federal public records laws. Private colleges and others not subject to those laws declined to release their forms. In those cases, ESPN filled in some of the blanks using financial information that public and private schools are required to provide to the U.S. Department of Education Office of Postsecondary Education. The only exception is Navy, for which no information was found.

1. Here are some interesting finds. First, my Alma Mater BYU: (Click to make bigger). ~$37 million in/~33 million out.

2. Or our in state rival Utah: ~$27 million in/ ~$28 million out (Losing money Utah!)

Compared to the two teams ranked #1 and 2, stating with LSU: ~$85 million in/ ~$81 million out.

And finally ending with Alabama: ~$124 million in/ ~$123 million out!

And there you have it. Some schools are both bringing in and spending > $120,000,000! Now, I don't care in the sense that I think it is wrong. But I will say I am amazed that college sports bring in this kind of money to individual teams! But on the other hand, I bet college football has an audience on par with many professional sporting programs. And I wouldn't be shocked to hear a professional sports team brings in over $120 million.

And just for fun on a Friday, I leave you this and let you decide how easy it is to find the correct answer:

Relativity Does Not Say Time And Space Are On The Same Footing.

2011-10-27T10:00:00.000-07:00

Many people claim relativity says that space and time are on equal footing and since we can move back and forth in space it doesn't make sense that we can only move in one direction in time. (Admittedly I have in fun used the argument myself but now I would like to give the reason I think the argument is wrong.)

To do so, I am going to quote from David Tong's lecture notes on String Theory that explains why time is *not* on the same footing as space even in relativity, and you are constrained to move forward in time after all unlike space.

First, here is the argument in a nutshell: We want our physics equations to be Lorentz invariant, and given Lorentz transformations mix up space and time, we want need equations where space and time are on the same footing. However!!! To do so we have to add a fictitious degree of freedom that isn't real. Therefore, this idea that space and time are on the same footing is just a mirage we created by adding a fictitious degree of freedom to get the equations to have a symmetry we want. Furthermore, given this fictitious degree of freedom is unphysical, your equations produce non-physical answers until you remove this non-physicality using constraint equations. Once you do you find that you have always been constrained to move forward in time... just as common sense dictates.

Now to Tong:

Although the [non-Lorentz invariant] Lagrangian is correct, it’s not fully satisfactory. The reason is that time t and space x play very different roles in this Lagrangian. The position x is a dynamical degree of freedom. In contrast, time t is merely a parameter providing a label for the position. Yet Lorentz transformations are supposed to mix up t and x and such symmetries are not completely obvious in (1.1).

So, even though a Lagrangian where space and time are not on the same footing is physically correct, in order to have the fancy symmetry of being Lorentz invariant we would like to change the situation.

In this course we will... promote time to a dynamical degree of freedom. At first glance, this may appear odd: the number of degrees of freedom is one of the crudest ways we have to characterize a system. We shouldn’t be able to add more degrees of freedom at will without fundamentally changing the system that we’re talking about. Another way of saying this is that the particle has the option to move in space, but it doesn’t have the option to move in time. It has to move in time. So we somehow need a way to promote time to a degree of freedom without it really being a true dynamical degree of freedom! How do we do this? The answer, as we will now show, is gauge symmetry. (I added emphasis)

Again, the first mentioned action describes reality and claims only space is a dynamical degree of freedom, not time. We want our equation to become Lorentz invariant sure, but we can't just start adding degrees of freedom where they don't exist without paying the price of our equations not being physical:

[After adding Lorentz invariance] Naively it looks as if we now have D physical degrees of freedom rather than D−1 because, as promised, the time direction X0 ≡ t is among our dynamical variables: X0 = X0(τ). However, this is an illusion. To see why, we need to note that the action has a very important property: reparameterization invariance...The upshot of this is that not all D degrees of freedom X are physical. For example, suppose you find a solution to this system, so that you know how X0 changes with τ and how X1 changes with τ and so on. Not all of that information is meaningful because τ itself is not meaningful.

And, since things are no longer physical, to bring reality back to our theory the unphysical aspects of our equations need to be constrained away:

The fact that one of the degrees of freedom is a fake also shows up if we look at the momenta. These momenta aren’t all independent. They satisfy p^2+m^2 = 0. This a constraint on the system... From the worldline perspective, it tells us that the particle isn’t allowed to sit still in Minkowski space: at the very least, it had better keep moving in a timelike direction with p0^2 >= m^2.

So, just as we perceive with our everyday senses: time is not on the same footing as space after all. The unphysical aspect of our equations giving the mirage that this was the case needs to be constrained away once again giving results showing we are allowed to freely move in space, but time is forced upon you as always moving forward in accordance with p0^2 >= m^2. (Here p is your momentum).

So in Conclusion, and to repeat: Don't be fooled. The "equations of relativity show time and space are on the same footing" claim is wrong. The equations only appear that way because we have introduced a fictitious degree of freedom to accomodate Lorentz invariance. In reality, that un-physicality needs to be constrained away to get physical solutions, and when they are, you quickly find you cannot move through time in any direction as you do through space but are constrained to move forward in one direction in accordance with p0^2 >= m^2. This constraint is often called the "on-shell" condition for those who care.

So time always moves forward, even in relativity... just as common sense experience shows.

In Defense Of Infinity.

2011-10-26T11:54:00.000-07:00

I would like to write a post in defense of Infinity. As some of you may know, there are those who would like to remove Infinity from mathematics since Infinity is thought to be an unnecessary assumption whose existence can neither be proven nor disproven: (And heaven forbid we believe anything that can’t be proven!)

The axiom of infinity cannot be derived from the rest of the axioms of ZFC, if these other axioms are consistent. Nor can it be refuted, if all of ZFC is consistent.

ZFC is the minimal set of axioms for modern math to work out. So basically a few things:

Modern math is just as consistent with or without Infinity. Every finite result in mathematics could have been derived with or without needing to refer to infinity. (Sometimes people do like when then claim things like they are “integrating to infinity”, but technically a reference to infinity isn’t needed to get the same answer)
No matter how hard you try, Infinity "cannot be derived...Nor can it be refuted" by ZFC meaning you cannot ever infer the existence or non-existence of Infinity from the rest of mathematics.

So here is the million dollar question: Do you get rid of Infinity given 1 & 2?

It would ruin mathematics for a lot of people, especially the mathematicians themselves, since infinity is required to produce all the most interesting stuff. Furthermore, what if infinity does exist and you are removing it just because you can't know either way given everything else? Think of all the intellectual damage done to mathematics if infinity is falsely removed! (There are entire branches of good math if infinity is real!) But then by that same token, I guess you also have to ask if myriads of mathematicians are just wasting their time studying an entity that you can only be axiomatized and no more.

As for me and my house. I for one double majored in mathematics and so am quite aware of the amazing intellectual structures that can be built with the assumption of infinity and to be honest... they are pretty amazing! At some point, the beauty, wonder, and to be quite honest *practical utility* (integrating to infinity is darn helpful sometimes!) of assuming the existence of Infinity outweighs any pros that seem to come from getting rid of armed by nothing more than philosophical arguments.

The reality is Infinity has been around for enough centuries to have proven it's utility, beauty and ability to make many magnificent contributions to mathematics. I can't say there is any evidence beyond philosophical wishful thinking to the claim that math would be better off without Infinity... even if you were to believe Infinity was false! I for one have tasted math containing Infinity and love it, am inclined to believe it, and am pretty sure I will be engaging in math containing/refereeing to infinity for the rest of my life as it seems like the most wise, lovely, productive and correct thing to do.

Student Loan Debt, Blaming Wall Street, And A Lack of Intelligent Solutions.

2011-10-20T08:10:00.000-07:00

I am not trying to diss this Occupy Wall Street movement too much, as some of their concerns may be legitimate, but I find it silly that one of their "concrete issues" may be that student loans are soaring:

Politico reports that student loan debt now exceeds one trillion dollars, an amount that should impress even Dr. Evil. Politico further reports that this is one of the more concrete issues driving the OWS protests and provides some enlightening examples of their particular gripes.

Really?!?! Wall Street is to blame for your student loan problems? Didn't your university warn you, as they are supposed to, that you better not take out a lot of student loans as they are risky? (And if you are sooo intelligent that you deserve a fancy college degree, do you really need to be warned of the obvious??)

To me, this seems like a "concrete example" of people trying to blame someone else for their own problems.

And sure, Wall Street has played their part in the current recession and in that sense maybe they have played a role in hurting the job market. But if you take out a massive amount of student loans, and don't have a plan B in case you don't get your preferred job, then you should perhaps be protesting yourself.

And don't accuse me of being the rich guy pointing the finger at those I can't empathize with. I am supporting a wife and two children off of a graduate student salary and the thought has never occurred to me to blame Wall Street for any student loan problems I may or may not have!!!

And if their goal is to "receive a student loan bailout", why protest Wall Street? Wall Street is never going to pay the student loans of angry protesters. Only the federal government has a chance of excusing student loan problems and so I am a little confused why, given they apparently payed soooo much to educate themselves, they can't seem to figure out who in reality is the right group to be petitioning/protesting.

I'm pretty sure these people need to:

Realize the responsibility of taking out too much debt, without a plan B when your preferred job falls through, lies first and foremost on you. (Don't forget... you were warned going into these loans!)
Use some of the education they apparently payed so much for to realize that only the federal government can deal with student loan relief, Wall Street will never care, and therefore they should pick up their signs and march down to Washington if the only solution they are intelligent enough to come up with is to demand someone else will bail them out of the risk they knowingly took on themselves.

Seriously! (Now back to research.)

Shameless Self-Promotion: Read Me in the APS News

2011-10-19T14:42:00.000-07:00

Many people have their 15 minutes of fame - mine started once the APS News (the monthly newsletter of the American Physical Society) hit mail boxes in physics departments everywhere. That's right, if you open your October 2011 issue of to page 4 you'll see an exceptionally well-written letter to the editor about the need for physicists to stop blaming politicians for recent funding disappointments and get active promoting basic science research to the public.

In all seriousness, I would recommend that we all look into joining Scientists and Engineers for America, which "is a nonprofit, nonpartisan organization that encourages technically-trained citizens to become more engaged in US politics and the policy-making process", or another organization like it. The issues facing science funding are clearly political, but generally not partisan. Pretty much everyone from both parties thinks it's a good idea to develop the science that will enable new technologies the way electromagnetism has enabled the development of wireless communication, but if we don't make our case effectively to the public some one else will convince politicians with short attention-spans to funnel resources elsewhere.

Big News: Einstein Is Still Right

2011-10-16T19:53:00.000-07:00

A couple weeks ago I posted that the OPERA collaboration had measured neutrinos moving faster than the speed of light in violation of Einstein's theory of special relativity. The experiment was very simple - neutrinos produced at CERN on the broader between Switzerland and France were shot towards a detector in Italy. The time between the pulses' creation and detection was measured using atomic clocks and the distance traveled was measured using GPS satellites. The result was that on average the neutrinos arrived 60 nanoseconds faster than if they moved at the speed of light.

It turns out that the problem wasn't too much Einstein but rather not enough. A Dutch physicist named Ronald van Elburg found that the OPERA team made a small mistake in the way they applied special relativistic corrections due to the velocity of the GPS satellites. This correction to the OPERA team's calculation should decrease the travel time of the neutrinos by 64 nanoseconds. You can read the pre-print here.

In response, Einstein says:

Renaming the VLA

2011-10-15T19:16:00.000-07:00

Today the National Radio Astronomy Observatory (NRAO) announced that they would be renaming the Very Large Array (VLA) radio telescope in New Mexico. Due to significant changes to the fundamental sensors that make up the telescope they felt that they should rename it since they essentially have a different instrument. Originally they were just going name it the Expanded Very Large Array (EVLA) but I assume that as a good PR move, and a way to say to normal people "Hey! We exist!", they decided to open up the renaming process to the public, which means you (yes you) can participate and submit your own idea for what it should be called.

How can you participate in this wonderful "Let's get the general public interested in radio astronomy" opportunity? Well if you follow this link you can find where to go to submit your own name, and perhaps they may just consider it. I know that I will be submitting one or two possible names. They have to be in by December 1st, and they will announce the result at the AAS (American Astronomical Society) meeting in January.

As a side note: In reading a news story on the BBC about this announcement I found this paragraph quite funny,

"The astronomy community has a long history of descriptive yet fairly unimaginative names - including the VLA itself, the Very Large Telescope in Chile, and the yet-to-be-built European Extremely Large Telescope (the design for which was chosen over the alternative Overwhelmingly Large Telescope)."

Comparing Sunglasses to Laser Safety Glasses

2011-10-11T16:23:00.000-07:00

I recently posted about the absorption properties of sunglasses, and Jonathan Livengood asked about how sunglasses compare to laser safety glasses. Since I had three pairs of laser safety glasses sitting around in the lab I decided to scan them and show how they compare here.

This image contains the three sunglasses that I showed in my previous post (the black, red and pink lines) and with it I have included the three laser safety glasses (dark, medium and light blue lines). The first thing to note here is that the sunglasses block out light across the visible spectrum (from ~400 to ~720 nm).

For example, the sunglasses that block the most light (the black line, and picture 4 below), and in particular absorb a lot in the blue part of the spectrum (400-500 nm) and therefore they appear to have a slight green tint to them. They also let in less than 10% of the total light. The other pair of good sunglasses (picture 5) also let through less than 10% of the total light. Even the little kid's sunglasses (picture 6) only let through ~30% of the total visible light. Compare this with the laser safety glasses which may allow between 10-80% of the light through depending on the type. Of the three kinds here they let through approximately 30%, 50% and 80% of the visible light. So if you are looking to use laser safety glasses as sunglasses, I would advise against it, they aren't made for it.

The purpose of laser safety glasses is to block out specific wavelengths but allow in as much light as possible in other wavelengths so that you can still see and work in a dark room. The three pairs of glasses here are mostly designed to work with HeNe lasers which have their strongest visible peak at 633 nm, or other red lasers (the lightest colored glasses have a very strong absorption peak further into the infrared, which corresponds to another mode of the HeNe laser).

As for cost, I have no idea what the three pairs of sunglasses cost that I have shown here but I would venture a guess that the two good ones cost between $20-$30, while the kid's sunglasses run about $6-$10 per dozen. So cheap and dangerous. I don't know how much these pairs of laser safety glasses cost, but they typically run from $140 to $300. The reason for this is seen in the tight peaks of absorption around specific wavelengths while letting in as much light as possible in other wavelengths so that you can still see to work. Also you have to buy a different pair for each type laser you are working with since what works for one type of laser will not work for another. This is why science is not cheap.

Pic. 1: Darkest laser safety glasses. Dark blue line in graph.

Pic. 2: Medium laser safety glasses. Medium blue line in graph.

Pic. 3: Lightest laser safety glasses. Light blue line in graph.

Pic. 4: Dark Sunglasses. Black line in graph. I found these in the lab. I have no idea how much they cost, probably about $25.

Pic. 5: Biker Sunglasses. Red line in graph. These belonged to my brother. He bought them in high school. I don't know how much they cost, probably about $25.

Pic. 6: Kid's sunglasses. These cost about $6/dozen.

The First Observations From ALMA

2011-10-05T19:03:00.000-07:00

The Atacama Large Millimeter/sub-millimeter Array (ALMA) has just started putting out its first results. ALMA is currently the largest telescope in the world, and it is only 1/3 the way built. This telescope is a radio telescope so it looks into wavelengths other than the visible spectrum, specifically it looks at radio waves (hence it is called a radio telescope).

For many people their only introduction to radio telescopes came from the movie Contact which featured the Arecibo radio telescope (which also featured in GoldenEye) and the Very Large Array (VLA). While the radio telescopes have been used to search for extraterrestrial life, their main purpose is to look into parts of the galaxy, and other galaxies, that other telescopes cannot see.

The reason why these telescopes are so important is because they have the ability to see some of the coldest, densest gas in a galaxy. By dense I mean 100-10,000 particles per cubic centimeter (yes that's particles/cm^3). For comparison air at sea level has about 10^19 particles/cm^3 (that's 10,000,000,000,000,000,000) and water has about 10^22 particles/cm^3. So dense is a relative term, but compared to the average density of gas in the galaxy (~1 particle/cm^3), it is pretty dense.

So why are these regions so important? Basically this is where stars, and planets form. It is these dense regions where we find the newest stars, and possibly get a glimpse of the planets forming around them. This will help us learn how solar systems form and will help guide us in our search or life bearing planets beyond our own. In short, it teaches about how we got here, and where our nearest neighbors might be.

Quote of the Day: Scientific Literacy Edition

2011-10-04T15:18:00.000-07:00

A recent survey by the Yale Project on Climate Change Communication found that:

"... 43 percent [of Americans] incorrectly believe that if we stopped punching holes in the ozone layer with rockets, it would reduce global warming."

Looking at this in a glass-half-full light, that means that the majority of Americans don't envision our upper atmosphere as coated in saran-wrap.

Nobel for Supernovae and Dark Energy

2011-10-04T10:35:00.000-07:00

The Nobel Prize in Physics this year will go to Saul Perlmutter of UC-Berkeley, Adam Riess of the Space Telescope Science Institute at Johns Hopkins, and Brian Schmidt of the Austrialian National University for their co-discovery of the accelerating expansion of the universe caused by dark energy. Perlmutter founded the Supernova Cosmology Project, while Riess and Schmidt founded the High-Z Supernova Search Team. These two group announced in 1998 that observations of extremely distant supernovae showed that the expansion of the universe was accelerating through a still mysterious force known as dark energy.

This has to go down as one of the least surprising Nobel announcements in recent history. The discovery that 3/4 of the mass energy of the universe is in some mysterious form that behaves as a sort-of anti-gravity was a block-buster from the day it was announced. The fact that subsequent work has confirmed this discovery continues to emphasize its importance. Good call on this one, Nobel committee.

Final Tevatron Shutdown

2011-10-03T07:47:00.001-07:00

In addition to a great conference weekend, there was another item of note this last weekend. This weekend, the Tevatron, Fermilab's principle accelerator had its final shutdown. The Tevatron, completed in 1983, held the record for the highest energy particle accelerator in the world until 2009, when it was surpassed by the LHC.

The accelerator's list of milestones is impressive by any standards. The Tevatron announced the discovery of the top quark in 1995, with a measurement of its mass by 2007. The B_C meson was detected in 1998, the tau neutrino in 2000, and the Sigma_b, Cascade-b, Omega_b and Xi_b baryons detected in 2006, 2007, 2008 and 2011, respectively.

In the Discovery News article reporting the shutdown, Jennifer Ouellette gives an impressive quote from Robert Wilson, the first director of Fermilab. When asked before a congressional committee what the new, proposed Fermilab would be good for, he responded,

It has only to do with the respect with which we regard one another, the dignity of man, our love of culture. It has to do with: Are we good painters, good sculptors, great poets? I mean all the things we really venerate in our country and are patriotic about. It has nothing to do directly with defending our country except to make it worth defending.