|Sunday, January 31st, 2016|
I hardly ever write public entries on LiveJournal now. When I first got on tenure track, I played it careful. Also, Facebook has taken over a lot of my online socializing. Sometimes I vent in a friends-only entry. Let's see if I have much to say in public now.
Sometimes I think over things I've written and how they might appear to different people. Sometimes I think about the last entry I posted here. The political lens through which I expect my words to be read has been changing over the period I've had this blog, which I started back in 2000. In my last entry I bemoaned that even though the U.S. has so much going for it, there's always this insistence that we are an extraverted, busy people, always active and aimed at external achievement. Usually in the 16 years I've had this journal I've imagined someone scanning it over from a view to my political right, but times are a-changing as they used to say. The left has been gaining strength. So I imagine a reader thinking: "That's really the only bad thing you can say about this nation, that the cultural temperament doesn't always match yours? A nation that encoded slavery in its founding documents, that nearly wiped out the indigenous population in its borders?"
Well, having been so angry during the Bush years (starting with the way his "election" was handled and through the travesty of the Iraq War), and now happy to see the candidate I supported in the primaries (Obama) ensconced as President, I've been content to dole out more praise than scathing criticism of the way things are. When the Seth Rogan movie about North Korea, "The Interview", was threatened, I could download the movie to watch, and say: yeah, America should be free!
Of course I'm familiar with Chomsky, Zinn, et al., and almost entirely agree with their critiques. Paradoxically the potential and actual good in our systems have sat so close to the evil, often within single individuals like Thomas Jefferson. I'll skip over my theories for why that is, for now.
I guess I could say that the unbalanced temperament I find in the U.S., the emphasis on motion and extraverted energy, is probably linked in some way to its persistent deficiencies, the racist police violence, the predatory capitalism, etc.
The emergence of Trump as the Republican front-runner is maybe something I can address here. The way he denigrates his rivals as "low energy". He seems to appeal in similar ways as George W. Bush, who I detested, even though Trump called out the pious elision that allowed some to say of Bush, "he kept us safe," as if 9/11 came from an outer space time machine and not from the real world when Bush had more power than anyone else on the globe.
The similarity to me comes into play with Bush's joy over calling himself "the ex-ec-u-tive," and "the decider", drawing out all the syllables, strutting over the fact that he's The Boss, scoffing, "I don't do nuance"--the crisp, clean, executive who's worthy by the very act of making decisions. Trump too is known for being a reality TV show boss, taking joy in his power to make his words reality, no matter how they are tested (as his multiple bankruptcies show, he doesn't always pass the test!)--"You're fired!"
There was something also about the run-up to the Iraq War that deeply offended my temperament. We now know that some of the TV networks required at least 2 war advocates speak on air for every war opponent. There was a fearful group-think in the media. Maybe because the media is so often accused of being liberal they shilled for the war to prove their bona fides. That also offends me about Hillary Clinton, if I may continue to fit how current presidential contenders mesh with my world-view...
Before I get to her though--hearing Trump and the other Republicans talk about ISIS as if we could fix up the Middle East if only we were more ready to use violence... That offends me too! I think there are few things more tempting to humans than the prospect of doling out aggression to those who truly deserve it. We have to keep ourselves in check all the time, but if someone out there is a "bad guy" then finally we don't have to! And that biases some terribly... For some it's always the eve of WW II and every enemy of the U.S. is Hitler, every peaceful resolution is "appeasement"... (There was even one young TV talking head war advocate who kept insisting Obama's policy was "appeasement" who, when pressed, could not even describe what the historical policy of appeasement was!
) And so there's very little I loathe more than when people fall into this trap.
I've become much more anti-war than I was when I started this journal. I viewed myself as liberal because I loved science, which is funded mostly through the government and not private industry. And so contrary to economic libertarians, I see a role for government, and it also made sense for the government to help those in need. I love science, and artistic expression, because they flow from our common humanity and imagination, and whether or not someone's good at making a buck, they share that common humanity and imagination and we should promote them and their lives as well.
But now I find there was something in the psychology of those who anticipated the Iraq War with joy that I despise. Also I've come to despise a certain kind of Conventional Wisdom that holds that certain things are politically inevitable, that must unfold in a certain way, and yet the ideas have been inherited from different eras. They no longer really apply but are being carried out blindly by political machinery--the way that guy accuses diplomacy of being "appeasement" because he knows it sounds bad even if he doesn't know what it means.
So that's part of what irks me about Hillary Clinton. The run-up to the Iraq War was a case of The Emperor's New Clothes. And there were several types of politician: those who hallucinated that the emperor did have new clothes, the type who could see the Emperor was naked but by political expediency assented to the consensus--or even worse, those who punched down, condemning those who spoke up and said, "he's naked!" Only a few would actually say "he's naked!" which is what helped Obama get the job in 2008 once we all saw the disaster Iraq was. Hillary Clinton strikes me as one who will always for expediency go with the conventional, even if it harms the activists who are getting it right from below.
Of course she did nothing wrong in Benghazi, but as Sec. of State she was far too aggressive in regime change in Libya. It was the old "get the bad guy" syndrome that led us to overthrow Saddam Hussein.
On the Democratic side though the election isn't turning on foreign policy so much, as that isn't Bernie Sanders's main interest. Were Biden to enter the race I'd give him a close look, because I know he's truly anti-war. The generals in Afghanistan called him "Vice President Bite-Me" because of his insistence that the war not be continued merely out of inertia and habit.
But when it comes to economics too, there's a lot of Conventional Wisdom that is making the present a prisoner to attitudes from the past. Both Obama and Hillary represented a post-Reagan synthesis, they were both middle-of-the-road politicians who were prepared to make compromises--only they would compromise in different ways. Obama has straddled the gap between neo-liberalism and leftism, and over the course of his presidency I have made the move from liberal to leftist. The next President probably won't be able to straddle those ideologies, but will have to choose. The neo-liberal advocates lower taxes, lower trade barriers, charter schools, thinks "our schools are failing" and teacher unions have too much power, thinks unions are archaic institutions that reek of the past and hold back the energetic dynamism of new transformative technology. Mostly the neo-liberal has incorporated the mind-set of the upper strata, and thinks, "If only the masses could have the discipline and energy of the elite! We must provide nudges for them, we must devise clever remedies for whatever infirmity led them not to be rich! But they always must be a win-win kind of deal; anything that would take away from the rich is anti-business, would hurt our competitiveness, would be class warfare, could not become political reality..."
Well, it's not 1980 any more... Not only are minority populations greater, but the Millennial generation has been completely screwed. Conventional politicians still think most Americans are middle-class. When I was in school I was taught we had a "barrel-like" wealth distribution in this country, mostly a middle class with smaller poor and wealthy classes. So many Americans now live paycheck to paycheck, so many have hardly any life savings to speak of. The Middle Class, a family that owns a house in a suburb and a couple of cars, is no longer normal, and the values of the class are not normal either. The reality is student debt... When liberal politicians like John Edwards invoked "two Americas", they were appealing to the compassion of liberals, but now so many Americans have fallen behind that such talk appeals to self-interest. Also on the theme of people living with a conventional wisdom of the past--the term "socialist" does not carry the baggage it once did! How many voter now never knew the Cold War?
I value nuance greatly of course, and believe that evolution is stronger and more stable than revolution. I believe that the incremental changes of the Obama era will really matter. We avoided the toxic "austerity" of Europe. But I also see that there has not been enough push-back to changes taking place largely out of their own momentum, changes pushed by advocates from another era--and the system is out of whack.
Anyway, maybe I'll end this here, and get on with my day...!
|Sunday, July 7th, 2013|
A rare public entry. At least my mysterious reader Monika in Poland might be pleased! But not really much to say about astronomy here. More contemplating life as it is passing.
A good couple of days. Life sets limits on us though and it's a tough burden to say these mere moments justify that weight.
Last night I went dancing at my old club. As usual I was extremely energetic. I love the exercise, and it keeps me young, but I am alert to detecting the slight slowdowns of aging--and also to those moments when I feel I break free of them. I started this journal at age 32 and am now 45. Sometimes I take aging as a challenge, as that worthy adversary that can truly motivate me.
Earlier I went to my gym here (I'm in Boston, on vacation from teaching near Atlanta, doing research on my own.) Not having a gym lock and living far from the gym, I ended up spending the day without my computer, a vacation from working on my projects.
I fall into a state of "kitch of languidness", a kind of stereotypical enjoyment of the possibility of relaxing, of putting aside struggle and attention. Spent some time in Davis Square just watching people go by and the play of light through the leaves of the trees. Extraverts seem to have no comprehension of how needed peace and quiet and uninvolvement are for introverts such as myself.
Also, 4th of July just passed, thinking about this country, both the unprecedented historical achievements and potentials, and also the disappointments, seeded in human nature, that not even such a well thought out system can avoid. Often during election years we hear about how Americans are always supposed to be Do-ers, the entrepreneur and risk-taking are celebrated, we are supposed to be a country that works hard and plays hard, not one that sits apart in contemplation--better to act even if it causes zillions of problems, than to stay still for a moment... I feel alienated when getting the message that this is the single temperament my country is supposed to value. And yet also there are the platitudes (one wonders how deep the committment) on how important teachers are (but not concerns bubbling up from below as much as the imposition of testing standards and overhyped techno-solutions), how important STEM (science technology, engineering, medicine) fields are (but mainly to have such a labor oversupply that costs are kept down...)
As I get the salting of white hairs in my beard I figure it's supposed to give me a sort of gravitas and dignity, but I haven't really figured out what one is supposed to do with gravitas and dignity. With youthful energy you go out and dance, you get upset at politics, you write music or poetry or a blog for your cat. Maybe you are just supposed to strike a pose, like, here I am a professor all dignified...? Maybe I'm supposed to have kids and be a role model or at some point buy a house with a lawn and get all cranky about the Kids On My Lawn.
Kurt Vonnegut in his novel Cat's Cradle wrote metaphorically about these "teams" that fate seems to put us in, working towards goals we only start to realize--he calls them granfaloons, karass, wampeter... I am not sure that I have completely found such a team. There are external challenges galore in this world, yet the thoughts churning inside me are still looking for a place to go. Teaching science is supposed to open up better lives for my students, but for myself I imagine a life like Grigory Perelman pushing away the world...
Though perhaps that's the kitch of languidness, and I do not always live up to that life... Had a brunch in a nice Brazilian restaurant today--not working over the summer, my finances deplete.
Reminded also of one of those amazing throwaway paragraphs in Olaf Stapledon's amazing science fiction novel of the 1930s, Star Maker... He imagines a planet with plant-men, creatures like trees that can vegetate when connected to their roots, but that can move about as animals and temporarily disconnect. Their society decides the roots are no longer needed, disconnects permanently, and proceed to live only as animals and not plants. They never recover from the damage that one-sidedness inflicts on them.http://synthaissance.blogspot.com/2010/12/plant-men-and-others-from-star-maker-by.html
|Friday, July 16th, 2010|
I have many things I should be doing, and want to be doing--job applications, astrophysics research analyzing particular star systems, my own idiosyncratic discrete models of quantum mechanics, finding a good sushi place to take a date--but for a while I've been musing about certain topics in history and anthropology, and I feel inspired this evening to finally write a public LiveJournal entry. So this is an indulgence; once out of the way I'll put schnoz to the grindstone.
As I've been getting older, I've been thinking more about history. My thesis advisor, I remember, told me about how interested he was in history. I think as one ages one looks more for a larger perspective of where we humans came from... So there are a few strands of these speculations I'll cover in this entry.
One item in the news from a couple of months ago: the genome of several Neanderthals have been mostly decoded and compared with those of modern human populations
. The main investigator was this Swedish guy working at the Max Planck Institute for Anthropology in Germany, Svente Paabo. The intriguing result is that non-African populations have 1-4% of their DNA from Neanderthals.
One can get a little queasy that investigations into human origins like this could be fuel for racists, and racism truly is rank bullshit. At least in this case the results kind of hack away at the received racist stereotypes; Neanderthals in popular culture are often depicted as subhuman, and white people have enslaved and oppressed Africans and white supremacists have often derided "mud peoples" as impure mixtures (when it turns out non-Africans are the mixtures). In the big picture it's so obvious that racism has been a driving force in human history and that the ways people measure "races" (African-Americans for example, can carry DNA anywhere from mostly African to mostly European) and measure differences are so biased as to be meaningless--even genes are expressed in different ways in different environments, the expression linked to fetal environment, diet, etc. etc.
But that aside, I think it's kind of neat
to accept this new information into one's worldview. It brings the distant past in greater variety down into the present. There have also been recent discoveries of other closely related hominid fossils--one in Siberia, and the celebrated Homo Florensis that only disappeared 13,000 years ago, the island "hobbits". So our myths peopled by elves, trolls, giants, dwarfs--that could represent a kind of lonliness for our missing also-human cousins.
The Neanderthals one can now assume were in our own species--at least according to the definition that they produced fertile offspring with us--unless, as was pointed out in one blog I read, one decides to call all non-African people members of a non-species, sort of like freak fertile mules! But before one goes too far, from what I understand the Neanderthals still were pretty different from modern people. They were, I gather, about 5 times further away from us, genetically, as the most far-flung people nowadays are from each other. Their mitochondrial DNA line, passed from mother to offspring, no longer survives. Given that I myself am stocky, muscular, with a big nose, prominent eyebrows, and small jaw, one might speculate about where in that 1-4% range I'm in--but for perspective on how different they were, it's worth realizing that unlike modern humans, Neanderthals couldn't even throw a spear because their arms and joints just weren't built for it. They apparently were very
muscular, and hunted by getting up close to Mammoths and spearing them (pretty badass!)--instead of throwing the spears or shooting arrows like modern folk.
By the way, it's amusing and sad how the internet kind of levels scholarly achievement... Any science crank with good web skills can make a case to the public in a way most people can't see through... For example this site
on Neanderthals (which bizarrely claims the recent study supports it), which superimposes a Neanderthal skull inside a chimpanzee head without regard to orientation, 3D shape, or scale, in an attempt to mythologize Neanderthals, in a contrarian fashion to current research, as nonhuman.
In actuality, Neanderthal and human lines are supposed to have diverged 500,000 years ago. As the received timeline gives modern human emergence as occurring 100,000-200,000 years ago, my uneducated guess is that either some of what made both lines human happened in parallel or there was some intermixture still in that time period. DNA analysis has shown that Neanderthals had the modern human version of the FOXP2 gene, which in the popular press is called the "speech gene". One (British I think) family which, by inherited mutation in this gene, had developmental problems which included being unable to pronounce words such as "hippopotamus", led to the association of this gene with speech. (I think birds also have a different version of this gene from other animals, perhaps related to their singing syntax.) But the role of FOXP2 is actually very complicated. It turns on and off a whole bunch of other genes in the course of development and life:
This is a network of the interconnection between FOXP2 and other genes. This reminded me a little of computer hackery--that sometimes randomly messing around with computer software you find something interesting--I remember in high school we had these PET computers that had only characters and no graphics. They had a memory add-on called "toolkit" that let you do "advanced" stuff like "trace" the BASIC program as it ran. You started up the "toolkit" by typing, "SYS 45056". One day I tried instead "SYS 55056", and found that it would give interesting behavior, always different--once it affected the computer's display so that the characters shrank into dots which followed each other around in a rotating ellipse--it seemed like magic to the other kids. Anyway, the power of random tweaking at the hardware level where things are interconnected--that seems to be underlying evolution.
Also it's interesting to speculate about what the importation of Neanderthal genes did for people... Could it have been that it wasn't so much a matter of benefit to individuals but to the population, to have these genes? Humans tend to live in tribes, and as baseball players play infield or outfield, we specialize in different skills and work best when there is variety and balance. The first hybrids with Neanderthals must have knocked out some genes in which the non-Neanderthals (I'll call them Cro-Magnons) had evolved differences from chimpanzees, but Neanderthals had retained the ancestral version, and vice-versa. But for example, if gene 1 had evolved in Cro-Magnons and then gene 2 evolved thousands of years later, was the interaction with gene 1 necessary to the success of gene 2 or not? Probably this depended on the case. And vice-versa--the hybrids would have some new Neanderthal genes which had never been paired with the ancestral genes--and some hybrids must have had the novel genes from both ancestors.
Apparently the tools of the Neanderthals were a little more primitive than the tools of the Cro-Magnons, but not out of the range of what one might consider cultural variation. There's evidence that Neanderthals created musical instruments, like this 40,000 year old flute carved from a bone from a bear cub:
And a diagram reconstructing how the full instrument may have looked:
There was speculation that the holes could have been bite marks of a carnivore, but there were no marks on the other side (from the lower jaw). The spaces on the flute mark do, re, mi, fa notes!
We don't know why the Neanderthals died out. There's some evidence modern humans killed them off. Also, they were adapted for Ice Age conditions, and may not have competed well with modern humans who could hunt with bows and arrows from far off, and who needed fewer calories to fuel their less-muscular bodies.* * *
In other news that has fueled my imagination and speculation, I've had snippets of my own DNA decoded, now that there are some affordable services that do this. I'll try not to blab too much about this, as it's pretty private information! Yet it's also very interesting, and it's motivated me to learn more about genetics and human populations and history, branching out from self-absorption to curiosity about the wider world.
There's been lots of speculation about where Jewish people come from, how closely related we are really to the ancient Hebrews of the Bible. Some of this speculation may have come from anti-Semites, religious nuts who admired the Hebrews who brought into the world the religion that would give Christianity as an offshoot--and yet thought that actual Jewish people were kind of schmucky, and couldn't have been related. There's also been legitimate speculation about a mysterious ancient Turkish group called the Kazars (the subject of a very interesting, playful, and experimental novel by the late Milorad Pavic) that may have converted to Judaism. And throughout the Jewish diaspora, there's been no way to know how much intermingling there's been with the European populations in whose midst the Ashkenazi or Sephardic populations lived.
Well, it turns out I'm pretty closely related to the populations that currently inhabit the Middle East, including Palestianians, the Druze, and Bedouins.
One interesting side-note is that my "paternal haplotype" (Y chromosome passed from fathers) as far as I can tell may be more common among coastal populations in the Levant than inland populations. One subset of Jews (not me), often with last name "Cohen", are reputed to have descended from the temple priests, and ultimately to be descend from Moses' brother Aaron. Actually there is no archeological evidence for Moses, or the Patriarchs of the Bible! Perhaps some day such will be forthcoming. There was a kingdom of David centered on Jerusalem, but it's a matter of some dispute how extensive this kingdom really was, and Jerusalem existed as a city before the Jewish people got there.
In any case, I might speculate that this Middle-Eastern coastal population I partly descend from may be a remnant of the ancient Pheonecians, seafaring people, centered mostly on Lebanon and northern Israel, who have mostly disappeared from history in spite of introducing the first real alphabet.
From the Bible as a text one imagines the Israelites influenced by ancient Sumeria: the epic of Gilgamesh also carries the story of a flood, and Hammurabi like Moses had a code. Though there's no evidence outside of the Bible for the Israelites being slaves in Egypt, there was an Egyptian pharoah, Akhenaten, who briefly introduced monotheism to Egypt.
But it is interesting also to look at history from the vantage not just of the inland peoples, but those on the Mediteranean coast. The Odyssey for example gives a picture of what life might have felt like at the time. And it's also interesting to think of forerunners
of the Israelite population. We often think that we can trace origins back through history, that my ancestors were Jewish, full stop. We retell the stories of those who were coerced into renouncing the defining monotheism of our heritage, we recount all the times we had our asses handed to us, by Babylon, by Rome, and yet persisted... And yet somewhere in that ancestry, there were probably Canaanites, Phoenicians, whoever--who were coerced into this newfangled Jewish religion that sprung up perhaps from some Bedouin goatherders inspired by rumors from Egypt, while other Bedouin goatherders still in the 21st century toil on in that ancient goatherding life as if all of this history passed them by!
So it's a change of perspective to look at the map of Europe and see instead of the land-masses and river-beds that gave rise to the inland nations, the "cradle of civilization" also centered on the Mediteranian Sea, birthing the Greeks, Carthage, the Phoenecians with their fancy triple-decked rowing ships trading prized purple dyes... I imagine it in some ways idyllic, the sun and sea, trading olives and wine and spreading an early version of a cosmopolitan life...
|Tuesday, June 22nd, 2010|
The work day is all candy and ice cream when I'm working on my own research projects! Just have to find a new grant or teaching position.
The Sco X-1 tomography is going very well. Even though there are hundreds of absorption lines eating up the spectrum, I can reconstruct what's going on with some confidence, although I want to make some more tests.
This is a double star system in which one star is a neutron star. The brightest X-ray source in the sky. But unlike many neutron stars, this one isn't a pulsar. A pulsar would help us figure out its orbit with great accuracy, by timing the pulses. Also there are no eclipses. Eclipses would help us figure out what's going on too: we'd see each little piece of the star system (gas funneling onto the neutron star, etc.) gradually eclipsed and could figure out what the light from each piece alone looks like. But we don't have that. So some aspects of this star system are not so well known.
That it's not a pulsar my follow from the neutron star having a low magnetic field.
Anyway, here's the Doppler tomogram without taking into account my model for all the absorption lines:
And here is the version with my correction for interstellar absorption lines:
Here are several Doppler tomograms of different emission lines from optical light from 2002 by Steeghs and his colleague, published in The Astrophysical Journal:
So my corrected tomogram looks a lot like the tomogram of He II (ionized Helium) seen in optical light--which is not surprising as the quintuply ionized Oxygen I'm looking at in far ultraviolet is similar to ionized Helium.
Anyway, the signature of an accretion disk in a Doppler tomogram is a ring centered on the lower plus sign (which is where the neutron star would be), and the teardrop shape shows the expected location of the normal star (distorted from spherical shape by rotation and gravity of the neutron star).
So there's evidence for BOTH an accretion disk and for the normal star being lit up by X-rays causing emission from ionized gas.
I'm gonna use this to learn about the accretion disk. Also, I can use the model of the emission to refine my model for the absorption, but I'm going to have to test against other emission lines too--one has to be careful using models to correct the data! However, one fact limits the models of the absorption so that I won't get too carried away and over-fit the data: the absorption has to be constant in time, constant throughout the 15 different times we observed the star system. That's because the star system is orbiting once every 0.8 days or so, and its light is changing, but the gas between us and the star is mostly constant.
|Monday, June 7th, 2010|
So my n
th postdoc is over--I'm rewriting my statement of teaching philosophy and sending out CVs. Meanwhile, I'm excited to get some time to work on my own research. (While still tinkering with the postdoc project as well.) I've been feeling pretty good this weekend. I have both some more speculative physics ideas to work on, and also the X-ray binary research I've worked on most of my career, which is more familiar to me and easier to direct myself on than the galaxy research I've started.
I'm making some Doppler tomograms for a colleague, and this motivated me to go back to data I still haven't published on the Scorpius X-1 star system. Sco X-1 was the first X-ray binary discovered--it's the brightest persistent X-ray star in the sky. If we had X-ray vision, we'd see this as the brightest in the night sky (except perhaps for some variable stars). It's both close by and intrinsically bright--about 1038
ergs/s is the energy rate of the X-rays, whereas the Sun gives off in visible light several 1033
erg/s, so it's on the order of 100,000 times brighter in X-rays than the Sun in visible light. It's a mysterious "Z source", a neutron star system from which we've never seen the regular pulsations that mark the rotation of the neutron star.
Anyway, the problem with this data was that it was the first observation of this star system in the far ultraviolet, and it turns out that interstellar gas absorbs the spectrum that far in the UV at multiple narrow lines, corresponding to all sorts of different atoms in different stages of ionization, and also molecules in different energies of rotation and vibration.
But when you're working on your own you can afford to be a hero. So I'm trying to go through and identify all of the lines in the spectrum that were eating up the spectrum. It was quite severe: there are two bright lines from the star system itself, emission lines, that I wanted to see in this observation. However, the absorption was so severe that only one of them could be seen! And one of my scientific goals was determining the ratio between the two lines!
But I'm impressed by how much I can reconstruct of what's going on by meticulous attention to the interstellar absorption. I can probably do better, but this is a major start.
Below I'm showing only a small portion of the spectrum--it goes from 912 Angstroms (the lyman limit: this wavelength corresponds to the energy needed to take the lowest energy level of an electron in hydrogen and break it free of the atom--below this wavelength, you don't see much through normal amounts of interstellar gas until you get to wavelengths smaller than a hydrogen atom. It goes from 912 Angstroms out to 1180 Angstroms or so, where the Hubble Space Telescope picks up. I helped a couple of my ex-supervisors with Hubble observations of Sco X-1 that looked at the spectrum from 1200 to 1700 Angstroms or so.
One thing that was neat was that I was able to take the model for the continuum from the proposal
I had written to get the FUSE observations of Sco X-1, based on our model of the Hubble observations--and what I wrote in the proposal matched almost perfectly with the actual data! The lines didn't match nearly as well, but the continuum did--although I am wondering whether I just got lucky. There's uncertainty in how much the interstellar gas reddened the spectrum, and I may be able to get a better handle on that.
What's going on here? The spectrum shows brightness (flux) on the y axis and the wavelength on the x axis. The jagged black curve is the actual data, averaged over 15 sub-observations. The red curve is my model--based on (1) the model for the continuum from the proposal, (2) a model for the emission lines (quintuply ionized Oxygen) as a Voigt profile (convolution of gaussian and lorenztian shapes--look up the defs in Wikipedia), with the ratio between the two lines as a free parameter, (3) absorption lines at known wavelengths from Silicon, Carbon, and Oxygen, and very deep absorption from Hydrogen ("lyman beta")--also absorption from H2, molecular hydrogen. The absorption lines are marked on the top of the graph with a little line and the name of the absorption--if it's from molecular Hydrogen I also mark the rotational level (j=0 to j=5). The smooth black curve shows my model (just continuum and Oxygen emission lines) without any of the absorption in the way.
You can see I was able to reconstruct the ratio between the two Oxygen lines!
Also, I mentioned that this is actually the sum of 15 sub-observations. I was able to measure the Doppler shift of the emission lines in each sub-observation. This tells us the velocity towards or away from us of the gas that gives off the emission lines. The observations were planned to cover the entire orbit of the star system, which lasts I think about 0.7 days. In the plot below I show my measurements with * and with a sine curve and a line I show what other researchers independently think are the expected motion of the neutron star and the velocity of the star system as a whole (it's "systemic velocity").
most of the observations previously had only identified emission lines from the normal star--these would be, based on the velocity, from the accretion disk surrounding the neutron star. Optical helium lines seem to move similar to these Oxygen lines, but with a phase shift.
Note that the alignment isn't perfect--it could be that I need to calibrate the zero velocity better. I will have to do that based on some of the interstellar lines. Right now I've only grouped the data to be accurate to about 15 km/s. It's also possible that the accretion disk isn't perfectly symmetric and may emit more from one side or the other. It's possible there is some emission from the normal star along with the accretion disk. Perhaps my empirical model of Voigt profile is not so good--I could make a double-peaked accretion disk model, broadened by turbulence instead.
So this might help constrain the mass of the neutron star better. Also, I want to make Doppler tomograms to see if we could map out structure in the disk. It will depend on my accurately finding the zero velocity. But also being able to correct for this multitude of interstellar lines is important.
Anyway, it's time to go to bed. I'm also excited to be reading a paper by Ted Jacobson on the Feynman checkerboard (old paper from 1984). It's much more sophisticated in regards to the physics than the other papers I've been working from. It's distinguished in several ways from what I'm doing; one is that he's not using a lattice--he's allowing one special dimension to be the spin axis/particle travel dimension, and then assumes the particle scatters randomly in the next step, defining the next special direction.
|Wednesday, April 28th, 2010|
Comet reporter (head of the Bureau of Astronomical Telegrams) Brian Marsden, science celebrity Michio Kaku, and me (squinting in the Sun). Kaku had just autographed my copy of his Quantum Field Theory book.
|Monday, April 21st, 2008|
|Artificial Intelligence Philosophy
I used to be much more of a booster of Artificial Intelligence than I am now. Growing up, I was into Godel, Escher, Bach, Hofstadter's and Dennett's "The Mind's I", and other similar books. In grad school, I used to get into debates online with Mikhail Zeleny, this Russian grad student, kind of a crank, who believed that AI was impossible. He was prone to obscure and kind of bizarre claims (computers would never achieve "noumenal perception of the infinite"), but in some ways was intelligent and erudite. He used to get into arguments with McCarthy, the guy who created the AI programming language LISP, and would cite obscure errors from McCarthy's papers, if I recall correctly.
Some AI critics have influenced my thinking even if I think that their criticisms are highly suspect. I think that Searle and Penrose have made me appreciate more that a human is a physical system, and that "intelligence", "thought", "cognition", etc. are abstractions we make based on that physical system. What seemed "natural" to someone growing up with programming was that the Mind was to the Brain as Software is to Hardware. That "we" as thinking beings could be equivalent to intelligent computer programs, but we were "running" on the "hardware" of a brain instead of a computer.
There's something a little arbitrary though about abstracting from a real physical system to leave only "thoughts"--though one has to admit that while arbitrary it's also not entirely artificial. Many cultures have imagined a separate spirit and body. I think what makes AI seem so transparently plausible is that computers are designed in such a way that the hardware is separated so clearly from the software. We know what Microsoft Word is (unfortunately!) independently from Mac or PC (or even PowerPC Mac).
Many supporters of AI think that "intelligence" is a perfectly coherent abstraction from a physical system, but "consciousness" is not--that it's vague, or meaningless, an "epiphenomenon" arising from short-term memory or the "Cartesian theater" of different computational "modules" within the brain interacting. I guess the reason why this is, is that intelligence is in some ways measurable, but not consciousness. Although what we measure is some statistical abstraction from tests, this "g" or "general intelligence" factor, is not necessarily what we mean by intelligence, and was only found (and considered to be similar to "intelligence") because of confidence that this concept we normally spoke about had some correlate in reality. It's hard to imagine developments that could convince us that intelligence (or its lack) is not a useful concept to apply. (Particularly after exposure to the works of George W. Bush.)
One easy way to make the brain-computer analogy work is to understand neurons as performing a parallel computation. But although Penrose and Hammeroff's speculations appear mostly bunk, they did convince me that there's a lot of really interesting stuff going on below the level of the neuron. The cytoskeleton of neurons (or all animal cells) is fascinating with these microtubles... And the way that messenger RNA sends signals around the cell, both through the bases of the RNA and through its shape--that's fascinating, and I'd like to learn more about it.
My guess is something like IBM's Blue Brain Project, that tries to simulate an entire mammalian brain, neuron by neuron, would not really reproduce the process by which neurons grow new outgrowths (or even new neurons are born and become interconnected)--that perhaps the short-term behavior of brains will be easier to simulate than longer-term changes, in which what goes on within the cell to change its growth might matter more.
When you look at, say, soap and water mixing, it's hard not to anthropomorphize and think the liquids have repulsion as humans do--and to think that some of how we "feel" is inseparable from actual chemical reactions, as opposed to patterns in which the underlying substrate doesn't matter. This is, of course, not a scientific argument.
What I'm getting at is that AI boosters and critics may be subdividing the world differently, and may frame the "ultimate" question differently. The boosters may be asking: "Can a computer do what a human does?" (Abstracting certain things that merely "make up" a person but don't count as to what a person "does".) Whereas the critics would say, "But it's not a human, so what?"
|Sunday, September 2nd, 2007|
I continue to be surprised when it's expressed, as in this recent book
by Matt Bai--that liberals and the left in the U.S. are out of ideas, or do not have the intellectual power or subtlety of conservatives.
First off, this seems just about 180 degrees from the picture I have.
And that's mainly because I think the liberal netroots blogosphere is responding
to what we see on the right. Often we express rage in our blogs (and becoming angry over politics while blogging is a bipartisan phenomenon--must be something about the medium) because the right has said or done something outrageous
For the Clinton decade (or so) we had to put up with right wing blowhards like Rush Limbaugh and during the Bush years we've had Karl Rove who ran the government along partisan lines and tried to push the image of anyone intelligent from the Northeast as effete and anyone opposed to conservative politics as nearly a traitor. And now with Fox News there's a major news outlet which I understand is transparently partisan in outlook.
And some of it may be that Bush's policies have not just been conservative but radical
--he's wanted to roll back not just the Great Society but also the New Deal. There is the point that the economy has been changing: becoming globalized, with a growing "information sector"--but it's not clear either how much of this is inevitable nor that Republicans, who isolate the U.S. and who deny evolution and global warming and who are too squeamish for embryonic stell cell research are in the best position to promote future science and technology.
Now, some of my innate feeling that the left is the party of intelligence and ideas may be because we are "resting on our laurels"--in that almost anyone in a liberal arts college environment is liberal. I consider myself intelligent from the years growing up when I kept acing the standardized tests they gave me and kept skipping grades in math. But I am not a social scientist and have never studied economics seriously.
I think the crux of the issue must come to play in the evaluation
of political ideas. Conservatives have had heavily-funded Think Tanks where they have honed their ideas and have their own newspapers like the Washington Times where they trumpeted their world-view.
The question is: was all that an echo-chamber? What's come to me through conservative blogs or e-mail list conversations hasn't seemed to me to be particularly insightful or subtle.
The NY Times book review of Bai's book calls the founder of Daily Kos an "intellectual lightweight" for not having read a founding book on Libertarianism--now to me that sounds pretty obscure (not like not reading J.S. Mill's "On Liberty" for example!), but perhaps conservatives, while pounding their "Willie Hortons" and "smoking guns as mushroom clouds" and all sorts of other rubbish to the public "debate" have had worthy ideas that they just haven't publicized that much? I've read Ayn Rand's The Fountainhead, clearly trash, which many libertarians endorse, but ok, maybe there's room for me to learn stuff.
I think the fact is that liberals and conservatives find different kinds of argument convincing--it's not merely a matter of who is making more rhetorical points or employing more fallacies. And these arguments appeal in the end to different visions of what's valuable.
As it is, I'm pretty baffled by this claim of intellectual vacuity from the left. We're the ones who've been damaged by the "egghead" label since Adlai Stevenson...* * *
What gets me about the Iraq war, which isn't hammered home enough, has been the outrageous cost. "Well maybe we can still win this, don't you care about winning?" No, I don't care about "winning". "Winning" is for sports teams. It didn't matter whether the U.S. "won" or "lost" in Vietnam. Arguably, it didn't matter which side won World War I. Arguably, it's a very rare war which really makes a difference--history's made by evolution more than revolution, which is frequently unstable.
What I care about is that every week
the U.S. is throwing away $3 billion, or the equivalent of the cost of the Hubble Space Telescope.
The Hubble Space Telescope:
- Gave the first accurate measurement of the Hubble constant (expansion rate of the Universe)
- Helped settle the ages of the oldest stars in the Universe
- By detecting far away supernovas helped measure and confirm the acceleration of the Universe
- Has contributed to education in the U.S.
- Has through Deep Field images given estimates of the number of galaxies in the Universe and has told us of the very earliest galaxies
- Studied transits of extrasolar planets
- Provided inspiring images and data available to anyone in the world to download
- Studied the first modern nearby supernova (SN 1987a)
all those beautiful nebulas and galaxies and gravitational lenses etc. etc.
The Iraq war has:
- Isolated the U.S.
- Killed 4000 of our citizens (more than died on 9/11)
- Wounded many more--who will require support all their lives
- Exhausted the U.S. armed forces
- Taken attention away from Afghanistan and the search for individual terrorists
- Made millions of Iraqis into refugees
There may have been some silver lining to this fog of war, but it's hard to see one amid millions of refugees!
Money's limited and I'd rather have it spent by the government on projects that could uplift humanity and make life worth living.
I think what's most important here is not intellectual power (which perhaps conservatives have behind the scene but mostly one sees Limbaugh and his ilk) but one's vision
of what society should be like. The conservative ideal is Sparta--like that move that was popular a year ago--it's life as war. Literal war, or unforgiving free market economics.
|Saturday, March 3rd, 2007|
I seem to be thinking a lot about politics these days--I'm not certain why.
With the Republicans scrambling to find a Conservative True Believer to succeed Bush, I've been thinking more about Reagan and his relation to George W. Bush. It's almost as if W. were Reagan returned both
as tragedy and
farce. He's certainly made Reagan, in retrospect, look better (as he's made his father look quite fantastic by comparison). Overall, I would say W.'s attempt to enact Reagan's legacy was like someone with no sense of rhythm banging really really hard on a drum to hide his deficiencies.
On Reagan, in spite of my great antipathy for him while I was in high school, the following could be said honestly and positively:
- His presidency was a time of general economic prosperity and peace--except for what appear to have been mostly minor skirmishes
- The Cold War ended without major bloodshed
On the other hand, the failures of the era were mostly behind the stage:
- Economic inequality rose
- The deficit grew vast, and was only closed up by George H.W. Bush and Bill Clinton
- Some of the "America is so strong now" posturing hid dishonest maneuvering (for example, Carter was so widely assailed for the hostage crisis while Reagan actually negotiated for hostages)
- Objectionable judicial nominees (Bork), an attourney general who was a pig (Meese), labor losing power, etc.
Although George H.W. Bush is largely thought to have been limited to 1 term by his breaking his "no new taxes" pledge, I think that's revisionist.
I think in reality, it was Pat Buchanan's speech at the Republican convention in 1992, calling for a "culture war", that alienated Republican moderates, the kind who just wanted peace and prosperity and were a little more sober-headed and less wild than Democrats seemed to be.
I remember working for Clinton that election and seeing the campaign office filled
with ex-Republicans turned off by Buchanan's right-wing rhetoric.* * *
Lots of Republican voters value morality, and unfortunately that's in their minds kind of coded up with lots of aspects that are really extraneous to true morality. It often seems limited to shielding their children from adult content, or castigating those who don't live in traditional monogamous heterosexual relationships, and not about truth and honesty and trying to understand and respect others. It often seemed curled up with warm feelings about living up to one's own religion.
It's troubling to see a book like that by Dinesh D'Souza, who used to get his culture war on fighting against multiculturalism in academia (which did have a faddish aspect in the mid '80s.) Now he seems to be arguing that the Islamic radicals who attacked the U.S. on 9/11/2001 were fighting against our permissive cultural values (not foreign policy such as troops in Saudi Arabia, Palestinian problems, etc.) and that conservatives should join this fight
(sort of to appease the terrorists, I gather.)
For one, of course, permissiveness is relative--in the 1950s Elvis shaking his booty on TV was quite shocking. Internally, if one has a problem with the culture, one shouldn't work to appease murderers from outside the society. (Yeah, I
might have a problem with the culture too, but not as a matter for legislation so much as (1) increasing education, and (2) increasing employment opportunities might increase quality
of stuff--I'm not offended by "vulgarity" and those who are can always look away...)
I tend to be a relativist who on the contrary feels that relativism is
morality, morality is fundamentally not imposing one's will on others. Perhaps the few conservatives left who really do have some intellectual cred--and who do not just like to paint pictures of strawman opponents as sloganeers--view themselves more as the successors of the Enlightenment, and view that time as having a stricter heierarchy of values... On the contrary, I'm influenced by developments such as non-Euclidian geometry--ideas from the last few centuries that have opened minds to how much our traditional culture closed off.
|Wednesday, December 20th, 2006|
|Carl Sagan, in memoriam
Today is the 10th anniversary of the death of Carl Sagan, the great science popularizer. Bloggers around the world are posting entries in honor of Sagan today. Nick Sagan
, son of Carl Sagan, makes an announcement in his blog. Official organizer
Joel Schlosberg announces day of blog posts.
Above, Carl Sagan on the set of Cosmos
As an astronomer (at times) of a certain age, you could guess that I was influenced by Carl Sagan, and you'd be right.
At ages 7-9 or so, I was into science fiction, but mostly the kind of science fiction that gave a "sense of wonder" that was also common in Sagan's books and in his TV series Cosmos
. I was into 2001: A Space Odyssey
and Close Encounters
. I was also interested in extremes, the way little kids are: I read closely the Guinness Book of World Records, I was fascinated by the tallest buildings (thinking for a while to grow up to be an architect) or the fastest cars, or, when I found rockets went faster than cars, I was interested in rockets. Then I kept becoming intrigued that the encyclopedia entries on rockets linked to "astronomy", whatever that was. I finally looked up "astronomy", and found an inspiring image of the Ring Nebula (M 57
) after a trip to the Hayden Planetarium with my parents.
I think my parents first pointed me toward Carl Sagan books when I was 9 or 10: I must have read The Cosmic Connection, and then at 10 or 11, Dragons of Eden (a fascinating but very speculative take on human evolution). Sagan was already (1976 or so) something of a science celebrity for his books and for his leadership of NASA press conferences and (I think) talk show appearances (he famously went on Johnny Carson a lot).
Me in 6th grade:
So by 6th grade, Carl Sagan had become a hero of mine, along with Thomas Henry Huxley and Isaac Asimov. I remember reading his long, dense book, in collaboration with I.S. Schlovskii, Intelligent Life in the Universe
in the 6th grade, and feeling very smart and distinguished for reading such a book.
I must have read Broca's Brain
in college, and then A Candle in the Dark
as a postdoc. The latter I greatly enjoyed, and with a different kind of vision after starting an actual career as a scientist. I think I eventually donated my copy to a prison book project, thinking that in prison libraries there might be a lot of pseudoscience and that the book could be what its title claims it to be: a road to clear thinking for someone in trouble.
I also read a biography of Sagan
a few years ago. I also read Shadows of Forgotten Ancestors
after reading the biography: Sagan and his wife Ann Druyan, who he wrote the book with, thought it was a good one.
So while I enjoyed Cosmos
when it appeared, I think it was Sagan's books that had influenced me more. By the time of Cosmos
I was already heading to the science track.
A couple of years ago I taught astronomy at Bowling Green in Ohio and they had all the episodes of Cosmos
on videotape, and the equipment to project onto the planetarium dome! I probably showed about 4 or 5 episodes to my class.
It was great! I think Sagan became the students' second favorite scientific personality after Tycho Brahe. And even there, that reminds me of the great dramatization of Brahe and Kepler in Cosmos
really hooks you emotionally and visually. It tells its stories dramatically, it's culturally relevant and artistically done, it's frequently amusing, goofy and wry at the same time. I remember him writing out all the digits of a google or illustrating Velokovsky's nutty idea of Venus popping out of Jupiter...
All told I think Sagan's biggest achievement in science popularization was to impart that sense of wonder through science fact.
The Cosmic Calendar, the speculations on the vastness of the Universe, about extraterrestrial intelligence, all that made one feel that science was opening one's eyes to a wider world than you'd have without it.Addendum
: Yesterday was J's birthday. An old pseudogirlfriend of mine. Once, years ago, when I was in grad school, I sent her a "singing telegram" for her birthday. I requested that the messenger dress in a turtleneck shirt (Sagan's style) and give a message about "billions and billions" of birthday wishes from me... I'm not sure if the agency was that familiar with Sagan or whether they faithfully mimicked him...