Wednesday, March 21, 2007

NASA's Fiscal Year 2008 Budget Request

You can find details on NASA's budget request for FY 2008 here. I have reproduced below, without comment, the subsection covering the Space Sciences.

Space Science

The President's FY 2008 budget requests $4.019 billion to fund NASA's space science programs, including Heliophysics, which seeks to understand the Sun and how it affects the Earth and the solar system; Planetary Science, which seeks to answer questions about the origin and evolution of the solar system and the prospects for life beyond Earth; and Astrophysics, which seeks answers to questions about the origin, structure, evolution and future of the universe and to search for Earth-like planets. The proposed budget represents a $16.5 million increase (or about 0.4 %) over the President's proposed FY 07 budget.

Programmatic content changes in the FY 08 budget include the following:

  • Geospace Missions of Opportunity Phase B studies not funded
  • MMS Solar Terrestrial Probe descoped to stay within budget profile
  • New Millenium ST-9 technology demonstrator mission award delayed at least two years
  • Planetary Science program reserves reduced and re-phased; future Planetary Science projects and Juno and New Frontier missions "re-phased"
  • New "Lunar Science" budget line created
  • GLAST and Kepler astrophysics mission launch dates slipped
  • Reserves for James Webb Space Telescope (JWST) increased
  • Space Interferometry Mission (SIM) deferred and reduced to a technology development program with no identified launch date
  • SOFIA project reinstated

The FY 08 budget request maintains the research and analysis (R&A) accounts at FY 07 budget levels and thus sustain the 15% R&A cuts included in the FY 06 and FY 07 NASA budgets. Astrobiology, an interdisciplinary field that NASA created to study the origin, evolution, and possible existence of life in the Universe, has been cut by some 50% since FY 06. The competitively-selected Explorer and small missions programs that National Academy decadal surveys have emphasized as vital, continue to lack the required funds to restore the 2-year cycle of issuing announcements of opportunity (AOs). The current AO rate has been diminished considerably compared to earlier periods. The last Explorer AO was issued in 2003; under the FY 08 budget request, the next AO is expected to be issued in late 2007 or 2008 leaving a gap of approximately 5 years in new selections.

Other Space Science issues include the following:

Mission Size and Programmatic Balance--The FY 08 budget request continues budgetary trends that are creating imbalances in science programs, especially in the research and analysis (R&A) accounts, which fund grants to analyze science mission data, and in the portfolio of sizes for science missions. Science programs that lack balance are not robust: they cannot be sustained or contribute adequately to high priority research questions laid out in National Academy decadal surveys. Moreover, in addition to their high scientific productivity, small and medium-sized missions are instrumental in training young scientists and engineers and in exciting the science and broader communities through the Principal Investigator team's promotion of the mission.

Cost-Growth in Missions--Several of the increases in the proposed FY 08 Science budget provide funds for projects that have run over budget or schedule, or that run the risk of doing so. The factors contributing to cost and schedule growth are not easy to pinpoint, but include underestimates in the technology developments required for mission readiness; increases in launch vehicle costs; inadequate models to estimate mission costs; internal decisions to delay missions or alter budget profiles; project management difficulties; and delays in contributions from international or interagency partners. Mission cost growth erodes opportunities to conduct other high priority science and can lead to delays, cancellations, or reduction in funds for other NASA science missions and activities.

Launch Services/ Access to Space--Officials from NASA's Science and Space Operations Mission Directorates have called attention to a potential crisis in launch vehicle access for science missions. The Space Science program has been a regular user of Delta II vehicles, which are reported to have a 98% success rate for science missions flown since 1961. Between 2007-2009, NASA's Science Mission Directorate plans to launch at least eight missions on the Delta II vehicle. NASA is uncertain about the availability of the Delta II beyond 2009 and is conducting a study to investigate options for alternatives to the Delta II. The potential loss of Delta II raises the question of reliable access to space for science missions. Shifting to alternative vehicles could affect mission costs and schedule.

Backus, the man behind Fortran, passes away at 82.

John Backus (informative biography here), winner of a Turing Award for his many contributions to computer science, passed away yesterday (20 March 2007) at the age of 82.

Backus's career included many notable firsts, including leading the group that developed the computer language Fortran in 1957. Fortran is considered to be the first high-level language. Fortran, or more specifically, its later (much improved) revisions Fortran 77, Fortran 90, and Fortran 95, for example, is still very commonly used in professional physics and astronomy. Although C or C++ is being more and more these days it seems unlikely that Fortran will disappear in the next decade or two.

Like all computer languages it has its strengths and weaknesses. Standard f77 lacks objects, derived types, dynamic memory allocation, pointers and so on, which makes certain tasks more difficult to perform, but also this also simplifies the code (very useful if you're reading some else's code, as using, maintaining or extending legacy code is very common in physics) and immunizes Fortran from a large variety of the nasty, pernicious and hard-to-find bugs that can invest C (for example).

Using the most common extensions to the language (such as not using upper case, using "end do" instead of to horrible labeled "continue" statements, "!" for same-line comments), and some experience, you can certainly write clean, elegant, and efficient (i.e. fast) code. Badly-written Fortran is of course, a nightmare to behold, but no worse than badly written C.

As an undergraduate we were taught Fortran 77, and although I now prefer to code in C++ or even python now, I still retain and use large amounts of Fortran code. For certain tasks it is still easier to write, test and use Fortran than C or C++.

Tuesday, March 20, 2007

Black holes everywhere

Follow the link to current the current HEASARC picture of the week. Almost every point of light in this Chandra image, created by Ryan Hickox, marks X-ray emission from super-massive black holes at the centers of distant galaxies. The region of sky observed is in the constellation Bootes.

Go here to read the preprint of Hickox et al's work.

Monday, March 19, 2007

The three NASA Great Observatory's view of the starburst galaxy M82

One day I'll try to take the time to write a wikipedia-level description of what a starburst-driven galactic superwind is and why they are important if we are to fully understand the nature of the Universe we evolved in.

But in the mean time it doesn't hurt to show you the archetype: M82, as presented by the Hubble Heritage team. There is even a video (quicktime or mpeg).

These images represent to combination of separate observations with three of the NASA Great Observatories: the Hubble Space Telescope (HST), the Chandra X-ray Observatory, and the Spitzer Space Telescope. These image were put together as part of a press release for Hubble's Sixteenth Birthday, which also marked the release of the deep and wide-field HST imaging of M82 with the (now defunct) ACS instrument.

What you see in these images is disk/spiral galaxy named Messier 82, viewed almost edge-on.

Starting with the HST image (top left), the disk of stars is colored blue. This galaxy is smaller and less massive than our own Milky Way galaxy (also a spiral), by factors of about 3 and 10 respectively, but M82 is not particularly small as far as galaxies go. From side to side the stellar disk is about 30 000 light years in diameter (9 kiloparsecs). The red in this image is H-alpha emission, light emitted from ionized interstellar Hydrogen gas which has a temperature of about 10 000 degrees Kelvin (this is hotter than the surface of the sun). What is immediately apparent is that much of this H-alpha emission in concentrated near the center of the galaxy, with prominent filaments and clumps extended out from the nucleus in to the halo of the galaxy. This is far away from the disk of the galaxy where most interstellar gas normally resides. In fact we know from optical spectroscopic observations that much of this H-alpha emitting gas is flowing out of the galaxy as speeds of about 600 kilometers per second (that is just over 1 million miles per hour).

(Top right). The X-ray view of M82 looks, at first glance, to be totally unrelated to the optical images. The galactic disk of M82, consisting of about 20 billion stars or so, comprising the majority of the baryonic mass of the galaxy, simply isn't visible in X-ray emission. There is vastly more to the Universe than that which can be seen with optical (HST) or near-infra red telescopes (e.g. JWST).

The energy of X-rays we detect tell us about how the X-rays are generated, and the composition and nature of what is emitting them. In these X-ray images from Chandra the red represents X-ray emission from photons having energy in the range 0.3-1.6 keV (kilo electron Volts), the green represents emission in the 1.6-2.8 keV energy range, and blue is 3.0-7.0 keV. By way of comparison, your dental X-rays have a typical energy of about 70 keV, much more energetic than the X-ray emission Chandra is sensitive to. The little dots of brightest X-ray emission are termed "point sources," and most of the ones visible in the center of the image are individual binary stellar systems in M82, comprising high mass stars with neutron star or stellar mass black holes as companions. Normal stars like the Sun do emit X-rays, but as only a tiny fraction of there energy comes out at X-ray wavelengths they're essentially invisible in Chandra images of Galaxies outside the Local Group. The X-ray emission we do detect can tell us useful things about the total amount of massive star formation in the star burst, but that is the topic for another post entirely. Other point sources in the image are most likely much more distant AGN, far in the background.

But the most prominent feature of these X-ray images of M82 is the diffuse X-ray emission, brightest in the central starburst region of M82, fading as it extends outward away from the disk of the galaxy. The red and green in the image is thermal X-ray emission from hot gas (technically a plasma) in the superwind, with a temperature of about 4 million degrees Kelvin in the outer (red) regions. We currently can not measure the speed with which the hot X-ray emitting gas is moving, but based on the theory of winds we would expect this emission to be moving at least as fast as, and maybe twice as fast, as the gas seen in the optical Hubble images. X-ray emission is a much more direct probe of the very violent processes creating the superwind than the optical, UV, or IR emission also seen in the wind.

(Bottom left) The image on the bottom left is the near infra-red (IR) as seen with the IRAC instrument on the Spitzer Space Telescope. In this case each IR photon detected by Spitzer has only a tenth (1/10) of the energy of the photons detected in the optical HST images, and one ten thousandth (1/10000) the energy of the X-ray photons. The blue again shows the stellar disk of M82, as normal stars still emit some decent fraction of their total power in the near IR. The red spread all over the halo of M82 is emission from compounds called Polycyclic aromatic hydrocarbons (PAHs), which are basically organic compounds, and you encounter them in every day situations as one of the components of cigarette smoke, car exhaust, and so on. Consider them to be tiny grains of soot, similar in origin but smaller than your average interstellar dust grain.

Dust and PAHs are a natural component of the interstellar medium (ISM), which normally resides in the disk of spiral or irregular galaxies. So why is it in M82's halo? We know the hot gas in superwinds sweeps up the ambient normal ISM, carrying it out into the halo with it. This is the origin of the H-alpha emission seen in the HST images, for example. Some fraction of the dust and PAHs in M82's halo are probably there because of the currently active wind. But its not as simple as all that.

Firstly, the PAH emission appears to be more widely spread in halo of M82 than the known wind-emission (the H-alpha and soft X-ray emission). Secondly, PAH's are pretty fragile. They're organic molecules, not particularly huge, and they can easily be destroyed by UV or X-ray radiation. So the wide-spread presence of the PAHs in M82's halo is not something we necessarily expected to see before Spitzer was launched. It may be that the numbers will turn out right for the wind to have put them there, and not have destroyed enough of them yet, but it also may well turn out that some other mechanism is needed to create a dusty halo BEFORE the current superwind started (the age of the current wind is perhaps 10 to 30 million years), so there may have been previous superwinds in M82. The PAHs may be a minor detail, as regards the starburst and superwind, but they may tell us something about the history of the wind that otherwise we would never learn.

(Bottom right) The final image is multi-wavelength, multi-observatory, montage of M82 using all three Great Observatories. From the HST ACS observations with have the light blue stellar disk, with the T=10000 K H-alpha emission in yellow (it is barely visible in this image because it strongly overlaps with the red PAH emission), from Chandra we have the soft thermal X-ray emission from the million degree plasma in the superwind, now shown in a darker blue, and from Spitzer the near IR PAH emission in red.

Images like this composite are both scientifically helpful and occasionally misleading. Knowing how the X-ray gas in the wind relates to the H-alpha emission and PAH emission can tell you (if you know the physics) what is actually going on.

I want to take a brief detour from the subject at hand to point out an important caveat for non-professionals to bear in mind. The intensity stretches used to make pretty color images can distort or exaggerate the natural gradations in intensity, and hence fool you into thinking there isn't emission in some place where in a monochromatic image you'd find it is there. Real data analysis is not done with photoshop or other common image formats, after all. For example, in this final image it looks like the X-ray emission comes from within the IR PAH emission, and that there isn't much PAH emission where the X-rays are bright. Yet the bottom left image shows that the PAH emission is pretty bright everywhere.

In practice, in professional astronomy the pretty press release images you end up seeing are never what was actually analyzed scientifically, so the case described above really isn't a problem for real science. On the web its another matter, as there are all sorts of people who take NASA press release images and play with them in photoshop and still somehow think they're getting valid information on the face on mars out of some lossy-compressed jpeg.

In conclusion we're seen the classic starburst galaxy with a superwind, M82, as seen with each of the three remaining NASA Great Observatories. Each covers as different part of the electromagnetic spectrum, and thus each probes very different physical conditions, from cold dusty gas all the way to plasmas at millions of degrees. In some ways the images are very different, yet share some common aspects (such as the superwind flowing out of the disk and into the galaxies halo). Together they provide us with parts of the puzzle for unlocking the nature and implications of starbursts and superwinds.

Image credits:
HST ACS (top left): . Gallagher (University of Wisconsin), M. Mountain (STScI), and P. Puxley (National Science Foundation).
Chandra ACIS (top right): NASA/CXC/JHU/D.Strickland.
Spitzer NIR (bottom left): NASA/JPL-Caltech/C. Engelbracht (University of Arizona).
HST/Spitzer/Chandra composite (bottom right): NASA, ESA, CXC, and JPL-Caltech.

Saturday, March 17, 2007

My take on the most significant Science Fiction and Fantasy works of the last 50 years.

A number of the science blogs (particularly those over at Seed's have been commenting on a list of the 50 most significant Science Fiction and Fantasy books of the last 50 years.

It is quite interesting to read these posts, as peoples views differ quite a lot. As a quick break from observing proposal writing I'm going to join in, commenting on Mark C. Chu-Carrol's post (which is shown in grey font), as he went to the trouble of actually commenting on the books (and he is apparently the Geek-Lord of ScienceBlogs).

PZ, Bora, Orac, John, and others have all put up posts about a list of the 50 most significant Science Fiction and Fantasy works of the last fifty years. As the reigning Geek-Lord of ScienceBlogs, I figured that I had to weigh in as well. Here's the list: the one's that I've read are bold-faced.

1. The Lord of the Rings, J.R.R. Tolkien.: A work of true brilliance. I have no idea how many times I've read it; all I can say is that I don't think I've gone for longer than two years without re-reading it since I first encountered it in sixth grade.

As a Tolkien junky myself I would agree that LoTR must still be counted as the greatest Fantasy work of this century, simply for the breadth and scope of Tolkien's development of Middle Earth's history, languages and so on. In terms of writing style and elegance, well, it if you like slow plot development and exhaustive description, then its great. Some aspects (swarthy, evil, easterlings and southrons, for example) have to be excused as regrettable facets of times in which it was written.

Now for the rest of them - which I hope are not meant to be in order of significance.

2. The Foundation Trilogy, Isaac Asimov. : Foundation definitely shows its age, and all of Asimov's flaws as a writer are on display. On the other hand, all of Asimov's strengths as a writer are also on display. Foundation is what really got me started reading SF, and I continue to believe that it's a masterpiece.

I've read the foundation trilogy once, and while I liked them at the time I got bored very quickly when I tried to read them again. I agree with much of MCCC's comment, its certainly an exemplar of the "old" SciFi defined by Asimov, Clarke and Heinlein, definitely influential, but I would not say it meets the standards a modern reader expects.

3. Dune, Frank Herbert: In general, Herbert was a pretty crappy writer. I'll never understand quite how he managed to pull Dune off. Dune is one of the great masterworks of science fiction - it's another of those books that I've read more times than I can count, and I still love it, and still find new details. It's just a spectacular piece of fiction, beautifully written, with a depth of detail and history that I think was unprecedented in SF. Unfortunately, the sequels were mostly back to Herbert's old crappy writing style. The depth in the setting did manage to shine through at times, but not enough to justify seven volumes. (I must admit that the series reads much better if you just pretend that the second book doesn't exist; there are a ton of continuity problems in the second book, but he mostly gets his act straightened out after that.)

The Dune trilogy, and the follow-up second Dune trilogy, were once favorites of mine and I still have the books. I recently tried to re-read parts of them, and it seemed more tedious than I'd remembered it being. Still, Dune did managed to create a sense of epic scale and deep history, something that pulled it above the mass of pedestrian SciFi.

4. Stranger in a Strange Land, Robert A. Heinlein: Gods, what an over-rated piece of dreck. I heard so much about this; when I finally managed to get a copy from my local library and read it, I was just astonished at how dreadful it was. It doesn't even make it to the level of mediocrity of much of Heinlein's later work. Heinlein's juveniles were often fantastic (I have incredibly fond memories of "Have Spacesuit, Will Travel"), but his later adult fiction was mediocre at best. And SiaSL is not his best. Ick.

I've only read three Heinlein books when I was first getting in SciFi; SinaSL, the Puppet Masters, and Job, and really gave up on him after that. With the exception of Job, I never read them again. 'Nuff said.

5. A Wizard of Earthsea, Ursula K. Le Guin. My second-favorite fantasy series after Tolkien. It's got a very different flavor to it, which is part of why I love it: Tolkien had such an influence on fantasy that almost all of the fantasies written for decades after LoTR tended to feel like ripoffs. Earthsea was different - subtle, original, lyrical; just a wonderful piece of fiction.

This was read to me by my mother before I could read, and the dark spirit Ged releases and its hunting of him truly terrified me. I can still remember the felling. While I never really enjoyed any of Le Guin's other work, she created something with a truly unique feel to it with a AWoE, and it certainly deserves to be in a list of the most influential SciFi and Fantasy.

6. Neuromancer, William Gibson.: Overrated. It had style - I'll give it that. But it's style was self-consciously cool; the whole thing had a sense of "I, William Gibson, the author of this book am so much cooler than anyone who'd read this stuff". It also had a terrible influence on science fiction - I was glad to see cyberpunk fade out and disappear.

I'm always surprised to encounter people who don't like Neuromancer. It has more than style, it is intensely elegant in just how smoothly concise and sculptured it is. Its an incredibly short book, yet brims with innovation, and yet tells more than than a hundred modern overblown 700 page SciFi novels. Its (almost, yes, I am aware of Bruce Sterling) the birth and highest achievement of cyberpunk in one package. I certainly don't feel its self-consciously cool, its the imitation by later lackluster authors that sadly tars all of cyberpunk. IMHO Neuromancer is one of the best Science Fiction novels ever, definitely in the top 5.

7. Childhood's End, Arthur C. Clarke: Overrated. Eh.

I've only read the short story in a compilation of A.C. Clarke short stories (which I thought was the whole thing), which I liked. I loved his short stories when I was young, and still have some of the compilations, but they, like all "old" SCiFi, have not aged well.

8. Do Androids Dream of Electric Sheep?, Philip K. Dick: This one was a shock when I read it. I'd seen the original Blade Runner (the cheesy version with the voiceover), and thought this was a novelization of it. (I was clueless, OK?) I loved the movie; I'm crazy for the directors cut of it; but this just left it in the dust. Got me well and truly hooked on PKD. I do have to say that "Blade Runner" came closer to DADoES than any other PKD movie has come to his stories. (The worse example being "Total Recall", which took a brilliant story with multiple layers of identity confusion, and stripped it down so that it had a shadow of one.)

Never read it. Didn't really feel the need to mess with my appreciation of Blade Runner (directors cut, of course) by reading the story it was extrapolated from.

9. The Mists of Avalon, Marion Zimmer Bradley: Loved this the first time I read it. Then I recently read it again, and couldn't figure out why I liked it the first time.

Never read this one. The one Marion Zimmer Bradley I read as a kid wasn't horrible (I can't even remember the name or what it was about), but somehow it put me off from reading anything else. Sad really.

10. Fahrenheit 451, Ray Bradbury: definitely a classic.

Definitely over-rated crap, you mean. Temperature where books burn, firemen, blah blah. Nice idea, when compressed into a paragraph, but god the book is horribly written. I feel people confuse the socio-political warning (admirable) from the actual execution of the idea (sucky writing) and all end up parroting this claim that its a classic.

11. The Book of the New Sun, Gene Wolfe.: Another one I've read too many times. I love Wolfe's writing. New Sun isn't exactly a fast-paced gripping novel. It's very slow at times; often rather grotesque. But it's a terrific read overall.

Never read.

12. A Canticle for Leibowitz, Walter M. Miller, Jr.: For me, this is the opposite of my experience with "Mists of Avalon". I first read Canticle in high school, and couldn't figure out why anyone thought it was good. Then I recently found my copy while doing some cleaning, and re-read it, and was just amazed - it's amazing.

Read once, one of those things you read to see what it is that people are talking about. Elegant, but its still a read-once-only thing for me.

13. The Caves of Steel, Isaac Asimov.: I love Caves of Steel; it's my favorite of Asimov's books. For some reason, Asimov's weaknesses as a writer just don't seem as glaring in this book, and it's got everything that I like about his writing.

I certainly found this the most enjoyable of Asimovs book, and re-read it multiple times. Of course, its really a detective novel...

14. Children of the Atom, Wilmar Shiras. Never read this one.

Never heard of it even.

15. Cities in Flight, James Blish: I was pretty sure I'd read this at some point; checking the description on Wikipedia, I definitely remember reading it, and wondering what all the fuss was about. Seemed like fairly mediocre space opera to me. Blish has never thrilled me as an author.

I've never read this either, although I'd certainly heard of it and Blish.

16. The Colour of Magic, Terry Pratchett: I love Pratchett and Discworld. I've got very nearly the entire series. But "Colour" is my least favorite.

Pratchett is great fun to read, but I've never had the urge to buy his books or read them a second time.

17. Dangerous Visions, edited by Harlan Ellison: OK, but pretentious. I've never been a fan of fiction that's very conscious of how cutting edge it is; too much of DV has that self-conscious feel to it for my tastes.
18. Deathbird Stories, Harlan Ellison: Harlan Ellison is a bit of a jackass. But when he puts his mind to it, man can be write.

I've only read a few of short stories, so can't comment on these.

19. The Demolished Man, Alfred Bester: Another big wow - this is an amazing book. Somehow, I managed to completely miss Bester until the SF book club re-issued a few of his books about 5-6 years ago, and it just knocked me out. Pure brilliance. I just can't believe I went so long as an SF fan without knowing about this!

Um, who?

20. Dhalgren, Samuel R. Delany.: God, what an awful book. Terrible, dreadful, awful, pointless. It took me at least a dozen tries before I managed to read this; I kept trying because so many people raved about how wonderful it was. I don't think I'll ever understand what people see in this. The style of the writing gives me a headache; the story is slow and almost entirely pointless, interspersed with terribly written and very unpleasant sex scenes which have nothing to do with anything else. God, what dreck.

I seem to have been lucky to avoid reading this.

21. Dragonflight, Anne McCaffrey: OK stuff; not great, but fun for a light read. Damn shame they had to ruin it by writing 70 or 80 crappy sequels.

I concur with MCCC's comment 100%.

22. Ender's Game, Orson Scott Card: Scott used to be such a good writer, with such a deep empathy for his characters. "Ender's Game" was a great novel, with a really compelling main character. I even loved the first sequel: "Speaker for the Dead" was a really great story as well, with some nice development of Ender as a character. I hate what he's done by going back and retconning the story by telling it from Bean's PoV; it's such an obnoxious conscious effort to re-write the politics of the story to fit his more recent ultra-conservative gay-hating war-mongering political views.

I started with OSC by reading "Seventh Son of a Seventh Son" series, and didn't bother completing the series or reading anything else he did, despite hearing people rave about Ender's Game. I though the SSoaSS thing just had unlikeable characters and annoyingly portrayed bad guys, and I couldn't be bothered to put up with it. I have no idea whether his rather distasteful current political views had come to the surface then, or whether it just wasn't my cup of tea.

23. The First Chronicles of Thomas Covenant the Unbeliever, Stephen R. Donaldson.: Mediocre. I've never really understood why people think it's so great. To me, it's always felt like an overly self-conscious take on "Yeah, but what if Frodo was a total asshole?".

At the time I liked the whole white gold wielder vs Lord Foul trilogy - it was a grittier, harsher, fantasy world than I'd seen presented before. It was unique in many ways. Even the discomfort of having a rapist as the "hero" was tolerable. Would I go back and read them again - probably not.

24. The Forever War, Joe Haldeman. Haven't read it.

I read the original heavily edited version, not the later expanded "author's" version, when I was young, and thought it was brilliant. The harsh, inhuman, timescales, societal changes, blind industrialized warfare with no understanding of the enemy, it thought about in ways I'd never considered before and presented them all wonderfully. Definitely a significant piece of work.

25. Gateway, Frederik Pohl: Eh. OK. Another one with too many sequels.

Read it multiple times. Was this the first book to have aliens hiding in black holes?

26. Harry Potter and the Philosopher's Stone, J.K. Rowling. : I love the Harry Potter novels. "The Philosopher's Stone" isn't my favorite in the series, but it is a great story. And it's well-worth going back to re-read after having read some of the later ones - there are hints hidden in it to things that happen in later novels.

Never read any of them, although not for any reason.

27. The Hitchhiker's Guide to the Galaxy, Douglas Adams. : 42. Need I say more? Ok - a little more. I've worn out three different copies of this. Any time I'm feeling depressed, I dig out one of the Hitchhiker's books to cheer me up.

I'd group Adams with Pratchett as masters of comedic fantasy. Definitely a classic, although some of the followups were less inspired.

28. I Am Legend, Richard Matheson. Not only have I not read this one, I have to admit that I haven't even heard of it before.

One of those things you've heard of, and probably seen imitated, so many times that you can't be actually sure you've read the original.

29. Interview with the Vampire, Anne Rice.: Ick. Ick ick. Ick ick ick ick ick. I hate Anne Rice; I hate her writing style, I hate her stories, I hate her characters, and I hate what she did to the vampire legends. Ick, ick, blech.

I wouldn't even deign to call this true SciFi or Fantasy. Its like confusing Goth music with Alternative. They're related, but they're not the same thing at all. Vampire books are a unique sub-genre of horror, sadly often blended with creepy eroticism. Having Tom Cruise be LeStadt (or whatever his name was supposed to be) just proved how sucky IwaV was, IMHO.

30. The Left Hand of Darkness, Ursula K. Le Guin: Another brilliant work by LeGuin. Love it, although not as much as Earthsea.

Never could get into the Le Guin stuff other than aWoE, but I'm sure this was influential on the field.

31. Little, Big, John Crowley: I started this, and got distracted, and then lost my copy. I don't remember much about it. Based on reading other Crowley, I suspect that I'd like it quite a lot.

Mmh - never quite liked the Crowley stuff I read. Or am I mixing him up with John Varley?

32. Lord of Light, Roger Zelazny: One of my all-time favorite novels. What an amazing piece of writing! It's one of those books that has a plot that sets its hooks in you, and keeps you engaged - and at the same time, is written in such a wonderful style that you sometimes have to just stop reading to ponder the beauty of a paragraph. Zelazny at his best - and that is one hell of a strong statement.

Never read.

33. The Man in the High Castle, Philip K. Dick: A good novel, but very over-rated I think. PKD wrote so many things that were so much better than this; I think it's a shame that this is the novel he's best known for.

It was worth reading, interesting, but I'm not going to read it again.

34. Mission of Gravity, Hal Clement. Never read it.

Tried to read this, based on rave reviews on Amazon, and regretted it. Finally slipped the copy into a box of books going to good will.

35. More Than Human, Theodore Sturgeon: Ok. Didn't knock my socks off, but it's a nice piece of writing.

Nope, never read this either.

36. The Rediscovery of Man, Cordwainer Smith. I've never managed to get a copy of any of Smith's books.

Nope, never read this either.

37. On the Beach, Nevil Shute. Haven't read it.

I've seen a B&W movie with this name when I was a kid, and liked it. Fine example of nuclear apocalypse. Is this the same thing?

38. Rendezvous with Rama, Arthur C. Clarke. Typical of everything I dislike about so many of Clarke's books. The man has interesting ideas, but he has absolutely no clue of how to hang a plot around them. Rama has great potential - but he managed to utterly waste it. I mean, what really happens in Rama? Human's discover what appears to be an artificial comet. They go to explore it. They find all sorts of interesting, but unexplained things. And then they have to leave it before it slingshots its way out of the solar system.

I liked the unexplained nature of Rendezvous with Rama. The biological machinery, etc etc, very interesting ideas. The much later sequels were horribly sucky though, and totally destroyed my remaining illusions that Clarke was a good author.

39. Ringworld, Larry Niven: Mediocre space opera.

OK, I must admit to be a big fan of Niven's early work, particularly the short stories, but also some of the novels. Protector - frigging brilliant, incredibly inventive story. General Purpose hulls, exploding galaxies, organ harvesting, guy was way ahead of his time. Ringworld was without doubt a super influential book (try counting how many books use ring worlds of one type or another these days) and I liked it. Followups, well... less great. But definitely to me Niven was the most interesting SciFi author of the 1960's.

His collaborations with Jerry Pournelle ran the gamut of innovative and great [The Mote in Gods Eye (the Moties were some of the most unique aliens ever imagined) and Footfall (the best alien invasion novel ever)], through nasty exhibits of racism (Lucifer's Hammer), to harmless but sadly weak sequels (The Gripping Hand).

40. Rogue Moon, Algis Budrys. Haven't read it.


41. The Silmarillion, J.R.R. Tolkien: This should not be identified as a novel written by J.R.R. Tolkien. It's a novel assembled by his son from notes left by the father. J.R.R. Tolkien would never have published it in this form. It's got some brilliant parts; and it's got some utterly dreadful parts. It's very sad to look at the "Unfinished Tales" published later, and see parts of the Silmarillion as J.R.R. Tolkien wrote them, and compare them to the versions edited by Christopher Tolkien.

The Silmarillion is a an essential part of Tolkien's work, and it is of great importance, but not as a novel. Must say I'm confused my MCCC's comment, it sounds as if he actually prefers the two Unfinished Tales to the Silmarillion, but that would be crazy!

42. Slaughterhouse-5, Kurt Vonnegut. Brilliant. I am not worthy to comment.

I never read this, for the weak reason that so many other supposed classics (e.g. Farenhiet 451, Brave New World, etc etc) had turned out to be less than great when I read then. Having just read the wikipedia entry on this book, I see I haven't missed anything.

43. Snow Crash, Neal Stephenson: A really fun read, but someone really needs to teach him how to write an ending!

Mmmmh - Neal Stephenson is definitely one of the better modern SciFi authors, but frankly his earlier work is not as good as his later work, and his endings were even weaker in his early work.

I feel that Snow Crash is particularly over-hyped by many of its readers, it's vacuum-formed production-line cyberpunk, that would have been significant if it had been published in 1985 rather than 1992. Honor him for his far more interesting Cryptonomicon, or the Baroque Cycle, but not Snow Crash.

44. Stand on Zanzibar, John Brunner: Eh.

Never heard of this either, but its wikipedia entry makes it sounds quite promissing. I'll have to find a copy...

45. The Stars My Destination, Alfred Bester: Remember what I said about "The Demolished Man"? I like "The Stars My Destination" even more.

Nope. Not read.

46. Starship Troopers, Robert A. Heinlein: What a piece of crap. Heinlein at his worst. A heavy-handed political tract.

Never read this either, but the movie was fun.

47. Stormbringer, Michael Moorcock: Profoundly mediocre. Like I said before, I have a dislike for self-consciously cutting-edge stuff. Moorcock's writing was almost always incredibly self-conscious. It's got that writing style that says "I'm a great writer writing this; look at how wonderful my writing style is!".

I actually liked reading Moorcock's works when I was young, and the perpetually-depressed Elric of Melnibone was an interesting character. I'm pretty sure I would not enjoy them as much if I read them now, though.

48. The Sword of Shannara, Terry Brooks. : What the hell is this doing here? An incredibly blatant ripoff, virtually scene for scene and character for character of LoTR. The worse piece of derivative garbage that I've had the misfortune to waste my hard-earned money on.

A commenter on MCCC's post points out that Brooks is influential because he marked a return to writing epic fantasy after a longish spell of no-one daring to venture where Tolkien had been. This is a good way of looking at it. Sure, Brook's multiple books were formulaic to the extreme, but at the time I really enjoyed reading them, which frankly is all that counts.

49. Timescape, Gregory Benford. I know I've read this; it's on my bookshelf. But I can't remember a thing about it. Which pretty much sums up my experience with everything I've read by Benford - totally forgettable.

I read quite a bit of Benford, and found them rather bleak and depressing, but I never read this one. Nevertheless he had some interesing ideas. I might not put him on my list of the top 50, but then very few of this set of 50 books would go on my list.

50. To Your Scattered Bodies Go, Philip Jose Farmer. Haven't read it.

As a teenager I used to love the Riverworld books, and re-read them many times. Definitely a classic.

OK, thats that. Maybe later, after the proposal deadline, I'll post on the very notable, and IMHO inexcusable, omissions from this list.

Back to the climate... again.

I often seem to end up blogging (or ranting) more about climate change than astrophysics, even though I am not in the climate sciences. But it is an issue of great importance (I'd prefer not to experience the possible consequences of unchecked climate change in later life) and the science (matter interacting with radiation, thermodynamics etc) is close enough to the physics I specialize in that I can understand why they're saying what they're saying.

After all, Earth is just another planet orbiting a moderately typical star, so its all astronomy at the end of the day.

The climate is, as with all science, interesting, and I try to keep up to date on whats happening in the broader scientific world by reading popular science magazines, science blogs and even newspaper science sections. Earlier this week the NYT published a piece by journalist named William J. Broad with the title "From a Rapt Audience, a Call to Cool the Hype." As you might guess, the subject is Gore and "An Inconvenient Truth". What is the article about? Well, here is the second paragraph:

But part of his scientific audience is uneasy. In talks, articles and blog entries that have appeared since his film and accompanying book came out last year, these scientists argue that some of Mr. Gore’s central points are exaggerated and erroneous. They are alarmed, some say, at what they call his alarmism.
I thought this claim seemed very odd. I've seen Inconvenient Truth, and found it very nicely presented. I didn't notice anything in it that really jarred me as being something outrageous that I'd never seem claimed in other reputable writing about climate change. There were one or two slips of the tongue, an over-simplification of a few physical concepts, but its a presentation. Even when talking professionally to scientific colleagues at departmental colloquia or full conferences you pretty much have to simplify some aspects of what you're talking about.

Talking to a general non-science audience is even harder, and Gore did a great job, I thought. So how many climate scientists would be so pedantic as take Gore to task? On reading further into the article I became very suspicious, very quickly. The very small number of named scientists who actually make negative statements regarding Gore's presentation, and the details of statements they made, all made me think this was a hatchet job by climate deniers, a sort of "OK, we cant get away with claiming that there is no evidence for climate change, or that its largely man made, so lets change tactics and says there no way its going to be a big problem."

Some of the rhetoric used really set off the alarm bells:

Criticisms of Mr. Gore have come not only from conservative groups and prominent skeptics of catastrophic warming, but also from rank-and-file scientists like Dr. Easterbook, who told his peers that he had no political ax to grind. A few see natural variation as more central to global warming than heat-trapping gases. Many appear to occupy a middle ground in the climate debate, seeing human activity as a serious threat but challenging what they call the extremism of both skeptics and zealots.
The scientists who've been studying climate change for decades, whose work and predictions have been independently validated in more and more detail, who were in a very real sense right about there being recent unprecedented climate change, are now "zealots" and "extremists" according to article. The people who continue to deny climate change in the face of ever-increasing evidence for it are also painted as extremists, but only as extremist "skeptics." Mmmh, there is a time for valid skepticism, but that time is long past. And so we're meant to accept that in a polarized argument about a scientific issue, between the vast majority of professional scientists and a fringe of contrarians and non-scientists with a vested financial interest in climate change denial, that it is really the people in middle, the self-proclaimed "centrists" who are the most intellectually honest?

Centrism as a word has very clear political overtones, especially in the modern theatre of US politics, so its use in an article claiming to be a-political is somewhat inappropriate. Nevertheless, and please don't misunderstand me, the "golden mean" or "happy median" is a valid concept in certain situations, buts its use here is just wrong.

Should we also accept that there is a valid argument about whether the Earth orbits the Sun or vice versa, and that in such a "debate" between profession astronomers and some very strange religious conservatives, that the astronomers are zealots, the fundamentalist merely skeptics, and the best position is to be centrist and say "we don't know"?

How about a purely hypothetical scenario, between zealous mathematicians proclaiming 2+2=4, and skeptics claiming 2+2=5? Is the even a valid debate, let alone something where "centrism" is valid?

Anyway, to cut the story short it seems like I was right to dismiss the article as pure propaganda. Over at RealClimate, Michael Mann (he of the hockey stick graph fame) and Gavin Schmidt dissect the William Broad article and reveal the inaccuracies (or to be honest about it, the deliberate lies and dishonesty) put forth by both the few scientists in the article, and its author Broad (who also appears to have a history of climate denial). The post is well worth reading, so please go read it (the link repeated here for those too tired to move the mouse up to the previous link).

Thursday, March 15, 2007

Million degree gas in the halos of spiral galaxies

Today is the deadline for the latest round of Chandra observing proposals, and it looks like I'm not going to finish my epic new proposal on time. Grrr.

But it reminds me that there really aren't many good pictures, on the popular astronomy side of the web, of what galaxies look like, as seen using the X-ray's the galaxies emit. AGN, star clusters, galaxy clusters. Tons of those, but non-active galaxies are much less represented.

The images above shown below are false-color composities of X-ray emission (blue), optical H-alpha line emission (red) and "normal" optical starlight (green), of nearby roughly-edge on spiral galaxies.

Note: blogger is doing something odd with displaying the table, its leaving a huge space, so scroll down a bit and the images will appear.

X-ray and optical images of edge-on spiral galaxies
M82 (starburst) NGC 1482 (starburst)
NGC 253 (starburst w/LLAGN) NGC 3628 (starburst)
NGC 3079 (starburst w/LLAGN) NGC 4945 (Sy 2 w/starburst)
NGC 4631 (starburst) NGC 6503 (normal)
NGC 891 (normal) NGC 4244 (normal)

Our own galaxy (the Milky Way) is a "normal" spiral galaxy, as is its neighbours M31 (Andromeda) and M33. Of the galaxies shown above, the Milky Way has long been thought to be closest in type, size, total mass and star formation activity to NGC 891. However more modern observations, particularly with Spizter, indicate NGC 891 is significantly more actively star-forming than the Milky Way.

These images are all shown in the same scale (the size of the image is roughly equivalent to 65 thousand light years on side at the distance of the galaxy in question), and they're all taken from one of my papers on Chandra observations of a sample of nearby edge-on spirals.

As you can see spiral galaxies are more than two-dimensional disks, and the more actively star-forming a galaxy is, the more likely it is to have hot gas (2 to 5 million degree plasma) in its halo, which is what we see in the X-ray data. The galaxies are shown in terms of their infra-red "warmth", a ratio of the brightness in two wavelengths measured with the old IRAS satellite. The IR warmth is physically a measure of the temperature of interstellar dust (more like soot really), which itself is determined by the average number of stars forming per unit area in the disk of the galaxy.

Galaxies essentially have atmospheres, and those atmospheres are important for a number of reasons I might get around to mentioning in a future blog. In some of the images you can also see that the H-alpha emission (from ionized gas at only T ~ 10000 degrees) also reaches into the halo. Other galaxies appear to show now emission in their halos, but at present it is not clear whether this really means they don't have gaseous halos, or whether there is just so little gas that its too
faint to detect - both hypothesises are consistent with present data.

For the brighter examples, the starburst galaxies, the halo emission is almost certainly not a static atmosphere but gas lit-up by, and incorporated into, a galaxy-sized wind flowing out of the galaxy, a phenomen otherwise known as a superwind.

More about superwinds some other time. The following informational is more background information on the images themselves.

The intensity scale is square-root in all images and in all bands (so in the images the galaxies all appear roughly equally bright), but in reality the absolute intensities differ from image to image.

Blue is diffuse soft (0.3-2.0 keV energy band) X-ray emission from the Chandra observations, which is basically the light emitted by a gas heated to several million degrees. These images have been rather heavily smoothed, so much of the genuine smaller scale structure in the X-ray data is not visible in these images.

Green is optical R-band, i.e. emission from stars, primarily old stars. In true-color galaxies are pretty close to looking white while R-band is somewhat red, but this can't be shown in the form of color composite image I'm using.

Red is continuum subtracted H-alpha, or H-alpha+[N II] emission, i.e. emission from warm ionized gas with T~10^4 K. Within the disk of these galaxies you're seeing HII regions (gas photo-ionized by the UV radiation of hot, massive, young stars), but the extra-planar H-alpha in the starbursts is also collisionally-ionized (i.e. heated by shock-waves) warm ionized gas being dragged out of these galaxies by the superwind at velocities between 200 and 1000 km/s, depending which superwind we're interested in.

Note:We did not detect any extra-planar (|z|> 2kpc) soft X-ray emitting gas around either NGC 6503 and NGC 4244 (normal, not starburst, galaxies). There is only weak extra-planar diffuse X-ray emission detected above the nuclear regions of NGC 4945. The X-ray emission apparent in the top left and bottom right of the NGC 4945 image, and that outside the optical disk in the image of NGC 6503, is at the noise level of the X-ray data (we believe it is noise).

[Update: 17/03/2007 - corrected some of the typos]

Monday, March 12, 2007

More scientists muzzled by the administration? Part II: The Non-satisfying Explanation

Last week I mentioned (my wife would say "ranted") the apparently politically-motivated muzzling of scientists working for the Fish & Wildlife service with regards climate change and polar bears.

In a follow-up piece in the NYT the situation becomes clearer, limiting the scope of the orders to two scientists at international meetings (one a diplomatic meeting, one not), but the official explanation for the gag-order does not clear the administration from the charge of unwarranted political interference.

The official explanation is that its really about being good diplomats, following protocol and staying on the meeting agenda:

The stipulations that the employees “will not be speaking on or responding to” questions about climate change, polar bears and sea ice are “consistent with staying with our commitment to the other countries to talk about only what’s on the agenda,” said the director of the agency, H. Dale Hall. [From the NYT article]

The meeting referred to here is "a delegation to Norway led by Julia Gourley of the State Department at a meeting on conserving Arctic animals and plants."

Are we really supposed to believe that conserving Arctic animals (e.g. polar bears, perhaps?) and plants can be done without discussing climate change?

The second case is of "...Craig Perham, an expert on polar bears, was invited by the World Wildlife Fund to help advise villagers along the Siberian coast on avoiding encounters with the bears, said Margaret Williams, director of the Bering Sea program of the fund."

This does not sound like a diplomatic meeting, and although not a true scientific meeting, it is certainly a venue where free speech should apply, and where the "diplomatic protocol" argument clearly should not be applicable (even if it had any validity, which I'm rather skeptical about).

Clearly the issue is that the administration, and the F&WL service itself, do not want its employees to discuss climate change and the associated environmental impact in any way that could be construed as a institutional endorsement of the validity of climate change or highlighting its severe consequences.

In a purely diplomatic setting the general concept is understandable - wrong-headed in this case - but understandable from the perspective that diplomats are generally expected to serve as the mouth piece of administration policy and not go off on a tangent of personal opinion (however well informed or correct they might be).

But this explanation does not work. Supposedly Bush and the administration now accept the validity of climate change [indeed, they're even trying to revise history so as to claim Bush has always agreed that GCC is both real and human-made], so why try to avoid the subject (especially when it the only valid basis under which to try to understand and solve the environmental changes in the arctic)? Why try to apply it to non-diplomatic meetings with known wildlife-lobbying groups?

If the "just normal protocol" argument we are being presented isn't true, then the alternative, that this really is classic Republican War On Science behaviour, remains the best explanation.

J. Marquis points out some important contextual information that I hadn't appreciated before:

Polar bears are a hot topic for the Bush administration, which decided in December to consider whether to list the white-furred behemoths as "threatened" under the Endangered Species Act, because of scientific reports that the bears' icy habitat is melting due to global warming... ...A "threatened" listing would bar the government from taking any action that jeopardizes the animal's existence, and might spur debate about tougher measures to cut the greenhouse gas emissions that spur global warming.

In other words this is not purely about not contradicting the administration's message, it actually has the potential to force real action on reducing greenhouse gas emissions, and thus to reduce the profits of the powerful companies that fund and control the Republican party. The claimed White House acceptance of the validity ongoing climate change appears not to be little more than a smoke screen, an attempt to reduce pressure on them when ultimately they have no intention of doing anything to curb emissions.

In other news...

The harmful effects of global warming on daily life are already showing up, and within a couple of decades hundreds of millions of people will not have enough water, top scientists are likely to say next month at a meeting in Belgium.

Coelacanths and evolution

PZ Myers has an interesting post on Coelacanths and the one remaining member of their once-great order, Latimeria, discussing the amusingly/annoyingly stupid arguments Creationists use when trying to claim that Coelacanths disprove evolution.

I try not to post on evolution and biology too much, given that there are so many blogs on the subject by professionals, but in the end I decided this was interesting and peculiar enough to warrant a link.

Thursday, March 08, 2007

More scientists muzzled by the administration?

Today's (08 March 2007) NYT has an article discussing charges that the US Fish & Wildlife service (i.e. the administration) has issued memos to its employees stating that they may not discuss climate change, melting ice, drowning polar bears etc, unless officially charged to do so.

[The image, originally from NASA, is of the extent of floating polar ice in summer now, compared to in 1979. See this page at the NRDC for a low-level Q&A that points out that this is not "normal" decadal variation.]

I hope this is not true, but I won't be surprised if it is true. We astronomers should be thankful that our pursuit of knowledge is not (yet) considered as a political threat by those in political power.

Of course, if you follow Fox news (or the WSJ) then you won't worry about this too much, as you have lots of unqualified hacks from various "think"-tanks to re-assure you that man-made global climate change is "junk." Strange how its only the right wing think-tanks, specifically the ones funded by old inefficient and dirty industries, that have worked out that the overwhelming majority of the scientific community is wrong.

But instead of having to spend time denying GCC every time some more evidence of it comes out, why not get the story to go away completely? See no evidence of you and your party's funders evil wastefulness, hear no evidence of your evil wastefulness. Brilliant!

[From Zenbowl at DailyKos]

Monday, March 05, 2007

Careers for young astrophysicists: The magic 8 ball says "Outlook not so good" discusses the grim outlook for young researchers in the astrophysical sciences in the US, given the budget crisis NASA has been experiencing for the last few years.

Although the article largely discusses post docs and grad students, the effects of reduced NASA funding also strongly affect researchers on soft money (i.e. those primarily support by NASA/NSF/DOE grants obtained by themselves, rather than teaching-related University pay). Indeed I would say that more than half of my contemporary astrophysicist colleagues I have known over during and after my PhD have now left research astronomy.

That there can never be enough funding to support all willing and capable researchers through a full career in science is a fact than no-one denies. Nor can we deny that the larger national and international political and economic environment will affect science funding in ways that can not be fully controlled and that do not necessarily make long-term sense.

But these "hard facts" do not mitigate the real negative effects on the individual human lives involved, nor the damage done to longer term scientific progress and the growing weakening of the US's once over-whelming scientific leadership. The article tries to end on a positive note - that...

"The saving grace for many young researchers is that they are good scroungers. Many fields that are under the gun at NASA are multidisciplinary, so a transition to another line of research is feasible, at least for young scientists with vision, initiative, and talent."

But to me this is wishful thinking. All aspects of NASA funded-science are facing cuts, so shifts within the subfields of astrophysical sciences (e.g. from X-ray astronomy to IR or even theory) are at best temporary stays of execution, should current trends continue. Leaving astronomy is almost always final, and most of my contemporaries who have left astronomy now do jobs very different from what could be considered academic scientific research.

Nor are there many in those who are forced to leave astronomy who do not have "vision, initiative, and talent" - they would not have made it this far without it.

Friday, March 02, 2007

Hiding in plain sight": A new star in the Southern Cross

Sub-title: What X-ray astronomy can do for you.

One of the most familar constellations to observers in the Southern Hemisphere is the Southern Cross (Crux Australis), which surprisingly for a constellation, actually looks like its name (the image is a cut out of an image at APOD, looking from Mauna Kea looking towards Mauna Loa).

Astronomers using the Chandra X-ray Observatory have discovered that one of the stars in the Crux Australis, specifically Beta Crucis (left hand middle, in the image shown) has a previously-unknown companion (NYT article here). Although many stars have faint companions, this newly-discovered star should actually be moderately bright in the visible part of the spectrum (11th magnitude).

How could you miss such a bright star? Easily, as Beta Crucis is much brighter than it. Beta Crucis is a massive star (about 16 times the mass of the Sun), while the newly discovered star appears (from my reading of the NYT article) to be about Solar mass.
Crudely stellar luminosity is proportional to the cube of the mass, so Beta Crucis should be about 4000 times brighter than the new star.

Other interesting things to be found in the Crux Australis: The coalsack and (famous) horsehead nebulae - you can even see the darkness of the coalsack in the APOD image above.