Thursday, March 31, 2005

I wanna be sedated...

Current iTunes: "I wanna be sedated" by the Ramones, as sponsored by PepsiCo and Apple.
Go Blue & White...

To compensate for this regression in intelligentsia status, I am currently unable to get any of the obscurish cool jazz that is de rigeur for academic bloggers and must settle for loading in the slightly ancient Debussy Preludes CD that fell out of a pile at home.

It is too depressing to talk about science. But for amusement go to the NASAwatch web site (-> there) and read the Marshall Space Flight Center "landscaping memo".

So, fiction. The best least known writer of short stories in science fiction right now is Ted Chiang, here is a random fan review web site harvested from Google.
Chiang's stories are infrequent, well crafted, and extremely thought provoking. The collection "Stories of Your Life and Others" published by Tor is one of the best single author collections around (comparable to Axiomatic by Egan, Otherness by Brin, Toast by Stross or "True Names" by Vinge).
The title story is very thought provoking, and I would argue that there is not a single weak story in the collection, they range from extremely good to outstanding.

"Hell is the Absence of God" is a story for our times. Sadly. More people should read this book.

Wednesday, March 30, 2005

bleedin' NASA - Exploration vs Science

So, at some recent past point I ranted that the breakdown of the wall between "Exploration" and "Science" at NASA might just possibly be a one way street, with science money bleeding down to exploration, to cover the fact that the Exploration initiatives are so grossly underfunded that they are essentially unfunded.

So, here we go. A "heads up" e-mail on Office of Space Science mailing list warns of an upcoming amendment to ROSES-05, the omnibus Research Announcement for Space and Earth Sciences. Wholesale cancellations and deferrments of programs. In particular ADP (Astrophysics Data Analysis) and LTSA (Long Term Space Astrophysic) are apparently to be cancelled. The former is the "non-mission specific" funding source for analysis of new and existing data; the latter is long term programs for broad multi-mission data analysis and modeling. Mostly University and contract Center funding, not in-house. The ADP carries a lot of postdoc and advanced grad students in the budgets; the LTSA is particularly important for junior researchers for long term funding stability and for getting serious chunks of money (ie advanced postdocs and untenured faculty, it can be the primary or only source of funding for many researchers at these stages, and it reduces the need to chase multiple, overlapping [and sometimes contradictory] little pots of partial funding). We may be facing a "year without jobs" for a large part of astronomy; and historically the negative perception associated with such whiplashing takes 3-5 years to dissipate, just when there was a sign of an upswing in the number of US undergrads and grads too.


"On or about March 31, 2005, Amendment No. 5 to NASA Research Announcement
"Research Opportunities in Space and Earth Sciences" (NNH05ZDA001N) will be
posted on its homepage Web site at (select
"Solicitations" then "Open Solicitations" then "NNH05ZDA001N")."

Solicitations Canceled

-  This amendment cancels the solicitation for the Virtual Observatories
for Solar and Space Physics Data program described in Appendix A.22.

-  This amendment cancels the solicitation for the Astrophysics Data
Analysis program described in Appendix C.2.

-  This amendment cancels the solicitation for the Long Term Space
Astrophysics program described in Appendix C.3.

PS: No, I don't "know" that the cancellations are explicitly linked to any specific funding shortfall.
I do know that the ADP/LTSA program is a nice chunk of money that is vulnerable to being raided by random senior NASA managers protecting their turf as budgets get tight, and that there had been open speculation that these programs would be "taxed" as the budget tightened. Coincidence? I think not.

Tuesday, March 29, 2005

A Doc is Born

Congratulations to Doctor John Debes.

That's one out the door...

Rare Earth Part I

Ah, science. What can we say about science?

Is the Earth rare (as opposed to well done, or raw?)?

Good question. Maybe.

Why does it matter? Well, there are several contrasting issues at stake. One is whether we are truly special; on a superficial level this is just the usual creative tension between the Anthropic Principle and the Principle of Mediocrity (the generalized Copernican Principle).
At another level, if we're really special, we should be careful - that is to say if life is rare, and intelligent life more so, then its existence is all the more precious (this leads naturally to an extreme environmentalist position centered on some sort of a precautionary principle). But, if we're not really special, but rather as common as dirt, should we not be careful and blithely accept extinction as really no big deal, I don't think so.
At yet another level, Rare Earth proponents move into blatant Deism, notably Guillermo Gonzalez, one of the original Rare Earth proponents who has expounded on this in a new book, Privileged Planet. This leads straight to an argument for Design, which inevitable falls for the usual fallacies of the Blind Watchmaker analogies (some of the stuff on, for example,, is just embarrassingly bad).
And, inevitably as the web goes, there is dedicated blogspot to combating this notion . Oh my. Fun read though.

So, is the Earth Really Rare. Well, yes, sorta maybe not really.
Hm, this is going to take a while.

In the meantime, one contemplates in turn the Drake Equation, which I remind you is an order of magnitude estimator for The Expected Number of Currently Existing Communicating Technological Civilizations in This Galaxy. Not of course to be confused with the extremely useful Date Equation (C. Kobulnicky et al sometime a few years ago).

To cut a long story short, given our current knowledge, it is hard to push the Drake Equation output to a value much smaller than 1 (ie low probability of even one civilization in existence at any given time). So, we get the Fermi paradox, of "where are they". This is subtler than it sounds.

To seriously consider what is going on, we need to contemplate the Habitable Zone, the Continuously Habitable Zone and the not-quite-so-respectable Galactic Habitable Zone (and can we please stop there, no more Zones unless they involve Vingean singularities and actual engineering).

To be continued...

Monday, March 28, 2005

Ye of little faith III - Devolution in Dover

Story on the Dover(PA) Evolution kerfuffle.

"We've been attacked by the intelligent,
educated segment of the culture," he said

"Evolution is just a theory and there are other theories,"
Mummert explained, smiling through his beard.

Ah, but do they have Cosmic Cows? Mine has a Cosmic Cow.

Also seen on Atrios and Independent Report and Sean Carroll

What can I say, I am so sorry. But you ain't seen nothing yet. Gentle scorn does not an attack make.

In another fit of news of the weird, I notice Bobby Fischer has been given Icelandic citizenship. If I ever get up the energy I will try to speculate on my countrymen's motives...

On a previous topic, Panda's Thumb notes that the Florida Academic Freedom Bill contravenes the Florida constitution. (Hm, a few years ago I seem to remember some interesting pontifications on what should be done to legislature reps who knowingly write laws that contravene constitutions, not much heard from those quarters in the last couple of years).
Figures, the intent of such posturing is not to actually put into existence enforcable laws, but to push back the middle ground and force scientists and academics to yield ground and guard their speech in fear, pushing back enlightenment and promoting theocracy.

Sunday, March 27, 2005

Academic Freedom Bill of Rights - ye of little faith part II

So, David Horowitz, Front Page editor, former red diaper baby, reborn as a right wing crusader and tilter at windmills (well, man's got to have a cause, any cause), has spawned a genuine piece of moronicness in his latest toils - the fight against leftie dictator professors has lead to a bill passing committee in the Florida legislature, providing for "Student and Faculty Academic Freedom"
Well, with a title like that you know it has to something really dumb. JJ King on Channel 4 (UK) has a good succinct review. The bill provides students with a legal right to challenge faculty who expose students to "controversial" things they don't like to hear - like evolution, or the geological evidence for the age of the Earth, or the Big Bang (a Bill sponsor - Rep Baxley, uses evolution as an explicit example of the sort of academic "controversy" forced upon poor unsuspecting students, and which should be legally challenged).

If this piece of anti-intellectual garbage passes the full legislature, I truly feel sorry for my Florida colleagues. If it spreads to other States, then the US is dead as a modern industrial civility. Further, faculty at any self-respecting university will have no choice but to defy the law - and any university that fails to legally back up its faculty should be de-accredited and expect mass resignations. While a case can be made that society may have some control on higher education institutions and matriculation requirements, such control is limited - even if the State provides the funding (and the reality is that most States provide so little funding to higher education that they have no right, nor leverage, to impose control on universities).
So, if Florida legislature wanted to mandate a semester credit in Religious Studies, or Comparative Theology as a graduation requirement from the State universities, I suppose they legitimately could. They would be stupid to do so, the universities would be worse for it, it would probably be unconstitutional in the US, but there would be some legitimacy to it.

As is, the law is unenforcable and unacceptable. Students have no right to feel any comfort in their beliefs. If their beliefs are so shallow and poorly established that they can't handle hearing scientific evidence that challenges their beliefs, then their churches and parents have failed. Their belief is simply inadequate and they must go in with their lives with that established. Scientists have a professional responsibility to present the best science known, the scientific method and the evidence accumulated. As revealed by inspection of nature and the best inference about what has happened. Whether or not some random student feels "comfortable" about that or not. To do less would be fraudulent, anti-intellectual, and completely destructive of the essential knowledge base on which US society rests. Any faculty member who backed off or toned down their presentation by one bit because of such law would have betrayed everything modern society stands for and 350 years of enlightenment and progress.

And of course that is the intent, not to actually pass moronic laws, but to establish a climate of fear and concern where liberal faculty back off and pre-emptively hold off on doing anything that might make these ignorants uncomfortable.
The instinctive thing to do is to pre-emptively fight back, to be even more in your face on the essential Truth of scientific knowledge in contrast with the Faith of religion. But there also lies a trap, too strong a backlash, or pre-emption, plays into the whole memetic corruption of the intolerant leftie dictator professor. Nasty, almost Clever.

So, we take the high road, tell the truth, present the facts and uncompromisingly challenge beliefs, while trying to be sensitive. This is hard, it is so easy, so reasonable, to yield to deism, or the "God-in-Nature" shell of the Intelligent Design advocates. But it is not science, and it is not right.

Why though we wonder, do these people want to destroy the US as a society? Is their faith so shallow that they would rather destroy all their forebearers worked for, than see a Truth revealed that contradicts their prejudices.

Saturday, March 26, 2005

casual cat blogging

Cat picture

Chloe is a proper lady; one of the prettiest and sweetest felines on the planet.
But very proper indeed.

Friday, March 25, 2005

Living Will form

For some reason the topic of "living wills" has been high on peoples minds.

The forms are available on the web, for example here at People's Lawyer (some UT law prof, no affiliation with him).

Here is another site, claiming to have the forms for each state. Caveart Emptor. Again not affiliated with me, and I provide no warranty. If you want to be sure, contact a lawyer and make sure several different people know your wishes are explicit.

I should note, that posting a living will on a blog or web site would leave a public and near unalterable trace of peoples intentions; at least if Google and other unnamed agencies continue to archive all walkable web pages, it will provide a permanent and public record.

Go blog your living wills, either way you want them.

Bad Astronomy Blog

I've long been a fan of the Bad Astronomy website.
I see Plait has now started a blog, should be interesting.

Thursday, March 24, 2005

Devolution revisited - or, ye of little faith...

So, Sean Carroll's blog tipped me off on the little controversy brewing over the refusal of some IMAX theaters, including ones in science museums, to show movies that explicitly made a reference to evolution or the Earth's true age, for fear of offending people. Thanks to Google, here is the original story on this, NYT 19 March.
This is personal, one of the movies is affected is "Cosmic Voyage", a couple of my office mates were involved in producing some of the simulations for that movie, and the "galaxy collision" in it used a code based on a code I worked on. (Dubinski and Mihos implemented the simulation, which uses, as I recall, a variation on the SCF code that Dubinski put together. The variation was based on a code I helped implement and test, based on Hernquist & Ostriker's algorithm, based on Bodenheimer and Ostriker's original concept. Phew). I use this movie in my intro class sometimes.

There are three issues here:

The science museum directors need to remember that they have a mission other than, and orthogonal to, just selling tickets and getting bums on seats. They have a mission to inform and educate the public, not shield them from controversy and avoid challenging their beliefs. If they want to become religious studies centers or commercial movie theaters with a neato gift shop, fine, just take down the "science museum" part of the title. You want science, go where the evidence in nature takes you.

Secondly, people, get a grip. If you are so challenged and offended by an off-cuff mention to the actual age of the Earth, or cosmogonic processes, then the problem is not with the movie, it is with you. Maybe it is time to look within your heart and contemplate your faith, because if it is so fragile and tenuous you truly do not believe.
I'm quite serious about this; people are welcome to their religion, but if their belief is so shallow that it does not hold up to even casual exposure to the evidence uncovered from an inspection of nature, then the problem is with people's faith, not the scientists presentation or discussion of the information in nature, or our reasoning and inferences about this data.

Finally, people need to be careful with their creation myths. Vili and his brother Vé worked hard to make sure that Ýmir's skull was secure over the fundament, I will not tolerate anyone challenging this millenium old worldview and the foundation of faith for generations of my ancestors. So cut out the fables about 7 days and gardens, if it doesn't have a Cosmic Cow in it, I don't want to hear it (Auðhumla for the infidels).

Ár var alda...

Wednesday, March 23, 2005

So you want to be an astrophysicist? Part 1.75 - should you go to grad school?

So, you want to be an astrophysicist? You're an undergraduate, doing astronomy or physics (or possibly engineering, mathematics or computer science, or something), should you go to grad school?

Why is there a question? Well, it is several years of your life, earning minimal pay, doing some grind work, including classes (1-2 years at most institutions) and exams (most places have some "admission to candidacy" hoop), with interesting but uncertain career prospects. And you have to do research. Supervised, but independent and original research. Not everyone wants to do that.

You can do stuff with a BSc or MSc, like start to earn money, and still be involved in research. In rare cases you can get promoted through to full professor/senior scientist, and lead major science teams etc, but the odds are bad. So, go to grad school, go for a PhD. It is fun.

We'll deal with the practicalities later. First, what is involved.

Well, learn math. Undergrads tend to be math phobic. Lack of math preparation is the major reason why interested people find themselves unable to go on to astrophysics. Not that you will be a mathematician. Mathematics is a tool, and you need the full kit (there are mathematicians who do physics, mostly in corners of particle theory, or, interestingly, in gravitational physics - relativity or quantum gravity, but physics is not math. Math is tautology, subtle, interesting, useful tautologies [sometimes], physics deals with "reality" with math as a tool of choice).

Now, what is there to do:

1) instrumentation - if you can build bleeding edge, high quality, fragile instruments, go for it. You'll be sought after and hopefully not too under appreciated. If you got the knack, you got the knack.

2) Observations - looking at stuff, using instruments... analysing data, planning observing strategies, and destroying perfectly good theories. There's people who know about that stuff, they can address it. Most astronomers are observers of some flavour (and most observers do some theory too).

3) Theory - are you a physicist doing astro (like astrochemist, or astrobiologist)? Er, well, lets get back to that last one some other time? Or are you and astronomer doing theory? Yes, one of those.
Lots of places don't even have an astronomy department, you're doing a theoretical physics PhD (me!) in an astronomical topic. Even if there is an astro dept, you can still do that. It actually doesn't matter much, it may restrict your choice of advisor a bit, but is usually not critical.

Why? Well, astrophysics covers all of physics (I challenge anyone to come up with a sub-field of physics not relevant to astro). You personally don't have to do it all; your goal after all is to "know less and less about more and more, until you know absolutely everything about nothing". But it is a good start, otherwise how do you know what you're missing.
Astrophysics is data drive, there is lots of high quality data. The quality is progressively improving, and there is no end in sight. Arguably particle theory is now driven by secondary inferences from astronomical data, or astroparticle data, at least until the next generation of colliders comes on line. Why, there's even a subset of cosmologists who are really refugees from particle theory, dabbling in beyond standard model physics (with astronomical implications) and having fun tweaking Lagrangians and seeing what happens.

Sound good? Then go for it.

Next, the practical details (like GRE), and the sub-fields (or some of them). Then, what astrophysicists actually DO. Personally I argue there are several "styles" of theory, and they are complementary. Some people disagree. Their way is it.

Tuesday, March 22, 2005

Black Hole observations - The Bet and BH-PSRs

A long time ago, August 2002 in beautiful Chania, I rashly made The Bet. That by Feb 7th 2008, a black hole-pulsar system will be found (by implication through radio timing observations of the pulsar - there is a caveat that this is a discovery date, not confirmation, so bet may take till 2012 to settle.
Further, I bet (with no stakes) that the system will probably be found in a globular cluster (ah, but which one, that I'd like to figure out). Although the field (ie disk of the Milky Way) is a fair bet too.

For a black hole-pulsar system to be found in the galaxy, it has to be formed as a binary, with either a conventional black hole formed first, regular pulsar formed second system; or, a neutron star formed first, with a black hole formed second, after partially respinning-up the neutron star to a millisecond pulsar (probably not a very fast MSP). The latter is lower probability, but is longer lived, so odds of seeing either are probably comparable, and in the one-in-few-thousand range. And we're up to ~ 2000 known pulsars, so any decade now, modulo selection effects. cf this paper.

In a globular cluster, you could make such a system by exchange, and I discuss the processes semi-qualitatively in this paper. That could generally involve a proper MSP, and have some interesting orbital parameters. The goal obviously would be strong field tests of gravity, which would be cleaner, in general in the field, a cluster pulsar is more likely to have contaminated dynamics, but it would still be very interesting.

Anyway, somewhat rash bet, but always helps to provide some incentives to the observers, and if the Nobel prize won't do it then a good bottle of Bonny Doon Red certainly will.

Monday, March 21, 2005

The Perfect Arconym

Vicky Kalogera at Norhwestern posed an interesting challenge at Aspen last summer - is there a true 4th level acronym, and are there any perfect higher order acronyms?

So, a second order acronym, is an acronym with an acronym in it: thus LIGO is the Laser Interferometer Gravitational wave Observatory, and Laser is itself an acronym.

Then LSC - the LIGO Science Collaboration is a third level acronym, and something like the LSC Software Package - LSP, would be a fourth level acronym.

So, now the challenge: what "natural" 4th and 5th level acronyms exist (ones not just created to satisfy the challenge)?

Secondly, are there any perfect higher order acronyms. A perfect acronym is, of course, an acronym ALL of whose components are themselves acronyms. I can believe a natural perfect second order acronym exists, I'd be skeptical that there are any 3rd level ones (ALL the letters acronyms, all of which themselves are ALL acronyms).

For a more perfect challenge - consider TLAs only, or only acronyms which are proper words (aka apronyms)!

Further, there are recursive acronyms - the most famous being GNU.
But, are there any circular acronyms? I can't think of any, they'd have to be 3rd order or higher. An artificial example would be as follows:

consider FOO

FLAP is the FOO Logical Analysis Package

FUM is the FLAP User Module

and FOO is the FUM Object Organiser!

I'm sure better examples can be thought of.

Some time this week I may have occasion to think of science again. For now, indulge me, I spent 5 hours in meetings today, more than half of which pertained to a TLA Federal Agency. At least I refrained from using bullets...

Sunday, March 20, 2005

Stop Devolution

Sean Carroll at Preposterous Universe passes on comment from Pharyngula on a news story that some IMAX theatres, including in science museums, are refusing to screen IMAX movies that mention evolution in favourable light for fear of offending some in the audience.
This madness must stop. Pass it on.
More later when I know details.

Saturday, March 19, 2005

new fictions

Another quickie.

Charlie Stross is one of the new wave of british science fiction writers, writing somewhat edgy (post-punk, post-thatcherian) fiction. Charlie does some very interesting "post-singularity" fiction, among the best, most interesting and technically informed sci-fi around. His "Antibodies" short story published in Interzone 157, republished in Dozois' Best Annual SF #18 is exemplary in both senses of word. "A Colder War" and "Lobsters" are also good examples. Buy the short story anthology "Toast" or one of his novels that have started flooding out.

Friday, March 18, 2005

Fun places to do science - the short version

IAP - Institut d'Astrophysique de Paris is a good place to visit - good scientists, good company, and the best little cafeteria of any astronomical institute on the planet (why, no I have not visited all of them. I stand by the statement, confident they'll rise to any challenge).
Stay either walking distance or short Metro hop away, on off-days, either get an open air baguette and vin rouge in a random corner shop, or better still by your own baguette, cheese and 1/4 bottle and have a picnic in a park. For dinner, avoid the touristy places (like most of the west bank!) and find some place good in a basement off the beaten path. Random walk-ins have high probability of being a success in this city, bad restaurants do not last long.

Thursday, March 17, 2005

So you want to be an astrophysicist? Part 1.5 - The Few, the Proud, The Astrophysicists

So, now you're at university, and you're headed for grad school (the following is horribly UScentric, 'cause that's where I am right now, the general principles are broadly applicable, the actual getting into grad school procedure bit in future post will be both US and THEM centric), now what?

Well, each cohort in the US is about 4+ million people, about 4000 of those major in physics. Since participation in the further education in the US is almost 50%, that is 4000 out of about 2 million, or 0.2% of undergraduates (specifically, about 1.2 million bachelors degrees are awarded each year, with physics major 0.34% of those, near historic lows, trend has flattened after many years of decline, see APS jobs in physics stats. For what it is worth, about 1200-1500 PhDs in physics are currently awarded each year, almost half to non-US students, so about 1/6 to 1/7 of undergrads end up doing a PhD. The "rule of thirds" you'd infer from the raw numbers (# PhDs = 1/3 # BSc) is surprisingly robust at each step. The number of astronomy undergraduates is much smaller still, since not a lot of universities (61 according to this article by Cabanela and Partridge in AER) have a separate astronomy department or a separate major (so a lot of people who become astronomers or astrophysicists start as physics majors, or have an astronomy minor). The number of astronomy PhDs is fluctuating around 120 each year, with significant Poisson noise, as one might expect. There are 25-30 major research universities which dominate the astronomy PhD production, so classes are small, and the intake is fought over hard.
Having said that, current astronomy undergraduate production is about 300 per year, and has grown significantly AIP stats summarises. A lot of those are double majors with physics. Naively them about 1/2 of undergrads go on to PhDs, but after you allow for the foreign intake, it is more like 1/4 - 1/5, since some also go into graduate school in physics (and of course other fields, but I am not considering those now).

So, the good news is that if you're in the major, you have a high prior probability of going to grad school. You just have to pass the classes, get good grades, not go broke, survive the insanity of university, enjoy life, and take the GRE exam, the only exam stupider than the SATs...

So, what should you do. First, take all the math classes you can handle, especially if your interest is astrophysics; take calculus of course, through ODE, PDE, Complex Analysis, and some course covering spectral methods (Fourier and Laplace transforms etc). Better know what a Bessel function is when you get to grad school, and know immediately where to start on solutions to second order differential equations. Take also probability theory and statistics, linear algebra, numerical analysis, and computational techniques. If you can stand it, differential geometry, topology, functional analysis and some advanced classes never hurt anyone.

Then take physics. You don't have to take all of it, but would it hurt to do so? Solid state physics, wave theory, optics and quantum field theory all show up somewhere in astrophysics (all of physics does, that is why astrophysics is the greatest sub-field in physics! ;-) oh, and take relativity if you're at one of the few places it is offered.

What else. Well, the prereqs and college mandated hoops of course. Don't burn yourself out, but given a choice, wouldn't you rather take a gen ed class on something that is interesting (to you). Funky minors sound fun and macho, but they can destroy a GPA, a graduation schedule and enthusiasm - approach with care. Then think about what you like to do when you finally get there? Like to build things, add labs and engineering classes (especially electronic and optics). Like data, add statistics and computing classes. Like to think, go buy a ruled pad and nice black ink pen (no pencils, this isn't kindergarten).

So, you did that, aced all the classes, are student president, captain of some NCAA team, and still have time to party.
Now what.

Well, a long time ago, there was a rule of thumb - the odds of an incoming undergraduate in physics/astronomy getting a faculty position at a research university is about the same as the odds of an NCAA division 1 football player making the NFL. But the earning potential is different (not as much as you'd think, lifetime average!). And in both cases, it is not a bad career move, even if you don't make it all the way, the alternate career paths can be sweet. Oh, and in both cases, where you go to school matters a lot, for your average odds. But remember, there is always a Jerry Rice!

So, end of your junior year, if you can still stand the field, you need to start seriously working on grad school applications, and planning for the GREs. More later...

Here is a link to a College Boards article on some career issues.

Wednesday, March 16, 2005

Oil on Mars?!

I came across this a long time ago. A Washington Post article from Jan 16 2004 on industry reaction to the Moon/Mars exploration plan.

I'm actually broadly in favour of human exploration of space, and think that starting with the Moon and then moving fairly rapidly on to Mars is a mostly sensible thing to do - with the caveat that if you're going to do it, you need to face the reality of paying for it, and I'd like the process not to involve the gutting of space science at NASA.

But, this article reads almost like a caricature of why people get sad and cynical about such proposals. At some deep level I don't think much of current individual US government policies are for the purpose of rewarding their buddies, the reward is "just" excessive glad-handing and buddy system done on a nod and wink. But this is just inappropriate.

"As an example of private industry's hunger for a Mars mission, Steve Streich, a veteran Halliburton scientific adviser, was among the authors of an article in Oil & Gas Journal in 2000 titled "Drilling Technology for Mars Research Useful for Oil, Gas Industries." The article called a Mars exploration program "an unprecedented opportunity for both investigating the possibility of life on Mars and for improving our abilities to support oil and gas demands on Earth," because technology developed for the mission could be used on this planet."

Here is the article text, quoted under "fair use", for posterity.

Soon, the far more interesting questions of: Natural Gas on Mars? Oil on Titan?


Approximate amount NBC CBS pays the NCAA for March Madness ~ $550 million per year.

2006 National Science Foundation budget request for physics and mathematics ~ $430 million for the year.

The NCAA 64(+1) team tournament in men's college basketball is one small part of the college basketball season, which in turn is a small part of both the total basketball market in the US, and a small part of the total college sport market in the US.

Physics and Astronomy also get substantial funding from NASA and DoE (and some other relatively minor contributors); but the order of magnitude comparison remains valid. Hm...

Tuesday, March 15, 2005

So you want to be an astrophysicist? Part 0 - gettting ready for university

Ok, I promise (myself) that I will get back to discussing some science like thing, like current research issues, and hot preprints. Real Soon Now.

In the mean time, Diane Ravitch has an interesting New York Times opinion article on US education. The basic thesis of the article is to counter Gates recent point on high school education, but countering that the key failure is in the middle schools (this sounds familiar... the universities always insist that it is not their fault, they have to deal with the high school product...). I think she has a good point.

Now, my perspective is as an outsider, I did not go through the US school system, and my kids are not in it yet. So I see snippets from the outside. From that perspective, the elementary schools look to be ok, if sometimes a little fluffy, but for the life of me I can't find out what students actually DO in middle schools. There seems to be no structured curriculum and no progress towards preparing for high school (yes, I know there are several thousand independent and different school systems, but honestly, they're not that different, and if anything I see the better ones). That time needs to be used to move students along, for them to learn more stuff and to push the ambitious and able to get ahead in their strong subjects, or you start losing students, through shear boredom if nothing else.

I disagree that there is nothing wrong with the high schools though, if nothing else the practise of teaching science as year long immersion classes and in succession is nothing short of insane - science needs to be taught simultaneously on parallel tracks over several years - 3-4 minimum - if it is to take, and any actual knowledge to stick in peoples brains. This has been the subject on an ongoing debate in APS journal letter pages. And don't tell me that it is impossible to schedule such course patterns - everyone else in the world does so!

So, a proposed solution is basically to introduce tracking, as is done in much of Europe, there'd be an "academic" track, with presumably 30-50% of students, and a "technical" track (basically vocational education). This works, in the broad sense that it prepares many students better for university, and it prepares many students better for the workforce. I don't see if being effectively implemented in the US for two reasons: it is anti-egalitarian, it removes equality of opportunity and in the US would invite lawsuits. Secondly, there is a critical flaw to it - it only works for other peoples kids...

The problem with tracking is it requires early identification of aptitude, and that is a flawed process; so some kids will be flushed from the system early, and it is very difficult to get back on an "academic" track once that is done. This is a waste. (I know the article says students from both tracks would be well prepared for higher education - they will not be in practise).
This introduces complementary flaws - namely the "activist" parents, college educated middle/upper-middle class who give a damn, and who will insist their kids (not universally, but disproportionately) go in the "academic" track. So you get people forced on that track who are not well suited to it - that is a waste that can be accommodated, and may benefit some of the students. The real crisis comes when the activist parents are told THEIR kid is NOT going on the academic track, that they are tracked to the vocational system. This will not go over well. Trust me I have seen it up close and personal in the quiet realms of north Oxford schools... (the upper class will go private prep, and not give a damn, but they don't give a damn anyway; and if any reader feels that US society can not be divided into upper/middle "classes", then just substitute income levels, they are good proxies).

So, interesting idea, be fun to see an implementation in some large districts, but I don't think the US can afford to wait for the results, the science educated population is already dangerously small.

So, what should YOU do, wanting to get into a good university and an astro/physics major?

1) Take all the math that is offered, and do well in it.

2) Take all the science on offer, and do well in that.

3) Get good grades overall; preferably straight A, but B+ will do. It will get you far enough to have a chance to see if you can hack it at the next level.

4) Do all of this without overextending yourself; university is harder with much more intense workload, you need to be able to step up the pace (and again at grad school).

5) Jump through whatever hoops are needed, try to enjoy the process, or just grit your teeth and do it; the real world is worse that way.

6) Enjoy life.

7) Read. Lots. Of everything.

8) Apply broadly, and aim for good universities, even if teachers and counselors advice you not to. Worry about funding after you find out where you got into, if you don't apply you definitely won't get in.

9) Go to a university you feel comfortable with, but that is academically strong. Reputation does count unfairly or not. And try to get out of your hometown.

10) There's these whacky things calles SATs. Do well on them. The exam sucks, the way they are used sucks, and they can be gamed; so they are unreliable indicators; but, they do correlate with performance (at least in academic mythology) and beancounters on committees love them because they are an "objective quantifiable indicator", you can cut on them and reduce the time spent thinking about peoples life, almost guilt free.

I've seen many criteria used for university admission, and the US fascination with multiple choice exams is the worst. But it works, in the sense of being functional and arguably not much less fair than all the others.

Monday, March 14, 2005

So you want to be an astrophysicist? Part I

First things first: Sean Carroll has a pointer to a "should academics blog" discussion percolating around. The answer is "don't know", "don't care". So why am I doing this. And is it really a blog if no one reads it? And will my dean^H^H^H^Hdept head really kill me if he finds this? (No, I have tenure, he'd just make my life miserable if he decided I had crossed some movable line).

Well, this is an unofficial private blog, which I am doing basically to see what is involved, the time committments, difficulty of keeping a topic flow and how blogs surface (or not) in the blogosphere. If this works out, then maybe it becomes some official or pseudo-official outreach effort. Or it vanishes and a completely unaffiliated bloggy thing appears somewhere else (eg if the consensus is that I choose boring topics and my writing is bad). Is it really a blog if no one reads it...?

So todays topic:You want to be an astrophysicist - 1?

This will be done in several pieces over time, lets start at undergrad, and slowly work our way to grad school and beyond (particularly since I'm on the admissions committee - this may be a good way to get relieved of that particular responsibility, what they call a win-win scenario...).

Should you do astronomy as an undergrad? (the following is in part shamelessly cribbed from prof Charlton's freshman seminar for our majors):

  • Do you like stars and stuff? If not, you probably should look for an alternative, on the general principle that at this stage of life you should at least try to do things you actually like.
    If you do, good for you. Now, do you have the aptitude?

  • Professional astrophysics/astronomy is not about looking at stars (except at occasional star parties, for outreach or as a sideline hobby - and a fair fraction but by no means all astronomers are enthusiastic amateur astronomers). Nor will you need to learn about constellations, or speculate about the meaning of it all, or the origin of the universe or other sophomoric philosophical issues (except over occasional beer sessions - except for the constellations bit).
    What you will need to do, is at least 75-80% of a physics major (and preferably all of it, physics double majors are a common path, as is just doing an all physics or math/physics (me!!!) path, and adding astro later). That's four years of 2 classes per semester, calculus based physics. You will also need at least 3 years of university level calculus, and if you find yourself taking as little math as possible, then your career options will rapidly shut down and you might want to rethink. Some computer science or electronic engineering wouldn't hurt, though most of the practical computing you need you will be expected to pick up through self-study. So, you would need, for example, to be able to look at HTML sample code, or a "how to web page", or in a pinch a book, and figure out in few hours or days how to do adequate HTML coding, as a minimum. Most astrophysics types are expected to know one major compiled language (C++ or Fortran most common), several macro/mark-up languages (like TeX/LaTeX, IDL or Perl) and higher level languages as needed.
    Most people find this to be hard work. You should be ready for hard work.

  • Do you like to read? Cause you'll be doing a lot of it. Books, papers, web pages, class notes; and, whether they admit it or not - science fiction (ok, not all astro types are sci fi fans, just most of them, secretly, open Trekkies, whatever).
    What do I mean by lots? (For an undergrad.) Mean output of a professional astronomer is 3-4 papers per year. Each paper has 30-40 cites to the literature on average. You have to have read those, all of them! Now, if you work in a single sub-field (not uncommon) there'll be a lot of overlap between cites in successive papers, but you'll also have to read 2-3 papers for each one you cite. And, you need to keep up with the literature, new papers every day... So, we're talking 1-200 papers per year.

  • Exams. Yep, we have those. Some people can't handle them. Don't know what to do about that, they include brilliant people. Same with essays and projects. Different people can't do those. Don't know what to do about that either.

  • Research. It is generally a good idea to try to get into some research if you can, typically summer after the end of your junior year, earlier if you can. It looks good on a resume, helps you get letters for grad school (if you still want to go) and lets you know if research is the sort of thing you want to do. Some people hate it. Better to find out before you spend ~ 5 years in grad school. That's a big opportunity cost if you just want to go out and earn money (or a wonderful life experience if you have the luxury to have those). Some people hate doing research.

  • What university should I go to? Well, the one you can. The "best" one if you have a choice.
    Does it help to go to a "name" university (top private, Big high profile State, or a high rep liberal arts college) - you betcha (analogous situation for other countries, I know the deal for some, not others).
    What does it buy you? 1) a shot at a good education. In the US there are maybe 50-100 universities where you can get a very good education in astrophysics; the other few hundred are "good in parts", but your odds go down sharply. 2) a second look at the next stage, the committees will look twice at people from places they know (and conversely if you do badly, they know too). 3) at some level you get what you pay for - there is not a perfect correspondance, but high correlation.

    So - the top private places (Ivy Leagues, Stanford, Caltech, MIT) - will give you a strucured, superb education, with access to top faculty (half of whom may not care about you). For a price. If you're willing to take advantage of it. And there's significant in-house competition. Not matter how good you are, you're going to meet someone better at those places.

    Big State: well, they're relatively affordable, they are big, so there's a broad range of courses and people, and they're well enough known that if you do well you'll get a look for grad school. The catch - you have to self-motivate, the place is big and you can all too easily vanish. Embed yourself in the department, not the dorm or the frat/sorority. Interact with the faculty, go to talks, talk to people. Profs are PAID to be there at office hours, and without exception they have a unique weakness, they love talking about "their research". Suckers. So go bug a prof. Lots, repeatedly. Oh, and get good grades and have natural math aptitude. If you do well academically (B+ GPA or higher AND a consistent good performance in the "hard" classes) and if you hook up with people to work with, you're set. But YOU have to take advantage of the opportunities. If you're lucky someone will reach out to you once, maybe twice, but beyond that it is up to you.

    Lib Art: small, fabulous teachers (on average, at the good ones, except when they're fabulously bad) and lots of personal attention. A disproportionate fraction of top researchers come out of majors at these places (like Reed, Vassar, Swarthmore etc) and they produce a disproportionate fraction of science majors, compared to their size (US state universities have an appallingly small fraction of science majors, and vanishingly few physical science majors). Catch, there a a lot of mediocre and bad ones...

    A bad university, in the physical sciences, is a career end, unless you have exceptional persistence. What to look for is a sequence of hard calculus based classes - look for advanced electromagnetism, or advanced quantum, with 2 physics prereqs and a high number math dept calculus based prereq. A lot of places let this slip, and you get soft, non-calculus based classes filling the major requirement. Fun, but you don't learn the basics you'll need later. The US "modular" course structure is particularly bad in this respect (more on that in another thread, but think about how much more in-sequence engineering and other serious professional majors tend to be... I'm biased, I was educated at a UK university. Viva la difference).

  • Publishing a refereed research paper as an undergrad always helps, but is not essential. Getting into a national summer intern/REU program helps, but is not essential. Having good solid grades, and doing well on the GREs is what matters.

    Grad school next. Then I'll iterate at some point to refine the ramblings.

Sunday, March 13, 2005

Beyond Einstein

... is the name of a series of overlapping, vaguely thematically linked NASA missions, which were for a while the key series of new projects in the "universe" sector of "science".

My personal favourite is LISA - low frequency gravitational wave detector, a close loop laser interferometer, with a nominal 5 million km baseline (yes I said Million). Way cool. I'll be saying a lot more about LISA and its proposed descendants. LISA is joint with ESA, which is also interesting on so many ways.

Con-X was another, next generation x-ray observatory, optimised for spectroscopy, it is in trouble, but on life support for now at least. I wish them well. More on that late too.

SNAP^H^H^H^H^H JDEM is another, a wide field camera, barely sub-Hubble, to look for type Ia supernovae and try to measure the equation of state of the dark energy (yes, more on that later).

Beyond that, it gets ambitious - cosmic microwave background polarization measurements, x-ray interferometers, detection of gravitational radiation from the Big Bang. Fun stuff, with 15-25 year planning horizons. All now deferred, postponed or possibly in the trash can of power point plans everwhere. Hopefully most will get done, in some for, eventually, and before a generation of expertise is lost waiting for the next mission.

Saturday, March 12, 2005

NASA Science and Singular Fiction

So, excessive speculation about NASA is going to get me into trouble, but why not live dangerously...

Several things have happened recently: there are reports of imminent layoffs of ~ 15% of the workforce NASA Watch story here. Basically Glenn, Langley, Stennis and Marshall are in big trouble for various reasons, ranging from having no major indispensable and immovable projects, to being political irritants for trite reasons. Ames may get major restructuring, possibly shifting (in part?) to a JPL like contractor center (there are UC signs inside the base already), and I suspect some people, for diverse reasons, would dearly like to see some of the land behind the fence being sold to developers and zoned for residential housing...
Kennedy and Johnson are politically immune and Goddard seems to have maneuvered to safety. Mostly. I could be wrong, but that's how it looks to an outsider.
Then, there's this - shutting down old, "past primary mission", but still operating spacecraft. NASA has always been prone to this, the money to keep these missions running is not provided up front and something has to give, but this is sign of some serious belt tightening.
Then there was the removal of the "wall" between "Exploration" and "Science" within NASA - funding can now be redirected between directorates, by the administrator, with some disgression. I have not heard any discussion which involves scenarios where exploration surplus boosts science projects - it is all pointing to the bleeding of science projects to support exploration shortfalls. Since exploration engineering projects can get very expensive, this can sideswipe a lot of science with little or no warning (ie inside a single budget cycle).
Then there is the change in accounting procedures, while it is reasonable for science missions to pay the "true cost" of launch services, as opposed to hiding the cost of some projects in the large standing budgets in other areas, the costs that are being estimated seem, again to an outsider (and, mercifully, a non-accountant) to be classic "dumb math", with sunk costs counted, and marginal costs ignored. I could well be wrong here.

At the same time, NASA has a very major new directive, negligible new funds to carry out this new mission, and a promise to the community to keep the various science sub-fields alive, if not thriving.

It can't be done - either there will be major and massive cuts (the scope of the problem is, for example, ALL of Earth Sciences to be cut, which ain't gonna happen, though expect to see them take a big hit some late friday afternoon), or NASA will get significant new money within the next budget cycle. Which it will not.

For example, upcoming projects require heavy launch to LEO and beyond (like any Prometheus class mission, and trans-LEO human mission) just as the Shuttle is to be decommissioned. With ISS to be abandoned there is also no place to assemble missions (and ISS is in a poor orbit to do that anyway). Delta Heavy and Atlas 5 ain't gonna do it; the Russians don't have anything and I don't see billions going to France for Ariane 5s. We're waiting for magic to happen, while relying on, what is to put it politely, obsolete jury-rigged crap artillery. And while there is some movement for private development, there's not exactly a development path from Space Ship One, to a launcher which can put 30+ tons into LEO. Maybe one of the private companies is sitting on the equivalent of a Sea Dragon, but for NASA to bet on that for what is basically their mandated future path beyond 2012 is insane. But they have no funding for a heavy. Maybe that is why Griffin brought up the old Shuttle-C variant. here for AstroNautix launcher list.

I expect "planets" will do fine, both inside and outside the solar system, and one or two other areas will go on, as proof NASA still does science. But the rest of the community will be devastated, with uncertainty and rapidly changing directions dominating the next few years in space science. This will not exactly cause a rush of of talent into the field, which is already hurting (for instance, the delays and uncertainty about the future of the Beyond Einstein missions has been doing damage, people and institutions made major committments based on the 2003 announcement of a committment to a research line, which a year later was wiped (and is not slowly crawling back in pieces here and there)). There is a balance between when you stop backing a losing proposition, and when you just capriciously change things on a whim with no stability, and while I happily accept that NASA has too often failed to let go when it should, swinging to the other extreme is not an improvement.

On a different note - Premack and Premack have a letter in Science, 4 Feb, 307, 673, citing a paper I have not read which purportedly demonstrates (some) animals can indeed do comparative arithmetic without having hard numeral arithmetic. Figures.


Appropriate author, and one of my favourites, former Comp Sci Prof V. Vinge.

Author of "True Names" a long out of print classic story about life online; now available. Also wrote two classic space operas, A Fire Upon the Deep, and A Deepness in the Sky; as well as the "Peace War" series, including the Libertarian Utopian classic short story "the Ungoverned".

But Vinge is best known for his promotion of the concept of the technological "singularity", aka "Rapture for Nerds". It is a very interesting concept, delving into hard Artificial Intelligence, but conceivable in the absence of it. It basically postulates that some development trends are faster than exponential, in fact going to essentially singular behaviour in finite time. I'l return to that later.

good fan site here at Caltech

recent short story published by IEEE available here

Most strongly recommended for hard science fiction fans.

Friday, March 11, 2005

NASA honchos and exotic locales reports that Mike Griffin is the new head of NASA nominee. Griffin is currently head of APL at Johns Hopkins University, his bio shows a aerospace heavy background, with previous stops at APL, JPL, HQ, Orbital Sci Corps, and CSC. And, interestingly SDIO and In-Q-Tel (I always wondered what came of that little venture, some interesting stuff, I'm sure - looks like primarily "knowledge technologies" according to their website). Degrees from JHU and UMd and some DC area universities, and USC.

So, what does this mean. Don't know. has Griffin testimony on NEO hazards before the Senate. That's pitching for APL missions. More interesting is his 2003 testimony on the Space Plane. Hm, he testifies as In-Q-Tel COO, in summary, he wants to shut down the Shuttle, abandon the space plane (moot point now) and rely on wingless ballistic capsules on disposables, while the private sector develops reusable launchers. Ping. This sounds familiar. My old friends, the California Libertarians for Space strike again. Impressive. Not sure this will work, but looks like you'll now get to try it. 1999 testimony as Orbital person supports this. I guess the space cadets in the White House staff did their homework well. But in 2004 in a quote on he argues for shuttle-C for Mars exploration lift to LEO. Ouch, article on ResarchResearch quotes him as saying NASA should get more money, but that the Mars exploration should proceed even if it means taking money out of the space science (ie university research lines). Wah. This will not make him popular in certain sectors, and casts new light on the removal of the Congressional "wall" between exploration and science. This is 2003 testimony, before the official launch of the Moon/Mars initiative. Interesting.

I suspect the text book "Space Vehicle Design" by M. Griffin will become a required read this month. Available from your favourite online book seller in 2nd edition now, for a modest $100 or so.

So, what does this all mean... well Moon/Mars rocks on. Shuttle and ISS are dead. Spam in a can until the market comes up with a cheaper, faster, better Reusable Launch Vehicle, and a lot of pain for some space science sectors. Expect there will be some creative tension just east of the beltway and south of the Smithsonian.

Fun places to do science...

Space Telescope Science Institute - Baltimore, just off the JHU campus (top of the parking lot across from physics and astro). Fun place, best place for good conversation and surprise encounter at lunch, just be on time and grab a random table. Beware of the local hotels, legendary for their permanent six-legged population, stay up Falls road and drive down. For dinner, try to get a table at Helmands (Afghan) close to downtown 806 N Charles. Used to be for afficianados only, but became very popular with journalists after 2001. The proprietor is well connected. Fabulous food, I recommend the pumpkin for desert and Aushak lamb for entree (we tried to recreate the recipe for Martin Rees once, worked fairly well, but then my wife is amazing).

Thursday, March 10, 2005

Trentham's dark galaxy part I

Neil showed this (dark galaxy pic?) to me ~ 6 years ago, I hear there's more to this now - more on the new data later.

Its kinda neat, and the suggestion is that what caused the interaction is a "dark galaxy" - a galaxy dominated completely by dark matter, with little or not normal matter. Essentially based on the point that we don't see anything like a normal galaxy where one ought to be if the galaxy pictured interacted with another galaxy. Could be. Could be the tip of the iceberg, in that it could hint at significant mass in dark matter concentrations of galaxy mass. Or we could be missing a perfectly ordinary normal galaxy somewhere near this field. Or maybe something else did the damage, the long running alternative scenario is "cannonballing" by a supermassive black hole (in excess of 100 million solar masses) which would have been ejected from some other galaxy (possibly far away - maybe millions of light years away). The ejection would occur either during a three-body interaction between supermassive black holes after successive mergers, or from the gravitational radiation reaction of a coalescence of two unequal mass supermassive black holes.

Gratuitous cat blogging

Do cats have a quantitative reasoning capability? One of our cats (Thor) was planning a daring jump to a window, and spent a lot of time staring at the assorted toys and junk on the window sill, before picking his spot and jumping. Conversely, our very proper female cat seems to be able to count "crunchies" as they are poured into a bowl, and gets very indignant if Thor gets more than she does...

Wednesday, March 09, 2005

Hubble part I

AAS just came out today with a statement on Hubble servicing.

To recap: Hubble Space Telescope was due for another servicing mission, to install two new instruments (WFPC3 and COS), do some upgrades, and, critically, to install new gyros. The old gyros have a very finite life, one will probably be lost in next year or two, the rest within a few more. Two are already gone, so one more lost means switching to a 2-gyro pointing mode with limited pointing range and worse stability. Lose another one, and HST goes into safe-mode, no more observing. Lose the last one it tumbles and burns in uncontrolled re-entry.

Past NASA head cancelled the servicing mission, Shuttle is to go to the Space Station only, based on a moderately convoluted interpretation of the Columbia accident panel recommendation, and an unwillingness to committ to having a second shuttle on the pad for a "rescue launch" (no rescue needed, the other Shuttle goes to Space Station or whatever). Part of the problem, as I understand it, is that NASA switched to a full cost accounting, and the science budget just can't bear the contingency funding for the 2nd shuttle launch. Sounds superficially sensible as an accounting method, is moderately insane in practise.

What is particularly galling, is that federal admin people came to the AAS meeting in San Diego, and without explicitly promising anything, strongly suggested that the HST robotic rescue mission would be in the President's budget. Chipper little OMB official, never promised anything. just suggested. Final budget has a billion to develope the capability and launch a robot to destroy Hubble through controlled re-entry. Not enough for a refurbishment mission.

What a waste.

From a strict monetary view, the case is ambiguous. It'd be comparable cheap to fly a new mission like HOP, with the built instruments. HST is old, except that just about everything but the mirror and frame have been replaced. multiple times in some cases. It was good for another decade with one more refurbishment. And the reality that the rescue/controlled crash funding is new money, there's no way the admin or congress would actually give funding for a new comparable capability telescope before NGST or SNAP fly.

US could be left with no serious optical/near-IR imaging or spectroscopy in orbit for a decade. Oh, and astronomers could be left without a key source of funding for individual and small group projects, but that is for another time (and not as self-serving as it seems, I'm a theorist).

Tuesday, March 08, 2005

string lens - final word

So, some discussion about CSL-1, the potential cosmic string lens discussed below.

There are hints of emission lines in the low res spectra in the paper, but impossible to tell from the published data. Chandra observations are still of potential interest. HST ACS imaging would also be useful, nail the photometry and see whether the isophotes are really undistorted or just smoothed by the low signal and resolution.

But, here's the naughty bit - the paper does not give the location of the object! The survey field is RA 12h DEC -12 or so, but it is 1/2 sq deg, and the finding chart is useless unless you have a comparably deep field. The object is hidden (and not id'd in the catalog paper for the field, and is not in the followup paper on candidate other lenses, as far as I could tell). So, no one else can follow this up.

This is not science, and the referee should never have let the paper through in this state. If they were not ready to publish a refereed paper, then they should not have published.


couple of years ago I was involved in a NASA press conference. Did well, made the cover of the Washington Post (which is what HQ cares about), and then the usual, NYT, PBS, ABC, BBC etc etc

What surprised me is what was ranked 2nd most important - we made the Daily Show with Jon Stewart - link is to google cache, ComedyCentral uses dynamic pages which expire!

Well, that wasn't very good here is a better copy, provided as a "fair use" archival copy

This was back in the good old days when they actually did fake news and made jokes about them, "stolen from the headlines" as it were, funny too. (My second time on the Daily Show, I'm in a short video clip they showed the year before, laughing at an inappropriate moment...). Nowadays they're all serious, with policy analysis and actual news items of major international and national import. Still, someone has to be, and it is not like any other show on television (except maybe Olberman) is actually doing news coverage.

Monday, March 07, 2005

More rambles on cosmic string lenses

Schild et al (A&A 422 477) discuss a string lens candidate, namely the classic lensed quasar Q0957+561.

This quasar has a well studied time delay, used to get an independent estimate of Hubble's constant, H0. or equivalently, the expansion rate of the universe. Analysis shows a second time scale for the time delay between the two images, which has been suggested is due to microlensing in the lensing galaxy. The new claim is for a third time scale, at low amplitude variability, with zero time delay offset - consistent with string lensing.

Sorry, but I don't believe it. The model parameters are implausible (if I read it correctly they require the lensing string be in the Milky Way, only 10,000 light years away), and the alignment with a classic lens is a priori very unlikely. Likely there's some instrumental systematic here, problem with baseline photometry.

Back to CSL-1: quick glance at the spectrum does not show any obvious AGN emission lines, so maybe x-ray observation is not a good bet - though if there were identical luminosity x-ray emitting nuclei in both images, it would strengthen the case, and there could be room for a low luminosity AGN, but one still detectable with Chandra. Similarly radio observation looking for low frequency radio emission would be a test, if both images had identical emission.

astro-ph/0406516, but Sazhin et al, discusses the statistics of close pairs of faint extended sources in the field, and the possibility of multiple other lenses along the string trajectory - they claim 11 source pairs (7-9 expected for a straight string, more for a curved string, so implication is a lightly curved string). Too early to tell if these are real, of course, but if they are, they've not only found a string but mapped it...

Still a long shot, but not crazy. Certainly worth some followup.
By someone.

Saturday, March 05, 2005

science and fiction

Some books just stand out - a recent example is Neal Stephenson's "The Baroque Cycle", a voluminous trilogy comprising "Quicksilver", "Confusion" and "The System of the World".

The books are a prequel to the "Cryptonomicon", a great book, and the probable start of a trilogy, except recent events make the continuation somewhat awkward...

These books are masterpieces - the background is the historical conflict between Newton and Leibnitz over the invention of the calculus, and the setting is Cambridge, London, Paris, with occasional sidetracking for round the world trips, pirates, and a quaint little place upriver from Boston.

A friend of mine, who read them at my recommendation, wondered how they could be best sellers. when, in his opinion, you need a PhD in physics from Caltech or MIT to read them. He has a point, there is some backstory where that helps for perspective, but the story itself just flows, gets better each volume, and, unusually for Stephenson, has an ending.

Most recommended, they won't teach anyone science, although they cover much of science. They are just a very good read.

Also a "must read" for anyone using a computer is Stephenson's classic essay: In the Beginning was the Command Line...".

Next "must read" discussion. V. Vinge - "True Names" and other stories, followed by Ted Chiang, Charlie Stross and David Brin. Later.

Friday, March 04, 2005

Cosmic string lenses

So there is a serious claim that a pair of ellipical galaxies are redshift 0.46 (about 6 billion light years away) [CSL-1] seen separated by 2", are in fact a symmetric lensed image, and the lens must be a cosmic string (Sazhin et al MNRAS 2003).

I've now read the paper and the followup, and the claim is surprisingly good. The galaxies are seen only 20 kpc apart in projection, they are at the same redshift, and have same brightness, colour and spectra, within the resolution of the data. That is somewhat surprising for a random pair of giant ellipticals. The authors argue convincingly that the isophote contours are too round and symmetric to be due to foreground point source (or galaxy) lensing.

Deficit angle implies a string density consistent with a GUT scale of little over 10^15 GeV (depending on where you let the coupling constant run to). If the data works out, then this is a major discovery.

Is this real? I don't know, but the evidence is better than the hype in the press suggests. It is also eminently testable, both by further observations of the galaxy, by looking in the field around to try to see more lenses (by the same string) - which that group has done, more on that next week; and by looking for anomalous fluctuations in the microwave background. Taking a Chandra image of this galaxy pair would be a seriously good idea.


There are many nice places to do science, and scientists, very sensibly go there, meet there and generally try to be there.
One of the nicer is UC Santa Cruz, with the main campus in the hill above the town of Santa Cruz, looking over the Monterey Bay.

Go there, do a tour of Bonny Doon vineyard and then go have dinner at Rosa's by the small boat harbour, or Gayle's in Capitola for light lunch.

Thursday, March 03, 2005

Gratuitous Cat blogging - Muon the IoA cat

Muon CatMuon

the Institute of Astronomy (Cambridge, UK) cat.

Rumour has it that she is the most heavily acknowledged sentient entity in PhD theses in astronomy and physics (I'd say all of physical sciences, but some of these people run, like, really huge labs; and if you're like that, you make sure everyone acknowledges you - Muon does it by pure charisma)

"hello world"

This is an unofficial "science blog", with random personal comments to be added as it suits me.

No promises on timeliness, comprehensibility or comprehensiveness.

Main focus will be speculative news and speculation on news in certain areas of astrophysics and related fields,
especially compact objects (liberally defined), dynamics and theory.

Maybe I'll be brave enough to ramble about policy issues, or stuff over the edge, or not.

This may turn into something official, if "we" decide there is something official to be done...


Oh, tripped on this
over on usenet (anyone remember that...?). Cosmic string candidate: funky.

Sounds shaky, for now, but something to keep an eye on; here is the original article on arXiv. Personal bet is this will go away, but if not the implications are interesting.

Add on - ok, this works. Layout needs some cleanup. We'll see how it goes...