Digital Diary of Ben Schwartz

A friend scheduled a roofdeck meteor viewing party last night. Our plan was clearly flawed from the beginning, being in the midst of the Boston glow, beneath thoroughly cloudy skies. Nonetheless, after tacoishes on delicious homemade tortillas, we made a perfunctory pilgrimage to the roof to look up at the thick bright orange cloud that hung low over our heads, and out to marginally clearer skies on the horizon. Not a single star, shooting or otherwise, was evident.

EDIT: We tried it again last night, from the same roof but with clearer skies. We had a lot more luck than I expected; I saw at least five meteors in at most an hour of watching.

Last year I got a fundraising “poll” from the Republican party, and I transcribed it here for the amusement of posterity. Now I’ve received one from the ACLU (an organization of which, unlike the GOP, I am actually a member) in an almost startlingly similar form, quite possibly prepared by the same direct-mail company. It opens

All across the country, a virulent, new form of extremism is taking hold.

By completing this survey, you can add your voice to the chorus of other ACLU members fighting reactionary forces that want to create an America where everyone is forced to live by their narrowly-defined beliefs and values.

Your answers will be held in strict confidence and will be tabulated with those of other respondents to form aggregate opinions. Your responses will in no way be identified with you personally.

Part 1 (answers are “Do Not Believe”, “Somewhat Believe”, “Believe”, and “Strongly Believe”):

1. I believe that separation of church and state is crucial to the health of our democracy and that government should stay out of Americcans’ personal religious beliefs and practices.
2. I believe that attempts to limit the rights of people to marry and/or adopt children based upon their sexual orientation not only hurts families but violates the most fundamental precepts of American freedom and must be resisted.
3. I believe that rapidly-developed, new technologies and weak, outdated privacy laws have resulted in a serious escalation of threats to my personal privacy.
4. I believe decisions about whether and when to bear children are fundamental to the health and equality of American women and that the right of women to make their own reproductive choices must be defended with every ounce of our energy.
5. I believe that it is wrong for states like Arizona to pass unconstitutional racial profiling laws that require the police to stop people on the street and demand that they “show their papers” based on how they dress, what language they speak or how they look.
6. I believe that it is wrong to use taxpayer dollars to fund abstinence-only education programs that promote a particular religious doctrine, deny young people access to reliable information about contraception and make it harder for them to avoid unintended pregnancies and sexually transmitted diseases.
7. I believe that even in times of national crisis, the government should not be allowed to violate the 4th amendment protection against unwarranted searches and seizures, and that nay search made of private property should only be permitted with a court-issued warrant.
8. I believe that it is wrong for extremist advocates of creationism and intelligent design to impose their religious beliefs on others by interfering with the teaching of evolution in public school science classes.

Part 2 (answers: “Very Important”, “Important”, “Somewhat Important”, “Not Sure”):

1. The ACLU is using lawsuits and other forms of legal action to challenge the constitutionality of the government’s actions and to insist that the courts demand adherence to the Constitution and the rule of law.
2. The ACLU is strengthening its national netowrk of over 50 affiliates that represent individuals who have been victimized and had their individual liberties denited — often relying on such cases to set strong precedents that will protect us all.
3. The ACLU works in the halls of Congress insisting on laws that protect our fundamental freedoms and opposing efforts to use the power of the government to promote a particular religion or version of morality.
4. The ACLU runs vigorous media outreach, public education and grassroots organizing efforts to inform and mobilize people about ways to strengthen and expand individual liberty in America.
5. To help the ACLU sustain its all-out efforts to restore our lost liberties and advance freedom, will you send a contribution today? (yes/no)

Somehow I get the feeling that they aren’t really asking my opinion. I find the whole thing really off-putting. I understand that the ACLU lost its main backer to the Madoff fire, but this make me feel like they have stooped to the level of the cash-strapped RNC for fund-raising.

On the other hand, the list of thinly-veiled policy planks is as good as the RNC’s is bad.

Another late night in lab, but this time I’ve got something to show for it. Not that I’m going to show you, here, but things are definitely coming along. It’s a bit unwieldy, still. Setting up requires festooning the scan room with string, and each run requires starting no fewer than six different programs in a precisely specified sequence; get the sequence wrong and you have to restart the scanner.

Setting some parameters still requires you to edit the source code.

Nonetheless, enough progress to make this a very good week.

Yesterday I went to an outdoor production of Othello, this year’s incarnation of the annual Shakespeare on the Common. It was really well done; I can recommend it without reservation.

I had only the haziest idea of the play’s plot, so the first 20 minutes or so were especially difficult to follow, but after that I could feel my ears adjust to the Elizabethan text and flow. I don’t know if my subconscious were dredging up deep-buried memories of Shakespearean grammar or decoding the language anew.

For a tragedy, the play has a large dose of comic relief, and the audience laughed in unison with some regularity. Sometimes we were laughing at Shakespeare’s jokes

Iago: Will you think so?

Othello: Think so, Iago!

Iago: What, To kiss in private?

Othello: An unauthorized kiss.

Iago: Or to be naked with her friend in bed An hour or more, not meaning any harm?

but more often we were laughing at some line that, by chance, was equally idiomatic in 21st century English

Othello: By heaven, I would most gladly have forgot it. Thou said’st, it comes o’er my memory, As doth the raven o’er the infected house, Boding to all–he had my handkerchief.

Iago: Ay, what of that?

Othello: That’s not so good now.

I can’t quite explain what’s so funny about a line like this, and yet the audience laughed uproariously.

I don’t really know much about it, but if I understand correctly it was a fictional show starring Andy Griffith, who played a character named Andy Taylor that in no way resembled Griffith himself.

I wonder if I am the only one who finds this monumentally confusing. Can you imagine if House had been titled The Hugh Laurie Show?

Blog posts have been sparse recently, mostly just because I’ve been working hard. I’ve been working on a lot of things, especially work: I was in lab until midnight last night. I’ve redesigned my motion phantom setup so that it can run with the scan room door closed. This has major advantages in the department of not getting huge RF contamination artifacts every time a Green Line trolley pulls away from a stop.

Making this work has presented a fun engineering puzzle. The driving motor has to be outside the scan room, and the rope it’s pulling on can only enter through a “waveguide”, a one-foot copper pipe that’s pointed in entirely the wrong direction and already half-filled with electrical cables. I ended up using four K’NEX pulleys and a length of PVC pipe from The Home Depot. None of the pulleys are actually attached to anything, a fact of which I am unreasonably proud. They are all held in place by the tension in the rope. One of them is actually suspended in midair during normal operation.

This is not how I expected to earn my Ph.D.

My apartment is full of leftover public food, some perishable and some not. Much of it dates to roommates who didn’t take everything with them. I hate waste, so I occasionally try to do something about it, by eating it (or getting other people to eat it).

I keep an eye out for confluences of left over ingredients that could align into a recipe, like Connect 4. This week a convergence of eggs (long past their sell-by), oil, and buckwheat waffle mix caught my eye.

I love waffles, and we have a waffle iron, so I made waffles for breakfast on Saturday, which went swimmingly. I started scheming for future waffletunities.

Tonight, we had left over: grapes on the verge of overripe, some unneeded chopped onion, and Korma sauce that someone got for free like a year ago. This became an appetizer (grapes on a waffle), a main course (sauteed onions and Korma sauce on a waffle), and dessert (grapes with cinnamon).

It was a great dinner, and there’s plenty of batter left for tomorrow’s breakfast, with jam. We still have at least 4 jars of jam whose origins are unknown.

A friend and I spent an hour last night fighting with a live USB boot system. We were using the venerable Unetbootin (who names these things?) to turn liveCD ISOs into live USB sticks, then booting them to install to disk. It had worked ten times before, but this time we somehow repeatedly ended up with some wrong, old version on disk. We tried rebuilding the ISOs, with no effect. We thought the ISO creator could have a bug, so we mounted the ISO, but its contents were correct. We thought Unetbootin might be the problem, so we loop-mounted its squashfs, but that looked fine too. We wondered if some subtle error was occurring, so we starting md5sum’ing everything … and somehow the squashfs checksum was perfect, right up until liveboot. On the live machine, after booting, it was different.

We were virtually tearing our hair out by the time we realized that there was another USB hard drive plugged into the system. We weren’t selecting it in the boot menu, of course, but we unplugged it … and everything worked. The bug was in the BIOS, which was booting from basically whichever device it felt like.

Moral: Don’t trust a PC BIOS to boot from the USB device you tell it to boot from. When in doubt, unplug everything.

The Senate has officially agreed with the White House to scrap the Ares rockets, and by extension the rest of Constellation. So far, so good. Instead, they’ve decided to fund NASA to make a Shuttle-Derived Heavy Lift Vehicle (i.e. really big rocket based on the shuttle). They don’t really want this rocket, but they need to build it to keep the money flowing to the huge contractors/employers/campaign donors, because it looks bad if you hand them money for doing nothing. Whatever. Fine.

What’s weird about this, to me, is that Ares V was a Shuttle-Derived Heavy Lift Vehicle … and in fact, so has been seemingly every launcher that NASA has proposed in the last 20+ years. Wikipedia, as usual, has a long list of these proposals, none of which has ever been built.

The specific phrasing of the bill seems to be code for this variant of the idea. It looked sensible enough to me, smarter than Ares anyway … until I realized that they intend to put people on the thing. The whole point of Ares was that the Shuttle was being discontinued for being too dangerous for humans due to the side-mount configuration. This is the same launcher, in the same side-mount configuration. Safety is obviously not a concern, anyway, since they also propose to do a shuttle flight without a rescue/backup on hand.

The contrast with SpaceX is sharp. SpaceX has one engine/tank/rocket design, which they propose to reuse for all stages and all boosters, across a range of sizes. NASA has a combinatorial explosion of different parts from different suppliers, and a political need to use them all at once.

Another small milestone today: I got my first demo of live transverse motion tracking working. That means I acquired a training ultrasound data set, processed it to extract the path topology, generated a lookup table mapping ultrasound lines to (topological) positions, and then used that table to determine position from ultrasound data in real time. Still missing is the MRI integration, which is of course critical for the target application.

I’m surprised this worked as well as it did. For this experiment, “real time” required 2000 cross-correlation searches per second on 3000-sample arrays. This was implemented using FFTW’s length=8192 complex->real single-precision iFFT, and a very naive search for the maximum cross-correlation value. Benchmarks showed the hardware could do just over 4000 searches per second. This is a single thread, on a 3 GHz Pentium 4, with the simplest possible C code.

FFTW FTW. I had begun to draw up laborious schemes for accelerating the database lookup, like GPU FFTs or an artificial-intelligence search, but FFTW is so fast that it’s irrelevant. With a newer CPU I might not even need to parallelize to hit my final performance targets.

EDIT: I turned this into a quick benchmark to compare the 3 GHz Prescott P4 with our new dual-quad 2.53 GHz Xeon E5630 (i7). The Xeon is faster by a factor of 2.66 … so like an 8 GHz P4. The i7 is doing triple the P4′s work per cycle. That’s not quite “Moore’s law” for single-thread speedup in 5 or 6 years, but it’s pretty good.

EDIT2: A 2.93 GHz Core 2 Duo (T7500) is faster than the P4 by a factor of about 2.1, which puts the i7′s advantage in perspective.