Thursday, April 28, 2005

Like Sausage

There is a saying that says "Laws are like sausage: you don't want want to see either being made."

Certain types of dose calculation fall in that same category. All I'm going to say is that there are FDA approved computer models that involve calculating the dose to the uterus in a healthy adult male...

Wednesday, April 27, 2005

Back Handed Reviews?

I just saw an advertisement for the movie version of "Hitchiker's Guide to the Galaxy".

One of the review blurbs they used was "original". It is a movie based on a book. Of all of the positive descriptors that could be used, "original" is not one of them...

My Brother the Mack Daddy

So my brother and mom went to a Rotaract conference last weekend.

Some female at the conference is going to be going to undergrad with my brother this fall. Her mom gave my mom her cell number and told mom to tell my brother to call the daughter.

Some people have it way to easy...

The Morton Salt Girl

I can only pray that I never become so desperate for love that begin writing mash notes to advertising icons...

Tuesday, April 26, 2005

The Importance of Large Sample Size

In my penpenultimate lab report of the semester, we had to compare the spectra from a radionuclide in two different circumstances. The data was stored in an ASCII file with the pulse heights represented by varying numbers of asterisks.

Rather than worry about important the data from the text file into a more sophisticated analysis program, I printed out the 15 page spectra and aligned them next to each other on my apartment floor. This was described in my experimental methods section, with a footnote stating that "I had hoped that I would be able to show that this measurement is independent of apartment by repeating this experiment in the presence of a female of beauty at least three standard deviations above the norm; sadly, circumstances did not permit this."

I got a comment back chiding me for thinking that one supermodel was a sufficient sample size in the first place.

Sunday, April 24, 2005

A Sign of Something

I just saw the Star Wars trailer on TV.

I'm not a big Star Wars fan. I actually think it's a little bit dumb. So I'm a tad biased.

But honestly, at first I thought it was a McDonalds commercial or something. The voiceover was just sorta...stupid sounding?

Friday, April 22, 2005

Fun With Matlab

When you cause a run-time error in a Matlab program, it behaves very well, giving you a tracethrough of exactly which line it crashed on. Sometimes it isn't your program that was the last step in the failure--sometimes it feeds faulty data to an internal function, which crashes.

Through this, I have learned that Matlab has an internal command called "doDirtyAction". I do not know if it is done dirt cheap, however.

Wednesday, April 20, 2005

Unusual Space-Saving Decisions

For reference, an MR image tends to be about 256kb per slice in size, give or take a factor of about 4, with the number of slices generally on the order of a dozen--so let's say that there are about 3MB to a series (with several series usually acquired for each patient).

Now, given all of that, why would GE choose to try and compress a dozen flags into two bytes of data in the header section of the raw data files?

Tuesday, April 19, 2005

How to Fight Terrorism

We should enroll the totality of the Middle East in graduate school. While this may not improve their dispositions, there is one advantage to this plan that is difficult to replicate in any other way. Graduate students, more than almost any other profession, are active and even enthusiastic participants in their own torture (where else can you find people who expend large amounts of time and effort selecting a group of people to give them oral exams?).

Later today, one of the grad students--who even happens to be Muslim!--is having a mock defense. We asked him, "So would you like for your so-called friends to attend for the purpose of mocking you and finding your every weak point?" And he said please.

If terrorists were grad students, they would calmly walk into the interrogator's office, report that they had been forced to redo their bath in hot oil because the thermometer was broken the first time, and then tell everything they know.

It's a foolproof plan!

Sunday, April 17, 2005

Rats are Smart

I admit it. I was cheap.

You see, at pet stores there are two kinds of hammocks you can buy for small animal cages. Some of them have pockets that the critter can crawl into to sleep, but they cost a few dollars more. I usually buy this type for Sparty--it may have saved him when he had to spend an evening in a house with no heating over Christmas--but I figured he wouldn't need one over the summer.

Thing is, I think he likes the pockets. He's already carefully chewed the two cloth layers of the hammock apart to create a hole he can crawl in...

Friday, April 15, 2005

Two Things I Have Learned This Week

1. Do not attempt to write lab reports under the influence of cold medicine. It just won't happen.

2. It is possible for you to learn that you have received a $418 award a month after the deadline for accepting it. Fortunately, the award involved came from Berkely and they are, if nothing else, laid back.

Tuesday, April 12, 2005

Quotes from the Director's Meeting

Today was one of our twice-yearly group meetings with the program head (and vice head), where the students may kvetch freely about wrongs and injustices. Here's some quotes:

"When you hear these sorts of rumors, let us know. We need to know what to categorically deny and what would tip you off."

"There is some probability that we will be offering a special topics in Monte Carlo this summer. I blame Dustin for that comment."

Monday, April 11, 2005

Hygroscopic Caribou

The phrase "hygroscopic caribou" is not a Google-whack. A Google-whack is a search phrase that only turns up one hit on Google.

And this is what I do with my lunches since all of the fun websites are filtered out...

Saturday, April 09, 2005

Looking at Faith through Rose Criterioned Glasses, or, What is the SNR of God?

Earlier today, for reasons I do not know, I was thinking about Littlewood's Law of Miracles. It is a favored argument among skeptics--and by skeptic I mean not the suspicious or agnostic but the militant templars of doubt--against the presence of divine intervention in the world. It is, simply put, a statistical argument. If one assumes that a miracle is an event with a probability of one in a million, then, assuming we perceive one event per waking second, we will generally see miracles once a month--some we will consider significant, some we will ignore.

Now, I personally consider the argument flawed, if not practically autoreduction ad absurdum. However, quibbling over assumptions is a poor way to defend one's faith--if I argue in favor of one set of numbers, someone else can assume another and I cannot compel their presumptions. I would rather concede the law entirely, and continue from there. The soul of Littlewood's law is the Law of Large Numbers--that in a world of so many people, where so many events occur, our perceptions of probability will be challenged.

At this point, I will digress into talking about what I do for a living. One of the basic questions of medical imaging or nuclear medicine is how one detects a signal in the presence of noise. For example, even if one locks a Geiger counter into a room lined with lead, it will still detect an occasional radioactive event. This spurious detection is called the background noise. The weakest radioactive source you can detect in the presence of the background noise is called the minimum detectable activity (MDA). Now, this is a blog post and not a submission to a peer-reviewed statistics journal, so I will gloss over the calculations.

If we assume Littlewood's law, then miracles are a lot like radioactivity, mathematically speaking (i.e. they are both Poisson processes). I have to discuss a technical point here. It's the fairly obvious and intuitive statement that the longer you are measuring a signal, the easier it is to distinguish signal from noise. Basically, when you calculate an MDA, you have to specify the time period you are measuring over (and how sure you want to be, for that matter). This will be relevant in the next paragraph.

In analogy with the case of radioactivity, permit me to define the minimum detectable spirituality (MDS) as the minimum number of miracles that have to occur in a period of time for us to be 99% sure. Let as assume that you want to look at, say, 25 years of your life. The MDS is 1 miracle every 6 months (so that means a total of 14 miracles in a year). If you look back over 50 years, you would need 1 truly divine interaction a year to reliably notice it, even in the face of the other 12 you would expect to see from pure chance.

And what does this all mean? That depends on what you believe. I believe in miracles. I think God's signal is above the noise. And that means that, if someone should repeat Penn Gillette's quote about "luck is just probability taken personally", I can honestly and flippently respond that "just because I'm paranoid that doesn't mean they aren't actually out to get me."

UPDATE: I wanted to add a less flippant conclusions. The long and short of all of this is that Littlewood's Law tells you nothing about faith. Our lives are long, and given how little "spiritual activity" has to present for us to be able to distinguish it from the background noise, it's not irrational to claim to see the hand of God.

Friday, April 08, 2005

Scientific Progress Doesn't Go Boink, I Pray

This is a picture of the setup from one of the recent setups we had in

a lab.  Yes, the camera tripod is being used to support a

radioactive source.  Yes, the biohazard box is being used to

support the camera tripod.  What's not obvious is that the piece

of imaging equipment the tripod is balancing above has a very fragile

NaTl crystal that costs about $30,000 to replace.

Image hosted by

Wednesday, April 06, 2005

Just Plain Cool

You can view a satellite image of the address you type in. The pictures are high enough resolution that I can pick out my own apartment.

I don't know how recent the images are, however--some of the buildings that have been constructed here in the med center recently are not in the satellite images.

Tuesday, April 05, 2005

The Ironies of Life, #987324

Because my office has several new postdocs and grad students, we just had a debate about where to go for our general health care--there is a walk-in clinic in an obscure location, but not much else that is convenient.

In order to sledgehammer the irony, I should point out that I work in the basement of a hospital in the Texas Medical Center.


I woke up at 6:30 and I couldn't get back to sleep. So what do I do?

I go do research...last night I was proofreading someone's dissertation at a pub.

I get to be angsty today, ok?

Monday, April 04, 2005

Who's Training Who?

My apartment has one minor design issue--there is a small opening in the side of one of the built in cabinets where a sufficiently agile and tiny creature could enter the food storage area easily and stealthily.

As the astute readers of my blog may divine, a rat is both sufficiently agile and adequately small to accomplish this.

Now, I have put a wooden block in the opening, but it is difficult to affix in any non-temporary manner and rats are intelligent enough to figure out how to wedge the block out. When the block falls to the ground, however, it makes a distinct thudding sound that I can easily hear, and I can go and claim the rodent before he does any actual damage.

The problem is that I feel sorry for taking the little guy away from the treasure trove he has unearthed--how would Indiana Jones feel if some guy grapped him by the scruff of the neck after he dodges the boulder trap--and so I pet him and often give him a treat.

This has resulted in Spartacus knocking over the block and then turning around and looking at me expectantly.

I think I am the one who got trained.

Sunday, April 03, 2005

Fond Memories of Childhood

I bought Teenage Mutant Ninja Turtles: Season 1 today after church. Season 2 comes out in a months.

I had planned on cooking dirty rice, but for some reason, I think I'll end up eating pizza.

Saturday, April 02, 2005

Spice Hunt

So Comedy Central is having a marathon of Mad TV...the first skit has been "The Great American Spige Hunt".

For the record, Sporty Spice lasted longest (because she's athletic).