Monthly Archives: May 2013

Crime Scene

Rollick appraised the scene. It was like your standard murder scene, except that all the techs were immaculately dressed in classic suits and wearing white gloves. Rollick bowed to the lead crime scene tech, and asked him what he had so far.
“Rollick-san, you can see here that the apparent cause of death is this gunshot wound in his neck. However, you can see that there is very little blood on the carpet here, suggesting that he was already dead when he was shot.”
“So, what do you think happened?”
“Well, we’ll have to wait for the pathology report, but in the meantime, we’re combing the room for clues. I would recommend you take a look at the display case over there. You might find it interesting.”
“Arigato gozaimasu.”
Rollick bowed and headed over to the display case.

Non-laminar Diffusion

So, we always talk about diffusion as being very slow and measured, whether we use Fick’s first or second law to model it, it still contains the fundamental assumption that diffusion is laminar.

What if this was not true? What kind of material properties would be required to make diffusion non-laminar?

Is this even a sensical question?

Basically, particles travelling through the material would have to be moving in such a way such that their trajectories would not for streamlines. That you would get turbulent mixing. You might be able to get this with something akin to strung-together ion channels, but this might only get you longer laminar flows in difference directions.

At the transition from laminar to turbulent flow, what exactly happens? Some of the particles can basically no longer roll over each other when they want to go faster than their neighbours*.

So they spin off in a chaotic** direction.

So, what would you need to do to make this happen for diffusing molecules?

What is diffusion, exactly?

In its purest form, it is a small (relative to the bulk) concentration of particles ‘diffusing’ into a large bulk of solvent.

At the macro level, it is a (relatively) simple application of entropy.

At the molecular level, it is a (slightly less) simple application of entropy***. Basically, molecules move around the solution effectively at random (really chaotically, but random is good enough for this calculation). Since the particles doing the diffusing are all in one place to start, and move randomly, they are more likely to move into the bulk than out of it (more out of the bulk, if they move in each direction equally likely, more of them will move into the bulk.)

For this motion to be turbulent, the molecules would need to ‘want to’ move quickly enough that they wouldn’t roll off each other when moving past each other. (What really causes the turbulence in large flow is that the molecules of the wall of the pipe are unmoving, and so there is a limit to how fast everything can flow.)

So, all we need to do is ensmallen the pipe, or make molecules stationary when others are diffusing? Some kind of matrix? Is it really diffusion then?

*Statistical molecular dynamics is really powerful.
**Not random.
***You are probably most familiar with Entropy as the law that systems tend to disorder. At the molecular level, this manifests as system states that have more ways they can happen (effectively higher probability) happen more often. These states tend to be more ‘disordered’. For example, for the system xxxooo, only two of the many (20) states involve the x’s and o’s separated like that.
xxoxoo, xxooxo, xxooox,
xoxxoo, xoxoxo, xoxoox,
xooxxo, xooxox, xoooxx,
oxxxoo, oxxoxo, oxxoox,
oxoxxo, oxoxox, oxooxx,
ooxxxo, ooxxox, ooxoxx,
Indeed, for each rule you give about how they have to be structured, you restrict the number of options, and reduce the probability of what you are proposing existing in real life without out some kind of outside influence.


Rollick always experienced a strange thrill the first time encountering a corpse.

It was the feeling that something monumental had just happened here, a great transformation. What before was a living and breathing human being was now just a pile of rapidly decomposing spare parts. The only thing that rivaled it was the sheer joy of creating life, but that was all too fleeting, and took too long to grow to really have the same impact. It made him want to finally get that tattoo on the back of his neck of an old-style UPC of 70 kilos of lean beef.


It’s the scent that reaches deep into your medulla oblongata and makes your heart skip a beat. The scent that would launch your trireme, if you could somehow haul it down Yonge Street. The scent that was emerging from the crime scene.

Rollick smelled her as he was walking into the crime scene.

“What are *you* doing here?”
“I could ask the same of you. What’s a retired corp investigator doing on the diplomatic beat? Shouldn’t you be doing a Bloc consult?”
“They said that there was a parsnip sculpted into a rose at the scene.”
“Oh, that. It looked like it came out of that trophy case, there. It was sitting on its side. The ambassador was known to collect Bloc artifacts.”
“So, you don’t think the White Rose was involved?”
“He’s never gone this far afield before. We think it’s a copycat or a red herring. Besides, what would the French Ambassador to Japan be up to that would interest the Eastern Bloc?”
“Right. So, why are *you* here.”
“You wouldn’t believe that I heard you were coming and rushed breathlessly to meet you?”
“Not unless I had something you wanted.”
“I was actually in Shinjuku on vacation, and I was the closest thing the Committee had to a criminal psychology expert nearby, so they sent me. It goes without saying that this is above top secret. They didn’t want any flights being recorded.”
“But we should be able to hide that from most organizations. You think Them is involved?
“We can’t know for sure.”
“Fair enough. Let me take a look.”
“You’ll be impressed. It was very professionally done, with an interesting twist.”

Rollick bent down to look at the body on the floor.


…or perhaps pastino. No one really knows where the genus name for Parsnips came from. “Pastus” meaning “food”, or “pastino” meaning “to prepare the ground for planting of the vine”. I had a feeling that meanings like these would have a greater bearing on this case than anyone expected.

We had had many dealings with the White Rose before. We’d never met him, of course, nor even ever seen him. Only the few scattered conversations, shunted through proxies around the world, voice scrambled and descrambled dozens of times, sent through an unhackable optical link in Rio, all the standard things a true professional would do.

And up to this point, the White Rose had seemed content to deal with internal Eastern Bloc matters. Some grievance some nation or city-state had with the former Russia, some internal squabble in one of the London or New York expat communities. But now, this was was different. What would the French Ambassador to Japan be up to that would interest the Eastern Bloc? Or worse, what if it had nothing to do with that? They said there was evidence of a struggle, which was odd. The White Rose was known to kill from a distance, or at least silently. If the ambassador put up that much of a fight, then they must be either very, very good to notice the White Rose, or something else was going on…


Rollick could hardly see his client’s face through the smoke. The smoke that covered the city like a permanent miasma.
“I need you to find someone for me.”
“I can’t tell you that.”
“Why not?”
“Because I don’t know who they are.” “What I can tell you is that they left a parsnip cut like a rose by the body of the ambassador.”
“The White Rose.”
“Exactly. No one has been able to find him, or even know who he is, but we think he has just tipped his hand by starting to play politics.”
“So, what *do* you have for me to go on?”