Tag: Science

Blindspin 8: A peek at the data

“If we don’t have a number, we don’t really know anything, and we can’t learn anything more.”

Since we plan to professionally publish the Blindspin results, we can’t reveal all the things we’re theorizing about yet. But here is a look at some things we’re seeing. (More information: Blindspin project page). 

For each test subject, we’re caĺculating the occlusion time OT (time spent driving blind) and the occlusion distance OD (distance traveled during that time). They will tell us different things…. but what exactly, that will remain to be analyzed.

Continue reading Blindspin 8: A peek at the data

Blindspin 4: How much will test subjects need to sweat?

 

We can now estimate the amount of sweat and pain that test subjects for the Blindspin project would need to endure (see project page). The experiment will require about 90 minutes, and approximately five kilometers of cycling, mostly at slow to medium speed. The cycling will happen in Turku, near either Raunistula or Itäharju. (Only self-experimentation will be done in Jyväskylä and Toronto). [Edit: Latest maps added]

The exact details will still evolve as we self-experiment.  The most boring part — driving back and forth on a straight empty road — is actually by far the most important. It will tell us what the absolute best-case scenario is. Let’s say that we find that a person can safely drive blind for a maximum of N seconds in such a case. That means that for any realistic scenario, with a curved road, or even a tiny amount of traffic, the safe time will be far, far shorter.

Finding suitable straight tracks is problematic, since so many safety features need to be considered (low traffic, no intersections, good quality surface, isolated from road). The search is still ongoing, but so far the following tracks have been found that are definitely usable.

In practice, we have two loci around which the tests could be performed: a western one near Raunistula, and an eastern one near Itäharju. Itäharju seems to be be by far the better area, but volunteers might be easier to find in the Raunistula region. We will make the final decision later.

JPGStraight

 

Estimating the effect of track curvature is much trickier, but it can be done relatively quickly and easily. We will simply have the volunteer cycle through several  curved paths. Our expectation (and experience from self-tests) is that if there is even a moderate amount of curvature, the cyclists will hit a wall, so to speak. It will be extremely difficult to drive blind for even a very short time. This is different from car driving, where the effect of curvature is linear and not particularly strong. For cycling, we would expect a strongly non-linear response.

Best identified tracks, western area.

JPGWest

Best identified tracks, eastern area. This will almost certainly be the area where the tests are centralized.

JPGEast

If any volunteer is willing to drive more than the minimum (say over several days or weeks), it would be highly appreciated. The more data we get, the better.

If you feel you might be interested in being a test subject in July/August, please contact Jakke.Makela{at}gmail.com.

See also Blindspin project page.

 

 

 

 

Blindspin 3: Why would someone want to volunteer?

 

Volunteering to be a test subject for Blindspin (project page) means that you may spend an hour or two of your life bicycling back and forth on a track and looking weird, probably picking up a heavy sweat, and potentially risking your personal safety. Why would anyone do that?

Short answer: because no one else has ever done this. Science means that you methodically pile bricks to create something useful. An individual brick is just a turd-colored clump of burned clay, but they all need to be in place. And in this particular niche of cycling safety, no one has really even picked up the first block.

What is the niche, and why is it interesting? The idea for this research spun off from work we’ve done in driver distraction. A large number of accidents are caused by the driver’s attention wandering to something irrelevant (these days, largely using a mobile phone). Yes, there are brute-force political ways to handle that particular problem, such as outright bans on mobile phone use (which don’t really work very well).

But if we actually want to approach the problems scientifically, we must ask simple-sounding questions that are measurable. In this particular case: how do we measure what driver distraction even means? How do we find numbers that allow us to compare how dangerous driver distraction would be in different scenarios?

We need those numbers before we can even think about how to think about answering more directly practical questions, such as: how do we design car interfaces so that they do not cause dangerous distraction; how do we intelligently attack the problem of driver mobile phone use; and even, how do we design roads (especially intersections)  so that if and when distraction does occur, the impact will be as small as possible?

For cars, a lot of research has been done, and some of it has found its way into safety recommendations (very slowly, but steadily). With cars, there are well-established safeguards that can alleviate the effects of such distraction — lane markings, brakelights, and standards for traffic light design, for example. For cycling, such safeguards have been far less systematically studied.

staubin-design

The science of car road design. (Source: paulstaubin.ca)

bridgewater3

The reality of cycleway design (Image source: madcyclelanesofmanchester)

Continue reading Blindspin 3: Why would someone want to volunteer?

The joy of lightning

On July 24, 2006, I had the honor of almost being struck by lightning. That was not the interesting part, though.

The truly interesting thing was the metallic click I heard just before. I was doing measurements on lightning for my PhD thesis in Finland at a meteorological observatory. The equipment was in a detached outbuilding to minimize radio disturbances. The storm was overhead, and I was having as much fun as a nerd with an oscilloscope can have. Excellent data.

Taking a small break, I went to the door to enjoy the sights. Immediately, lightning struck an electric pole on the other side of the road.

I have never been more frightened. The shock wave from so close is truly mind-boggling, in the sense of boggling your brain. The hairs on your body rise up and the skin goes into goosebumps. For some reason, you feel nauseous for a long time afterwards, as well as a metallic taste in the mouth. I suspect the latter is due to an adrenaline rush. All of this is standard operating procedure (SOP) for near lightning strikes.

What was not SOP was something I did not expect. And could not immediately explain. At the same exact time the lightning hit the pole, and significantly BEFORE the shock wave, I heard a loud metallic click. Very much like the crack an electrified fence makes when touched (try it).

Sound takes half a second to travel that distance, so there seemed to be no logical explanation for this. A hypersonic pressure wave? Perhaps, but nothing like that has been reported, and it does not satisfactorily explain why the intermediate time was so quiet. It took detailed study of lightning processes to understand what was possibly going on.

One thing to understand is that a lightning stroke does not in fact travel all the way to the ground. Rather, it travels down from the cloud as a stepped leader. Just before it hits the ground, there is actually an upward stepped leader which travels from the ground up and connects with the downward leader. The real current only starts to flow and the big kabuum is heard when the connection occurs.

There can be several such attempted upward leaders, which do not manage to join the downward leader and hence die out.  This is well seen in Figure 1 (photograph by by Antti Tiihonen). Multiple downward leaders try to reach the ground. Two of them actually do; this kind of forking is quite common. Several attempted upward leaders jump up from the treetops. One clear one is seen next to the right-hand branch; there are weak upward leaders near the left-hand image as well but they are very poorly visible.


Figure 1: Downward and upward leaders.

The best hypothesis was that an upward attempted leader was the cause of the click. An attempted leader is after all a spark that can meters to tens of meters in height, and could create a sonic boom of it own. Such a noise simply had not been recorded before.

Figure 2 shows a map of the area. There were two possibile sources: a 20-meter metal observation tower about 100 meters away, or the hut itself. There were also some grounded buildings nearby. Looking at the time dfferences, the most logical choice was that the upward leader was driven from the hut. In other words, if the downward leader had happened to connect with “my” upward leader, the flash would have hit the hut and, with any luck, me.

The hut was well grounded as it had been used for storage of hydrogen for weather sounding balloons. It probably would not have been damaged badly. Nevertheless, the idea was not attractive. I was standing at the door of the hut, so the lightning could have taken any path. Almost certainly, there would have been hearing loss.

Figure 2: Map of the situation. The instrumented tower and the observation point are almost equidistant from the strike, so the tower cannot have been the source of the click. The source almost certainly was the hut itself.

The anecdote remained just that: an interesting occurrence that no one seemed to have replicated. Some amateur storm chasers did report various kinds of crackles before close flashes. (Professional lightning researchers, at least those who want long careers, try to avoid close flashes). My hunch was plausible — but unverifiable.

However, in 2009 I noticed a paper which suggested my explanation was correct. The phenomenon had been observed accidentally by Lu and Walden-Newman (2009). An attempted leader occurred near their equipment, and they got both (partial) video, electric field, and audio signals from it, ensuring that the interpretation is correct. Figure 3 shows the audible “click” quite clearly about half a second before the krakabuuuum of the actual lightning flash.

Figure 3: The first known actual recording of such a “click”, by Lu and Walden-Newman (2009).

There was not enough data for me to even consider publishing the event (no video, no audio, only a badly distorted electric field recording) so that the authors are the first ones to have measured this effect in any real scientific sense. It is nevertheless a satisfying feeling to have observed something, come up with a hypothesis, and then later found proof that suggests the hypothesis was correct.

Moral of the story? Perhaps it is always worthwhile to stay observant for anomalies, whatever the situation? And take notes. I collected what information I had, and wrote it up rather quickly. There is an old science saying: “If you didn’t write it down, it didn’t happen”.  It’s a good motto for life in general.

Writing this post, I feel nostalgic for my research days. Science is cool, especially lightning science.

Being rigorous at being what?

 

Can the Zygomatica blog serve any useful purpose, when we have made a conscious decision to not focus on anything for any significant periods of time?

I do not speak for the other members of Zygomatica, although they have peer-reviewed this posting (see below). This is my own question, and my own answer.

Most bloggers have no need for such a question. If writing a blog is something that comes naturally and causes real joy, then no question: just do it.  For me, writing does not come naturally and is not a real joy. It is difficult. The Zygomatica team has a policy of internally peer-reviewing every posting, meaning we are lucky to end any given day on speaking terms. What, then, is the point?

The point, as I see it, is to maintain and develop my skills of rigorous thinking. It would be exhilarating to create something that people actually enjoy reading, of course. But above all this is an exercise in self-discipline. But self-discipline to what purpose?

A famous paper  (Ericsson et al 1993) notes that it takes 10,000 hours of practice to achieve exceptional proficiency in any task, meaning 10 years of more or less obsessive practice started at childhood.  That is completely excessive though. I have no desire to operate at the “grandmaster level” of thinking. Collegiate level perhaps.

At slightly less obsessive levels, Cal Newport has argued that one should focus tightly on exceeding at one skill at a time, rather than diluting one’s focus. An interesting example is provided by an analysis of the skills of comedian Steve Martin:

“But when you study people like Martin, who really do live remarkable lives, you almost always encounter stretches of years and years dedicated to honing craft.”

Somewhat depressing. I do not have a passion or dedication for any particular craft. On the other hand: neither do I desire to lead a “remarkable life”. Feeding my family, being an passable father and husband, and dying more or less content is enough. But for me a content death requires some intellectual stimulation, which I think requires skill. And even a minimal level of skill does not come easily.

In addition, my idea of fun intellectual stimulation is not exactly shared by normal society. Apparently, I would bore a Vulcan. But a commentary by Cory Doctorow on the concept of “too much time on his hands” warms my heart:

“‘That guy has too much spare time’ is one of the most odious, intellectually dishonest, dismissive things a person can say. It disguises a vicious ad-hominem attack as a lighthearted verbal shrug…..  [T]he slur brooks no possibility that the speaker has failed to appreciate some valuable, fulfilling element of the subject’s hobby.”

I love the attitude. An Asperger-like stubbornness to do what you do and ignore the ridicule is something that I admire and respect very much. Genuinely. But I do not have such a clear-cut hobby. (Nor do I exactly have very much time on my hands).  Coming closer to home, John D. Cook writes optimistically of the concept jack of all trades and a master of none.

“Calling someone a jack of all trades could be a way of saying that you don’t have a mental category to hold what they do.”

The negative connotations might come from the fact that some seemingly unfocused people have skills that are simply not recognized. This is potentially reassuring. In a similar vein, Venkatesh Rao writes on the  “calculus of grit”. A crucial passage:

“So what does the inside view of grit look like?…. It simply feels like mindful learning across a series of increasingly demanding episodes that build on the same strengths.“

I would like to take some comfort from this. My career interests seem to have no coherent pattern at all (space plasmas; memory optimization; temperature sensors; lightning detection; other stuff). But in fact there is a unifying theme. Any problem, literally any problem, can be attacked by the basic tools given by a scientific training — but with a catch.  A perfect metaphor for half my thinking is the study on the fastest lane in the supermarket by Dan Mayer. The following line resonates:

“This problem has obsessed me for years. It’s my DaVinci code. It’s my love for math, for mathematical reasoning, for the relentless deconstruction of something that seems simply intuitive into data, models, and computation.”

I love the quote, but it is only half the truth.  Meaningful real-world phenomena cannot be reduced to simple mathematical/scientific models. You can always prune down the problem until it can be modeled. But at some point the model is too simple to describe the original problem statement. To me, only half the work is done when the math is done. The other half is to evaluate whether the solution actually has any relevance to the problem. As often as not, it does not, and then it is back to the drawing board.

Perhaps that is what makes Zygomatica a meaningful exercise. Using rational methods to skeletonize a seemingly intractable problem into a scientifically solvable one; trying to solve the problem; and then relentlessly and ruthlessly deconstructing whether the solution has any real-life meaning whatsoever. That is actually a skill set that is not taught at university. This is a mindset that I have applied to problem after problem, project after project, year after year. And that plodding is just perhaps what separates Zygomatica from being a mere exercise in dilettantism.

I may be overoptimistic and covering for an inner insecurity. On the other hand, this is where an Asperger-like attitude comes in handy: I really do not care if this sounds ridiculous. It is my thing. And the Zygomatica thing.

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