Narrow fact-checking is less than useless

Last night, Donald Trump gave a speech that included a bunch of statements about crime that the New York Times fact-checked for us. This summarizes what they found:

Many of Mr. Trump’s facts appear to be true, though the Republican presidential nominee sometimes failed to offer the entire story, or provide all of the context that might help to explain his numbers.

Putting aside the ridiculously low bar of “many facts appear to be true”, they failed to mention or explain that in every case, despite his factoids being narrowly true, the conclusions he was drawing from them, and suggesting we draw from them, were absolutely, incontrovertibly false.

This kind of reporting drives me bonkers. Crime stats, like all stats, are noisy, and from one year to another, in a specific city, you can find an increase or decrease — whatever you are looking for. But the overall trends are clear, and Trump’s assessment was utter bullshit.

Another, somewhat less savory, media outlet did a much better job, because they took the 10 minutes of Googling necessary to assemble some charts and put Trump’s facts in context.

Would it have been partisan for the NYT to put Trump’s facts into context with respect to the conclusions he was drawing from them? It just seems like journalism.

 

Nerding while sweating

I was slowly cranking my way of Claremont Avenue the other day on my trusty Bianchi when I started wondering why I was so slow. Well, that was easy. I’m pretty heavy and I’m somewhat out of shape. But which is more important, which would have a bigger impact if improved?

First, I used a website like this one to determine the average grade over a certain familiar portion of the route. In this case, it was 13.3%. I also have a speedometer on my bike that tells that I average about 5 mph over that stretch. Finally, I weigh about 100 kg, and my bike is another 10 kg.

So, given that the energy to raise a mass up h height is m*g*h, the power to raise a mass at r rate is m*g*r.

Result:

claremont_power: 317.67222 (watts)

That is, that’s how much power it takes to lift my mass up a hill at that rate. Note the trig to change my speed up the hill to a vertical speed. There are losses in pedaling a bike, and on the tires on the road, etc, but this is a good estimate of the overall order of how much power I can comfortably sustain. Let’s call it 300W.

Now, another thing I’ve noticed while riding is that on flat ground, I can maintain about 17 mph. In that case, I’m not adding power to climb a hill at all, all of my power is overcoming road friction and drag.

It happens that power going to aerodynamic drag goes by the cube of the velocity. (There is more going on here than wind drag, but, eh, it probably dominates at higher speeds…) So, if we assume that on level ground I’m capable of the same ~300W that I do while climbing, I can calculate the constant in:

P = c * v^3

This is a simplification of the more general equation linked above, assuming constant air density, yadda. For 17 mph and 317 W, I get about 0.72376 kg / m. kg/m is a strange dimension, but it it what it is.

So then, I wondered, how fast should I be able to go with a given power budget while climbing different grades?

I created this equation which combines the power to climb and the power to overcome drag

P = c v^3 + m g v sin(theta)

where P  is power, c  is the drag power constant calculated above, m  is mass, g  is the acceleration of gravity, and theta is the angle of the hill. (The angle is the arctangent of the grade, by the way.) Oh, and v  is my speed.

It turns out that my brain doesn’t perform the way it once did and I can’t solve that cubic equation on my own, so I resorted to a Python-based solver which is part of the sympy package.

This function gets the job done:

Note this equation has three solutions, two of which are complex. Only interested in the “real” solution.

Now, this is finally where the fun starts. Want to know how fast I can climb different grades, or how actual athletes who can summon more power than me can get up?

How fast I might get up hills if I could make more power.
How fast I might get up hills if I could make more power. (mass = 110 kg)

Like I said, I can make about 300W, but I saw a youtube video of a dude who could make about 1kW, at least for long enough to make toast.

Then I was wonder, would losing weight help much? It does. Interestingly, it helps on the middle grades. On the highest grades, I’m nearly stopped, and the numbers get small. On flat grades, drag (a function of my shape, not my size) dominates. But in the middle, yeah, there’s an effect.

Dave might go faster if we was less fat.
Dave might go faster if we were less fat.

So there you have it. If I lost 10 kg and could increase my power output by 15% I could go from about 5 mph on Claremont to about 6 mph.

Actually, that’s depressing.

What is the “Middle Class?”

On the radio today, All Things Considered did a little “Brief History of the Middle Class.” Apparently, according to Pew Research center, a family is in the middle class if its income is between about $47k/yr and $141k/yr. They also have breakdowns of wealth (if you are in net debt, you are not middle class) and consumption.

 

My own definition middle class has more to do with economic security than it does with wealth, income, or many types of consumption. To wit:

If you do not need to worry about food, housing, transportation, health care, education for your children, and safety, and can look forward to a retirement with those same basic needs satisfied, and you are not at risk of losing any of those things immediately on some negative shock, like an accident, negative diagnosis, or loss of job, then you have achieved middle class status. My definition doesn’t have anything to do with iDevices, high speed Internet, vacation or dining out.

It’s tricky, because I think a lot of people who do have nice things, like fancy cars, and big houses, don’t actually have solid economic security. I don’t know if they’re middle class or not.

What do you think the definition of middle class should be?

technological progress, freedom to v. freedom from

Technology progresses. Most of the time, progress is good, sometimes bad, but in all times it creates new circumstances, and those circumstances have winners and losers. Our society is not good at recognizing when circumstances have changed. We tend to take, for a long time at least, the world-as-it-is as the world-as-it-ought-to-be.

But I see no reason it must be so. I wish we were better at evaluating our reality, deciding if we like it or want something else, and then, coming to consensus on what, if anything, should be done at a policy level to control our circumstances.

 

For example, remote control airplanes have been around for quite some time. They were rather expensive toys, and not easy to fly. Similarly, aerial photography has existed almost since the dawn of flight. Because paying a pilot of fly over some location for you and photograph it is not cheap, it tends to be done where value of the resulting photograh is high enough to justify the expense.

For whatever reasons, we were pretty much OK with that status quo and the laws surrounding it. For example, yes, someone could photograph you through your window, and a passing plane could catch you sunning in your yard. People do not like those thigns, but it was hard enough to do and easy enough to stop, that basically, everyone but celebs and paparazzi seemed fine with the world as it was.

Enter inexpensive, simple aerial photograph with UAVs. Today, anybody with a few hundred bucks can get aerial imagery, and in a few years, that might be $10’s or even $1’s. Whole new possibilities for surveillance open up and people are suddenly uncomfortable about their vulnerability.

Does this mean we need laws to stop aerial surveillance “abuse?” Or maybe we need to adjust our expectations of privacy? I dunno. We need to evaluate the situation anew, since technology has changed circumstances. The fact that the existing laws were fine does not mean they are fine.

Totally rad UAVI can think of lots of contemporary examples of this sort of change: facial recognition along with ubiquitous video cameras make it possible to track everyone, everywhere they show their faces. License plate reader technology allows someone to track everywhere you go. You could do the same before, with detectives or private eyes, but now it can be done in bulk, cheaply. Cookies on websites allow someone to track most of what you look like on the Internet. In essence, people’s expectation of privacy was actually the complex combination of the state of technology and the law together, not either separate from the other.

None of these technologies are sinister in and of themselves, but dropped into a an environment that was in legal equilibrium without them, I think we should expect that equilibrium to shift.

Zoom!Of course, there are historical examples of such adjustments. Prior to the ubiquity of the automobile, people did not need carriage licenses, nor did they need to carry liability insurance for carriage accidents. How long after cars became popular did we realize they were dangerous enough and important enough that we should require that drivers get training? I think most (though not all) people today regard drivers’ licenses as a good idea. A few decades after that, we started requiring drivers to carry liability insurance and today most states have some requirement, though it is amazingly low in some places. (I know that agreement is hardly universal that liability requirements are a good idea, but we have them.)

One contemporary problem that is not typically considered in this light is gun violence. One might say that extremely capable weapons have been available for a long time, but that they have been expensive enough and just tricky enough to obtain, that we, as a society, were comfortable with the status quo. Collectors and sportspeople had them, and they used them safely, more or less. Enter cheap, easily available weapons, and all of a sudden the game has changed. In fact, today you can 3D print a gun at home, and maybe in a few years you’ll be able to 3D print a most of a not-too-shabby automatic weapon. The technology is not going to go away, but because of the technology change, the status quo is going to shift. Can or should we try to shift it back?

 

My point is that I think there are many  people who advocate for a kind of technological determinism, suggesting, “well, tech marches on.” But history tells us that we clearly do not have to accept such outcomes if we don’t want them.

Freedom-loving readers will notice a whole lot of “we’s” in this essay. I’m afraid they’re right. I’m suggesting that the group sometimes make decisions that restrict an individual’s freedoms. I know there is a cost to that. But I also see costs in letting individuals restrict the freedom (and well-being) of many other individuals.

As always, practicality and balance will be hard to achieve. We all seem fine with driver’s licensure, but pet grooming licenses seem perhaps too far. Required liability coverage for drivers is OK, but we probably would not tolerate such a requirement for many other potentially dangerous-to-others activities.

I hope we will have spirited, informed debates on issues like privacy and autonomy and that the outcome, if not new norms and laws, are new, explicit reiterations of existing norms that were previously implicit.