Monday, December 19, 2011

Regenerating self-signed Dovecot and Exim SSL certificates in Debian

I run my own mail server, including STMP (exim4) and IMAP (dovecot). Connections to both of these are encrypted with SSL; however, I’m too lazy and cheap to buy a real certificate. Instead, I self-sign and pay attention to the fingerprint when approving the connection on the client end.

The problem is that these certificates expire. And, they don’t do it very often, so I forget how to generate new ones, and for some reason my google-fu is severely lacking in this area. So, here’s notes on how to regenerate Exim and Dovecot self-signed certificates on Debian, for future me and perhaps you too.

(The above notwithstanding, lately has emerged as a good resource for these and many other programs. That’s where much of the below came from.)

Anyway, first off, it’s not always obvious which certificate has expired. You can find out with:
$ openssl x509 -in /etc/exim4/exim.crt -text -noout | less
$ openssl x509 -in /etc/ssl/certs/dovecot.pem -text -noout | less
To regenerate for exim:
$ cd /usr/share/doc/exim4-base/examples ./exim-gencert --force
$ /etc/init.d/exim4 restart
$ openssl x509 -in /etc/exim4/exim.crt -fingerprint -sha1 -noout
That last line will print the SHA1 fingerprint of the new certificate, which you can (and should) verify when connecting with your e-mail client, to make sure there’s no man-in-the-middle happening. (With a “real” certificate, the CA chain and your domain name verifies this, IIRC.)

On to dovecot:
$ rm /etc/ssl/certs/dovecot.pem
$ rm /etc/ssl/private/dovecot.pem
$ dpkg-reconfigure dovecot-common
$ openssl x509 -in /etc/ssl/certs/dovecot.pem -fingerprint -sha1 -noout

Saturday, December 17, 2011

Golf course hike

Went on a brief walk this afternoon with Erin and Melissa, along the Walnut Rim Trail near the golf course. This is the trail which is at risk due to golf course expansion plans.

The above is pretty sad: this is all that’s left of the Golf Course Pool, where I spent a large fraction of my childhood.

Snowy Jemez Mountains. Supposedly we have more snow in the works for early next week.

All of these trees would be cut down under some of the golf course expansion options.

Sunday, December 11, 2011

Should we cut down mature ponderosa forest to accommodate a golf course expansion?

Some of the latest drama here in Los Alamos is a proposed golf course improvement/expansion project which involves cutting down a significant amount of forest in North Community (both north and south of Diamond Drive, depending on the option). As you might guess, I don’t think this is a good idea. I’m in favor of golf course improvement (they really need it), but not at the expense of our internal community forests, especially after two major fires.

On December 8, there was a big public meeting at Fuller Lodge; about 150 people showed up. There was a lot of passion, but a very respectful and community-minded tone for the most part (with the exception of a group of golfers sitting behind us). The Monitor had a moderately good writeup and a few letters to the editor (1 2 3) (all behind a paywall, unfortunately). The county also has a fair amount of background information, with the usual level of bureaucratic disorganization. There are other blog posts appearing (1 2 3), and the Los Alamos Trails Facebook group is pretty stirred up.

If you want to weigh in, the county is listening. Please write to the Capital Projects and Improvements Department at or to the Parks & Recreation Board at It’s unclear to me which is preferable, so I wrote to both.

Please also don’t hesitate to get in touch with me if you want to talk more about this or swap ideas and strategy.

My letter to the county is below.

Dear Mr. Walker, Mr. Aragon, and members of the Parks & Recreation Board and Capital Projects and Facilities Department:

Thank you for the opportunity to comment on the Golf Course Improvement Study. I attended (and spoke at) the public meeting on December 8 and found it extremely valuable, particularly in understanding the perspective of the golf course community. I was persuaded that the golf course indeed needs work, and that a quality golf course is in the best interests of both forest users and golfers. However, I still have significant concerns about the project, which I detail below.

For context, I grew up on Woodland Road and recently returned to town to pursue my career. I now live in Western Area. When I was little, I spend a great deal of time in the woods within and close to town, particularly between Woodland Road and the golf course. Much of this time was unsupervised, something uniquely possible in Los Alamos, with its well-bounded interior forests. As a returning adult, I am spending time in the county forests at least once a week; when it’s lighter in the evenings, I expect to spend more. I am expecting my first child in May and hope to be able to provide him or her with the same extraordinary and unique outdoor experiences I was lucky enough to have when I was young.

I have never played a round of golf and expect never to do so. This does not mean I am anti-golf; rather, I am simply indifferent to it. However, I do believe strongly in community and realize that a viable community has diverse interests. Thus, it is important to me as a community member to support the interests of local golfers, to the extent that they do not threaten my own, and in this specific case, it is important to me to reach some kind of agreement which satisfies both golfers and forest users. I am happy to put in significant work towards this goal (e.g., by serving on a working group).

My concerns about the project fall into three basic categories: the removal of trees, the expectation that an improved course can really be a regional draw, and the validity of the safety concerns expressed by the golf course.

Removal of trees

First, I believe the framing of the impacts is incorrect. The central issue is not trails, but rather their context: the forest. Neither matching nor increasing the trail mileage is sufficient; it is the impact on forest that should be considered. Trails are simply a means to access the forest.

Most importantly, I stand by my opinion that the goal of the project should be zero trees removed. This is not an extreme position. Our forest is particularly precious after two major wildfires in the past decade, once of which had severe effects within North Community itself. Should we not think long and hard before reducing what little we have left? The forest and its trees are a core asset for the people and wildlife that use them, and it is perfectly reasonable for us to ask that they be left alone.

I worry too about the erosive precedent we would set by removing trees: a few trees here, a few trees there, and pretty soon we’ll have nothing left. Many mountain communities have followed this unfortunate path. Let’s not become one of them.

Allow me to make an analogy. Suppose that instead of trees, the golf course were surrounded by boulders and cliffs – features prohibitively expensive to remove. Would the golf course simply throw up its hands and give up on improvements? Of course not. The course’s planners would get creative and produce a great solution within the constraints. My point is this: the cost of removing trees is in fact prohibitively expensive. It is just that the expense cannot be measured in dollars. And thus, I ask the community to work towards creative solutions which respect the magnitude of this expense.

Similarly, project planners must not hide this expense. When presenting options, planners must quote clearly (a) acres of forest to be removed and (b) number of mature ponderosas to be removed. If the golf course is going to ask forest users to give up part of the forest, it has a duty to be explicit about the impact.

I also note that the golf course invoked the notion of sustainability several times. I found this frustrating – does not sustainability include preserving our rapidly disappearing natural heritage? It is impossible to plant mature ponderosas; a “sustainable” new course does not make up for lost trees.

I believe strongly that the golf course has not made its case for removal of trees. The way to make this case is to show first that zero-tree options have been creatively and exhaustively explored, and then make a persuasive case that such options really are unworkable. Currently, it is clear that improvement within existing boundaries (currently Option C) was not explored anywhere near as thoroughly as the expansion options. The golf course must do so in order to credibly ask for tree removal.

Can an improved course really be a regional draw?

I sympathize with the golf course’s desire to become a regionally known course that draws golfers from beyond our community. However, I’m not yet convinced this is a realistic goal. In particular, I note that anyone coming up to Los Alamos to play golf must drive past courses in the valley which golfers in the meeting acknowledged as excellent. Thus, if the course were to become a regional draw, it would need to not only match neighboring courses in quality but exceed them sufficiently to justify another half hour of driving. As I mentioned, I’m not a golfer, but that seems like a tall order to me.

In particular, I am concerned that factors beyond course condition have a significant effect on the course’s ability to become a regional draw. I believe the golf course has a responsibility to quantify the degree to which course condition has hurt the course as well as the degree to which improving it would help. What data support the theory that improving the course will lead to increased interest (and accompanying player numbers)? How much of the cited play decline, and the expected play increase, are due to course condition as opposed to other factors, including construction and improvement of nearby courses, change in popularity of golf in general, and the economic downturn? How much does the additional driving beyond competing courses matter to players?

In other words, why should the golf course attempt to become a regional draw rather than an excellent community course? My point here is that the golf course must be improved under realistic assumptions and toward realistic goals. The golf course must make a credible case, backed by data, that becoming a regional draw is in fact plausible and likely under the proposed changes, before asking the community to endorse steps towards that goal.

Safety concerns expressed by the golf course

While I certainly agree that safety is an important consideration in most things, I do not believe the golf course has adequately made its case that meaningful safety problems exist and that the proposed improvements would mitigate them. At the meeting, evidence supporting the existence of a safety problem was limited to course standards and anecdotes (and especially in this town, the plural of anecdote is not data). No evidence at all was presented supporting the implicit claim that the course is meaningfully worse off than similar courses. (While the golf course showed that it did not meet current design standards, that is not the same thing.)

The golf course must present data showing (a) that a safety problem exists, and the specific nature of that problem, (b) that these problems are significantly worse than similar courses, and (c) that the proposed improvements sufficiently mitigate the problem. Additionally, the similar courses must be selected appropriately; new courses constructed to the most modern standards would not qualify. In these analyses, the golf course must be clear about who in particular is benefitting from improved safety, and to what degree. Golfers? Motorists on Diamond Drive? Hikers in the forest? In particular, simple signage could go along way towards improving hiker safety (if indeed there is a problem).

At this point, I worry that the golf course is simply “playing the safety card” in order to get what it wants. Being more specific and quantitative about the issue will allay this concern.

Moving forward

I do believe, based on the respectful and community-minded tone of the meeting as well as my own goals, that an agreement can be reached which would satisfy both sides. I also agree with Mr. Walker that a proposal that does not enjoy broad support would probably be unsuccessful (certainly, I would vigorously oppose a proposal which I believed did not adequately take into account the interests of forest users).

I also believe that keeping this constructive tone is important. While in general I do not see any problems emerging in this area, one that concerns me is vocabulary. The county is calling the plan an “improvement”, but several of the options include increasing the size of the golf course, which clearly meets the definition of “expansion”. (In particular, I was frustrated and worried when Mr. Stupka stood up at the end of the meeting and asserted repeatedly that the golf course was not seeking to expand. Denying the meaning of common words is an important ingredient in the collapse of good will and common purpose. I hope that the golf community will not continue down this path.) I suggest renaming the project to “Golf Course Improvement and/or Expansion Project”, in order to reflect the fact that some of the options involve expansion.

Along those lines, I’m interested in serving on a working group to hash out an agreement. It seems to me that having stakeholders sit down, get to know one another, and work out disagreements at length is a fruitful strategy that would lead to a solid agreement supported by both sides. (It is not clear to me that the current process really involves the two sides working together.) I’m sure it’s obvious that that I am firmly on the side of the forest, which I believe makes me an excellent candidate for a working group – if I’m satisfied, then there is a good chance that most forest people will be satisfied.

Again, thank you for the opportunity to comment, and I would love an opportunity to participate more deeply in this process. Please do not hesitate to contact me if you have any questions.

[my full name, address, phone number]

Sunday, December 4, 2011

A few Los Alamos hikes

Erin and I went on a few short hikes around town this weekend: a little bit of Hidden Canyon Trail off Trinity, East Fork Trail near the golf course, and Kwage Trail behind the stables on North Mesa.

Pajarito Mountain from pretty much someone’s back yard, near Hidden Canyon.

Not actually East Fork Trail – we got lost. The tracks lead to someone’s back gate.

Just below the stairs on East Fork Trail.
Also just below the stairs on East Fork Trail.

Kwage Trail on North Mesa. The mountain on the right is Caballo.

The end of Kwage Trail, overlooking the new old sewage treatment plant.
Barranca Mesa from the Kwage Trail.

Saturday, November 26, 2011

On the causes of the Cerro Grande fire

I read a very interesting book on the Cerro Grande fire, a prescribed fire that got out of hand and torched the homes of over 400 Los Alamos families in the spring of 2000. I was in college at the time. The book is: Inferno by Committee: A History of the Cerro Grande (Los Alamos) Fire, America’s Worst Prescribed Fire Disaster.

It was a really interesting read, albeit somewhat infuriating at times. The following is the book’s interpretation of events, which I found quite persuasive.

The central question: “What caused the Cerro Grande fire?”

Notably, the question “what started the Cerro Grande fire?” is of pretty much no consequence. It is true that the Park Service made some mistakes with the prescribed fire, and the Forest Service exacerbated these mistakes, leading to Cerro Grande escaping control. But this is essentially irrelevent – what we really care about is: “Why was the the fire so destructive, and why were so many homes lost?”

A big fire in Los Alamos was inevitable, and it was only bad luck that it was a prescribed burn that started it. (The Dome Fire of 1996 very nearly came into town in essentially the same way that Cerro Grande did, and the Las Conchas fire of this year would probably have come into town if not for the fuel removal by Cerro Grande.)

The official investigations focused almost exclusively on why the fire started, rather than the bigger picture. In particular, a hasty and incompetent witch hunt that released its “findings” only a week after the fire passed through town (while it was in fact still burning in other locations) defined the popular understanding of the fire’s causes with falsehoods that still form the conventional wisdom today.

Anyway, the answers are:

The fire was so destructive because the fuel load in the forests surrounding Los Alamos was far in excess of what is healthy for a dry, Southwestern ponderosa pine forest. A healthy ponderosa forest has remarkably few trees, just a few dozen per acre, with grassy meadows beneath the trees, and it burns at a low intensity every 10-15 years.

Instead, a policy of overgrazing, logging, and fire suppression left the forests with up to tens of thousands of trees per acre and a thick layer of dropped pine needles on the ground – a huge quantity of fuel just waiting for a fire and some wind. And the Forest Service was largely uninterested in forest health and fire preparation, preferring to focus on resource extraction (mostly logging) that actually lost money for the U.S. government.

So many homes were lost because of poor preparation. The wind-driven crown fire largely missed the town; most of the burned homes were ignited by either ground fire or embers falling from the sky, which are relatively straightforward to prepare for.

Residents generally failed to prepare in the years before the fire: for example, they did not keep vegetation away from buildings, remove pine needle accumulation from yards, or install fire-resistant roofing. Further, and inexplicably, firefighters failed to bulldoze a fire break around the west side of town when they had the opportunity – during two days of calm weather, the fire paused on the south side of Los Alamos Canyon, and bulldozers were in town and ready to go during those two days.

Either or both of these actions could have saved the bulk of the homes that were lost. The would have reduced the number of structure fires in town, and that would have freed firefighting resources to deal with more effectively with the structure fires that did start.

Friday, November 25, 2011

Salida train tracks

I’m visiting my sister in Salida, Colorado this weekend.

Monday, November 21, 2011

Natural Arch hike

Erin and I walked up to Natural Arch on Sunday. This was one of my favorite walks when I was a little kid. Of course, it’s not a forest hike anymore; very little of the walk seemed familiar.

The big views are fun, but I do miss the woods. I suspect it’s greener in the spring and summer – the scrub oak would be green, and supposedly there are a lot of aspen up in the hills.

Saturday, November 12, 2011

Cave of the Winds hike

Erin and I went up to see Cave of the Winds yesterday. This is a small cave (more or less one room perhaps 100 feet long) about a half hour’s walk from our house.

View from near the cave, looking up Los Alamos Canyon towards the ski hill on the horizon. Note missing trees from the Cerro Grande and/or Las Conchas burns.

Erin and me on the canyon rim above the cave.

From the Cave of the Winds trail towards the town site (not visible) and the Truchas Peaks across the valley. The large ponderosas are survivors of Cerro Grande, while the small ones have sprouted since the fire. This area did not burn in the Las Conchas fire.

Sunday, November 6, 2011

Red Dot Trail

We’ve now been in Los Alamos for a couple of days. No stuff yet – we’re camping out with a card table and inflatable bed in our mostly empty house – but so far it’s pretty nice.

For example, we can go on walks like this, down the Red Dot Trail, just a few minutes outside town:

Saturday, November 5, 2011

Big news!

Erin and I are having our first baby, due in mid-May.

If you’d like to follow along, we have a private blog for friend and family – please e-mail me and I’ll add you.

Wednesday, October 19, 2011

Moving to Los Alamos, New Mexico

Erin and I are moving to Los Alamos, New Mexico next week so I can take a postdoc at Los Alamos National Laboratory.

Recruiting brochure published by LANL. Scanned by Colleen Bryant.

It’s an interesting move in a lot of ways. First, the work itself promises to be very exciting. I think it might, and I hope it does, turn into a permanent career (something that I knew IBM never would).

Second, as some of you know, Los Alamos is my hometown. I was born there and lived there until I left for college. I never in a million years expected to come back, even after I became a researcher – who goes back to their boring hometown these days? The lab is for physicists, not HCI people. And besides, I was a city person now.

However, this spring, Erin and I visited Los Alamos and I gave a talk at the lab, because why not, and it might be good networking and/or practice. The talk went quite well. Afterwards, my dad, who also works at the lab, was riding home on the bus (yes, Los Alamos has a bus system now!) with someone who had also been at the talk, and this person asked: is he recruitable?

Later my dad related this to me and asked if the lab was something that I would consider. Not really, I said. But over the next few weeks, Erin and I talked it over periodically, and the idea grew on us. It would be close to family. It was an institution whose legacy I was proud of, filled with smart and friendly people, and where I really could work on saving the world. I could park my bike outside without worrying about it.

So, yes, we decided, I was in fact recruitable. My dad gave me some names, and I wrote a bunch of emails and talked to lots of people on the phone; this turned into an interview visit and that turned into an offer. And now the movers will be here in a week.

Boys from the Los Alamos Ranch School on a pack trip. From Los Alamos Historical Society.

I’m confident that we’ll be happy in Los Alamos. It will take a little more getting used to for Erin, since she doesn’t have 18 years of history there to build on (for example, I am told I’m not allowed to give directions according to what used to be there). And I think for a while things will be rather strange, since all my memories are through the eyes of a child. Net, however, it’s a very positive move and a tremendous opportunity for us. I’m extremely thankful that we are fortunate enough to be able to do it.

Finally, Los Alamos and northern New Mexico are a wonderful place to visit! We hope you will do so and would love to have you.*

*Assuming we know you. If not, accomplishing that is a suggested first step.

Sunday, October 9, 2011

Sunny, open-plan Cambridge condo for rent, hardwood floors, $2500, available Nov. 1

We’re moving and need to re-rent our 2 bedroom, 2 bath condo on Fayerweather St. in Huron Village (map). It’s available November 1.

It’s really a very nice place to live. The apartment is quite close to things (Porter Square 15 minutes on foot; Harvard Square 20 minutes on foot or less by bus; Whole Foods and Fresh Pond Mall 15 minutes; library, hardware store, coffee shop, bakery, restaurants, and other businesses within a few blocks; largest park in Cambridge one block away) and in a pleasant neighborhood with lots of trees.

The apartment itself is great. It’s a 2003 renovation, so the appliances are new and there are plenty of outlets and whatnot. Washer/dryer in the unit, dishwasher, hardwood floors, granite countertops, central air. Master suite has a private bath. Private balcony and shared yard. It’s open plan and very sunny, with big south facing windows.

Rent is $2500; it’s a fee apartment, but the fee is half off. Happy to answer any questions; please e-mail me at To set up a showing, contact our realtor, Andrea, at 617-953-5378.

Bottom line, it’s a wonderful place to live and we’re very happy here. If we weren’t moving out of town for work, we’d want to stay for a long time.

More photos:

Sunday, September 18, 2011

Fresh Pond, and mobile blogging

I do enjoy this (albeit cliched) sunset from the dog pond at Fresh Pond last night, but this post is mostly an experiment to see how well blogging from my phone works. Comments welcome!

Thursday, September 8, 2011

Old boots, new boots

Above are my two pairs of hiking boots. The one on the left has been resoled once and desperately needs it a second time. The insoles are falling apart. It has large cracks in the leather. The double seams in the heel are blowing out. The pair on the right has all the same problems, plus the inner is falling apart (note duct tape) and it’s been resoled at least twice. I believe the two pairs are 10 and 11 years old, respectively.

So, time for some new boots.

Fortunately, my dad had found a pair of nice all-leather boots at a rummage sale, nearly new and extremely cheap. Unfortunately, they were just a tiny bit too small, despite being nominally half a size bigger than the boots above. (I am passing them on to another local hiker.)

I agonized for several days about whether to buy another pair of Sundowners or try something new. Laziness won out. I do like the Sundowners a lot. REI doesn’t carry them any more, but Zappos does. Hopefully they will last another decade!

Below is an old boot on one foot and a new one on the other:

Wednesday, August 31, 2011

Greater Boston has a signage problem

Quick, what the hell does this traffic sign mean?

One of the infrastructure things greater Boston totally does not get right is street signs. For example, you might think, given the fact that the street network is an insane tangle left over from a variety of historical baggage, good street-name signs might be a priority. They are not. Such signs are frequently missing, hidden, and/or oriented incorrectly.

Anyway, the above sign marks a street where the top layer(s) of asphalt have not yet been laid down, but the manhole frames (which are of cast metal, I assume) have been installed. Since said frames are level with the complete street, on the incomplete street they stick up a few inches. I assume “castings” is a jargon term. It is a bit depressing that whoever approved these signs did not empathize with the average driver before doing so.

Monday, August 29, 2011

Post Irene

Last night around 6:30 the storm seemed to have pretty much wound down, so I went out for a walk around Fresh Pond.

Blossom in the street.

This tree had broken off. It has apparently blocked the road and been dragged out of the way already.

There were quite a lot of sticks and leaves strewn around the neighborhood.

This large tree was down across the path around Fresh Pond. (Note that the greenery in the background is standing, undamaged trees.)

After returning home, I paid less attention to the storm, which still gusted occasionally, and went about my business until it was time for bed. I looked out the windows (as I often do before bed) to discover this:

Fortunately, the car was undamaged. However, it seems my assumption that the storm was more or less over was incorrect – I'm pretty certain I would have noticed this when I returned from my walk about 8pm.

In the morning, there was a lot more tree damage in the neighborhood than I expected based on my observations of the storm. Perhaps we have wimpy trees around here? I've been in some pretty memorable windstorms while camping, and it sure didn't seem that Irene was as windy.

Street blocked off with some power lines down.

Another mess in the road.

Sunday, August 28, 2011

Irene Interim Report

So far, Irene is pretty much a non-event in my neighborhood. Currently, winds at ground level are breezy, and often calm. At treetop level, my (inexperienced) guess is that the steady wind is Beaufort force 5 (18-24mph) with gusts of force 7 or 8 (31-46mph). This is significantly less than was expected now, though it's supposed to continue building until 5 or 6pm. The rain has stopped (it was never heavy after I got up today) and radar suggests there won't be much, if any, more. I've opened some windows because it is stuffy and humid in the house (88% according to our thermostat).

Things seemed pretty safe outside, so I went out to poke around.

The most “serious” damage I saw, around the corner from our house. The broken branch is touching some power lines, so there'll be some attention needed on that. (The car is undamaged, and it had been moved by the time I came by again on my return.)

I did not know there was an apple tree in the park.

Berries down!

Another big branch down in the park.