Sore.

The Boy and I went backpacking this weekend. Awesome. It was a 10 mile loop with a back country campsite at the half way point. I forgot to take a camera, so the only photos I took were with my cell phone camera. I'll put up a picture of the boy fully loaded once I get it off my camera.

I rented a kids backpack at REI that was so close to small enough for The Boy. I thought about buying it, but figured we should rent it first and see how it went. I'm glad I rented first. He is so skinny that it was really tough to get it to sit properly on his hips. As a result, we were constantly tweaking the adjustments trying to move the load onto his legs, and not his shoulders/back. Plus the padding at the back of the hip belt didn't work right on his short torso. The stay sort of dug into his bum, and really started to bother him after about three miles on the hike back. He needs to grow a bit (maybe an 1" in his torso and 2" around the waist) before this pack will fit him properly. If anybody knows of a rucksack with a proper hip belt that can fit a small child (11.5" torso), let me know.

His pack was 10 lbs. My pack was about 35 lbs. So by pack/body weight ratio, he worked harder than I did by just a bit. We both made it all the way. Go us. The weather couldn't have been better. It was spectacularly dark (no moon), and cool enough to sleep comfortably at night. The tent was really roomy with just the two of us.

So, now we are both home, and my legs are sore. I was surprised at how much effort it took.

In other news, my two week trip to Switzerland/England went well. Going back to Sheffield was a bit strange. Kind of like that feeling you get when you would go home after being at college all year. Sort of a "yeah, this is my other home" feeling. I closed my UK bank account. I think that was my last solid tie of residency. I did some walking in The Peaks and bouldering at The Climbing Works. The Climbing Works rocks, and I wish it were in St. Louis.

Circle Puzzle Answers

This puzzle ended up being much more popular that I anticipated. Aside from the comments on the blog, some coworkers and other friends that don't post got into it. The name of the puzzle is Bertrand's Paradox.

rpc did some of the math wrong, but did point out another solution. If you randomly pick the cord and then orient the circle so that the cord is vertical, then all cords between x=-1/2 and x=1/2 are longer then sqrt(3). Therefor, the probability is 1/2.

The third classic answer is that the midpoint of the cord uniquely defines the cord. So, we randomly pick a point inside the circle and construct a cord so that that point is the midpoint of that cord. Now, any point we pick inside the circle of radius 1/2 is longer than sqrt(3), and outside is shorter. Comparing the inside area of the circle to the area of the whole circle gives a probability of 1/4.

Now rpc did the most work on this, and some of his ideas were on track to a cool outcome. He and I did some discussions at climbing on Tuesday, and he cleaned up the reasoning so that we can now cover all probabilities on the interval (0,1). It's not [0,1], just (0,1) because I wouldn't let him do constructions at infinity. I've modified it a bit from what rpc came up with. He used two constructions to cover (0,1/2) and (1/2,1), and then we filled in 1/2 with the previously mentioned case. I figured out a way to do a single construction to cover (0,1).

Start with the vertical line at x=-1. Pick a point at (n,0) where n>1 (but finite). Draw a line tangent to the circle from (n,0) to (-1,y); y>0. Randomly pick a cord, and then orient the circle so that one end of the cord lies at the point (-1,0) and the other point is oriented so that its y coordinate is positive. Now create a 1-to-1 and onto mapping (bijective) of every cord to a point on the tangent line (n,0);(-1,y) via the cord's projection. Because it is bijective, it is equivalent to randomly pick a point on the tangent line and look at the probability that the associated cord is longer than sqrt(3).

If n is very close to 1, then y is very large, and most points on the tangent line are associated with cords of length less than sqrt(3). If n is very large, the y is very nearly 1, and most of the cords will have length more than sqrt(3). Given any probability desired over the inteval (0,1), a tangent line can be constructed that gives a bijective map with that probability.

It is not an ill defined problem. The problem is that there are an uncountably infinite number of cords on the circle. I can create an uncoutnably infinite set of mappings of cords to the interval [0,1] such that I can get the probability to be whatever I want.

I don't let n be equal to 1 or infinity, because then I can't map the cords to the inteval [0,1], which seems necessary to get any sense of the problem (which fraction of the interval maps cords of length more than sqrt(3)). But since n>1, and n is finite, I get the full range of probabilities from (0,1).

Super duper extra credit to rpc for inspiring this solution.

A Probability Puzzle

I had my first day of classes towards my D.Sc in Systems Science and Mathematics. I'm taking "Probability and stochasitc processes". Just to convince us that the idea of "probability" is not trivial (and also that this class could very well kick our collective asses), the professor posed this problem. Super bonus points to any one that can give the complete answer (without cheating on Google).

Start with the unit circle. Randomly select a cord, AB. What is the probability that the length of the cord is greater than sqrt(3)?

If you are brave post your answer in the comments. Extra credit for showing your work. I don't think anybody in the class really "got" the answer. Or at least all of it. I got one part of it, probably the easiest part.

New Post

Is anybody checking this?

It's been a while since my last post, and lots has happened. I don't even know where to start.

1) I bought a new grill this weekend. I haven't consummated the relationship yet, but plan to Wednesday. I got the Jenn-Air that Consumer Reports liked (#4), is pretty stainless (3oo series!), and was massively discounted at Lowe's for end of season clearance. Yeah!

2) I've been struggling with the lawn this year. Today I went out to the front yard and saw that a nest had been formed in a patch that some ants had destroyed. I figured the ants were back, so I went again to destroy the nest. That's when I saw that it wasn't ants. Tiny bunnies that didn't have their eyes open yet. Probably five of them. Amanda convinced me not to destroy them. I'm not sure I really could have. So, the grass will grow long for a week or two while the bunnies get big enough to hop away.

3) I gave a presentation on effective technical communication a couple of weeks ago at a work conference. I won one of the best presentation awards, which bugs me. Some of it is the irony. Mostly its the fact that the judging criteria was 50% technical content, of which I had basically none (not a technical topic). The award was not so much a reflection of how well I did, but how poor the other presentations were.

4) Amanda finally relinquished her old laptop to me. Ubuntu is up and running. A very accommodating OS for the masses. I've had to tweak two things total I think. Not bad for Linux. Right now I'm using the desktop, 'cause I still love a full sized keyboard for any real typing.

5) I just got back from DC. It went great! I think I will be joining the ANSI B5.54 standards committee. Yeah! I might contribute to an industry standard. How's that for geek-cred. Also, I (and another guy) came up with a wicked cool implementation for "optimally" sizing the G and Q matrices in a damped least squares controller. Like LQR, but not iterative. I'm going to see if it is publication worthy.

6) I'm about to start my D.Sc. I have a class picked out for fall, but I still need to register. I also need to go over my proposed curriculum with the department chairman, and see if it will work. It mostly hinges on getting my Master's work to count. I should have my doctorate degree by end of 2012. I think. It's scares the hell out of me.

7) I pulled my shoulder several weeks ago, and it is still not back 100%. This sucks, as it has affected my climbing. I'm totally plateaued at 5.9, and can't seem to get to 5.10. It's too hot to run, so I've tried doing some swimming at the Y. By tried, I mean I've gone once. My conditioning is off and my strength is mediocre because I can't load my shoulder. Frustrating.

That can't possibly be all, but hopefully it gives a clue as to what is going on in my life.

Oh, I bought the Ety's and they rock. I never did go backpacking, but I did take the kids camping and we had a great time. Longs Peak is postponed for a year. Still a goal.

Backpacking

I was planning on going backpacking next weekend. So far two potential camping mates have bailed out on me. Does anybody want to go backpacking? You'll need a backpack and a sleeping bag, but that's about it. Everything else I have. I may take the girl if no one else wants to go. I made a trip to REI today to get the last bit of kit that I would need. I'm itching to go before it gets insanely hot here. The tentative plan is a moderate 5 mile hike in and out. Ten miles total over two days. You barely have to be in shape for that. C'mon, join me in ditching the world. If your up for a longer treck, I'm more than happy to do a 25 mile loop or out-and-back on the Ozark Trail.

My brother in law got me The Orange Box. Portal is of course genius and I'm working on the Bonus maps now and then. However, TF2 is sucking away my free time. Damn him. I suck, but I have loads of fun. I manage to stay alive for about two minutes on average. I tend to average probably just over 1 kill per life, so I guess I'm causing more harm then I'm taking. Right now I'm trying to get better at rocket jumping. I tried being a spy for all of about 30 seconds.

We are switching to AT&T U-verse. From the reviews that I am reading online, I think I'll be happy with the switch. Especially getting better bandwidth. I also signed up for the HD package. Although from what I read, it's a highly compressed lower bandwidth version of HD that isn't as good as other providers. It's $10/month, but if it sucks I can drop it.

Oh Canada!

(OMG, a new post!)

I'm in Canada. Specifically Waterloo, Ontario. I went bouldering tonight at a local gym. I like it that my climbing shoes take up basically no room in my suitcase and most cities have a climbing gym somewhere nearby. Climbers are a friendly bunch, and it's easy to start tackling a problem with one or two others. Even for an introvert like me.

(heh, they just said "aboot" on the radio)

At home I've been busy. Gardening, closets, a mysterious water leak, slab for the grill, trips to Illinois. I like to keep busy, so no complaints by me. What I've been struggling to find in this is solitude. Here and there some alone time, but not solitude. I noticed this on the flight up. The plane was mostly empty. I guess nobody flies to Toronto from St. Louis. So, I was in a row to myself. Headphones in (same Sony ones as before). Reading my new book. And I was relaxed. Really, really relaxed. There was nothing I needed to get done, no external pressure. I could just be solitary on the plane. It was very enjoyable.

The book I picked up is the Presentation Zen book. I'm only a bit into it. I'm reading it slowly and my mind wanders to my own presentations while I read it. I'm probably getting less out of it then someone who doesn't already know Garr Reynolds approach. But still, it's nice to have it all written down in book format. I can recommend (and lend) it to you if you want to really change your presentations to not suck. It's work. It's not a formula or a procedure but a new way to think about the form and function of presentations. It has basically nothing to do with PowerPoint, and everything to do with story and design. Conferences would be much better if everyone really worked on their presentations. I had to sit through a few today. Slideuments so typical and boring that I don't even bother listening since I know I'll get a CD with all the words later and I can pretend to care then.

A few more days with our neighbors-to-the-north. Endless hockey on Sports Center. Lousy food, but very cold beer. Great sunshine. Then back to St. Louis. I'll try to keep writing.

Earphones

I have a pair of ear canal phones. Specifically, I have the Sony MDR-EX71. These are not ordinary ear buds by any stretch of the imagination. They use a silicone seal to isolate the earphone in the ear canal like an ear plug. They sound good, but not perfect. Way better then the stock iPod earbuds.

But what I really like is the sound isolation. With them in and my Nano turned to a normal listening volume (say about 70dB), background noise is gone. Not just diminished, but gone. All that is left is music. The kids could be screaming at each other the very next room over and I wouldn't hear them. The wind could be howling outside and it wouldn't even sound like a breeze. At work I took them out at one point and was surprised to hear a jackhammer going in the car park (construction caries on). Lost in the music without having to crank it to deafening levels. This is, to me, the greatest feature.

Anyway, as I said they sound good, but not yet great. I've looked at more expensive and better reviewed ones, but have restrained myself from dropping a C-note on earphones. Etymotic sells a pair called the 6i. Much higher sound quality (balanced armature instead of coil-based driver, better sound isolation). MSRP of $150 (ouch!). Newegg is currently selling them for $73. I am very tempted.

Cars Suck II

At work, I've just moved into the new building. It's not quite done yet, so there is still a load of construction work being done. And debris in the car park. You know, like screws. Like the screw that punctured my tire (tyre?). Fortunately, I had reason to leave before lunch that day, and discovered the flat. I was able to call the leasing company and they sent out a service to replace the tire.

I got the right part for Amanda's car yesterday also, and went to my coworker's house to get the job done. He used to be a mechanic, so that made life much easier. After removing the fan belt cover, I discovered why the pulley failed in the first place. Whomever had installed the fan belt (probably from the factory) didn't get it over the power steering pump in the right location. As a result, it was putting side load onto the idler pulley. This caused the bearing to fail. If this car had been driven normal mileage during its life this would have been a warranty repair. But, it has always been a city car. It only made it to 40,000 miles after 9 years. Warranty long expired.

After getting the fan belt off, we had to 1) drop the alternator out of the way, 2) take off the bolts holding the casting that the idler and power steering pump were mounted to, 3) use a crow bar to pry it off of the rusted pin holding it in place, and then 4) replace the remnants of the old idler. This was actually easier than it sounds. Especially after we got the crow bar out.

We reassembled the bits together and went to put the new fan belt on. We tried three times before concluding that there is no way this belt fits. We fished it out and compared it to the old belt. Sixty millimeters short. Damn. Put the old belt on, and head home. Two hours.

Today, Amanda called me at work to say the battery had died. It was getting weak anyway, and the weather dropped well below freezing today. I figured that that was the end of the battery. When I got home from work today, I pulled the old battery out (marked as being installed in 2003, so very much due for replacement) , went and got a new battery, and swapped belts. Oh, I also noted that the light stock indicated that the headlights had been left on. :) (update: Amanda pointed out that there was some ambiguity as to who left the lights on. Amanda did.)

Of course nothing with this car has been simple. Not even the battery. Peugeot uses this weird terminal clamp on the positive terminal that is a one time install thing. You can try and pry it off, but it just ends up breaking. So, when you replace the battery you also have to replace this post clamp thing. Stupid French. Because this is after work, I now have to go to the Peugeot dealer tomorrow and get this stupid post clamp. It really is a stupid design. Why not just have a normal bolt on clamp like the rest of the world?

But that is it. The car should give me no more grief over the next few weeks. And in the end, I've spent less than ₤100 on Amanda's car, which is not bad for an el cheapo vehicle meant to get her around for a year. The total inventory on this car comes to:
Remove and replace blower motor to rid of voodoo spirits. ₤0.
Replace spark plug wires. ₤15.
Replace fan belt and idler pulley. ₤30.
Replace battery. ₤40.

I'm happy with how it all came out.

Spring Is Here?

I'm probably getting my hopes up, but today was beautiful. The sky was clear blue and the temperature was in the 40's. The girl and I drove to Castleton and went on a 3.5 mile hike up Mam Tor. Sort of the Peak District version of Half Dome, except it only has a prominence of about 800 feet. Our hike took us from the bottom of the valley up to Hollins Cross and then across the ridge to the top of Mam Tor. We took our time and stopped multiple times for snacks and photos. The best weekend weather in a while. As a result, it was crowded everywhere. We couldn't find any parking places in Castleton, and had to park at a lot near Speedwell Cavern (about a half mile out of town). This actually ended up being a great place to start off from, though a bit pricey for a car park (minimum of 3 pounds for four hours).

If the weather stays like this (fat chance) it will be hard to go.

Cars Suck

Pop quiz. Do you know what this is (or more appropriately, what this used to be)? It's the mangled remains of the idler pulley for the auxiliary (a.k.a. fan) belt in Amanda's car. It appears as though the bearing seized, which led to the plastic shearing away from the bearing. This then rubbed against the remains of the bearing, melting down to just a rim. Finally, it slipped over and the belt ate away part of the outside. In it's last grasp for freedom, it threw itself off of the mounting shaft and into a cavity in the engine compartment, where it got tossed around by the fan belt with a clatter loud enough to get Amanda to call me.

She drove home safely and I found the above piece wedged between the fan belt and the chassis. Amanda and I fished the part out that evening and I took it into work the next day. After scanning some photos on e-bay with my co-workers Wednesday, we determined that it was the tensioner pulley for the fan belt. So, I called a local parts store and ordered the part, as well as a new fan belt. I picked up the tension arm assembly Friday. Sure looks like the part. Then Friday evening I take a look inside Amanda's car again. Not the tension pulley. Only the idler pulley. Hard to explain why this was an easy mistake to make, but it was. It wasn't clear until I was holding the part in my hand and comparing it to what was in the car. And by comparing I mean looking into dark recesses with a torch and feeling around with my hands. They pack everything in so tightly these days.

Today, I'm calling around seeing if anybody has it in stock. It's not looking promising. So that means I'll have to take Monday off to fix the car. However, the good news is that while the tension arm set me back about 50 pounds, the idler pulley is only about 15 pounds.

Onomotopoeia

I may get scorned for this post, but I think it's worth it.

What word do you think best describes the sound of a sock hitting a pillow? Poof maybe? How about flif (I made that one up)? According to Amanda the correct answer is, "...Hit the pillow with a thud." Thud? Thud is the sound of a brick hitting hard dirt. Thud is the word for your head slamming into the door that was closing when you weren't paying attention. Thud in no way describes the sound of a SOCK hitting a PILLOW.

Let me back up a bit.

I have to wake up about 45 minutes before Amanda, which in and of itself sucks. As I was looking for a pair of socks in my sock pile (who folds their socks, really), I came across one of Amanda's. So, to segregate it from my stuff, I tossed it onto my pillow which happened to be next to Amanda's face while she slept. No harm, no foul.

After I got home from work that night, I mentioned that I found one of her socks in my sock pile and left it on the bed for her. She said, "Yes, I noticed it this morning when you tossed it at my face and it hit the pillow with a thud."

I couldn't stop laughing. It was like a phrase that Douglas Adams would write ("Hung in the air in much the same way that a brick doesn't"). But here's the thing, she was serious, and my laughing was making the whole situation worse. How can you not laugh when someone describes the sound of a sock hitting a pillow as a thud.

If I could write, the above would be funny. I guess you had to be there.

I guess you also had to be me.

8 Weeks Left

There is a bit less than 8 weeks until we all come home. I don't think its enough time to finish my last project, but I'll get close enough. There are some unanticipated bugs (aren't there always) that are slowing me down, and on top of that the AMRC is upping stakes and moving into a new building. The upshot is that all the machines are being moved and I can't get some parts made. I think by the time I get my part, it will be time to pack it in. Eh.

January has been a bit dull. Jenny and Lance were here and that was great fun. We did one of the caverns near Castleton, which I enjoyed. I took some photos, but they weren't very good (too dark, too slow, all blurry). I'll post what I got on Flickr. I've been running about once a week. Only doing 5K at a time. But running. My cold-weather running kit is nice. Warm and comfy.

I also did a big panorama from our upstairs balcony of our view of Sheffield. This is about 20 photos stitched together, which is probably too many because Autostich struggled to blend out the seams. I'm pleased with it none-the-less.



Overall this month the weather has been winter in England. Rain, wind, gray. I think the lack of sun has really gotten me down. I'm really sick of the short days and the lack of sunshine. I'll even be O.K. with the bitter cold winters of the states just to get some sun back. We notice the days getting longer again, but it's not happening fast enough for me. I think my mood varies with the sunshine quite a bit.

For diner tonight we had a small leg of lamb roast (just the joint, already boned). It was really good. I'm going to miss how easy it is to get a decent piece of lamb.

There are still some hikes I'd like to take. And I fancy another trip up to the Lake District (Amanda would rather go to Edinburgh). The Boy wants to do a bit more bouldering (in the gym). I'd like to do a bit more bouldering as well, but in the peaks. I took a friend who just started climbing to the bouldering gym Thursday. We had a great time, and I really wore myself out. My fingers still ache. I go back and forth between bouldering and routes. Right now, I think I favor bouldering.

I've been watching too much TV and playing too much Forza (although I've gotten much better at it). I wish I had more cool stuff to talk about and cool stories to tell, but it's been ordinary day after ordinary day lately. Winter sucks.