Yeah Buddy!!!

First of all, I’m still alive. Sorry for not posting for a couple of months. I’m working on an academic related post about what I’ve been up to, but first, rowing.

For those of you who were listening to the radio coverage of bumps (www.cur1350.co.uk), I just want to say they really dropped the ball, claiming that we rowed over.

We marshalled in the cold, miserable, pouring down rain (15mph winds, 50°F, an inch of rain collected in the bottom of the boat in ~30 minutes). We were chasing CCAT II (Anglia Ruskin Univ.) and chased by Robinson III. Christ’s IV apparently crabbed or something, and CCAT bumped into them almost immediately, at First Post Corner. Just like the first day of Lent Bumps, Christ’s just sprawled across the river ahead of us. However, thanks to some extra eyes on the bank and some epic steering by our cox, we snuck past. Nobody else in the division made it through the carnage.

With CCAT out, our only option was to overbump Curchill III (or row over, which we weren’t about to settle for). They started 3 stations (7.5 boat lengths) ahead. The also didn’t have to deal with the CCAT/Christ’s insanity, which cost us another several lengths. But we didn’t give up, and kept on it hard, slowly but surely reeling  them in. By the time we came onto the Reach (~1.5 km from the end), we were down to 4 lengths. By the railway bridge (500m from the end) it was 1 length, at which point we were all completely dead, but dug deep pushed harder and took the rate up. Churhill apparently completely cracked under the pressure and exhaustion, and we ate up the last length in about 15 seconds, to get the overbump.

And, as if getting overbumped was not emberassing enough for Churhill, they were rowing in one of our old “Black Prince” racing shells bought from our club earlier this year, whereas we were rowing in a heavy, double hulled plastic boat.

It was absolutely epic. Tomorrow we are 2nd in the division, so if we bump we will become the “sandwich boat” and row again immediately afterwards at the bottom of the next division.

My first rowing in a pair

…and my first swim in the Cam. Cambridge University is currently on holiday, so most people have gone home. This makes rowing in VIIIs next to impossible, so we have had to go out in IVs and even pairs instead. Today was my first attempt at a pair, and I learned a few things about them very quickly. First, they are much less stable than larger boats, being more narrow and having fewer oars. Second, there is no cox, so the rower in the bow has to steer. These two factors turned out to have rather disastrous consequences. I was rowing stroke side (aka not the person steering). Things were tippy, and every few strokes we had to stop to keep from hitting something. Then things seemed to be going alright until I glanced over my shoulder and saw the biggest barge on the Cam right in front of us. I desperately tried to avoid the collision, but it was too late. We hit it, and then I felt the boat slowly tipping over. And there was absolutely nothing I could do. Splash – we capsized. And the water was very, very cold. The nice man on the barge helped us figure out how to untangle our boat from a mess of ropes on the side of his barge, and then we swam our boat across the river, got out, grabbed the bikes from our bank party, and hauled ass back to the boathouse to avoid hypothermia. I hope they got the boat back safely. Next time I think we’ll try to arrange a IV. Now to go get warm and wash off all this nasty grime from the Cam.

BUMPS!

I just finished Lent Bumps and despite every muscle in my body being tremendously sore, I still feel like this was one of the most satisfying weeks of my life. Bumps are by far the the most exciting sport I’ve ever competed in or watched. I’m not sure I can convey just how awesome they are, but here it goes. Line up 18 VIIIs (rowing shells with 8 rowers + 1 cox) along the river with one and a half boat lengths of clear water between them. Fire a cannon to start them all rowing. Every boat is trying to crash into the boat ahead before getting crashed into by the boat behind. When 2 boats collide they are swapped in the start order for the next day. Do this every day for a week; the order at the end of the week becomes the starting order for the next year. Details here.

I’m in our club’s M4 (fourth mens’) boat and we were surrounded by M2 boats in the bumps order, so we knew things were going to be tough, but we started out optimistically hoping to bump Clare II on the first day (Tuesday). Unfortunately Fitz II, who turned out to be very slow, was right ahead of them, so Clare bumped out almost immediately. Then Clare completely failed to clear the river blocking our path. Our cox called to hold it up so we didn’t smash into their stationary boat. Usually in this situation we would have been awarded a “technical rowover”, meaning we would stay in the same position. However, the marshal decided that there was enough room for us to go around, so he awarded the bump to Magdeline II who was chasing us. A very disappointing start.

Wednesday: Chasing Magdeline II, chased by Peterhouse II, with the amazingly slow Fitz II ahead of Magdeline II. We went off very hard trying to catch Magdeline before they caught Fitz, but it failed. We were all working very hard, but the technique was absolute rubbish, and Peterhouse bumped us.

Friday: After a day off on Thursday we were chasing Peterhouse II, chased by Caius II (that’s pronounced Keys, by the way). We knew Peterhouse was fast, so we were hoping for a rowover. Caius, however, also turned out to be very fast. They closed on us quickly, and it was beginning to look like Wednesday all over again. In the first big corner they overlapped our boat by a foot or two, but thanks to an immense push by us, missed the bump. At this point all of us in the boat, our coaches on the bank, and even the radio commentary on the race thought the bump was imminent. We just decided to prolong it as much as possible and make them really work for it. In the next corner, they got overlap again, and nearly bumped, but the timing of our strokes worked out just right so that they missed again, by less than an inch according to our coaches. We danced like this for over 5 minutes until they tried to cut too close around the last corner, causing blade clash with a boat that had bumped out, and then a crab, allowing us to hold them off down the reach to the finish. Everyone who saw the race, including the coach from Caius, said it was the most exciting rowover they had ever seen.

Saturday: The slow Fitz II was now head of us, with Caius II out for blood behind us. We all knew Caius was the faster crew, and they likely felt a little robbed after our narrow escape in day 3. The race was for us to bump Fitz before Caius could bump us, and Fitz was not going to go down easily because they were fighting to avoid spooning (going down all 4 days). Sure enough, Fitz was rowing well, and we gained on them slowly. We kept putting down big pushes to reel them in, and I was quickly growing even more exhausted than I had been the day before (which I hadn’t believed possible). Right about when I was beginning to seriously question my ability to take another stroke, we got the “hold it up” call; we had bumped. We pulled over to the side to collapse and then get our greenery (meaning “We Bumped”) and beer. Where was Caius the whole time? Rather anticlimactically they had just slowly fallen further and further behind us. Here are a couple of photos from the race (Thanks Niels):

Finally, the week ended with end of term rowing party: A big, formal, drunken dinner followed by a huge “bop” (”party” in american) with St. John’s, our (mostly) friendly rivals. Complete with lots of friendly, drunken singing, like “Oh, I’d rather be at Oxford than St. John’s” (to the tune of “She’ll be coming round the Mountain”). The John’s people seemed to have a similar song about us, but I didn’t really understand the lyrics.

Pembroke Regatta

I was at the boat house at 6:40 this morning, ready for a nice day of racing in the Pembroke Regatta, a side-by-side tournament. The river has been flooding severely the past week due to large amounts of snow and rain, and was still roughly a meter above its usual level. Our nice concrete bank that lets us launch boats without getting our toes wet was completely submerged, so we had to do a lot of wading around in freezing cold (snow melt) water.

When we finally made it up to the race marshaling area, we found out that our competition (Kings M3) had dropped out, so we just rowed back to the boat house to wait for the next round 3 hours later. Needless to say everyone was a little annoyed at waking up that early and not racing. We went up to marshal again for the second round, only to find out that LMBC (St. John’s) M5, who we were supposed to be racing, had broken their boat and dropped out. So no race again.

Our first race was the semi-finals against our own M3. We spent several minutes bantering on the starting line, including one suggestion that we both “back it down”  (i.e. rowing backwards) the whole race, which the marshals were quick to forbid. The race itself was epic. They got a slightly better start, and then, due to some dodgy (malicious?) coxing on their part, they came right over into our half of the river, causing a massive blade clash (oars smacking against each other making it quite difficult to row), after which they were a little over half a boat length up. During the rest of the race we held them there, and they finished less than a boat length ahead (i.e. overlapping their boat by a meter or two). It hurt like hell, but was quite satisfying because they were supposed to be a faster crew, and beat us by 30 seconds in the race last weekend.

So basically I spent all day faffing about on the river for one nice race.

Also, living in a country the size of the U.K. has some advantages. I ordered some new strings for my guitar yesterday afternoon, with standard shipping, and they arrived here less than 24 hours later.

Massive Update

I promise I haven’t died. Lots has been going on in Cambridge. We had around 6cm of snow last week – a big snow storm by English standards. I went sledding on the roof of the CMS. The roof has grass and is one of the only hills in Cambridge. There is a picture of the building at www.maths.cam.ac.uk. Cambridge, and especially Trinity were absolutely beautiful in the snow. Unfortunately the “make all my pictures really blurry” switch on my camera seemed to be turned on, so these were all I got:

There was a second snow storm last Friday that didn’t really do much but make enormous piles of slush everywhere and flood the Cam.

I was also racing on Friday in the Robinson Head. Despite the freezing, snowy conditions we did quite well. I’m in the 4th men’s boat for Trinity (”M4″) and we beat all the M4 crews, all the M3 crews except Trinity M3, and about 2/3 of the M2 crews. And we did it with  a completely new crew who had rowed together exactly once before the race.

This Saturday we have a regatta (side-by-side racing). and then, starting on the 24th is Lent Bumps! That’s THE race of the term: 4 days of ramming VIIIs together. Check out here if your curious. Our Bumps prospects look very favorable: in the Robinson head last Friday we beat the crews starting ahead of us by around 20 seconds. If all goes well we should be bumping the St. John’s (i.e. the big rival) M3, which would make our M4 higher than every M3 except our own.

In other news I think I’ve completed my first original, potentially slightly interesting mathematical result since arriving in Cambridge. Here is the necessary definitions and the theorem (the proof is somewhat longer):

A -regular hypergraph consists of a vertex set and an edge set where each edge is a set of vertices from . A hereditary property is an (infinite) set of -regular hypergraphs that is closed under isomorphism and taking induced subgraphs (i.e. if is in then any relabeling of the vertices of is also in , and so is any hypergraph obtained by removing some vertices in ). If is a hereditary property, then is the set of all in such that has vertices (i.e. ).

Theorem: The asymptotic behavior of (i.e. the number of hypergraphs in with vertices) must fall into one of the following categories:

• Constant: there is some such that for all
• Polynomial: there are some integer polynomials such that for all
• Exponential: there are exponential function such that for all
• Factorial or above: there is some such that for sufficiently large

So, for example, there is no hereditary property with as that would have to lie between constant and polynomial. This is a generalization of a result in a paper I was reading for my essay [Scheinerman and Zito, On the size of hereditary classes of graphs, J. Combin. Theory Ser. B, 61, (1994) 16-29]. They proved the graph case, i.e. where .

Yay for wordpress !

The Printners are Screwing With Me

I just ordered a number of math books recently, and when they arrived yesterday it was like a mathematical Christmas. But then I opened up my topos theory book, and what did I find? The text had all been replaced by a book about matrix algebra for statisticians. The disappointment was harsh. Hiding a statistics book under the cover of logic is just cruel. Amazon is kindly sending me another one, hopefully with the correct text this time.

Back in Cambridge

Hello everyone. It was nice to see those of you who I got a chance to, and sorry I missed the rest of you. After lazing around for a month, I’m back in Cambridge, and back to work. This term I’m thinking of taking:

• Set Theory and Logic
• Topos Theory – a branch of category theory
• Percolation and Combinatorics – combinatorial questions related to models of liquids percolating through a porous substance. So far this seems to focus on questions about random subgraphs of infinite, locally finite (each vertex has a finite number of neighbors) graphs.
• Decision Problems in Group Theory – Given a presentation for a group, what properties of that group can be computed (e.g. is it abelian, etc)
• Additive Combinatorics – Combinatorics with a dash of analysis, or analysis with a dash of combinatorics. We are starting off with discrete Fourier analysis and Roth’s theorem on the existence of 3-term arithmetic progressions in any sufficiently dense finite subset of the natural numbers.

I will probably be dropping one of these courses at some point because its just too many, but right now I can’t decide which.

I went rowing today for the first time in over a month.

In other news, there was a large march today in Cambridge protesting the Israeli invasion of Gaza, and the occupation in general. I was busy working when I started hearing the chant “Occupation is a crime! Free, free Palestine!” coming from outside my window. On the street below there was a very diverse group of a few hundred people.

Americans have forgotten how to protest. This looked bigger than any demonstration I ever saw in Fort Collins (a city about the same size as Cambridge), even during the height of the Iraq war. There were apparently similar protests across the UK today, with 5,000 people turning up in Birmingham and 20,000 in London, for the second week in a row.

End of term

I’ve now recovered from the blur of rowing and partying that was Thursday and Friday. Rowers are a rowdy bunch. I now see why finding venues for their parties is so difficult. Our end of term party on Friday was at a hotel that apparently forgot that the whole boat club had been banned for life 10 years ago (something about a drunken food fight I think). I don’t think we got banned this time, but it was pretty crazy.

Yesterday was a recovery day spent sleeping, watching Battlestar Galactica Season 4, and playing Civilization IV. Now I’m back to more productive things like laundry, packing and writing this blog.

The term is now over. I survived the Cambridge academics, rowing and partying, and even managed to keep the 3 in reasonable balance. Nothing to do now but get ready to leave and start studying (which will occupy much of this “break”). I look forward to seeing all of you soon.

Fairbairn Cup, Day 2

The senior Fairbairns race on Friday was not quite what I expected. I got home late Thursday night after the BA Christmas party only to find an email saying that due to illness and injury, we were unable to field 2 boats for the race Friday. The remaining members of the first 2 novice boats were combined together into a single boat, and because there were too many bow side (aka starboard) rowers, I wasn’t in that boat.

At the crew photos on Friday morning I was informed that the person rowing bow had gotten completely lashed (british for trashed, wasted) and was unable to get out of bed, much less row 5km, so I was in. Out of 16 rowers in the top 2 novice boats, only 7 were actually able to row. The 8th, rowing stroke (furthest back, sets the rhythm for everyone else), was our usual cox, and we had a substitute cox. We had no chance to practice together; our first stroke as a crew was the start of the race.

Considering the circumstances, we did alright. We only crashed once on a very tight corner. The cox, trying to help bring us around, put her arm into the water. This is usually quite effective, but she unfortunately put the wrong arm into the water and sent is straight into the bank. By the time we got straightened out, the crew behind us was overtaking, so we had to wait and let them by.

We did not finish last, and even beat the 2nd Trinity alumni boat.

Also, our cox rowing in front of me had the splashiest stroke I’ve ever seen. Every stroke, for 5km (about 1000 strokes) I got absolutely drenched. Before we even passed the starting line I felt like I was swimming, not rowing.

Fairbairn Cup

Some of you are probably getting the impression that all I’m doing over here in Cambridge is rowing. I assure you that this is (mostly) an illusion. I really do academic things too, but I thought that most of you would find my rowing stories more interesting than my maths. I’m now done with lectures for the term and am starting to review and starting to look at papers for an essay that I will be writing next term. I will either be writing about Lagrangians of hypergraphs with Imre Leader, or on hereditary properties of graphs/hypergraphs with Bela Bollobas.

For everyone back home who doesn’t know already, I will be returning to Fort Collins on December 10th and staying until January 10th. I hope to see all of you while I’m there (and do a lot of skiing).

Ok, now on to more rowing. Today was the first day of the Fairbairn Cup, the biggest race of Michaelmas (Fall) term. The morning got off to a good start at 6AM when I discovered that the sandwich I bought for breakfast had been nicked out of the kitchen. The weather was, with the exception of the hail storm, the worst I’ve seen since arriving in Cambridge. Freezing temperatures, 20 MPH winds, and sleet. We were wearing no gloves (hinders blade control) and minimal clothes (hinders movement), and had to row 2.8 km into a head/cross wind. Then we had to wait at the other end for about 1.5 hours while everyone else did the same thing before we could row home.

The race itself (aside from the frozen, blistered hands and the whole body screaming with every stroke) was fantastic. Our crew came together better than we ever have before. Our stroke man had been having serious issues with rhythm and stroke length that were throwing off the whole boat, but he pulled it together magnificently for that race. We all stayed together, didn’t crab, and gave it everything we had. It hurt like hell, but it was everything we had been working towards for the last 2 months, and it made it all worthwhile. We finished 19th, which was not what we hoped for, but thats fine. Back at the boathouse 2 of our rowers threw each other in the Cam.

Oh, and we’re double entered in the senior race as well, so tomorrow we do it again. Except its twice as long. The weather should be better, however, and I don’t have to wake up quite as early.

Now I’m off to enjoy the merriment and free alcohol of the BA (graduate student) Christmas dinner/party.