27 May 2012

Ryder Hesjedal takes the Giro d'Italia!

Canadian Ryder Hesjedal edged Joaquim Rodríguez of Spain by just 16 seconds to take this year's Giro d'Italia.  Road conditions shortened the final stage, which most definitely affected my prediction!  Below are the results with the average speed for Marco Pinotti of Italy, who won today's time trial.
  • Stage 21:  33' 06" (actual), 39' 39" (prediction), 6' 33" slow (19.79% error - not real!)
  • Stage 21:  14.2 m/s (31.8 mph)
But, wait!  Don't kill me for that large error.  I didn't know until just as the race began that the final stage would be shortened from 31.5 km (19.6 miles) to 28.2 km (17.5 miles).  That 10.48% reduction in distance makes all the difference.  Using my predicted average speed with the new distance, my prediction changes to 35' 30", which reduces my error to 7.25% slow.  Pinotti still completed the stage faster than I would have predicted, but my prediction was not nearly as bad as it first seemed.

It's now on to preparation for the Tour de France.  Modeling the final week of the Giro d'Italia has been fun, partly because it's been such a good learning experience.  Check back in early July for predictions of Tour de France stage-winning times.

26 May 2012

A little better on Stage 20 ...

Belgian Thomas De Gendt's great solo breakaway did the job in today's Stage 20 of the Giro d'Italia.  Below are the results with De Gendt's average speed listed afterwards.
  • Stage 20:  6h 54' 41" (actual), 6h 30' 56" (predicted), 23' 45" fast (-5.73% error)
  • Stage 20:  8.80 m/s (19.7 mph)
It boggles my mind just how good those athletes competing in the Giro really are.  That final climb was amazing.  I love the snow!  The past two mountain stages have given me a new appreciation for the challenge of completing the Giro with such a strenuous ending.  As someone heretofore more familiar with the Tour de France, my respect for the Giro and desire to model it more completely in the future have grown considerably this week.

Below is our prediction for tomorrow's final stage, which is an individual time trail.
  • Stage 21:  39' 39" (prediction)
It should be a fun ending in Milan tomorrow!

25 May 2012

Too fast on Stage 19!

Roman Kreuziger of the Czech Republic won today's Stage 19 of the Giro d'Italia.  Below are the results with Kreuziger's average speed listed afterwards.
  • Stage 19:  6h 18' 03" (actual), 5h 43' 12" (prediction), 34' 51" fast (-9.22% error)
  • Stage 19:  8.73 m/s (19.5 mph)
Having our prediction under 10% is of little consolation!  As I noted yesterday, we were worried that our prediction might be too fast.  Cyclists looked to be gassed by the time they reached the final climb.  We simply had too much power in our model.

At 219 km (136 miles), tomorrow's Stage 20 is even longer than today's stage.  Cyclists end tomorrow at the famed Passo Dello Stelvio (Stelvio Pass), which is the highest paved mountain road in the eastern part of the Alps.  The final 44 km (27 miles) of Stage 20 will have riders climb over 2 km (1.2 miles) of elevation as they ascend to the 2757-m (9045-ft or 1.713-mile) peak of Stelvio Pass.

Moving on to our prediction for tomorrow's stage, we obviously rethought our power outputs.  The last 10 km (6.2 miles) of today's Stage 19 saw Kreuziger average less than 5 m/s (11 mph), which was about 10% less than what we thought riders would do.  Below is our prediction for tomorrow's stage.
  • Stage 20:  6h 30' 56" (prediction)
The best thing about being wrong in science is the opportunity to learn something.  I hope we now have a better feeling for power outputs in tomorrow's stage.

24 May 2012

Stage 18 results and Stage 19 prediction ...

Italian Andrea Guardini won Stage 18 of the Giro d'Italia today, just beating out Mark Cavendish of Great Britain.  Below is a comparison of the winning time with our prediction, followed by Guardini's average speed for the 139-km (86.4-mile) stage.
  • Stage 18:  3h 00' 52" (actual), 3h 11' 49" (prediction), 10' 57" slow (6.05% error)
  • Stage 18:  12.8 m/s (28.7 mph)
I'll take a 6% error on a race I just started modeling this year, and at the end of the race at that.  As  I have noted in previous posts, modeling these cycling stages is not only a great deal of fun, it is hard.  If my model is too simple, I am glossing over complexities that influence a race.  If my model is too complicated, I am making too many a priori assumptions, many of which are certain to be incorrect in the actual race.

Okay, on to Stage 19, which looks to be a brutal mountain stage.  Starting in the north Italian city of Treviso, the stage ends 198 km (123 miles) later in Alpe di Pamepago, which is in the heart of the Dolomites.  Beginning at just 15-m (49-ft) elevation, cyclists will reach the 2047-m (6716-ft or 1.27-mile) peak at Passo Manghen after 123.3 km (76.6 miles) of biking.  The final 8 km (5 miles) will make for a grueling uphill to the finish line.  Here is our prediction:
  • Stage 19:  5h 43' 12" (prediction)
I hope cyclists have enough fuel in the tank to make it up the final climb fast enough that our prediction is not too fast!

23 May 2012

Giro d'Italia Stage 18 Prediction

Our prediction for tomorrow's Stage 18 is below.
  • Stage 18:  3h 11' 49" (prediction)
The downhills from San Vito Cadore to Vedelago should make for some wonderful racing!  Riders should not kill themselves on tomorrow's stage because two monster mountain stages await them on Friday and Saturday.

Not a bad first stage!

Joaquin Rodríguez won today's Stage 17 of the Giro d'Ialia.  The Spaniard just edged Italian Ivan Basso in an exciting finish.  Below is how today's result compares to the prediction I posted yesterday.
  • Stage 17:  5h 24' 41" (actual), 5h 28' 26" (prediction), 3' 45" slow (1.15% error)
I told my student, Brian Ramsey, that that's not bad for his very first stage prediction!  Below is how the average speed came out for Joaquin Rodríguez in the 187-km (116-mile) stage.
  • Stage 17:  9.60 m/s (21.5 mph)
Check back soon for a prediction for tomorrow's Stage 18, which looks to have a lot of fast downhills.

22 May 2012

A try at Giro predicting ...

The 2012 Giro d'Italia is nearly over.  I've only modeled a couple of stages of this race in the past, mostly because my spring semester keeps me extremely busy as the race gets underway.  This year has been no exception.  A rising sophomore Lynchburg College physics student, Brian Ramsey, is working with me this summer in preparation for modeling the 2012 Tour de France.  We thought a nice warm-up exercise would be to model a few stages of this summer's Giro.

To introduce Brian to what it's like to stick one's neck out for science, I had him model tomorrow's Stage 17 using the model I developed for the Tour de France.  Tomorrow's stage is a wonderful mountain ride that takes cyclists from Falzes to Cortina d'Ampezzo.  Here is our prediction for tomorrow's stage:
  • Stage 17:  5h 28' 26" (prediction)
We shall see what happens!

15 May 2012

Ping-Pong Physics and Vlogging

One of my favorite results from Classical Mechanics has to do with the stability of rigid bodies as they rotate about certain axes.  I demonstrate this theorem in a YouTube video, which is my first attempt at vlogging (though these words may render my attempt but a partial one!).  Click on the video below (or click here) to see and hear me talking about rotating ping-pong paddles.  If you don't own a ping-pong paddle, try my demonstration at home with your television's remote control.  You should easily be able to find the axis about which rotation is unstable.  That's how I discovered one of nature's beautiful workings when I was a teenager.

06 May 2012

Way to go Owls!

Ever since my family and I lived in Sheffield, England during my last sabbatical (2008-09 academic year), I have followed the ups and downs of Sheffield's two football clubs, Sheffield Wednesday (the Owls) and Sheffield United (the Blades).  After the Owls defeated the Wycombe Wanderers 2-0 yesterday, they secured the #2 spot in the Football League One table.  The Owls join top club Charlton Athletic for automatic promotion to Football League Championship for next season.

The Blades finished in the #3 spot in the table, just three points behind the Owls, after yesterday's draw against Exeter City, a club that will be relegated to Football League Two for next season.  The Blades now join Huddersfield Town, Milton Keynes Dons, and Stevenage for the League One play-offs.  Two matches with Stevenage (11 May and 15 May) await Sheffield United.

Congratulations to the Owls!  Go Blades!