Ski Evolution

At the Northwest Snow and Avalanche Workshop this weekend, Off-Piste Magazine handed out free copies of the October issue as usual. Thumbing through the ski review, I couldn’t help but wonder: How have things changed over time?

Thanks to Off-Piste’s deep archive of back issues, only tedious retyping was needed to find some answers.

This is the money plot:

The absolute scale makes the scatter part of the plot small, but you can see by exactly how much skis have widened and lightened over time.

For zoomed in plots and more, head down the rabbit hole. Continue reading

Free Bagels

Free food is a standard perk/fact in the modern software industry. It saves people time, lets them focus on work, and makes them feel appreciated.

It works for Google, but can it work for our academic lab of ~50 people? Will ravenous students eat infinitely many bagels? How much does it cost to provide free food to employees?

Experiment is the arbiter of truth.

An email made it known that 30+ bagels a day would appear in the breakroom for at least a week, and I kept a tally of bagel consumption over time. Sufficient attention to supply ensured that we never ran out.  Happy bagel eaters were skeptical at first (“Are these really free?”, “What’s with all the bagels?”, etc.), and then hopped aboard the plan.

The answer? ~27 bagels/day, or less than $15/day. Cream cheese is ~30x more popular than butter.

It’s a rather inexpensive experiment (bagels averaged <$0.50 cents each), and it’s provided the faculty with the information they need decide whether or not they could fund such a program.

Best of all, it was fun!

Storm Surge

Thanks to the excellent data/interface provided by NOAA (click here for Montauk data), I was able to throw these plots together.

I have family on Long Island. As I understand it, if Hurricane Sandy’s storm surge is more than ~6 feet above high tide, the house will flood. So, I’m interested in the current ocean level. It’s still early in the storm, but the plots don’t look good.

For realtime updates, click the NOAA link above.

Plots updated 10:45 AM PDT 10/30/2012, final update. Status of the house is unknown, but everyone’s fine. Note small after-surge that’s happened today. Neat.

Measured sea level at  The Battery, Montauk, Kings Point, and New Haven during Hurricane Sandy. Data are NOAA measurements. ‘MLLW’ is “Mean Lower Low Water”

Good luck to everyone on the East Coast!

More HN numbers

I’m curious whether the Hacker News post will lead to long-term increased traffic.

Edit: 10/30/2012. After the post regarding Hurricane Sandy, this experiment had to end; traffic from the new post started to matter. These numbers are the total hits to all-things measuredmass, not just the Google post. So, the above is the final plot. 

By October ~26 (that spike) traffic was coming in bursts from various countries, especially Germany. I’m not sure that the >10 hits/day rate would have remained sustainable for more than another few weeks. Time will tell. 

Hacker News

140 countries in a day! 30,000 hits!


I didn’t expect that post to reach the top spot on HN, let alone stay there. It would’ve been neat just to ping around on the front page for a bit before falling to obscurity. I’m glad you’re curious about it too.

Now I’m curious about you : ).

Continue reading

Google Homepage Size Over Time

This afternoon, I looked at the source of the main Google page with my browser. It spans my whole monitor and takes 15 pushes of the scroll-wheel to see it all. Whither minimalism?

Off to the Wayback Machine. One must be careful to avoid including Wayback Machine Javascript and comments when assessing file size. I think I got it right. File sizes were assessed with `ls -l`, and included only the size of the ‘.html’ file, no images or fanciness. Dates were sampled pseudo-regularly, trying to get about two points/year.

6 points corrected. Thanks ‘qxcv’! Archive, curl, and browser data noted. Thanks ‘zzzwat’!

Time for a log plot. The difference between a browser-acquired page and a simple curl request is an order of magnitude.

Fun with Torque

\vec{\tau}=\vec{r}\times\vec{F}  ?

Nope, this kind of Torque – an excellent Android app that interfaces with the OBD II port in your car.

I’d bought an inexpensive “LM327” bluetooth adapter for my car months ago, but never got it running with my laptop. The Android solution worked trivially, and the application works well.

If you want to play with datalogging with Torque and you’re using the free version, you must explicitly select each sensor every time you use the application. Tedious, but free.

I finally went on a real drive with the car (~10-15 mi) and got logging working. There are many sensors to log, but most of them don’t betray fundamental properties of the car quite like these two do.

Lines are not fit. I tweaked the 5th gear line to match the 5th gear data, then used the gear ratios from here to predict the lower four lines. The ratios used were 3.545/2.111/1.448/1.088/0.780. Wikipedia has two values for the 5MT. The other ratio stated for “All 1990-2003 with EJ engine” of 3.785/1.945/1.500/0.994/0.780 is in obvious error when plotted with the same procedure. I submitted an edit to this effect; time will tell if it sticks.

Same plot, with incorrect ratios.

The GPS and my engine computer’s speedometer are neatly locked, but there’s about a 1 mph constant offset between them (easier to see in the residuals). Neat.