52 States in 8 Months

The US Postal Service wants to have my money.

Posted in Stupidities, USA by Ulf on June 19, 2009

A few days ago I wanted to send a small letter to Europe:
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Nothing special so far. Sending this letter should cost $0.98. A few weeks ago it was still $0.94, but they’ve increased the fare. Alright, I can live with that. It’s still much cheaper than the Deutsche Post (they want to have about $1.40 for the same service).

However, there is one thing that I didn’t like. This automatic stamp dispenser doesn’t make any sales for less than $1. Now look at my options:
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The machine asks me whether I want to pay $1.42 or $5.38. The only alternative is to cancel the purchase. I decided to go into some other menu where I could manually buy a $1.00 stamp so that the machine is happy. Grrrr.

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Wasting water.

Posted in Newark, Stupidities by Ulf on June 10, 2009

A few days ago I had to observe how a water tower was drained (look at the water hose that leads to the street!):
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It took more than a day until the whole thing was empty. I was really feeling sad when I saw this waste of natural resources. But let’s do the math:

a) How much water is thrown away?
From Google Maps I would estimate that the water tower has a diameter of about 13m. Let’s assume it is a sphere, that would give it a capacity of 1,150m3 of water. Let’s take 1,000m3 to keep the calculations simple.
Different sources suggest that the average indoor water usage per person is about 70 gallons/day. What does that mean for our water tower? A single person would need more than 10 years to use all the water that was wasted here! Enough to supply 4,000 Americans for one day. I don’t know about the water prices here in the US. In Magdeburg it currently is at 1.81 Euro/m3. If the price in the US is similar, then about $2,500 where thrown away when this water tower was drained (assuming that the water tower was full when they started the draining).

b) How much energy is thrown away?
Looking at the picture, the structure might be about 30m high. Once again, assuming that the tower was full, then there were 1,000,000 kg of water in there. That gives 294,300,000 J of potential energy, or about 81.75 kWh. That means that with American power prices (roughly $0.12/kWh), it costs about $10 to fill the whole thing (electricity only, I’m not considering the water at this point).
It’s hard to translate that to CO2 because different power plants give different numbers. At 700g CO2/kWh it would be 57kg CO2 for filling this tank.

Edit: A few days after the water was drained I finally saw someone working on the tower. Not the right job for me!!
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Printed twice!

Posted in Stupidities, University stuff by Ulf on June 4, 2009

I’m currently changing some citations in my thesis. Originally I planned to cite some Wikipedia articles such the one about Differentiation of inverse functions. They have a section about higher derivatives of those inverses, and those were really useful for my work! Unfortunately I can’t find a normal textbook which also presents these formulas, so that’s why I wanted to cite Wikipedia.

Mascha was the first one who tried to convince me that citing Wikipedia is not a good idea. I didn’t listen to her. Alex was the second one, and I did listen to him (sorry Mascha!). Without any quotable source I had to add an appendix page in my thesis just for showing the derivation of these formulas. Okay, that Wikipedia citation is gone. Unfortunately there are still a few others left.

While I searched the formula in different textbooks, I found this the 1968 “Schaum’s Mathematical Handbook of Formulas and Tables” by Murray R. Spiegel. It claims to be printed both in the United States and in Korea. Sounds like good teamwork, eh?

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Do not waste your money on “Try-It-Racing”.

Posted in Stupidities by Ulf on April 30, 2009

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During the Washington Auto Show in February Alex and I met a chap called Soloman who convinced us to get whelen_americansome racing experience with “Try it Racing“. On April 19th we finally went to the Old Dominion Speedway in Manassas, Virginia. This is one of about 60 tracks nationwide that are used for the weekly “NASCAR All-American Series“, the lowest level of racing which uses the NASCAR label (“National Association for Stock Car Auto Racing”).

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Now, Alex and I paid about 180€ each for driving around the 3/8 mile oval 15 times on our own, and afterwards being taken around the track another five times by a professional racing driver. Now, as you can already guess from the headline, this was not the adrenaline filled experience which they promised (please don’t be confused by my “thumbs up” gesture on the next picture — that was before the racing).

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So, let’s start with our own 15 laps driving. Driving they 355 cubic inch V8s was very simple. The clutch works just like in any other car, and you only have two gears: first gear for starting the car, and a second gear for driving it. Yes, really! It sounds stupid, but that’s it! Obviously these race cars were not designed to make use of the power which the engine could have offered. Then, what was the “racing” itself like? You start you car and continue driving behind the pace car for 15 laps.
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They told us that one bend of the oval would be tighter than the other one, but that was a completely useless information: since the pace car was going very slowly we hardly felt any centrifugal forces. Therefore we really didn’t have to worry about the curve radius. To give you an impression of how boring the whole thing was: I never ever had to use the brakes during the whole event! My pace car never allowed me to go anywhere near full throttle, and somewhere in the middle of the straight it already started to decelerate. The engine drag was enough not to keep me away from rushing into the pace car. Come on, racing without brakes, what is that? Seriously: my weekly trips to the Kaufland in Stuttgart (a local supermarket) were more exciting than our “Try It Racing”!

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The ride-along was a little better. Michael Southard (he was on position 188 in the 2008 All-American series) showed us that their cars can in fact go around the track fast enough to produce some lateral forces, and he even had to use the brake a few times. Still, I was taken around the Porsche test track in Weissach in either a 911 Carrera S or a 911 Turbo by some Porsche research engineers (I’ve forgotten which car it was). That joyride was free and much better than Mike Southard’s ride-along. When I was working for GETRAG we also took the Ferrari California from Heilbronn to Würzburg on the A81 which also was more thrilling than the Try it Racing.

From analyzing my video material I concluded that we averaged 75mph during the ride-along and roughly 55mph when we drove on our own. How boring is that? There are normal roads in some states where the local authorities encourage you to drive 80. And on the Autobahn, the officially recommended speed is 81 mph.

Before I forget it, an advice to all Internationals: Mike Southard (who apparently runs “Try It Racing”) really isn’t easy to understand on the phone. He is mumbling all the time, and only after asking him three times what he said he opens his mouth and suddenly speaks English.

Now, some doubts about the professionalism of “Try It Racing”:

  • I did not see any safety stewards around the track. So if I had an accident, well, I don’t know what would have happened. I hope my crash would have had been louder than the engines at the grid, but I’m not sure about that.
  • I did not see any fire extinguishers at the grid. Therefore even if I had witnessed an accident of another driver, I’m not sure if I would have had been able to help him.
  • I did not see any fire extinguishers in the racing cars.
  • During the drivers briefing we were not told how to get out of the car in an emergency. That means that we’ve never trained to open our seat belt, we’ve never trained to open the window net, and worst of all: When I tried to get out of the car I realized that I did not even know how to remove the steering wheel, so there was no way of leaving the car! From a safety perspective, “Try it racing” is probably one of the most dangerous things I ever did.

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And now about the power itself. Since these cars do not have rev limiters it’s pretty much impossible to quantify the maximal engine power. Soloman told us something about 600 horse power, and on the track they said something about 400hp. Now, let me calculate an upper bound on the power we’ve actually used:
four_stroke_cycle_compressionTheir V8 engines have a displacement of 355 cubic inch which is 0.0058 m3 (a little less than 6 liters). I’m pretty sure they don’t have any turbo chargers and only use air instead of NOx for burning the fuel. That means that they can only burn 0.0058 m3 of air with every two engine revolutions. Assuming that the throttle valve is fully open (not true, I was never close to full throttle), the intake pressure could be close to 1 bar. That means that I could have burned n=pV/RT= 100000 N/m2 · 0.0058 m3 / (8.314472 J/K/mol) / 300K = 0.232 moles of air in the engine with every two rotations (if I would have completely pressed the gas pedal). Since air weights about 0.029kg/mol, that is about 0.0067kg of air. At an air ratio of about 14:1 I can burn about 0.00048 kg of fuel with every two engine rotations at full throttle, which releases about 43 MJ/kg of heat. That is about 20 kJ of energy per two rotations, or (assuming an engine efficiency of 30%) roughly 3400 J per engine rotation. Now, this is a new information: we did not have a speedometer in the car, but we could see the engine revs. We never made more than 3000rpm which is 50rps. That is 170000 J/s=170kW=230hp. And please keep in mind: t_cycle_ottoI did not consider any losses yet besides the heat-to-work conversion efficiency of 30%, and also I assumed that the throttle valve is completely open which is nowhere near the truth. And during most of the laps we were well below 3000rpm, so that also makes it an overestimate. If you want to hear a serious guess: We used about 50-80hp. Alex guesses it was even less.
What they call a racing car might look like one from the outside, and it might also sound like one since they did not bother to put on any real silencers. But when it comes to the engine power, you’re better of if you take any street with a real gear box (which allows you to always keep the engine revs somewhere close to the red line). It doesn’t even have to be an M3. I could have taken my Audi 80 for keeping up with the pace car! When they say something about 400hp, they’re simply lying.

One last blame on Try It Racing: While we were there Mike made doughnuts with two of the passengers during their ride-alongs. Well, I also asked him for one, but he refused. He said he wanted to save his tires for a child which has his birthday or something. Sorry Mike — I guess I paid no less than this child, and I’m also a customer who wants to be satisfied. And you did not manage to come close to anything of what you promised! But your not driving a doughnut with me makes it even easier for me to ask any potential Try It Racing customer not to waste their money!
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So, to conclude this: Try It Racing claims that they “offer an experience of a lifetime”. They do indeed. But the experience has nothing to do with racing, it is the experience of having tossed money out of the window.
If you really want to have fun, go to some Go-Kart track. It’s cheaper, much more fun and way safer!

WordPress’s next strange offer

Posted in Stupidities by Ulf on April 9, 2009

WTF? Some weeks ago WordPress offered me “52statesin8age.com”, and now they think that I might want to buy “52statesinsideeightmonths.com”.
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Wordpress, why don’t you just offer “52statesin8months.com”? Or maybe “44statesin8months.com” which would reflect my current status…

WordPress is weird.

Posted in Stupidities by Ulf on February 21, 2009

This is a little ad which WordPress put on my dashboard today.
wordpress_ausschnittWTF??

Closed Source Software

Posted in Stupidities by Ulf on February 4, 2009

epicgames_logoClosed Source Software sometimes tends to have really interesting features. According to the Heise Newsticker, the copy protection routine of the computer game “Gears of War” ran amok on January 29th. Since that date the software complains that the executable has been altered (which is not true) and therefore won’t start.

The problem seems to be some certificate which expired:
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I’ve just created a new category on my blog. This one goes to “Stupidities”.