matter

If this doesn’t make you stop eating those burgers, I don’t know what would.

Here is an excerpt from a conversation in the movie “Fast Food Nation” - the movie is based on Eric Schlosser’s 2001 book with the same title.

[Background: Mr. Anderson (Greg Kinnear) is sent on an investigative trip, by his boss, to a meat packing factory to figure out how fecal coliform bacteria were found in some of their burgers]

According to EPA website - “fecal coliforms and E. coli only come from human and animal fecal waste.”

*****
Anderson (to Rudy): How…could cow manure get into the meat?

Rudy (to Rita): Mr. Anderson here would like to know if the meat over there is clean. He wants to know how cow manure could ever possibly wind up in his hamburger.

Rita (to Anderson): Well, there’s lots of ways. My brother used to work at the gut table…and, you know, they have to pull out the intestines and the stomachs…and they just don’t have enough time to do it right. The line is moving too fast. So when they are pulling the guts out - and they make a mistake - all the poop and stuff just pours out all over the meat.

Anderson: Okay, okay, okay…all right. But, really, how often does that happen?

Rita: Everyday…anything else you want to know?
*****

I sense some indigestion in my stomach right now.

There is another interesting converstation between Mr. Anderson and Harry Rydell (Bruce Willis), but before that here is a quick video on a hamburger’s journey from the cows to your car - in a fast rewind mode.

[youtube]V_eN0FogI6Y[/youtube]Click here to watch the movie from the source.
Now, on to the juicy conversation between Mr. Anderson and Harry (while they are savoring some burgers).
*****
Anderson: Harry the meat is filthy. Do you know they got untrained people working at the gut table? Yeah, I mean - Harry, there is sh*t in our meat.

Harry: I think there might be a little bit of sh*t right here in this meat. Just a teeny little bit. Microscopic. [Later] There’s always been a little sh*t in the meat. You’ve probably been eating it your whole life.

[After a few more lines]

Anderson: Listen, there is cow sh*t in our meat because we are running the lines too fast.

Harry: Just cook it. That’s all you need to do. You see? That’s one of the things that’s bugging me about this country. really bugging me. Americans have become these great big fraidy cats. Afraid of everything. Everything’s got to be sterile and germfree. Well, everybody needs to grow up. That’s what they need. [Later] Just cook the meat and you will be fine.
*****

There..now how do you like them burgers?

Now, this is Eric Schlosser’s side of the story (dramatized in the movie) - and obviously the fast food industry refutes his version. To counter “Fast Food Nation”, some folks have come up with a website called “Best Food Nation” (you won’t see any big fast food names here - they are probably hiding behind these guys). Best Food Nation categorically claims that “Ground beef is contaminated with cattle feces” is a myth. But you know, they also claim that “Fast food is a major factor in the increase of obesity in the U.S.” is a myth.

I am sure my wise readers know who is lying and who is not.

To bias you a little bit, on Sunday, USDA reported a Class I (high risk) recall of about 75,000 pounds of ground beef on the suspicion that it might be contaminated with E. coli. So such things do happen. Probably, there may be cases in which stuff like this goes unnoticed in burgers (unlike the spinach episode) - just because people cook them before eating.

Anyways, before we bring this post to an end, here are some money facts as claimed by the book/movie:

• Americans now spend more money on fast food - $110bn last year - than they do on higher education. They spend more on fast food than on movies, books, magazines, newspapers, videos and recorded music - combined. (the movie which was released 5 years after the book reported an updated number of $134 billion)
• Fast food industry leads the US in low pay jobs while fighting any minimum wage increase.
• Meatpacking is some of the most dangerous work in US, but pays 24% less than an average factory job.

Did I save you some bucks on future fast food expenses?

Image source: www.wisconsin.co.nz

What do the credit card numbers mean and how are they generated? I need to start with a disclaimer: Do not use any credit card numbers, except your own, to buy things off internet. It’s wrong and it’s illegal. The purpose of this post is *not* to create fraudulent workable card numbers. It is to explain the math and the science behind those numbers that most of us see day in and day out; and hence this post should be viewed from a purely academic perspective.

Typical credit card anatomy

Before we understand how credit card numbers are generated, here is a brief explanation of what a typical credit card number means.

• Out of the 16 numbers on a typical credit card, the set of first 6 digits is known as the issuer identifier number (read this for details), and the last digit is known as the “check digit” which is generated in such a way as to satisfy a certain condition (the Luhn or Mod 10 check). “Luhn check” is explained later in this post. The term sounds intimidating, but it’s really a very simple (and elegant) concept.
• Taking away the 6 identifier digits and 1 check digit leaves us with 9 digits in the middle that form the “account number”.
• Now, there are 10 possible numbers (from 0 to 9) that can be arranged in these 9 places. This gives rise to 10⁹ combinations, that is, 1 billion possible account numbers (per issuer identifier).
• With each account number, there is always an unique check digit associated (for a given issuer identifier and an account number, there cannot be more than one correct check digit)
• Amex issues credit cards with15 digits. The account numbers in this case are 8 digit long.

What is the “Luhn” or “Mod 10″ check?

In 1954, Hans Luhn of IBM proposed an algorithm to be used as a validity criterion for a given set of numbers. Almost all credit card numbers are generated following this validity criterion…also called as the Luhn check or the Mod 10 check. It goes without saying that the Luhn check is also used to verify a given existing card number. If a credit card number does not satisfy this check, it is not a valid number. For a 16 digit credit card number, the Luhn check can be described as follows:

1. Starting with the check digit, double the value of every second digit (never double the check digit). For example, in a 16 digit credit card number, double the 15th, 13th, 11th, 9th…digits (digits in odd places). In all, you will need to double eight digits.
2. If doubling of a number results in a two digit number, add up the digits to get a single digit number. This will result in eight single digit numbers.
3. Now, replace the digits in the odd places (in the original credit card number) with these new single digit numbers to get a new 16 digit number.
4. Add up all the digits in this new number. If the final total is perfectly divisible by 10, then the credit card number is valid (Luhn check is satisfied), else it is invalid.

When credit card numbers are generated, the same steps are followed with one minor change. First, the issuer identifier and account numbers are assigned (issuer numbers are fixed for a given financial institution, whereas the account numbers are randomly allocated - I think). Then, the check digit is assumed to be some variable, say X. After this, the above steps are followed, and during the last step, X is chosen in such a way that it satisfies the Luhn check.

This part is a bit confusing and takes some time to understand. However, don’t get stuck here…continue reading through the examples below and you will figure out what this is all about.

Credit card numbers valid or invalid?

Have you ever wondered if those numbers on the fake plastic or cardboard credit cards that come with the “preapproved” offers are real or imaginary? If they are not valid, how do you know it?…Just apply the Luhn check and all the those fake credit cards will invariably fail.Here is an example of a VISA credit card (look at the expiry date - 01/09 ..it’s still valid ! )

Note that the credit card number starts with “4″…so it is indeed a VISA issued credit card (VISA cards start with “4″ and MasterCard/Maestro cards start with “5″). Now, let us apply the Luhn algorithm to this card. To make it easier on you guys, I have created a schematic of the steps towards the Luhn check (below) for this card number 4552 7204 1234 5678:

• In this case, when we sum up the total, it comes to 61 which is not perfectly divisible by 10, and hence this credit card number is invalid.
• If such a credit card number is ever generated, the value of the check digit would be adjusted in such a way as to satisfy the Luhn condition. In this case, the only value of the check digit, that will create a valid credit card number, is 7. Choosing 7 as the check digit will bring the total to 60 (which is perfectly divisible by 10) and the Luhn condition will be satisfied. So the valid credit card number will be 4552 7204 1234 5677.

Let’s try another example, this time with a MasterCard.

Again, performing the Luhn check on this credit card number, we have:

• The total comes to 65 which is not perfectly divisible by 10. Hence this credit card number is invalid.
• In this case, a valid credit card number will result only if the check digit is 8. This will bring the total to 70 which is perfectly divisible by 10. So the valid credit card number will be 5490 1234 5678 9128.

Closing remarks

If I still have your attention, here are some additional thoughts. In the context of this post, by the term “valid”, I mean “mathematically valid”. A mathematically valid credit card does not mean a “working” credit card. The Luhn formula validates only the credit card number; it does not validate the expiry date and/or card security code (CVV, CVC). Plus, as discussed before, the 9 digit account number will yield 1 billion combinations; so the chances of getting a working credit card number are very remote. It should also be noted that, this validation is usually employed at the transaction end; which means that numbers that do not satisfy the Luhn check are not forwarded to the card issuer and the transaction is terminated. If you have a fake credit card which satisfies the Luhn check, it will go through at the transaction end, but the card issuer will most likely catch the mischief. So don’t go about trying to use these numbers to buy stuff.

Just to be clear on this, I don’t expect comments like these (check out the source of this comment):

hey. im hearing good things about your site! i need some money to jump start my poker career. Probably about 40-100$ would do. i dont have a credit card to use and it pisses me off because i know i could beat the majority of the people online. please help

If you intend to post such comments, at least be extremely funny.

So you think you can separate out valid and invalid account numbers now? Here are a couple of trial numbers for you:

• 5491 9469 1544 4923 - Valid or invalid? If invalid, what should have been the correct check digit to make it valid?
• 4539 9920 4349 1562 - Valid or invalid? If invalid, what should have been the correct check digit to make it valid?

Sudoku fans will quickly figure out multiple valid combinations of the above numbers. If you don’t want to do the math, here are some ready made valid (”test”) credit card numbers from Paypal.By the way, the Luhn check is also valid for debit card numbers.I am still in the learning phase with this topic and trying to further understand how people use (or misuse (?)) such information. If you have some insight in this matter, please feel free to share it with us.If you liked what you read above, go ahead and subscribe to this blog to get more updates. It’s easy - just click on one of the buttons below and get the feed.

Resources and References

There is a vast amount of literature on the Luhn algorithm and a quick Google search will enlighten you on how popular this topic is. If you don’t want to read all that, here are links to some interesting reading.

• Card Identification Features (pdf file) - extremely useful, must read.
• Credit Card Numbers and Credit Card Generator @ Graham King.
• Anatomy of Credit Card Numbers.
• Credit Card Number - Wikipedia.

VISA card image source: http://www.hkuaa.org.hk, MasterCard image source: http://www.nscs.org

Drive to Burger King

Buy a Texas Triple Whopper

Enjoy your meal !

*Offer valid only in Texas

Nutritional information source: www.calorieking.com

I went for a haircut yesterday, paid $10 plus a $2 tip, and to make a long story short, let’s just say that every day will be a bad hair day for the next month or so. It’s not really new for me, this has been happening for quite some time. In the last 4~5 years, I must have had only 5 or 6 good haircuts. I have changed barbers, changed barbershops, tried showing loyalty to certain barbers (in the hopes that building a good rapport might get me a good haircut), but nothing seems to work.

I am not sure what the reason is, but the most probable culprit (to me) seems like the electric haircutting machine that these guys use. It’s a one-size-fits-all gadget and some barbers seem to use it like a chainsaw…no thinking, just hacking. Somehow, I get a better haircut when barbers rely more on plain old scissors than the chainsaw…I mean haircutting machine. Scissors make the process a bit slower, but I guess that’s what gives the barber some time to think about what’s happening with your hair.

The fastest (and the crudest) haircut I ever had must have taken like 3 minutes. I agree it’s a fast world, and everyone is in a hurry, but $10 for a 3 minute job seems like a bit too much. That’s $200 an hour. I don’t mind paying at that rate if it’s a good haircut…but that doesn’t seem very likely to happen.

Anyways, after some observations, I have figured out some hacks that may improve one’s haircutting experience (and yet, it does not mean you will get a *good* haircut…you may just get a better haircut than a bad one). Here are some of them:

• Don’t go near closing time or you will get a bad haircut.
• Go when you are not feeling sleepy; it’s very easy to doze off when you are doing nothing sitting in the barber’s chair. This is just so that you don’t regret it when you open your eyes.
• Don’t go when there is a football or basketball match going on TV. You will be watching the match and so will your barber (so nobody’s watching the hair).
• Keep talking to your barber (so that he/she is not distracted by other customers/barbers). If your barber starts talking to other barbers, it means he/she is loosing interest in cutting your hair.
• In addition to whatever numbering system they use (like number 1 = just cut 1/1000th of an inch or number 10 = make me bald) give some length clues. For example, “make it half of what it is right now” or “shorten it by 1 inch“, etc. The number system is tricking; different numbers mean different things to different barbers.
• Wash your hair before you go for a haircut. There are a couple of advantages to this. Your barber won’t need to spray gallons of water to wet your hair (I hate it when they spray too much and it starts dripping over the eyebrows). Plus, this will also keep your barber focused on cutting your hair instead of trying innovative ways to avoid the smell of dirty hair.

By the way, I still give them a 20% tip just for agreeing to cut my hair; this is to appreciate two facts: 1. it’s a standing job, and 2. if they refuse to cut it, there is absolutely no way I can do the job on my own. In fact, I am ready to give a 50% tip if someone does the job well…ever.

Over this weekend, make sure you check out the Freecycle.org. This website is run by The Freecycle Network, a nonprofit organization that encourages recycling. “One person’s trash can truly be another’s treasure!” is the basic premise behind the network. This is a must-see website for all those who are trying to save money and/or for all those who are going green. It’s all about giving and taking things for free. *Free* is the keyword here. All communities that are linked through this website emphasize something to this effect:

All items posted must be 100% free; no trading, buying, or selling

That sounds nice.

When you are on the website, click on the link “Groups in your local area” in the left sidebar and you will be ready to go. All communication between members is administered through Yahoo! Groups…expect these groups to be fiercely moderated (this is good, it keeps out a lot of spam, politics, and other junk). This also means that there might be a small delay before the moderators approve your membership and you start giving/taking.

Some communities are extremely active with thousands of listings every month, whereas some manage with barely a dozen in the same time span. If, at present, you don’t have a Freecycle group in your local area, there are instructions on the website on how to get one going.

Note that this is not just limited to the US; there are Freecycle groups located all over the world, so look it up for your country. If your country doesn’t have one, start one yourself.

Btw, on a personal note, we students have our own recycling network going on in our local area. Most dumpsters serve as hubs for this kind of activity. Hopefully, with the Freecycle Network idea catching on, the dumpsters won’t be our middlemen in future.

Image sources: freecycle.org and www.withoutatrace.biz

Presently, I have taken upon myself, the task of learning more about how to (efficiently) invest in the stock market. There are two reasons for this: 1. I am a stock market dummy, and 2. I miss not writing about investments and stock market on this blog. The depth of my lack of judgement in this matter will be very clear if I mention the fact that my first ever investment in the stock market was in WorldCom….just a few months before it collapsed! Fortunately, it was just an experiment and I didn’t loose much in the debacle.

Ok back to the subject. So I was reading a few things on the internet and came across this website which describes the work of Eugene F. Fama, in which he concluded that the behavior of stock market is essentially unpredictable (this was done in 1965). The theory made a lot of financial analysts and investors uncomfortable. Here is an interesting story that follows Fama’s theory:

At the 1968 Institutional Investor conference, one irate money manager insisted that what he and others did for investors had to be worth more than just throwing darts at the Wall Street Journal. The “dart board portfolio” soon became a new benchmark for active investors, appearing in newspapers, magazines, and in a 1992 20/20 ABC news segment entitled, Who Needs the Experts? In that segment, a giant wall-sized version of the Wall Street Journal was made into a dartboard. Reporter John Stossel threw several darts as he described the firms he randomly hit. The results of that portfolio were compared to those of the major Wall Street Firm experts. The darts beat ninety percent of the experts! When ABC requested interviews with several of these expert firms, none of them would speak or comment on their humiliating inability to beat the darts.

If you are game, you can try this yourself (of course, at your own risk) and create a model portfolio and see how it goes from there. May be you won’t make a killing, but my engineering instincts are ready to give you some hopes.

If you are unsure about what I mean by “engineering instincts”, it’s time for you to read Dilbert more often.

To put a closure, Fama’s work suggests that the stock market is mainly governed by randomness due to a variety of factors. Due to this random nature, very complicated mathematics is required to attempt the prediction of performance at a future date. Investors don’t appreciate this fully, but the very idea of portfolio diversification is based on this kind of market behavior. If it were possible for financial analysts  to *guarantee* better performance for certain stocks in future, there would be no need for any diversification.

After uploading the post titled “Gasoline Prices: Why $2.189 and not $2.19; Why The Third Decimal Place?” on late Thursday night, I tried to check my website yesterday around noon and kept getting error messages. I was just about to lodge a complaint with Dreamhost when I read this email from Dreamhost Tech Support:

I’m writing to let you know that your domain thetaoofmakingmoney.com was
getting too many hits and consequently kept crashing the shared apache
service. I set a restriction on the domain: it can receive 75 connections
in 5 seconds which resets every 5 seconds. This is to bring down the load
on your server, but still leave your site operational.

From the Sitemeter referral page it was obvious that one of my post got on Digg.com. Here is a screenshot of what happened at Digg.com - 930 diggs so far !:

If you want to add to those numbers - Digg here …also you could entertain yourself with some nasty comments on that digg link.
And here are my Sitemeter statistics showing the digg-ing blip that goes near 13,000 !!

Seems like I really need to stop being a moron and read something about how to make websites survive the Digg assault by caching and staticizing. I do run WP-cache 2.0 plugin, but apparently that didn’t help much and the crashing continued on and off.

I am still wondering about what attracted so many diggs to this particular article…certainly there have been better articles in the past on this blog.

Here is a funny product, the purpose of which I don’t really understand (other than to flush $299 down the toilet): The Fish n’ Flush Aquarium. Marketed by fishnflush.com, this doodad of a toilet has the water tank in the form of an aquarium. Here is an image of the product.

The marketing guys at this company must have had a hard time trying to sell these toilets to people. Here is how they try to promote it on their website:

I don’t understand how having a fish tank wrapped around your toilet tank is going to “maximize space”. May be it means that you can now move your fish tank from the living room to the toilet and save some space in the living room. Those who are interested in observing your pretty fishes will have to compulsorily visit the restroom and try to peer from across the pot….ewww. Also, the “entertainment” and “excitement” …of all the places in the house, why would you want the toilet to be entertaining and exciting? I agree with the “conversation piece” stuff…it will surely make you famous as the village-idiot who has too much money to spend on toilets.

I also have some technical conceptual issues with the design. Below this paragraph is a schematic of a busy person in the restroom. Now with the current design, the damn aquarium goes behind the person’s back….OK..so even if it’s entertaining, it’s not going to provide the entertainment when most needed (unless they also come up with an innovative style of sitting) and obviously lacks ergonomic considerations :). There are cases in which a person may be looking towards the aquarium (opposite to the line of sight shown in the image)…but then he would be standing and the tank would need to be at about 5 feet height.

Also, when the toilet is in use, the lid goes up (duh!) and partially covers the aquarium. So what’s the message here? look at the aquarium when the toilet is not in use? So you expect people to go to the restroom, sit on the seat with the lid down and turn their faces towards the aquarium for the “entertainment” and “excitement”?…yeah sounds like fun.
The product is mentioned in a small article on this website. An excerpt from the article says this:

The first time people see it, they fear the fish are going down the drain along with everything else. While it was designed as a fish tank, Reel says you can put other things in here, too. “If you don’t want fish, if you want to make it for scorpions, snakes, lizards…”

Dude…this is going too far. Scorpions, snakes, and lizards behind your back when you are in action !? That’s a sure ticket to some long term constipation for anyone who visits your restroom…may be that’s the “excitement” they talk about in their promotion

All this “excitement” doesn’t come cheap at $299. Below is a screen shot of the price listing for the product which also mentions about some fancy “LED light system” for an additional $25. I am not sure exactly what they want to accentuate with the LED lights:

So go ahead, buy the toilet if you like…or might as well just do something like this:

[Image sources: www.fishnflush.com, www.birdsinthebelfry.com, www.carsonmania.com]

During our holiday driving in the past few days, we came across this large advertisement on a state highway..made us slow down and pull into the gas station to see if we can benefit from the ultra-low prices

Disapointment was quick and expected. The gas terminals at the station seemed unused for a long time and there was not a soul in sight. A brief inquiry at a neighboring retail shop enlightened us to the fact that the gas station was shut down and deserted about 4 years ago !!

Yet another evil gas station that seem to like the “gotcha sucker” game. Anyways, at least they are not showing one price and selling at another higher price (that would have made a sensational scam story instead of this lame post).
$1.38 per gallon would have saved us about $10 for a full tank, compared to current prices. Instead, it wasted 10 mins of our travel time and just reinforced the wise words: when something seems too good to be true, it is too good to be true.