# Probability, Stochastic Processes, and Airport Security

I’m an engineer.  This means, like most engineers, I survived a couple of courses on probability.  For some engineers this knowledge is critical to their work.  For many it merely provides background knowledge about the behavior of the physical world.  As a group, however, engineers have a much better understanding of probabilistic events than the man (or woman) on the street.

The average person so poorly understands probability and probabilistic events that casinos get to sell a guaranteed long-term loss as gambling.  For example, engineers understand that if you play a slot machine long enough, you get back exactly what you put in minus the casino’s take.  Not only that, electromechanical slot machines can be and are easily adjusted by the casino as needed to accommodate their marketing and profitability needs.

Engineers understand there is no magical force connecting statistical events such as coin tosses.  That is, no matter how many heads in a row have been tossed, a fair coin will always have exactly the same probability of heads on the next toss.  The chance of heads on the very next toss does not decrease because heads has already been tossed repeatedly.

Given that engineers, at least those who stayed awake during their classes, understand the basics of probability, one must wonder why the fraternal order of engineers has not complained loudly against the concept of random searches for terrorist related activities.  Specifically, if a terrorist organization has thousands of followers ready to die for a cause, random testing does no good whatsoever.  This is worth saying again.  Read this until you understand it.  Testing 3%, 10%, or 50% does nothing.  If you happen to thwart one terrorist, the next one or the next or the next will get through and accomplish the mission.  Anyone in a position of authority recommending random testing or searching either has some agenda in mind or has a dangerous lack of understanding of probability.  Anything other than 100% testing or searching is meaningless with respect to terrorist activities.  Yep, the fear of getting caught may deter NFL players from using steroids but getting caught means nothing in the terrorist scenario.  They just recruit the next in line willing to blow themselves up.  If the target were important to the terrorists they would send their minions until one slips through the random searches.  Numerically speaking, not many would have to be sent to get through even 50% testing.  3% testing seems useless.

OK –

So if we assume the proponents of random searching for terrorist activities have a brain, or at least listen to knowledgeable advisors, their reason must be something other than actually dissuading terrorist activities.  To me, the answer seems obvious.  All in the position of protecting us from harm know they will eventually fail.  There is no question about this.  No matter how good you are and how hard you work, you can’t be perfect every time and every day.  Sooner or later a bad guy will get through.  Sooner or later we will lose another plane, or a train, or perhaps even a city.  When this happens, the executives in charge of protecting us will be pilloried by congress and the press.  The executives need a way to deflect blame and the way they seem to have chosen is highly visible security theater.  Given my somewhat poor understanding of human nature and the society in which we live – I predict that, in fact, the TSA executives will get an automatic free pass for failure if they are summarily ordered to back down from intrusive searches.

I found it remarkable for many years that our monuments were still standing.  From perhaps the 1970s until 9/11, I would occasionally reflect that someone was doing an incredible job.  I assumed every nut in the world wanted to do us harm – yet our monuments were untouched, there were no explosions at the super bowl, and political figures were rarely assassinated.  Then, somebody screwed up and 9/11 happened.  Suddenly everything that was being done quietly in the background became theater.  At the airport I observed people pulled from the security line and searched within view of the other passengers.  Being an engineer I understood that such random attention was meaningless and perhaps even harmful in that it gave those with a poor understanding of probability a false sense of security.  The fact that it was done within view of others in line made it terribly obvious the intent was to visibly covey those in charge were doing everything possible to keep all of us safe.

As a society, we transitioned from our guardians quietly doing their job in the background to overtly warning us that we are in danger and need protection.  We now live at a perpetual threat level of “elevated” and regularly hear of new risks that are being detected.  We hear, for example, that German agents have apprehended the great uncle of some guy who heard from his cousin that there is some plot involving bottles of shoe polish.  In response, bottles of shoe polish are banded from carry-on airline luggage.

Look, guys…

Why do you feel you have to advertise these kinds of things?  You are wrong if you think occasionally publicizing the great job you are doing or periodically reminding us how much we need you is going to protect your job in the event some terrorist manages to accomplish their mission.  If a problem occurs, you guys are screwed and heads will role.  Sorry, it isn’t fair but that is our society.  Just do your job the best you can, quietly, as your predecessors did.

The battle against terrorists is a continuing evaluation of relative risk.  This means everything is about acquiring information, statistics, and probability.  Our uniquely American culture believes that all life is precious and must be protected and nurtured.  As an American with more than 50 years of experience with this culture, I think we will all or almost all agree that the lives of those who fly on commercial aircraft are of exactly equal value to those who drive cars or are patients in hospitals.  If this is true, if all lives are of equal value, how do we explain our infatuation with airport security and neglect of other areas badly in need of money and attention?  Every year, every single year, we kill something like 40,000 people on highways.  Every year, every single year, hospital errors are responsible for the deaths of 90,000 people.  How many airline passengers died last year due to terrorist activities?  In fact, the enemies of bad software and mechanical failure statistically seem to be far more dangerous than any terrorist activity.

To be fair it is possible that our low incidence of terrorist related aircraft death is due to the skill and hard work of the various protective organizations.  Consider, however, that something like 770 million people fly through American soil each year.  If we assume a flight on average carries 200 people, terrorists would have to blow up 200 flights per year to match our automotive death rate and 450 flights per year to match the number of hospital deaths.

Why are we so fixated on aircraft issues?  Well, one big reason is aircraft were the vehicle of choice for the 9/11 attacks.  Had the terrorists used busses, we would have focused on them.  Our kneejerk responses to various attacks do not bode well for our ultimate safety.  There are an infinite number of ways we can be attacked and pouring all or most of our resources into protecting us from the old methods may make us unnecessarily vulnerable to a new method.

OK, so what about those new airport scanners?

The media continually refers to the new security devices at airports as “scanners”.  Although I’m an engineer and somewhat in tune with technology, only last week did I understand that these devices are based on two emission technologies – one emitting x-rays and the other emitting microwaves.  Remarkably, I haven’t heard much about dangers and risks associated with these devices.  New x-ray devices, like new pesticides, are always deemed “safe” when they go into use.  Years later we find out how dangerous they really were.  History says only a fool would say that these x-ray and microwave devices pose no danger whatsoever to any risk group – even people with skin cancer or pregnant women.  I haven’t been to an airport recently and wonder if they have warnings posted for pregnant women.  Hopefully the TSA is righteous enough to recommend pregnant women get fondled rather than x-rayed.

It is reasonable to assume some frequent travelers who are repeatedly subjected to x-rays or microwaves will suffer soft tissue damage, develop cataracts, cancer, or other problems.  Once again, we are looking a relative risk…

But won’t the naked pictures of travelers and personalized fondling make us all safer?  Sadly, no.  What it will do is force the evil organizations to surgically implant bombs or biological devices inside the terrorist’s body.  Only visual inspection of the body will detect scars from the implantation of non-metallic devices.  Also, a terrorist need not get on a plane to create terror.  What do we do the first time someone detonates a bomb while standing in line waiting to go through security?  We have no answer to that.  The first time this happens, our protectors will look like the keystone cops running in circles.   I can’t even imagine the solution they will propose for this problem.

Likewise, it is merely wishful thinking that any images obtained could never-ever be released to the public.  Consider what Wikileaks has done with secure military information.  Banks seem to accidently expose credit card numbers on a disturbingly regular basis.  Do you really believe it is absolutely impossible for images to be leaked?

Gee, I wonder if recognizable tattoos show up in these images?

What of homosexuals?  Do they have the option of being fondled by someone of the opposite sex?  For that matter, do heterosexuals have the option of being fondled by someone of the opposite sex?

What of homosexuals working for the TSA?  Does TSA execute a don’t-ask-don’t-tell policy?  Can there be undisclosed homosexuals doing pat-downs/fondling passengers?  Is it absolutely impossible for a sexual pervert to make it into the ranks of the TSA fondlers?

Who cares anyway?  If your job requires travel and you don’t want to deal with the airports – just quit that job and go get another one to support your family.  Jobs are plentiful.

But enough negativism –

If we do continue down the current path, I see a number of unique opportunities offered by this new surveillance technology.  Consider:

1. Aluminized foil appliqués worn under the clothing for advertising purposes.  Prostitutes, for example, might have a message something like – “Like what you see?  Call 800-555-1234”.  Or the foil advertisement may suggest a place for the TSA agent to eat when they go off duty.  Or a new movie may be advertised.  Or…  The sky is the limit here.
2. Nevada, for example, could offer airport secure saunas and messages.  Highly trained TSA certified masseuses could cavity search travelers – and provide a number of other relaxing services.  The secured travelers would then be escorted directly to the aircraft.  For an extra fee, some may choose to be bound in latex for the duration of the flight.
3. Somehow the homosexual thing must be solved.  The easy solution also opens and entire world of other money making opportunities.  Simply line up the TSA agents, both male and female, and let the traveler select the one to conduct the fondling.  Some agents would likely develop regular customers from among the frequent flyers.  Yes, I envision a frequent flyer telling Lars, the large TSA agent of Scandinavian heritage, “[wink] see you next week, Lars”.

Final thoughts –

I’m an engineer, so I really like engineers getting paid to build sophisticated equipment.  On the other hand, I’m also a taxpayer.  Can’t we make air travel secure in a more economical fashion?

We live in a democracy.  If the majority decides airline travelers must be strip-searched and anal-probed, then so be it.  But… We don’t need sophisticated technology for this.  Why not just have everyone strip and be cavity searched?  They would then be issued an airline provided prison gown and put on the plane.

Another possibility comes to mind.  This has the down side in that it takes power from the hands of the bureaucrats and gives it to the people.  Hence, it is not likely many in big-government positions of power would support it.  What if… now I’m just thinkin’ here… what if instead of pat-downs and high-tech x-ray imaging we just told everyone getting on the plane:

” Do not let anyone take over this plane”

I look forward to hearing from those who can correct any of the information or statistics I used in this article.

Oh, and one final, final thought –

I hear that, because of their well-established security credentials, members of Congress are exempt from the new imaging and fondling.  Does this mean that EVERYONE with a high-level security clearance is exempt, or is it just the kings and queens of society?  Hummmm, kings and queens…