Debunk Delight
I’m all for dramatizing IT in television and movies. Mostly television; movies tend to have a little more time to make things realistic, where television is generally on a serious time crunch. But, as a general rule, I don’t mind that each keypress makes a beep and that somehow the Des Moines city bus system has a high-tech tracking portal with blinky dots for each bus, but yet is hackable within five seconds by the right cyberpunk genius. By the way, the movie The Taking of Pelham 1 2 3 has one of the best dramatized IT platforms I’ve ever seen.
What does bother me is the complete mischaracterization of stuff like GPS. If you watch the average whodunnit show, anything with a GPS receiver (note that it is not called a transmitter!) will broadcast your location through some kind of cloud, providing yet another blinky beepy tracking dot to anyone with the skills to listen.
GPS satellites are positional beacons. They go “ping” but not “pong.” Wikipedia says it takes four satellites (the fourth one, while not mathematically required to resolve three dimensional space, eliminates a significant amount of potential instrument error) to resolve one’s position. The satellites are effectively screaming “I’M AT POINT X1 AT TIME Y1! I’M AT POINT X2 AT TIME Y2! I’M AT POINT X3 AT TIME Y3!” and based on the time it takes the messages to arrive from each satellite the receiver assembles all that evidence into a good picture of his own location.
It’s an elegant and very one-way process. Now, if that “receiver” connects to the internet via 3G and publishes the location it calculates, you’re looking at a tracking device. But that’s separate from the core function of a GPS receiver.
So, in summary, “His phone has GPS!” does not necessarily mean the case is in the bag. Maybe if he has one of those kiddie tracker apps installed, but otherwise, keep searching, buddy.
Interestingly, while not as accurate as GPS, tracking via cell tower proximity is a much more realistic way to track someone whose phone has not been otherwise compromised. I’ve seen that a few times on shows, but GPS is often chosen even though there’s a more realistic actual method available. I think a lot of show writers think the cell tower triangulation is the same thing as GPS. This is probably further egged on by the continuing misconception that cell phones communicate directly with satellites for their basic operation.
The whole digital picture “enhance” thing has survived a surprising lot of popular ridicule. It’s of course possible to attempt to “sharpen” an image using an algorithm, but all an algorithm does is create and/or destroy information using a certain assumption.
For example, if you see a 350-sided polygon whose outside border is never that far from its center, we might assume that in real life this is a circle, only perceived as being jagged due to the limitations of a camera’s sensor (resolution). It’s a lot easier to zoom in on a circle (mathematically increase the radius) than it is to “digitally zoom” in on a 350-sided polygon (interpolate, pixellate, etc.).
Calculus will tell you that a circle can be drawn as a polygon with an infinite number of sides, all the same distance away from its center. Therefore, correctly identifying a perceived n-polygon as a circle means that the information created by the algorithm’s assumptions is useful, providing an “enhancement” to the picture when resizing. If it turns out that the polygon was in fact a sawblade, you’ve just destroyed good information (the geometry perceived by the camera would be overwritten by the computer with a “smooth” circle).
Economics’s “no free lunch” policy applies strongly to data. An algorithm like the above hypothetical one is only as good as its assumptions are applicable to the current situation.