If there’s one totally inexhaustible vein of comedy, it is in previous generations’ excessively optimistic view of the potential of technologies and blindness to its limitations.
There are a few technologies that were originally seen with so much enthusiasm, with wildly optimistic predictions, before more is learned about them.
In short, biometrics are the use of a person’s unique physical characteristics to identify them.
The simplest biometric device are fingerprint readers, but a very common one, used in military intelligence, is the Retina Scan, a staple of the cheeseball military and espionage story trying so hard to be high tech. Retina Scans work because optic nerve in the back of the eye is unusually reflective to light, and it can easily be seen with a flash of light (even handheld ones, which is what those little devices at the Optometrists’ office do). Since everyone’s optic nerve is different, it gives a relatively reliable identification, and since optic nerves can’t be changed, it is unfalsifiable. It sounds relatively ideal for security purposes.
But there are so many problems with retina scan technology, that they have never been used on a wide scale. Take for instance the cost of equipment; a good old fashioned lock is cheap, and even retina scan bolts doors in much the same way. Then you have the fact that it is possible to be falsely identified when a user gets glaucoma or astigmatism. Sometimes low tech is just better.
What I find absolutely amazing is how the very movies that feature “futuristic” biometric security also show exactly how easy it is to circumvent them. The fingerprint scan device can always be fooled by getting a shotglass belonging to a person and dusting it for fingerprints, then using sticky tape to get the prints. The more hardcore way is to chop off a guy’s eye and press it against a retina reader!
The Bussard Ramjet
Back in the sixties, the Buzzard Ramjet was believed by most rocket scientists to be THE solution to interstellar travel.
The biggest problem with interstellar travel is fuel. It weighs a lot and eventually you run out of it. Continued acceleration is also impossible. The faster you go, the greater mass a ship has, and the more fuel is needed to continue to speed up, which imposes an absolute limit on space travel speeds.
But wait! Space isn’t entirely empty. In fact, the interstellar vacuum is filled with loose hydrogen atoms. (Hydrogen is actually the most common element in the universe.)
The Bussard Ramjet involves a space ship that doesn’t carry its fuel with it. Instead, it would use a charged ionic collector, several miles wide, and gather together the hydrogen necessary. As these are ions (in essence, loose protons as they have no electrons) a negative charge can thrust them inside. Using magnetic force, they can be merged into a fusion drive that is constantly self-replenishing. As a result, it’s possible to accelerate up to a point where thrust and drag forces even out, which some guess is around 80% of the speed of light.
(For those not up on their avionics, the original meaning of a “ramjet” is a jet engine that doesn’t use a turbine, which forces air inside and expels it. It only functions at speeds above 375 mph, which means some other means of travel is required to get to that velocity. Ramjets can always be identified as “pods” on the end of the wingtips of jet fighters. There are also turbo-scramjets, for supersonic combustion ramjets, which only operate at speeds above Mach 3.)
The biggest blow to the idea of the Bussard Ramjet came when it was discovered the interstellar medium was much thinner than suspected, with a lot less hydrogen. Second, it was demonstrated in 1985 that the output of a magnetic fusion reactor would require more energy than it produced by a factor of one billion!
So, what's the moral of the story?
Glad you asked, reader. A little earlier I was talking about how silly previous generations and their scientific predictions often were. In some ways, it's almost wrong to laugh, because the history of science technology are littered with the debris of ultimately unfeasable or limited technology that made engineers and science fiction writers go ga-ga. In fact, I’ve come to the conclusion that nanotechnology is to today what atomic energy was to the 1950s and 1960s, and electricity was to the turn of the century: a “Snake Oil” that futurists predict will do just about anything, both a floor cleaner and a desert topping.
The end result of all this is science as a humbling endeavor.