Newer Isn't Always Better

Written: 2000.07.10
Last Revised: 2001.04.30

Magnetic bearings vs contact bearings

If you've heard of magnetic bearings, you'll know how cool they are. You'll also know that they're a perfect example for the SW vs ST debate. Unlike conventional ball bearings or fluid bearings, a magnetic bearing uses forcefields to suspend and control the rotor inside the stator. Since the system is inherently unstable (a common failing of forcefield-dependent technologies), a computerized control system must constantly monitor the shaft position and adjust it thousands of times per second. It does this by adjusting the current flowing through a series of electromagnets arrayed around the shaft. It's far more advanced than primitive contact bearings such as ball or roller bearings, so contact bearings will become obsolete, right? Wrong. It all depends on the application:

But ...

So they're newer, they're more advanced, and they're definitely reminiscent of the sort of thing you would see on Star Trek. But while a Star Trek writer will always replace contact equipment with forcefield equipment, real engineers aren't so foolish. The vast majority of the bearing systems in the world are still contact bearings, even though magnetic bearing technology is already quite mature. Newer isn't necessarily better. Real engineers tend not to throw out old technologies in favour of new ones, but rather, they tend to add new technologies to their growing inventory of tools.

Aluminum vs Steel

Steel has been in use far longer as an engineering material than aluminum, due to the relative ease with which it can be mined, refined, and processed. Aluminum was developed for industrial use more recently than steel. It's used heavily in high-tech applications such as aircraft and race cars. This means aluminum is simply better than steel, right? Wrong. It all depends on the application:

But ...

Other non-ferrous alloys such as magnesium and titanium-based alloys also have a combination of strengths and weaknesses, making them good for some applications and bad for others. As with the previous example about bearings, the history of materials science has been that new materials supplement existing ones in our engineering inventory, rather than replacing them. I have often been criticized for being too hard on people who don't know these things, but you don't need to be a materials science expert to know this. You just need to think!

We still use cast iron heavily in spite of all of the more "advanced" materials available to us; don't people ever wonder why? "They only use it because it's cheaper", some might object, but leaving aside the fact that the situation isn't quite that simple, I would point out that cost efficiency is a legitimate engineering parameter, just as legitimate as any other parameter such as strength or weight. Cost concerns won't disappear as productivity increases with new technology; no matter how advanced you are, some things will always be easier to make and process than others, so you will always face the choice.

There are myriad parameters influencing an engineer's choice of materials, so it's not as simple as a Star Trek writer or a wet-behind-the-ears high school kid might think. There is no universal "best" material, and newer isn't always better.

Microwave heating vs convection heating

Sure, microwave technology is newer. It's more efficient. But if you think a microwaved T-bone steak tastes better than a barbecued T-bone steak, you must have lost all of your taste buds in a childhood accident. OK, I admit, this example is a bit facetious. But I do love barbecued food, so I couldn't help it.

In any case, there is no universal "best" way to heat things. Microwaves are quite good at what they do. Barbecues are quite good at what they do. Yet again, we didn't obsolete an older technology in favour of a new one; we simply augmented our technology library.

Nuclear weapons vs chemical explosives

Obviously, nuclear weapons are superior to chemical explosives, right? They're far more powerful. But you don't have to be a nuclear physicist to know that they're not exactly ideal for every situation. Only an idiot would replace every conventional explosive in the world with nuclear weapons, because nukes tend to make things radioactive. They also can't be built in arbitrary yields; there is a minimum yield defined by the minimum critical mass required to produce a nuclear fission chain reaction. This makes them extremely difficult to use in most situations.

Newer isn't always better. Yet again, we didn't replace an old technology with a new one; we added the new technology to our inventory.

Aircraft vs naval vessels and ground vehicles

The first major vehicle was the wagon. Second came the boat. Both were repeatedly improved and refined over the millenia, until they were both superseded by the newest vehicle: the aircraft. Wait a minute ... that's not right. We still use cars, trucks, and ships, don't we? Is this because we're too primitive to wholeheartedly embrace the airplane? Surely not even the most devoted technology-caste advocate would try to sell that one. Boats and cars have some obvious advantages over aircraft, which also have advantages of their own. It all depends on the application. You design to suit your purpose, not to deliberately use a particular type of technology.

Yet again, we didn't replace land and sea vehicles with aircraft; we added aircraft to our inventory of vehicle types. Newer isn't always better.

Polyester vs cotton

'Nuff said :)


Acknowledgements


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Valid HTML 4.01!Valid CSS!This website is owned and maintained by Michael Wong
This site is not affiliated with Lucasfilm or Paramount
All associated materials are used under "Fair Use" provisions of copyright law.
All original content by Michael Wong is copyrighted © 1998,2004.
Click here to go to the main page