Thursday 15 August 2013

COMPUTERS VS PHYSICS


 
There is an excellent article at Defense Industry Daily on Canada’s CF-18 replacement program. (1) They make several valid points.

“The thing to remember is that stealth isn’t invisibility, just a shorter detection distance. To use a very simplified and very Canadian analogy, a mosquito will have to be a lot closer to you before you’ll see it, compared to a sparrow. Hence all those “surprise” bites, as they exploit the gaps in your perception and get in close enough to strike. They aren’t invisible, though you might swear otherwise at times. On the other hand, if you use other parts of the spectrum by employing your ears, even a tiny mosquito can be detected at uncomfortably long distances in a quiet room. That’s just the beginning of your problem, of course. Awareness must be followed by pinpointing and tracking its location, and then it must come within your killing range. It’s basically the same sequence for enemy systems against a “low observable” target.”

Americans” they say “have placed their entire future fighter bet on stealth, and are paying the accompanying costs.”

They also point out that;

“The Europeans, in contrast, looked askance at the added construction and maintenance costs of stealth, and at how difficult it is to make aerodynamic changes to a stealth fighter. They opted instead for radar cross-section reduction that stopped short of full stealth, plus high kinematic performance. Protection would also come from advanced electronic warfare and defensive systems integrated into the planes, non-standard sensors like Infra-Red Search & Track, and long-reach weapons like the Meteor missile.”

In the end the different approaches have resulted in very different aircraft, albeit with similar, very high, prices.

Canadian Defence Matters is reminded of another set of technical choices made by a defence contractor in a different situation. They later reported that they realized that the two different methods they were examining for resolving their problem boiled down to either betting that physics would get easier or, alternatively, computers would get faster.

Once having stated the problem correctly the answer became obvious and the company in question went with an approach predicated on the belief that computers would get faster.

It seems as if the United States is in the same kind of situation. Stealth is going to be compromised if better sensors and faster computers are brought to bear on the problem. At the same time the design choices that have been made mean that the F-35 will never be capable of much higher kinematic performance then it now has.

In effect, they are betting that computers will not get faster. That seems unlikely and what is equally unlikely is that there will be any fundamental changes in the laws of physics.

It is often said that the U.S. in particular and the western world in general have no option other then the F-35 as it is the only advanced fighter aircraft available. It’s not true. By allowing Lockheed-Martin to define “Fifth-Generation” aircraft we have missed the fact that both the Eurofighter Typhoon and the Dassault Rafale are both advanced “new-generation’ aircraft, simply ones that have made different design choices.



(1) Defense Industry Daily; Canada Preparing to Replace its CF-18 Hornets