On Fri, Jul 04, 2003 at 04:09:28PM -0500, Robert Seeberger wrote: > I got your point Erik, its just silly and exagerrated.
If you did, the you just don't understand the physics involved. And yes, the comment was meant to illustrate the point in a silly way. > Once the load is applied to the bungee cables, they will stretch > out to the maximum length. Unless you are proposing some "magical" > "supernatural" or "Godlike" bungee cord that does not exist in reality > at this time. Its a irrational proposition which is why I deem it > silly and exagerrated. Rob, are you at all familiar with stress/strain curves? Did you even read any of the links that have been posted in this thread? Because you are dead wrong here on several points. > Too late, its already stretched from the weight of the cab. That is not how it works, Rob. If that were the case, the stress/strain curve would have infinite slope. If you can find a material with an infinite stress/strain slope, then you will be famous indeed, Rob. > As long as the bungee is able to support the load without failing it > would. Thats how elevators work. Its a seperate system that controls > "leveling". Actually, no. The system is designed to work with steel cables, which have very little elongation with stress, less than 0.2% over the range they are designed to work under. If you replaced the steel with something like spider silk that could stretch more than 10%, the control systems would surely be unable to cope. Perhaps you could design something much more complicated that would be able to do the job, but it would be far from a simple engineering design. > 1 It ignores the control systems of an elevator and the fact that > control systems operate independent of current cable length. No, they do not. They operate within the parameters of the steel cables, which is very different from those of a more rubbery cable. > 2 Loading on the bungee cord would take it to its maximum length > (assuming it could even support the load of a cab). The bouncing you > propose is likely a fantasy making the proposal irrational. No, you are wrong about the way loading and elongation works. Maybe you should read more about it. > Erik is a really smart guy, and I would never say anything other. My point > is that his analogy doesn't pan out when filtered through practical > experience. So, you have experience with actual elevator systems suspended by bungee cords? By the way, you have definitely missed the point of the example. You have experience with steel cable elevators. You are drawing conclusions based on an extremely limited set of experiences. Bungees and spider silk behave quite differently than steel cables. That was part of the point of the example, which was meant to illustrate that compared to what we do now, IT WOULD BE VERY DIFFERENT TO USE SUCH A MATERIAL IN OUR ELEVATORS. You steel cable experience is not instructive precisely because it would be so different. Experience definitely has its place, but I think you need to understand the limitations. Your writing often appears like the descriptions the blind men give from feeling parts of the elephant, but if they had simply listened to a book about elephants (or been allowed to study the entire animal), they would have a much better understanding. > Don't the bungee cords you've used have a maximum length? The maximum length is when they break. Obviously you wouldn't design an elevator to operate near the breaking point of the cable. > xponent I'm Soooooooo Stupid Maru rob I don't think so, but you certainly are cavalier in jumping to conclusions that others are wrong based on your own limited experience, rather than understanding of the principles involved. -- "Erik Reuter" <[EMAIL PROTECTED]> http://www.erikreuter.net/ _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
