From: jhk6@cunixb.cc.columbia.edu (John H Kim)
Subject: Re: Military Mechs?
Reply-To: jhk6@cunixb.cc.columbia.edu (John H Kim)
Organization: Columbia University
Date: Tue, 28 Jul 1992 15:49:34 GMT

jwadsley@vaxc.cc.monash.edu.au writes:
>Hang on here. Fusion engines produce electricity directly? Since when. I
>haven't read Battletech in detail but if this is an assumption then this 
>little garbology has to rank as one of the worst flaws in Battletech. 

	Fusion power in general is pretty heavy garbology, yet it remains in 
use as a science fiction staple. Already the mech has insufficient shielding 
to protect its pilot form the neutrons produced in the fusion process. At any 
rate, a sufficiently advanced technology might combine fusion power heat with 
magnetohydrodynamics (using the fusion plasma as a conductor which passes 
through a magnetic field, forced by its own heat expansion). 

>
>Even if fusion engines do produce electricity directly, there is no reason why
>it can't be easily converted into mechanical energy via the usual means, which
>is very efficient. If vehicles have extra weight that is an electrical engine 
>then mechs have that weight as myomer fibres.
>Mech: Heat -(magic)- Electrical - Myomer
>Vechicle: Heat -(magic)- Electrical - Mechanical

	Myomer is supposed to be a lighter and more efficient conversion 
process - which is not that tough. The efficiency of electrical motors 
converting electrical energy to mechanical is no than the efficiency of 
electrical generators converting mechanical to electrical. 

>
>Anyway a comment on energy conversion:
>   heat to mechanical - inefficient
>   mechanical to electrical - efficient
>   electrical to mechanical - efficient
>   heat to electrical - not possible as far as I know
>
>Disclaimer: I haven't looked at this stuff for years!
>
>There is no scientific basis on which to argue that mechs are more efficient
>than normal vehicles. This applies to energy usage and weight of engines and
>power sources. 

	People have been trying to predict technology for years, and not 
doing a terribly good job. Saying that you are out of date and then making 
a blanket statement like 'There is no scientific basis...' is rather 
presumptuous. MHD turbines work - the problem is that they are unable to 
withstand the heat they generate. Fusion power does not (thus far). I do 
not profess to know what the technology would be like to solve these 
obstacles. I don't have a problem with people pointing out errors in Btech. 
(Heck, given their original building and repair rules, there would be no 
mechs at all in a couple of years.) However, I do have a problem with people 
with simlistic assumptions about how technology will proceed. 
	At any rate, power seems to be easy for mechs - the real problem 
seems to be heat. Mechs have greater surgace area than tanks for radiating 
heat. 

>
>I think we are getting to the heart of the thing here. This magical efficiency
>of myomer and fusion engines compared to everything else appears to be a major
>assumption behind the existences of 'mechs' ( Size and shape arguements put
>aside ).

	Kindof like the 'magical' efficiency of superconductors compared to 
everything else, or the 'magical' efficiency of fibre-optic communications 
as compared to electrical lines. (A single, hair-sized fiber optic cable 
can support 10^12 bits of information per second, with no need for repeaters 
with present technology.) 

	Yes, you can invent future technologies without postulating startling 
innovations or discoveries - but don't try to tell me they are more 
'realistic' than others; they are just more comprehensible. 

----------------------------------------------------------------------------
John Kim                    | "All the world will be your enemy, Prince with 
jhk6@cunixb.cc.columbia.edu | a Thousand Enemies. And when they catch you, 
Columbia University         | they will kill you."         - Watership Down