Re: Fusion energy was: SNOW JOB

K.H.Ranitzsch schrieb:
> ----- Original Message -----
> From: "Brian Bilderback" <bbilderback@hotmail.com>
> > >As an illustration: The effect Nuclear weapons is 
> > > measured in Megatons, that is a million (10^6) tons of 
> > > conventitional explosives. 

> If you just assume the factor 1 million:
> Take a tank whose conventional chemical engine has enough 
> hydrogen fuel to run for a day (about typical for today's tanks). 
> Exchange the engine for a nuclear engine and the same fuel will 
> last for a million days ! That is about 3000 years. If Pharao 
> Ramses had had such a tank, it would still have fuel today, 

To Roger :
(Sorry, hit the delete button before I decided to answer)

I was not talking about antimatter annihilation, but about fusion and 
fission. Nor about high efficiencies. I illustrated my argument with 
nuclear explosion which are awfully inefficient. 

http://www.phys.virginia.edu/classes/252/home.html
Has a section on nuclear physics where the available energies are 
discussed.  
They are given in eV (Electron Volts, a convenient energy unit for 
events at the atomic scale) and MeV (Million Electron Volts) :	

Ennergy from antimatter annihilation (proton + antiproton) : 2x 1875 = 
3750 MeV 
Energy from fusing two protons (hydrogen) : 2.2 MeV
Energy from the fission of one Uranium atom: 200 MeV
Energy binding an electron to a hydrogen atom : 13.6 eV
The latter is an upper limit for what you can get from a chemical 
reaction. Burning hydrogen and oxygen will produce rather less (sorry, 
don't have a number handy). A factor of about a million. Anitmatter 
annihilation produces a thousand times more than that. 

http://www.compusmart.ab.ca/plambeck/index.htm
"The binding energy of the atom is given by the Einstein equation as 
[...]  1.43 x 10+13 J/mol). This amount of energy is much greater than 
the normal energies which are involved in the formation of chemical 
bonds, a few to a few hundred kJ/mol." 

"a few hundred KJ" is 10E+5 J, compared to 10E+13 this is a factor of 
10E+8 (100 Million) 

Whatever way you cut it, and even assuming extremely poor efficiencies, 
with a nuclear engine you wouldn't have to worry about refuelling for 
the foreseeable mechanical lifetime of the tank. This holds even for 
any energy use which we can realistically asses (e.g.GEV mobility or 
Laser guns). 

How long a tank with grav drive and a plasma gun will run on a full 
tank of hydrogen is left as an exercise for the reader :-) 

Greetings