[meteorite-list] Speed-of-light question

[Chris Peterson]

Well, that energy is on the same order at the mass-energy equivalence, so it 
doesn't seem unreasonable. You just need an efficient fusion generator. A 
matter-antimatter annihilator seems like another possibility. And what's 
wrong with Bussard ramjets, or some similar system that scoops up reaction 
mass along the way?

Obviously I'm not saying any sort of practical spacecraft capable of 
sustained 1G acceleration is going to happen without decades or centuries of 
continued technological development. I'm only saying that no fundamental 
physics stands in its way. That is not the case for something that shields 
the contents of that spacecraft from feeling acceleration. The former is 
science fiction right now; the latter is fantasy.

Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com


----- Original Message ----- 
From: "Darren Garrison" <cynapse at charter.net>
To: "Chris Peterson" <clp at alumni.caltech.edu>
Cc: <meteorite-list at meteoritecentral.com>
Sent: Wednesday, August 26, 2009 11:32 AM
Subject: Re: [meteorite-list] Speed-of-light question


On Wed, 26 Aug 2009 09:46:42 -0600, you wrote:

>Like I said, a mere engineering problem. Nothing in physics precludes a
>battery on your ship with that amount of energy content.

Let's round up the acceleration from .7xg to 1g-- just to provide Earthlike
artificial gravity.  According to the calculator, on that 4.37 ly trip to 
Alpha
C, at 1g of acceleration, the maximum kinetic energy of the ship will be 
around
200,000,000,000,000,000 joules per kilogram of mass.  And, remember, the 
fuel
used to generate that acceleration will have to be carried, too, and will 
itself
have to be accelerated (unless you have some sort of Buzzard ramjet 
arrangement,
which could provide some of that fuel.)  What energy source are you 
proposing
that could provide that energy?