|11-27-2004, 11:55 AM||#1|
Join Date: Oct 2001
Location: The Backside of the Internet
Emerging possibilities for space propulsion
Its a long article, some of it is highly technical but if you can get through a few technical sentences that meant absolutely nothing to me, then you will be rewarded with a layman's explanation of anything that might be confusing.
Some of the theories I thought were interesting because I had not heard of them before and I TRY to keep up with this sort of thing. Like the below excerpt:
Another viewpoint on gravity and spacetime: As mentioned earlier, the ideal interstellar drive must not use propellant. Instead the ideal drive would have to use some means to push against spacetime itself. One of the major objections to this notion is the issue of conservation of momentum (ref 19). In order to satisfy conservation of momentum, something must act as a reaction mass. For rockets it is the expelled propellant; for aircraft it is the air. If one considers propelling against spacetime itself, then one must entertain the possibility that the fields of spacetime have an energy or momentum that can serve as a reaction mass. Although existing physics does not provide this perspective, a recent theory has emerged that might. A news article published in December 94 (ref 6) introduced a theory (ref 20) that is challenging Einstein's general theory of relativity. The theory is generating a bit of controversy because it claims that the Einstein field equations need a slight correction. Without this correction it is claimed that the Einstein equations can only predict the behavior of simple one-body problems (where only one gravitating mass exists whose affect on an inconsequential test particle is described). For two-body or n-body problems, this new theory shows that the Einstein equations are inadequate. The required correction is that another term must be added to the matter tensor, specifically a term for the stress-energy tensor of the gravitational field itself. This suggests that gravitational fields have an energy and momentum of their own. This may be a foundation to address the issue of a reaction mass for the ideal space drive.
We keep tweaking our physics, eventually we will have the understanding necessary to manipulate spacetime and gravity itself.
Of course, like the article says, its only theory and cannot be confirmed or denied at this point, but the various theories presented are kind of exciting avenues to pursue (for a physics geek anyway). I liked the idea of pushing against spacetime as a reactionary mass, thats a cool idea and, if feasible, would go a long long way in our ability to travel in space.