2300 FTL drive vs CT Jump Drives

[Anthony]

<BLOCKQUOTE>quote:</font><HR>Originally posted by BMonnery:
How so? The velocity is retained, and turning is accomplised via thrusters.

Bryn
<HR></BLOCKQUOTE>

Simply retaining velocity doesn't help with conservation of angular momentum, because angular momentum is the cross product of velocity and displacement; since it can be computed as displacement from several different objects, conservation of angular momentum makes any form of teleportation or pseudovelocity that doesn't use reaction mass impossible.

 

[Uncle Bob]

<BLOCKQUOTE>quote:</font><HR>Originally posted by robmyers:
Well, I was implying rotation but if that's nonsense I'm sorry.

As for the amount of energy required, we're back to warp drive feasability.<HR></BLOCKQUOTE>

Accordinhg to Van Den Broek a warp drive needs on the close order of -10E13 Joules of energy. Consuidering that the 10 tonms of hydrogen needed for a minimum jump has 6E15 J available just as fusion.
The negative sign is a problem, but just three years ago we thought you needed -10E50 joules.

 

[TimAllan]

The differences in reiltive velocities are easily delt with. Destination solarsystems have to have bodies large enough that their gravity fields are big enough to discharge the stutter warp in. These same gravity gradients can be used, with the ade of the stutter warp displacements, to impart on the ship the required orbital velocitiy. It does mean that the ship has to fart around for a while hovering around the correct gradient until the apropriate velocity is achieved, but it should be quite doable given the magnitude relationship between gravitational accelerations and in system stutterwarp speeds. This should take care of any celestial and Newtonian mechanics, leaving the quantum mecanics side of things, the good oil on which changes about as often as some people change their underware.

 

[Uncle Bob]

<BLOCKQUOTE>quote:</font><HR>Originally posted by TimAllan:
The differences in reiltive velocities are easily delt with. Destination solarsystems have to have bodies large enough that their gravity fields are big enough to discharge the stutter warp in. These same gravity gradients can be used, with the ade of the stutter warp displacements, to impart on the ship the required orbital velocitiy. It does mean that the ship has to fart around for a while hovering around the correct gradient until the apropriate velocity is achieved, but it should be quite doable given the magnitude relationship between gravitational accelerations and in system stutterwarp speeds. This should take care of any celestial and Newtonian mechanics, leaving the quantum mecanics side of things, the good oil on which changes about as often as some people change their underware.<HR></BLOCKQUOTE>

That should work. And all you need is one planetary object. You have 10 kps relative to planetary north (+Z)? Stutterwarp in to about 2500 km over the pole, where gravity is about 5 m/s, and use just enough stutterwarp to keep station for 2000 seconds (37 minutes) until gravity kill the velocity. So all you have to do is figure out which spot is right for you and hover there for 10 minutes to two hours while gravity does the work between "tunnelings."

An elegant rules change. Thanks, Tim Allen

 

[robmyers]

<BLOCKQUOTE>quote:</font><HR>Originally posted by TimAllan:
It does mean that the ship has to fart around for a while hovering around the correct gradient until the apropriate velocity is achieved, but it should be quite doable given the magnitude relationship between gravitational accelerations and in system stutterwarp speeds. <HR></BLOCKQUOTE>

Yes, this is great. Can the adjustment be factored into the final approach to make it more gradual? This would be safer and would leave the current description of the experience of warping between systems unaltered.

I assume that if velocity needs to be gained the ship can slingshot itself using the gravity well.

 

[aramis]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Uncle Bob:
That should work. And all you need is one planetary object. You have 10 kps relative to planetary north (+Z)? Stutterwarp in to about 2500 km over the pole, where gravity is about 5 m/s, and use just enough stutterwarp to keep station for 2000 seconds (37 minutes) until gravity kill the velocity. So all you have to do is figure out which spot is right for you and hover there for 10 minutes to two hours while gravity does the work between "tunnelings."

An elegant rules change. Thanks, Tim Allen<HR></BLOCKQUOTE>

One hitch: this is dangerous to the planet and the ship if right near the limit distance.


------------------
-aramis
=============================================
Smith & Wesson: The Original Point and Click interface!

 

[TimAllan]

Probably not dangerous to the planet, as the amount of radiation reliesed by a diying ship would not be large on a planetary scale. The fact of being near the stutterwarp linit just means that the velocity correction needs to be done over a longer time. The stutter warp has difficulty moving a ship more than gravety does when the gravety field exceeds that to produce 0.1g, so the velocity correction needs to be done at this or less. That's ok though, as you can start using the gravety gradients as soon as you can measure them, somewhere in the outer system. Thats why it is good for a ship th have gravetatioal scanners, you spend a lot less time calculating the potentials and can plot the ships cource to make best use of available gravety wells. Fro that matter, as long as atmosphere doesn;t become a problem, a properly directed ship would be able to meke fairly radical velocxity chenges by means of sling-shoting around planets. A bit more radical than hovering on gentle incline, but when you need delta V favt, its there. Docking with stations and non stutter warp ships would of coarse require a ship to be in a stable parking orbit and use maneuvering thrusters. Figuring all these things out and getting your ship int the right place with the right velocity is why it would be inadvisable to let just any monky pilot a starship.

 

[Uncle Bob]

Of course we are violating conservation of energy (gravitic potential energy) all over the place, but that's built into Stutterwarp anyway. I think we have to wink at it.

I had a bad exampler in the 2500 km hover. I should have suggested 12,000 km and 3-12 hours to kill the velocity (or build it up: its all just vectors).

So when you arrive in as new system by Stutterwarp you have to spend 2D6 hours "surfing" the gravity wells before you can use "thrusters" to settle into orbit. Even moving from planet to planet is a system will require a few minutes "surfing the well" before going onto thrusters.

I like it: this adds depth and texture.

 

[Anthony]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Uncle Bob:
Of course we are violating conservation of energy (gravitic potential energy) all over the place, but that's built into Stutterwarp anyway. I think we have to wink at it.<HR></BLOCKQUOTE>

Well, if you change the speed of stutterwarp it's ok. Maximum speed should be on the order of 0.1 km/s * (power in MW)/(mass in tons * local gravitational field). As a helpful simulation, escaping the gravity field of an object takes the same time as it would require to reach the center of the object at current acceleration. Thus, escaping the earth from the 0.1G diameter, at 1 MW/ton (1 km/sec at 0.1G), would take around 20,000 seconds. Escaping the sun from 1AU (150 mkm, 0.0006G) takes around 250 hours.

 

[robmyers]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Anthony:
Well, if you change the speed of stutterwarp it's ok. Maximum speed should be on the order of 0.1 km/s * (power in MW)/(mass in tons * local gravitational field). As a helpful simulation, escaping the gravity field of an object takes the same time as it would require to reach the center of the object at current acceleration. Thus, escaping the earth from the 0.1G diameter, at 1 MW/ton (1 km/sec at 0.1G), would take around 20,000 seconds. Escaping the sun from 1AU (150 mkm, 0.0006G) takes around 250 hours.<HR></BLOCKQUOTE>

As a physics layman I don't understand the numbers you're plugging in here. Stutterwarp, in a very real sense, doesn't have speed, which is where this handwaving started. Stutterwarp efficiency varies between drives, 1.0 is about 100m/cycle, so energy pumped in isn't the only factor.

 

[Anthony]

The numbers come from the potential energy difference between locations.

 

[Murph]

Stutterwarp seems remarkably inefficient in moving around in orbit, or intra-system.

 

[BMonnery]

Originally posted by Murph:
Stutterwarp seems remarkably inefficient in moving around in orbit, or intra-system.

In part it depends what rate you use (an STL conversion of 6.45AU/day and .645AU/day are used in the same book).

Using the fast rate, a warp 4.81 ship (unloaded, unarmed Kennedy with all power to drives) can go 17.9% of lightspeed insystem, and about 5.4kps in the discharge zone, enough maybe for most orbital maneuvers?

See http://groups.yahoo.com/group/2300NonCanon/message/1944

Bryn

 

[aramis]

Originally posted by TimAllan:
Probably not dangerous to the planet, as the amount of radiation reliesed by a diying ship would not be large on a planetary scale.

It isn't the radiation issue; it is the fact that if a polar presentation is normal, it wil skew a major worlds orbit.

After all, a few bits of chaange won't make a difference, but Earth, AC, and Beta Canum all get plenty of traffic. so the shed is going to need to be dispersed as much as possible to avoid "Orbit shift". And just remember that 1E-100 m/s adds up... and unless cancelled appropraitely becomes an issue.

Besides, most worlds will have preferred hemisphere, or even 8th of a sphere, due to major population centers, and good local conditions. Which will magnify the chances of asymmetric accellerations if you dump by hovering over a pole.

Additionally, if a ship does have a failure, it will:
1) Slingshot off
2) fall into an erratic eliptical orbit
and/or
3) produce a notable EMP.

3 is the problem. Especially for worlds with large satellite useage (Earth and a few other core worlds) or beanstalks.

also, please remember that, in order to reduce a vector, you need to reduce said vector in relation to the objects against which you are measuring their speed. So you need, for optimal drain, to put yourself so that your vector is colocated along the ray starting at mass center and proceeding throguh the ship.

Personally, I think the polar approach to be the worst position; you want to have maximum flexibility to shed that vector.

As for CoE; and PE changes; you're going to have a long term effect on the body or bodies you use to dump vectors. (I've always assumed it was done mosly automatically oer the travel time in system, aided by ion thrusters. Shifting the star hurts less than the planet.)

 

[Tarn]

Another Greenpeace issue... Save the Planet from Orbital Degradation...

Stop Illegal Velocity Dumping!!!!!

We don't need your momentum!!!

And so on and so forth.....

 

[aramis]

Originally posted by Tarn:
Another Greenpeace issue... Save the Planet from Orbital Degradation...

Stop Illegal Velocity Dumping!!!!!

We don't need your momentum!!!

And so on and so forth.....

We don't Need Your Trade.... Dump your velocity Elsewhere!

 

[Uncle Bob]

I just found this:
<a href="http://www.grc.nasa.gov/WWW/bpp/summ.htm#Malloy%20Task" target="_blank">"Detection of Superluminal propagation at low or near resonance frequencies
and the dynamics of the Forerunners"</a>

It is a long way from a useful drive, it is not even a substantiated theory, but

Although it is premature and non-scientific at present to suggest a detailed and direct connection between the proposed tasks and possible future BPP devices, the suggested tasks are in close correlation with the expressed desire of "conducting experiments or advancing theories that address critical unknowns, make-or-break issues or curious effects." In other words, while the proposed ideas are far from becoming breakthroughs in near future, they provide a starting point for scientifically assessing the ideas regarding the application of these anomalous effects to propulsion physics

 

[Murph]

Yes, but can it work?

Originally posted by Uncle Bob:
I just found this:
<a href="http://www.grc.nasa.gov/WWW/bpp/summ.htm#Malloy%20Task" target="_blank">"Detection of Superluminal propagation at low or near resonance frequencies
and the dynamics of the Forerunners"</a>

It is a long way from a useful drive, it is not even a substantiated theory, but
</font><blockquote>quote:</font><hr />Although it is premature and non-scientific at present to suggest a detailed and direct connection between the proposed tasks and possible future BPP devices, the suggested tasks are in close correlation with the expressed desire of "conducting experiments or advancing theories that address critical unknowns, make-or-break issues or curious effects." In other words, while the proposed ideas are far from becoming breakthroughs in near future, they provide a starting point for scientifically assessing the ideas regarding the application of these anomalous effects to propulsion physics

</font>[/QUOTE]

 

[Uncle Bob]

Originally posted by Murph:
Yes, but can it work?

No-one knows, not even the investigators. At least stutterwarp appears less preposterous now.

The Alcubierre/van den Broek warp drive (pretty near the Jump Drive) is still better developed.

 

[Anthony]

Actually, the article isn't even proposing a way of accomplishing FTL; it's a way of detecting whether FTL has occurred, along with a general statement to the effect that it doesn't seem to occur.

BTW, the alcubierre warp drive has been shown not to work at FTL speeds due to boundary effects, though it might still work as a fast sublight drive.