acceleration limits?
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far-trader
SOC-14 10K
Warning! Danger, Will Robinison! Danger!
C-Rocks on collision vector! Danger! Danger!
:smirk:
C-Rocks on collision vector! Danger! Danger!
:smirk:
There's no limit. You can push your 1G engine until you reach lightspeed and beyond. A good 10G engine will take you across interstellar distances in about 40 days.
But, Far-Trader's warnings apply.
G. Kashkanun Anderson
SOC-13
That's good to know; 'cuz once we all get to Marc Miller's fabled "Heat Death of the Universe" T4 milieu, the interstellar distances are going to have stretched out to quite a bit further than your basic J-6 FTL ship can make.:nonono:
Heh. I know of no canon evidence for M-drive being able to exceed the speed of light, though I can't say it would horribly bother me, since it means that M-drives are necessarily pseudovelocity drives of some sort.
pendragonman
Absent Friends Margrave
There is also no canon reference that denies it either.
True, though there are enough cases of sublight colony ships that you'd think they'd mention FTL capability. In the Imperium boardgame, you can make sublight interstellar trips, but you cap out at about 0.9c.
Andrew Boulton
The Adminator
Relativity still applies.
Exactly. In short, then, fractions of C just aren't considered important to Traveller's rules, where jump is considered the fastest way to get anywhere, and relativity just sort of seems to be assumed not to matter.
Maybe drives shut down at a certain point. Or maybe ships break up. Or not. You might have to come up with something to fill that gap.
Maybe drives shut down at a certain point. Or maybe ships break up. Or not. You might have to come up with something to fill that gap.
Then so does conservation of momentum - no reactionless drives.
If relativity applies, then jump drive would allow time travel into the past. (It's complicated, I know. It has to do with spacetime not being Euclidean.)
So it seems like only some relativity applies.
--Devin
0.5Pc hex (1.625LY) per 6 months? ISTR that light only goes 0.5LY per 6months...:devil:
If relativity applies, then jump drive would allow time travel into the past. (It's complicated, I know. It has to do with spacetime not being Euclidean.)
So it seems like only some relativity applies.
--Devin
Of course, you can always say those primitives back on pre starflight Terra just got it wrong and didn't figure out their mistake until they developed jump drive
Icosahedron
SOC-14 1K
I think the safest line to draw would be to say that Relativity is somehow bypassed by the Jump Drive (Myand Wave Theory), but the M-Drive still needs to account for it.
As a rule of thumb, you can use the book-2 formula derived from Newton's equations of motion up to about 0.1c. After that, you need to start using the Lorentz Transforms, and I never did entirely get my head around how to use the equations for Speed, Mass and Acceleration simultaneously, so I can't help much there. Figuring those out is somewhere near the bottom of my to-do list.
If you find out how to calculate it, let me know.
Unfortunately, even at 1G, you would experience relativistic effects before you reached the half-parsec turnaround point, so the standard formula is only good for in-system or far-companion range.
As a rule of thumb, you can use the book-2 formula derived from Newton's equations of motion up to about 0.1c. After that, you need to start using the Lorentz Transforms, and I never did entirely get my head around how to use the equations for Speed, Mass and Acceleration simultaneously, so I can't help much there. Figuring those out is somewhere near the bottom of my to-do list.
If you find out how to calculate it, let me know.
Unfortunately, even at 1G, you would experience relativistic effects before you reached the half-parsec turnaround point, so the standard formula is only good for in-system or far-companion range.
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Plankowner
SOC-13
If you are using HePlar, then you will be limited by the exit velocity of the plasma from the exhaust nozzle.
Realistically, you would be limited to about HALF that speed since the difference in velocity would be reduced greatly reducing the thrust of the drive.
Current theory puts an upper limit at about 0.1 or 0.2c, but using gravitics and HePlar, maybe you could get to 0.5c.
Relativity and Lorenz Transformations are OK and DO play an effect at lower velocities, but until you get to about 0.5c, the time dilation isn't too bad, and you could probably ignore it in most games.
I DO have a book that has all the formulas for Relativity if anyone is REALLY interested. I could dig it out and send it along.
Here is a REALLY abbreviated form:
TOTAL MATH/SCIENCE/ENGINEER GEEK MODE ON
The key formula is the calculation of Gamma, which is:
Gamma = Sqrt(1/(1-(V^2/C^2)))
So, as velocity increases, the value of Gamma increases, but if V = C, then the denominator of the formula becomes Zero and the value of Gamma becomes Infinite (OK, actually undefined, but that is math, not engineering).
If V > C then you get a negative value inside your square-root and things become imaginary (not related to reality).
Gamma can be used to figure out the time dilation of a trip or the relative mass vs the rest mass of an object (it is a multiplier).
So if you are moving at 0.5c the value of Gamma is 1.15
So for every second on the ship, 1.15 seconds passes in the "real" universe. That is only a 15% difference, or about 1 in 6, so not too bad.
At 0.9c, the value of Gamma is 2.29.
TOTAL MATH/SCIENCE/ENGINEER GEEK MODE OFF
If anyone wants more details, PM me.
Realistically, you would be limited to about HALF that speed since the difference in velocity would be reduced greatly reducing the thrust of the drive.
Current theory puts an upper limit at about 0.1 or 0.2c, but using gravitics and HePlar, maybe you could get to 0.5c.
Relativity and Lorenz Transformations are OK and DO play an effect at lower velocities, but until you get to about 0.5c, the time dilation isn't too bad, and you could probably ignore it in most games.
I DO have a book that has all the formulas for Relativity if anyone is REALLY interested. I could dig it out and send it along.
Here is a REALLY abbreviated form:
TOTAL MATH/SCIENCE/ENGINEER GEEK MODE ON
The key formula is the calculation of Gamma, which is:
Gamma = Sqrt(1/(1-(V^2/C^2)))
So, as velocity increases, the value of Gamma increases, but if V = C, then the denominator of the formula becomes Zero and the value of Gamma becomes Infinite (OK, actually undefined, but that is math, not engineering).
If V > C then you get a negative value inside your square-root and things become imaginary (not related to reality).
Gamma can be used to figure out the time dilation of a trip or the relative mass vs the rest mass of an object (it is a multiplier).
So if you are moving at 0.5c the value of Gamma is 1.15
So for every second on the ship, 1.15 seconds passes in the "real" universe. That is only a 15% difference, or about 1 in 6, so not too bad.
At 0.9c, the value of Gamma is 2.29.
TOTAL MATH/SCIENCE/ENGINEER GEEK MODE OFF
If anyone wants more details, PM me.
Plankowner
SOC-13
I will see what I can put together over the weekend and send it out to you (and anyone else who wants it).
Actually no. The equivalence of FTL travel to time travel is established by Special Relativity, which deals with Euclidean universes. It depends on simultaneity not being invariant. You don't need General Relativity (which deals with non-Euclidean universes) to demonstrate that FTL travel is time travel.
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