What a light year is

[glitterboy2098]

actually, with Einsteinian time dilation, it might be 2 years to an outside observer, but 2 weeks for those on the ship.

[Marrowlight]

It's just a piece of interesting information that should be known to younger players, though I think they would not care.

Hrm...I wonder how many Young Players Palladium actually has.

[KLM]

Sonar in Nebulae?

No other use pops up, and it still needs a bit of handwaving.

Adios
KLM

[Nekira Sudacne]

I came across a statement in the Three Galaxies, stating that it would take a craft, using sub-light engine, several weeks to traverse a few light years of space. Now that is somehow improbable.

Firstly, a sub-light engine usually do a certainly fraction of the speed of light. For example, 0.5c is technically half the speed of light.

So how much is the speed of light? 1,079,252,848.8 km/h, or approximately 186,282.397 miles per second, or 670,616,629.4 miles per hour, or roughly 300,000 km per second

So how long is a light year? 9,460,730,472,580,800 m, or 9,460,730,472,580.8 km, or 5,878,625,373,184 miles.

(Figures are taken from Wikipedia)

Now, if a spacecraft is trying to traverse a light year using sub-light speed of 0.5c, technically it would take the people inside 2 years to complete a light-year.

technically, going 98% of light speed is still sub-light...

[Daikuma]

I came across a statement in the Three Galaxies, stating that it would take a craft, using sub-light engine, several weeks to traverse a few light years of space. Now that is somehow improbable.

Firstly, a sub-light engine usually do a certainly fraction of the speed of light. For example, 0.5c is technically half the speed of light.

So how much is the speed of light? 1,079,252,848.8 km/h, or approximately 186,282.397 miles per second, or 670,616,629.4 miles per hour, or roughly 300,000 km per second

So how long is a light year? 9,460,730,472,580,800 m, or 9,460,730,472,580.8 km, or 5,878,625,373,184 miles.

(Figures are taken from Wikipedia)

Now, if a spacecraft is trying to traverse a light year using sub-light speed of 0.5c, technically it would take the people inside 2 years to complete a light-year.

So a light year is 5.8 Trillion Miles...would it help if I got out and pushed?

-Daikuma

[Greyaxe]

Sublight speeds listed in PW and the soruce books are for maneuvering into a FTL position and entering atmospheres. You would still use a FTL drive to go between planets in a given solar system. It would take weeks or months to travel from one planet to another otherwise. You use the sub lite propulsion to maneuver the ship into a position where you engage the FTL drive even and 1 ly/hr to go say from earth to the jupiter station where you work would be aproximatly a two hour commute, maybe a bit longer to account for positioning , slowing down and re-entering atmospheres.

[Daikuma]

Sublight speeds listed in PW and the soruce books are for maneuvering into a FTL position and entering atmospheres.

And Combat! Don't forget combat & dogfighting

You would still use a FTL drive to go between planets in a given solar system. It would take weeks or months to travel from one planet to another otherwise. You use the sub lite propulsion to maneuver the ship into a position where you engage the FTL drive even and 1 ly/hr to go say from earth to the jupiter station where you work would be aproximatly a two hour commute, maybe a bit longer to account for positioning , slowing down and re-entering atmospheres.

Wouldn't it be impractical to use FTL drives (most of them anyway) to make micro jumps? I have seen in most sci-fi that the need for such good stellar navigation is that if you misjump way too far out-system that it could take hours or days to "taxi in" from wherever you end up, because FTL jumps can take a long time to calculate.

I even implemented a rule where it took the sensors 5D6x2 minutes to recalibrate cartography after a jump to allow for local planet shift and space debris in any area, and the pilot had to make a Read Sensors roll to minimize the time by a percentage. The only way to do random short haul jumps was to make a "straight up or down" jump outside the plane of the elliptic of the solar system, then jump in or out system, and taxi in from a shorter distance.

To much chance of smacking into something otherwise.

-Daikuma

[Greyaxe]

It is impractical to do an FTL on the fly but not going between known objects in a solar system like a bus route. You could upload a course from the navigational bouys (in civilized areas of space) and to a jump to get from point a to point b quickly

[glitterboy2098]

You use the sub lite propulsion to maneuver the ship into a position where you engage the FTL drive even at 1 ly/hr to go say from earth to the jupiter station would be aproximatly a two hour commute, maybe a bit longer to account for positioning , slowing down and re-entering atmospheres.

wrong.

1ly/h is 8760 times the speed of light.

even the 40 light minute distance from sun to jupiter would only be a 3 second trip.

[shadrak]

Look, even at sublight speeds (.1-.9), commuting between planets is a pretty quick proposition. Light travels from the sun to the eath in just over 8 minutes. Figure an unadvanced sublight engine can cover 1 AU in 80 min, and with solar bodies being a few AU apart (Jupiter is about 4 from the earth, Pluto is about 39), the trip is feasible with out using an FTL drive, which, as has been pointed out, is not very feasible.

Basically, with a slow sublight speed drive (10% of light speed), a trip from Earth to Jupiter would take just over 5 hours. Thats about 32 min. at lightspeed, assuming it were possible.

[glitterboy2098]

It's really clever of you to use FTL to travel from a gravity well to another.

First, when you start doing FTL near Earth's gravity, it will distort your navigation. If one is lucky you will end up in open obstacle free space, if not you might become a permanent exhibit on another planet with half of the vessel out of the planetary surface.

actually, according to the books, your free and clear 300,000km from an earth type planet. i'm assuming this means 1g=3000,000km interdiction radius. one light second.

300,000km is slighlty less than eart to the moon. the moons .16g means it has a 48,000km interdiction radius.

jupiter has a 6,936,000km interdiction radius.

you'd only need to sublight a few minutes to reach a safe point for FTL.

[Greyaxe]

You use the sub lite propulsion to maneuver the ship into a position where you engage the FTL drive even at 1 ly/hr to go say from earth to the jupiter station would be aproximatly a two hour commute, maybe a bit longer to account for positioning , slowing down and re-entering atmospheres.

wrong.

1ly/h is 8760 times the speed of light.

even the 40 light minute distance from sun to jupiter would only be a 3 second trip.

Your right I was thinking at the speed of light. I dont see any reasons why a FTL drive cant move at the speed of light at say an Idle or something like that.

[Nekira Sudacne]

I came across a statement in the Three Galaxies, stating that it would take a craft, using sub-light engine, several weeks to traverse a few light years of space. Now that is somehow improbable.

except the speeds in question for sublight engines are listed.

the speeds for sublight engines in phase worlds are calculated as multiples of Mach, not fractions of C. they are MUCH slower than that.

and technically, any speed below lightspeed is a fraction of C, but you get my meaning. less than 1% of C.

[glitterboy2098]

unless you read the pilot skill Spacecraft: Small

which tells you that you can indeed go much faster.

"typical speed is about half the speed of light"

I've forgotten what Glitterboy mentioned the acceleration times to be, but it was something like 100 days or so.

about 182 days at 1g of accelleration. for higher accellerations, divide that time by the square root of the accelleration in g's. (IE, 4g's = 1/2 the time. 9 g's = 1/3rd the time. 64 g's =1/8th the time. ect. )

(i may be off a tad, these #'s represent a grossly simplified version of a complex situation, so should not be considered an absolute. but they make a good guide. also note, these assume that 1g = 10 meters per second per second.)



of course, applying accelleration profiles and the .5c referance means you have to totally junk the mach speeds, since regardless of the accelleration rates, after a few minutes your going to be travelling at velocities much higher than the listed mach's.

and it's kinda hard to justify being a hare in transit but a tortise in combat.


thus why i went to my 'mark' system (1Mark = .005c). i just assumed a non-inertial boosting component for all non-gravitic drives, and replaced all referances of %c and/or mach #'s to my Mark #'s, and assumed all ships could accellerate to full velocity within one melee. much simpler.

[Daikuma]

Would not a simpler method be to simply take the ship's "Mach in Space" rating, and make that the acceleration?

i.e.: if a ship can go at "Mach 10 in Space" then modify that to say that the craft's rate of acceleration is "Mach 10 per melee each melee", meaning that after 5 melee rounds (1:15) they are travelling mach 50 (or 50 times the speed of sound (or 38,050 mph, using 761 mph as our reference for mach speed and the expedience of argument).

Now at that rate od speed, the time to go 1 AU (93 million miles) is about 101 days, but that is only if you shut off the engines at that point. Say you were to maintain that acceleration for five minutes? SO Mach 10 x 20 combat rounds = Mach 200 current acceleration when you shut down the drive - you are still coasting at 152,200 mph, which means that you are looking ar 25.5 days to travel 1 AU.

Now keep up the acceleration fo half an hour. Regardless of how far you have travelled at that point (no I am not doing the math for you, mess with it yourself if you really want) you are now travelling 913,200 mph. At this speed, you now take only 4.24 days to go one AU, and nothing says you can't keep the sublight drives going at this point. Take a full hour to spin accelerate, and that mach 10 rated ship is going 1.826 million miles per hour, and will go the full AU in a little over two days.

Of course, you travelled with this type of acceleration, then you were more than 300,000 km away from a significant astral body in the first ten minutes, could have kicked in the FTL drive for a few light seconds, and have been having pizza on pluto long before it got cold when you ordered it twenty minutes earlier in low earth orbit.

Seems practical to me, and doesn't need the expensive casio calculator to figure out the numbers, neh? Come to think of it, you made the trip from earth to the moon in under eight minutes using these method. If you want to set limits, assign time attenuation to kick in at around .5c, and you have the motivator for folks to use that FTL as soon as they can.

-Daikuma

[Daikuma]

The thing is Mach is relatively slow in sublight. You will need several hours to reach half the speed of light.

The ST has a really nice system where each speed factor is an exponential of the earlier speed, but that would make things quite complicated in PW.

Right, that is why this system works, it becomes impractical to travel even close to .25c; just turn on the FTL drive ASAP for anything that fast.

Using the sublights to get clear of anything is really all they should ever be used for...that and dogfighting or short haul to stations or moons

-D.

[glitterboy2098]

The ST has a really nice system where each speed factor is an exponential of the earlier speed,

only for FTL speeds.

trek has two different systems. the orginal series (and Enterprise used a 'warp factor cubed' formula (WF^3), where the listed speed (warp 4, for example), would be cubed, (4x4x4), which was the multiple of light speed the ship was travelling. (warp 4 = 64c)

The Next Generation, DS9, and Voyager use a modified scale where each warp facot has a different exponent, gradually increasing as you near warp 10. (which has been generally been described as a power-use barrier, except for one VOY episode, which has been deemed non-canon after the fact by it's own writers. go figure) (Okuda's own notes imply a formula along the lines of WF^10/3 for everything under warp 9, with 9.X speeds having unique exponents in ever increasing rise.)


unfortunately, Slower than light travel in trek is horribly unknown. we know that most ships use 'impulse' drives, which seem to be a high end fusion drive with somesort of mass lightening effect on the ship, but aside from a referance to .8c in 'The Motion Picture', we don't have a known velocity. TMP has .8c, the TNG tech manual says .25c. we don't know if ships accellerate at differing rates, or if all ships have the same top speeds.

(personally, i side with the 'all ships max out at .9c, but accellerate at differing rates' veiwpoint. so a shuttle might accellerate faster than a starship, and accelleration rates vary depending on the technology of the time (so an Enterprise era ship would be a snail compared to a TOS ship, which is sluggish compared to a TNG/DS9/VOY eraship. since we see this kind of comparison in the shows/movies, it is highly probable.

[glitterboy2098]

i have all three tech manuals (TOS, TNG, DS9).

Well, as far as I know, (the once-great-but-now-gone) Gene Roddenberry thought that the speed factor should not go on forever, so he places Warp 10 as absolute speed limit. It is not only a power barrier but a "physical" barrier. Anything at warp 10 would be any place in the universe at that moment.

the great bird of the galaxy did set warp 10 as the max, but he never defined it. Okuda drew a curve by hand to set the speeds, but never explained it.

the warp 10 'infinite velocity' theory was presented in the TNG tech manual (non-canon), and VOY: Threshold, the aformentioned no-longer-canon episode. (discounted by both Berman and Braga, and they wrote it.)

a better explanation is a kind of 'warp relitivity'. warp numbers reflect the # and strength of the warp feilds, and generating warp 10 is physically impossible, and the closer you get the more energy you need to create the feild, to the point where warp 10 is 'infinte energy use', just like conventional relitivity as lightspeed as requiring infinite energy.

things like transwarp conduits, quantum slipstream, and Voth transwarp operate on different principles, by not bringing subspace to regular space, but by 'submerging' ships in subspace, which bypasses the warp 10 limit.

[glitterboy2098]

but if that's the case, then there is a lot of confusion.... so is Warp 10 absolute? I always thought transwarp is 9.999999 or something to that effect. And I think the only beings able to generate enough energy and power to create warp 10 would be... who else but Q

have you ever done those algerbra calculations with the Asymptotes?
when graphed, lines under the asymptote can reach infinite length on one end without ever touching the asymptote. the same is true for those above the asymptote.
basically, it serves as an unreachable ceiling for the area below, and an unreach able 'floor' for the area above.
you can approach it from either side, but you can never actually intersect it. you just get infinitely close.

in warp, warp 10 represents the unacheivable upper limit for convnetional drives. it also represents the unreachable lower limit for unconvnetional drives.


of course, this is all non-canon, but it's internally consistant, has few to no shown exceptions, and requires next to no modification to episodes to work.

[glitterboy2098]

Just out of curiosity, do you have any idea what is the impulse speed? I don't remember reading it from anywhere.

no clue. we know that in Star Trek: The Motion Picture Sulu calls out .8c on the way out of the solar system.

other than that, we just know that there is a full, half, 1/4th (ect.) impulse in regards to giving orders. this is probably shorthand to make giving orders easier, since otherwise you'd be saying either 'accellerate at X g's' or 'increase speed to .Xc'.

odds are they never explained it so people wouldn't complain. in real space travel, accelleration is everything. but most people think in terms of steady speeds like planes, and thats the form you see in most TV shows and movies (like star wars, for example). by not explaining it, they avoid confusing normal veiwers, and avoid ticking off the scientifically minded veiwers.