STL between systems

Tchklinxa's picture
Tchklinxa
March 15, 2015 - 9:27am
I was looking over my notes on the Sol-Corps colonization plan from C.J. Cherryh's books and the STL tech used to get from system A to system B is a combination slingshot, solar sail. Now based on my notes from the net (I do not have the books this tech appears in) the ships might be reaching speeds near C. I did the math using the timeline notes I have and it seems that the time of Travel in Earth Years is X LY between systems rounded (distance) + 1 additional year (probably representing part of the acceleration & deceleration time is my guess).

I am not physics savvy but time dilation thoughts keep nagging me.  I have next to 0 education in physics (it is just what I have absorbed over the years)... so input on this welcome.  How fast would the average speed of a ship be for say 7 Earth years to pass between departure and arrival traveling 6 LY in distance?

Though storyline game time wise her formula is slow but not too slow to make the travel, trade & colonization between star systems not impossible. 

I have not found any descriptions of her ideas about the solar-sail ships (yet), but I would like to work on how this might work in SF.

I would also like to work up ship ideas that are based on other STL tech as well.





 "Never fire a laser at a mirror."
Comments:

TerlObar's picture
TerlObar
March 15, 2015 - 11:01am
Yeah, her ships do get up near light speed.  The average speed of a ship traveling 6ly in 7 years is just 6/7 or 85.7% the speed of light.

The people on the ship would age 7 years.  The time dilation for the surrounding universe would be 13.6 years apparent elapsed time assuming they traveled at that speed the entire time.  If they spent half a year getting up to 0.95c 6 years traveling, a half a year slowing back down, then it would still be 7 years on-board but now just over 20 years would have elapsed in the outside world.  Although I'm not sure that's actually correct as relativity even makes my head spin and I'm an astronomer/physicist.
Ad Astra Per Ardua!
Webmaster - The Star Frontiers Network & this site
Founding Editor - The Frontier Explorer Magazine
Managing Editor - The Star Frontiersman Magazine

Tchklinxa's picture
Tchklinxa
March 15, 2015 - 2:45pm
TerlObar wrote:
Yeah, her ships do get up near light speed.  The average speed of a ship traveling 6ly in 7 years is just 6/7 or 85.7% the speed of light.

The people on the ship would age 7 years.  The time dilation for the surrounding universe would be 13.6 years apparent elapsed time assuming they traveled at that speed the entire time.  If they spent half a year getting up to 0.95c 6 years traveling, a half a year slowing back down, then it would still be 7 years on-board but now just over 20 years would have elapsed in the outside world.  Although I'm not sure that's actually correct as relativity even makes my head spin and I'm an astronomer/physicist.

That is what I was wondering the time math didn't seem to be working just in what I so little know... the time that passed on Earth was 7 years, and the time given for the ship's crew was also 7 years and that did not seem right... so I need a simplified real enough formula but not make my head spin... as I want to have STL be more common, would this give me a rough enough number for game play:

Keep the original formula for the experienced travel time on board the ship Xly + 1 year = years aged (ya) by crew.

But for Galactic Time Line purposes would this work? 3(ya) in the example 7 x 3 = 21 years on the time line or does it get too wonky for longer distances? So if a hypothetical ship went 11 ly it would equal 36 years on the Time Line but only 12 experienced... people's PC aging will need to be tracked more carefully.
 




 "Never fire a laser at a mirror."

rattraveller's picture
rattraveller
March 16, 2015 - 9:00am
Silly question time. So if light is travelling at the speed of light, is it subject to time dilation?
Sounds like a great job but where did you say we had to go?

Tchklinxa's picture
Tchklinxa
March 16, 2015 - 9:57am
I don't know, but that is a good Q.

It occurred to me if these Solar Sail ships are traveling around 85% of c, than velocity wise they have the speed to become FTL per game rules... I decided in my setting the ability to go FTL had to do with the radio tech invented around the tachyon and then from that new discoveries in propulsion came about... so in theory a Solar Sail Ship that can reach 1% c and then activate the tachyon tech necessary could indeed enter the void.

But Time Dilation in STL space colony scenarios would result in isolated independent colonies developing with long delays in HW interference, but once FTL happens suddenly they have to deal with HW authority in real time ways, versus it taking 20 years for a new HW official to darken their port. If the HW gets FTL, and decides all those independent, attitude giving, free thinking folks on the fringes need to be brought up to HW standards of doing things... instant conflict. And how much of human history is just that, someone showing up and telling everyone already living someplace how to eat, live, think, pray and so on, 'cause they know better, and if you don't like it to bad.
 "Never fire a laser at a mirror."

RanulfC's picture
RanulfC
March 16, 2015 - 3:25pm
Tchklinxa wrote:
I don't know, but that is a good Q.

It occurred to me if these Solar Sail ships are traveling around 85% of c, than velocity wise they have the speed to become FTL per game rules... I decided in my setting the ability to go FTL had to do with the radio tech invented around the tachyon and then from that new discoveries in propulsion came about... so in theory a Solar Sail Ship that can reach 1% c and then activate the tachyon tech necessary could indeed enter the void.

But Time Dilation in STL space colony scenarios would result in isolated independent colonies developing with long delays in HW interference, but once FTL happens suddenly they have to deal with HW authority in real time ways, versus it taking 20 years for a new HW official to darken their port. If the HW gets FTL, and decides all those independent, attitude giving, free thinking folks on the fringes need to be brought up to HW standards of doing things... instant conflict. And how much of human history is just that, someone showing up and telling everyone already living someplace how to eat, live, think, pray and so on, 'cause they know better, and if you don't like it to bad.

Actually did that without actually having STL per-se in that Clarion, (Gollywog's "correct" name IIRC) was settled by refuges from the loosing side in a religious war on the human "homeworld" by a cobled together wreched alien ship they'd found. Couple of hundred years later after they managed to get a viable "colony" going the original humans show up in more "alien" ship they'd found on one of the homeworlds moons which had this address (among a few others) pre-programed in. Needless to say the colonist were in no shape to re-fight a war they had already lost once and the entire "feudal-system" currently existing is based on the original resistance structure that arose in opposition to the "re-subjugation" (and re-naming of their world to "Gollywog" after the conquering commander) efforts of the homeworld. (Whose "fleet" ended up finally falling apart and loosing them their little "empire" until they were re-contacted by the Federation. By the Vrusk luckily... If the Clarion folks had found them, well things would have gotten ugly rather quickly :) )

Non-Frontier Humans in my SFU are real a**holes :)
(Even compared to us "real" ones)

Randy

Tchklinxa's picture
Tchklinxa
March 17, 2015 - 10:50am
I am thinking the beginning of the monarchy for Clarion/Gollywog will be along the lines of colonists become commoner & crew become nobility/royalty... because they had the weapons, where awakened first, went to sleep last, awakened off and on through trip as needed... the colonists where awakened from hibernation at arrival after the crew was already up for at least 6 months decelerating a STL ship and the colonists then had the situation explained to them that the colony was not going to be a democracy, if you said no you got shot... now this is in ancient history and kept secret, and there has been changes in the Monarchy family lines since... but basically the colonists got strong armed. I will probably include an indentured servitude issue as well with certain Companies, still hammering out the real history of Clarion for my back history... I will probably borrow a few ideas from Plateau by Larry Niven. 

I think Niven's "Covenant of Planetfall" idea fits nicely.

 in the Alliance/Union universe these ships actually are some how pushing or pulling or bringing along the colony which is actually a modular Space Station, then the ship can somehow disconnect and become independent and return... I am a little fuzzy on the details, but that is the basic idea. Sol Corp builds the stations & ships. 

So I am also thinking it might be interesting to work up a Solar Sail STL freighter... just kicking the ideas around.

25,000 ly from Earth to Core is a long trip... at STL at 85-6% of c... I imagine the real math number for time passage on Earth would be huge even using my cheat 3 times the distance +1 is huge 75,003 years. I am thinking away off course ship, maybe put off course on purpose even. 

Clarion is going to be colony number one for the Humans though in my setting reboot.

 "Never fire a laser at a mirror."

RanulfC's picture
RanulfC
March 17, 2015 - 3:38pm
Considering my "original" human colonists came off a certain Starship "Wodan" (Warden) for the "homeworld" part I'm assuming the only time the humans used STL is when the last alien ship fell apart and "Gollywog" was just to far to reach.

(The colonist/crew idea is a good one and I may in fact "steal" it myself at some point but for right now I need there to be a 'reason' the humans of Clarion are adamant about being in opposition the other humans of the homeworld... Which is "Hu" by the way, "Hu-Man" and all that :) )

Randy

Tchklinxa's picture
Tchklinxa
March 17, 2015 - 6:35pm
I poked around in trying to understand the ideas behind some of the tech I found mentioned in the A/U Space & one was that radio communication was neutron based, my understanding is the fastest that can go is 10% c which though fast would still not let a timely message go from Clarion to Old Terra, (of course I could move Terra closer). I am pretty sure the time dilation is way bigger than my cheat number... but the desire of someone to talk with HW might have led to Tachyon research, especially if the secret of how the government was set-up was either so well covered up no one knows what really happened (including current royal house) or someone knew and wants to destabilize the government even though things have improved drastically on Clarion. 

I have been reading how Solar Sails have been used, and I wonder if the ship was large enough if the spin many seem to have would be enough to create gravity? Boy I do feel dense on the astrophysics/real life science. 

I also wonder how big sails would have to be with current materials for various KH SHs: I am thinking the sails could be smaller maybe if some hand-wave technological advance or material ended up reducing the needed size.



I am thinking the Colony Ship would need to be pretty large, even with Cloning abilities for livestock and useful plants... the cryogenic real science wake up needs, maybe that should set how far one of these ships can go before everyone must wake-up... I need more info on the shelf-life issue.

I really need to learn how to calculate TD. Sealed 
 "Never fire a laser at a mirror."

TerlObar's picture
TerlObar
March 18, 2015 - 5:40pm
time dilation is easy it's:

dt' = dt/sqrt(1-v2/c2)

where dt' is the dilated time (i.e observer), dt is the time on the ship, v is the velocity and c is the speed of light.  so if you have 7 years ship time at 80% the speed of light  you get

dt' = 7/sqrt(1-0.8*0.8)
    = 7/sqrt (1-0.64)
    = 7/sqrt(0.36)
    = 7/0.6
    = 23.333 years
Ad Astra Per Ardua!
Webmaster - The Star Frontiers Network & this site
Founding Editor - The Frontier Explorer Magazine
Managing Editor - The Star Frontiersman Magazine

Tchklinxa's picture
Tchklinxa
March 18, 2015 - 9:50pm
Okay looks straight forward... I must find my ancient scientific calculator I horrified my college math teacher with (he said I would never be able to pass the class with the antique... I passed despite his disbelief). Where's the slide-ruler... Foot in mouth

I am figuring 25,000 ly will equal 41,666.6667 years at 80% 

so 85% will be 43,859.6491 years, plenty of time for any HW to have all sorts of issues. Of course how long the drive solar or hybrid types could function without maintenance is another issue.

I understand there is a self-life to deep freezing people and I have read it is because of the naturally occurring radioactive materials in the human body... I can't seem to find my original number I read but I think it was 50-60 years, but other sources suggest vaguely anything from 100's to 1000 years... so I know colonists would have to be woken up if on ice, just not sure about when. 

Would the same formula work for figuring out the delay on a neutron based communication system?


 "Never fire a laser at a mirror."

RanulfC's picture
RanulfC
March 19, 2015 - 3:52pm
"Depends" I supposed in the method of Suspended Animation. If you have "freeze-fields" pretty much all molecular motion stops so you're "time" factor could be tens of thousands of years.

The "Advanced Technology" thread at the nasaspaceflight.com forums have some detailed information on various issues with, and different types of, suspended animation but my search-fu fails me at the moment for links.

Randy

Tchklinxa's picture
Tchklinxa
March 20, 2015 - 10:06am
Thanks I will check it out.
 "Never fire a laser at a mirror."

Tollon's picture
Tollon
March 21, 2015 - 7:03am

Late to the party again, and about to throw a monkey wrench into the whole discussion:

Can't remember where I read it or heard it, but it was a synopsis on FTL space travel.  They were discussing the evolution of FTL in stories and on TV.  When they got to Warp Drives and where things might go wrong, the author stated that of instead of "bridging" the gap created by warping the space, an author wrote a book describing what might happen if the ship follow the curved space created by the warp drive.  This made the trip longer in real time than it appeared on board the ship.

A trip that took x number of days actually took x number of years.

This concept solves several things you have been discussing in the thread.  There is no need for fuel and power worries, food consumption or how long the people are in cold storage.  Time on board the ship remains the same, while time outside ship advances by years, decades or centuries.  This only becomes know to the ship's crew and passengers after they have completed the trip.

Considering the Timeline in SF and the encounter with a hostile race, then being aided by a friendly race who may or may not know exactly how the Terran stardrive works.  It is possible that this sort of thing might have happen if there is a misunderstanding betweeen the Terrrans and the freindly race when it came down to the math.  It is only after they arrive do they discover this error and with no chance of repairing the error until they have colonized a planet and build up their technological base is there a chance of them reaching out to the other colony ships in the area.  This would cause the time lag discussed between reaching the SF zone and the destruction of the ships.

Perhaps the incident drill home the fear all alien races were out to get them?

The downfall to this scenario would be the view of the humans against the other races in the area.   It would make them xenophobia and conflicts would arrise between the other three races in the area, causing a dark feel to the early SF Timeline.  It is only after the Sathar invasion do the races bond together to form the UPF.  This can also explain why the four races have the military ships available to them at the time of the invasion. 

  


Tchklinxa's picture
Tchklinxa
March 21, 2015 - 8:26pm
Tollon that is an interesting take on the problems with FTL and a good reason for everyone being all confussed about HW issues...  so basically they are so far into the future they be it. 
 "Never fire a laser at a mirror."

SFAndroid's picture
SFAndroid
March 27, 2015 - 10:59am
Hey All, long time no see.

Ok, I'm going to step in the poo here, but...I'm a big fan of the Babylon 5 Jump Gates. /duck

I'm at work and don't have the time to Google it, but, I believe it was Einstein who said it'd be easier to enter a different dimension than trying to accelerate to lightspeed. Traveling in "the Void" as described in KH is odd to me. Moving at 1% of the speed of light makes you "POOF" from one place to another? That makes you travel FTL, thereby causing a dilemma based on how folks view the plot holes of Hyperspace and Warp Drive. Heck, the Void makes all the rest of these travel options look sick by comparison.

The jumpgates theoretically make all ships, that can store enough fuel, able to traverse hyperspace. Even fighters can make short range jumps from gate to gate. I planned it a bit like this. Ships that enter and leave hyperspace via a jumpgate don't use up a "Jump toward Overhaul". If a ship is capable of "Void" travel, the ship can open a jump point. (though, I limited it to HS4 as the smallest to hold a jump engine, sorry Assault Scout) If they make the jump, either into or out of hyperspace (each counts as a jump), it uses an overhaul counter. Most civilized worlds have jumpgates. Interstellar commerce can be run with most any ship that can make the trip from Gate A to B.

That begs the question, how long does the engine on a fighter supply power? Most games show a fighter as a high output/low duration craft.  For that matter, if an HS20 ship never makes a jump, how long do the engines supply power?

Here is a B5 resource that I've been using to try and coalesce my scatterbrain.

http://www.kitsune.addr.com/SF-Conversions/Rift_SF_Conv.htm#

This site has TONS of ships from all kinds of games, converted to a Rifts-based system. I'm not the biggest Rifts fan anymore, but, the author does a good job of breaking down engines, reaction mass and hyperspatial travel.

Ok, I'm babbling and have probably left points out. Call me out and I'll do my best to elaborate later.

Nice to be back.
You can't argue with the invincibly ignorant. - William F. Buckley

Tchklinxa's picture
Tchklinxa
March 27, 2015 - 6:29pm
I am open to different races using different tech myself... which then creates options for plot lines, tensions between groups and so on...

I am one of the folks that agree the 1% thing is odd unless there is some missing tech so I figure that is the Tachyon Radio research that led to an additional break through, my kindergarden grasp of physics is Tachyons travel faster than light...

Now Gates are doable to me & in fact one of my many recycle projects is a TSR Sci-fi race that has what appears to me to be Gates, they are on my back burner right now, I need to finnish up the two current race projects.

I also am considering the "rabbit hole" idea, specific points in space usually involving gravity wells that allow ships to jump. 

I like the idea of different cultures using different tech and traveling different ways... with different races having preferences. There could be races that refuse to go FTL for some reason they will not discuss. It adds flavor to have differences. 

In my reboot I am considering FTL new tech, expensive & rarer than what we normally see in SF. 

 "Never fire a laser at a mirror."

jedion357's picture
jedion357
March 29, 2015 - 4:32am
TerlObar wrote:
relativity even makes my head spin and I'm an astronomer/physicist.


This statement makes me chuckle.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

KRingway's picture
KRingway
March 29, 2015 - 5:59am
The Void drive that I'm currently working on for addition to the Knight Hawks 2.0 project tries to address things. That said, I'm not trying to be realistic. I'm merely using the Void as a useful segueway to create a new type of drive that flips a ship in and out of the Void when it jumps. There is no need for jump gates or anything similar.

If anything, what I'm working on is broadly similar to hyperspace a la Star Wars, but with longer jump plotting times. That said, those times are still a tenth of the ones given in Knight Hawks.

IMHO it's probably not all that useful trying to make the KH/SF rules stick too much to absolute reality unless you run your SF games as a hardcore setting.

Tollon's picture
Tollon
March 29, 2015 - 6:24am

I have no problem with the idea of known world, with established routes, being plotted by the navigation computer and off you go to the next world in a matter of several minutes or hours.  The way KH describes plotting a new course and it taking 10 hour per light year is reasonable to me.  I think a skill chart is need to narrow down the proceedure for FTL. 

Any type of FTL system should not be able to work in a planet's gravity well or atmosphere, the reason are those dramatic escape scenes.  SO there has to be a safe distance from the planet before a jump takes place.

As I've state most of KH problems is the lack of description or carelessness on the orginal authors part. Updating those descriptions and bring them in line with common sci-fi ideas will lessen the confusion of players and GMs when it comes to starship construction and rules concerning travel between worlds.


Tchklinxa's picture
Tchklinxa
March 29, 2015 - 7:07am
Make you wonder what KHs would have ended up looking like if TSR had put a Zebs guide out on it too.. (don't throw things at me). Just wondering what they had in mind in R&D before SF got killed.

I probably should rummage around and try and locate my old Gurps Space stuff, for TL ideas as I am retro-ing up my setting a lot. 


 "Never fire a laser at a mirror."

jedion357's picture
jedion357
March 30, 2015 - 5:48am
Tchklinxa wrote:
Make you wonder what KHs would have ended up looking like if TSR had put a Zebs guide out on it too.. (don't throw things at me). Just wondering what they had in mind in R&D before SF got killed.

I probably should rummage around and try and locate my old Gurps Space stuff, for TL ideas as I am retro-ing up my setting a lot. 




In truth, the material in Zebs Guide is the vision of one designer who wanted a more Douglas Adams take on on the setting mish mashing it with Gamma World. Hence the plant creature PC ported over from his Gamma World campaign, the osakar. So I think the ultimate expression of Zebs Guide would be very un star Frontiers as we know it. Volume 1 didn't go very far because it introduced a new mechanic and retraced character creation which in effect meant that it was covering a lot of the same ground that AD had covered. I would guess that if there had never been a Buck Rogers product that Zebs Guide would have been better, slicker, more polished and ultimately a different game and the Star Frontiers community 30 years latter would be even more staunchly divided on the Zebs vs AD divide
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

Tchklinxa's picture
Tchklinxa
March 30, 2015 - 8:14am
Well that is all true, just sort of wondering what they would have done to the actual Space end of SF, for better or for worse, but we will never know.

Yeah I know that one guy had a lot of pull... you know though plants as intelligent life have been in Sci-fi over the ages & if my memory serves me right GURPS has a plant race in the Basic Space rules I have some place. 

Red Dwarf, Hitchhiker's Guide to the Galaxy are things that you should only selectively draw from, unless you want to do a mad hat setting. The various ideas I have been borrowing from Sci-fi are not presented in their original form as that would not work with SF, or the idea was only sort of presented and not developed enough or its an interesting idea but would be better if or more intriguing if I make some changes. 

Having available for sale something like the "Hitchhiker's Guide to the Galaxy" that gave less then correct info. or only sometimes correct info. or just useless fun facts that don't help... might not be a bad idea. Maybe it is made by a Dral company? The Traveler's Guide to the Frontier:
It could include such fun advice as "The Universe is beautiful and inspiring, but remember it wants to kill you! So kill it first!" or that great Firefly line "If someone try s to kill you, you kill them right back."

Foot in mouth



 "Never fire a laser at a mirror."

jedion357's picture
jedion357
March 31, 2015 - 3:46am
Tchklinxa wrote:

Having available for sale something like the "Hitchhiker's Guide to the Galaxy" that gave less then correct info. or only sometimes correct info. or just useless fun facts that don't help... might not be a bad idea. Maybe it is made by a Dral company? The Traveler's Guide to the Frontier:
It could include such fun advice as "The Universe is beautiful and inspiring, but remember it wants to kill you! So kill it first!" or that great Firefly line "If someone try s to kill you, you kill them right back."

Foot in mouth





I think that this could be done as a random generator. collect a bunch of quotes like the ones you suggested. Include the d100 list of SF rumors I half remember being in one of the magazines, include dozens of snippets of basic setting information and package it as a web based generator. A referee will be able to tell it to generate 1-20 "Guide" entries and he will be able to seed that with upto 5 rumors/clues based on the adventure he's running (the seeded rumors would be the material that could help the players). Generate and print. It would make a great tool to assist a referee. and calling it Zebulon's Guide to the Galaxy would be a nod to Douglas Adams and a bit of an "in" joke since many folks consider Zebs to be mostly useless much of what it generates would be considered mostly useless from a game stand point.
I might not be a dralasite, vrusk or yazirian but I do play one in Star Frontiers!

Tchklinxa's picture
Tchklinxa
March 31, 2015 - 6:46am
Foot in mouth Yet another project... lol. But yes it would be good to have. I like the name suggestion. I am going to start another thread on this specific. LOL.

 "Never fire a laser at a mirror."

Tchklinxa's picture
Tchklinxa
March 31, 2015 - 7:42am
Well, it seems I can reply to existing posts right now but not start new ones... really weird. I will try again latter. 
 "Never fire a laser at a mirror."

RanulfC's picture
RanulfC
April 5, 2015 - 5:17pm
SFAndriod: There was a very long discussion on the "how" of Void travel on another forum at one point and I pointed out that Void travel IS travel through another dimension. As described its a form of sub-sub-space where the overall distance is smaller than subspace. (Though the "1-day-per-light-year" comment messes that up as 0.1% SpeOL {Perry Rhodan reference} would not change the "1-light-year-per-hour" to a full day per light year... then again "I" personally and in game ignored that comment)

I have adopted somewhat the idea of a "gravity" in the Void which is part of your calculations (along with Void circuit "bleed" rate to tell you how long you can remain in the Void even though time does not appear to pass for the crew. for this I'm imagining the "stopped-time" effect from the horrible Wing Commander movie here) as you "bounce" off whatever is actually the Void.

For the most part my players never seem to care that much and its mostly my obsessive "background" nature that comes forward in such discussions.

Randy :)

bossmoss's picture
bossmoss
April 29, 2015 - 10:11am
When I first played Star Frontiers as a teenager, we didn't worry about time dilation, but as I got older I started to think about it.  I tried to implement it, but quickly discovered that it completely messes up any attempt to play the game within one consistent time frame.  Every time someone goes somewhere, they leave society behind for good.  My solution was to say that Void travel somehow negates relativistic effects by entering another dimension.  Yeah, I know... but it made the game playable again.