Implications of this ftl system

[Rhadamantus]

In a fictional universe I am designing, FTL is governed by the mass of the star. To jump from one star to another, you must be at the point where the radius of .01g crosses the line between the two stellar cores (give or take about a hundred klicks). You can also only jump if the distance between the two stars is less than 30*(mstar^1.75) (in solar masses and ly). This means red dwarfs are jumpable to, but not from. As far as I can guess, this should also mean O-type stars become galactic scale transport hubs, and Supermassive Black Holes let you jump clear across the universe. Anyone else care to think this through?

[Lord Revan]

Personally I would make it so that you cannot jump to a system unless you can also jump away from it, granted it would help if I knew what you were planning on using the universe for, in a game a well known hazard might work as a "failure state", but for a story it wouldn't work as well as atm Red Dwarf stars repesent a "every dies a slow and horrible death" ending which I don't think would make a really good story (though it could work in a story if you somehow were able trick the bad guys into jumping into a "certain death pit" system), but in the end an FTL system in a narative work is a tool and all it needs to be is dictated by the needs of the story and it physics have seem plausible enough and generally less detail is better.

[Rhadamantus]

Personally I would make it so that you cannot jump to a system unless you can also jump away from it, granted it would help if I knew what you were planning on using the universe for, in a game a well known hazard might work as a "failure state", but for a story it wouldn't work as well as atm Red Dwarf stars repesent a "every dies a slow and horrible death" ending which I don't think would make a really good story (though it could work in a story if you somehow were able trick the bad guys into jumping into a "certain death pit" system), but in the end an FTL system in a narative work is a tool and all it needs to be is dictated by the needs of the story and it physics have seem plausible enough and generally less detail is better.

It provides a clean way to eliminate red dwarfs, which are less interesting story wise usually.

[Lord Revan]

Personally I would make it so that you cannot jump to a system unless you can also jump away from it, granted it would help if I knew what you were planning on using the universe for, in a game a well known hazard might work as a "failure state", but for a story it wouldn't work as well as atm Red Dwarf stars repesent a "every dies a slow and horrible death" ending which I don't think would make a really good story (though it could work in a story if you somehow were able trick the bad guys into jumping into a "certain death pit" system), but in the end an FTL system in a narative work is a tool and all it needs to be is dictated by the needs of the story and it physics have seem plausible enough and generally less detail is better.

It provides a clean way to eliminate red dwarfs, which are less interesting story wise usually.

OK let ask you this then what purpose does the ability to jump to red dwarf stars serve rather them just being impossible to visit. For example your FTL system could so that it certain Stellar mass threshold to enter FTL and then it takes certain Stellar mass Threshold to exit FTL the details aren't really that important, most people will accept "it's impossible" and don't need a multi-page explanation about the physics involved, that way you exclude certain "boring" startypes without having "certain deathpits" what you're current system has. Your current system has potential but it needs tweeking to avoid certain storyrelated issues, like having a place if entered would most likely mean certain death to characters since you can't FTL out of there and an FTL ship wouldn't most likely have provisions for a sub-light trek to the closest star that you could use FTL from space is huge and mostly empty after all.

[Rhadamantus]

Personally I would make it so that you cannot jump to a system unless you can also jump away from it, granted it would help if I knew what you were planning on using the universe for, in a game a well known hazard might work as a "failure state", but for a story it wouldn't work as well as atm Red Dwarf stars repesent a "every dies a slow and horrible death" ending which I don't think would make a really good story (though it could work in a story if you somehow were able trick the bad guys into jumping into a "certain death pit" system), but in the end an FTL system in a narative work is a tool and all it needs to be is dictated by the needs of the story and it physics have seem plausible enough and generally less detail is better.

It provides a clean way to eliminate red dwarfs, which are less interesting story wise usually.

OK let ask you this then what purpose does the ability to jump to red dwarf stars serve rather them just being impossible to visit. For example your FTL system could so that it certain Stellar mass threshold to enter FTL and then it takes certain Stellar mass Threshold to exit FTL the details aren't really that important, most people will accept "it's impossible" and don't need a multi-page explanation about the physics involved, that way you exclude certain "boring" startypes without having "certain deathpits" what you're current system has. Your current system has potential but it needs tweeking to avoid certain storyrelated issues, like having a place if entered would most likely mean certain death to characters since you can't FTL out of there and an FTL ship wouldn't most likely have provisions for a sub-light trek to the closest star that you could use FTL from space is huge and mostly empty after all.

This seemed a better way to go about it.

[Lord Revan]

The "star system of certain death" your current contains is something that must be used some form or another and honestly you don't even have to specifically "exclude" boring systems, unless one your players (if for a game) or alien races gets off by being bored to tiers there would be no need nor reason to visit a "boring" system during the story. If you just said that "there's some places you can't visit because how the FTL system works" it's enough for most people they don't need or want to know the details.

In essence you're running into a much larger problem while trying to solve a problem that's not really a problem.

[Jub]

The red Dwarf thing, as it stands, could be interesting. It's obviously a hazard and potential trap, but what if certain modified or advanced engines could jump from smaller masses? This leaves places to hide things in "impossible" places. It also means that you can turn these boring common places into something more if you ever have need of it.

[Caiaphas]

The question that immediately comes to mind is "where is this story happening"? If it's happening in the Local Cluster, then you can very easily look up starmaps and actually plot out what routes are available to ships in your universe and therefore what systems would become trade hubs, strategic chokepoints, so on and so forth.

Which brings me to another point that I feel needs addressing. How much power does your FTL system require, and, as a corollary, what kind of power generation is available to the peoples of this universe? If you can figure that out, you can figure out if you're dealing with only governments and major mega-corps able to afford interstellar travel on a regular basis, or if you can travel to Alpha Centauri like I can travel to Canada.

[FedRebel]

The Red Dwarf factor could have some potential,

The apparent one way trip would incentivize penal colonies and outlaw havens...which would eventually bite the galactic government(s) in the butt.

The former outlaws and/or prisoners eventually devise a variant of the stardrive that works with dwarf stars, they then blindside the governments....

Kind of like the fall of the Western Roman Empire...in Space!

[Rhadamantus]

The question that immediately comes to mind is "where is this story happening"? If it's happening in the Local Cluster, then you can very easily look up starmaps and actually plot out what routes are available to ships in your universe and therefore what systems would become trade hubs, strategic chokepoints, so on and so forth.

Which brings me to another point that I feel needs addressing. How much power does your FTL system require, and, as a corollary, what kind of power generation is available to the peoples of this universe? If you can figure that out, you can figure out if you're dealing with only governments and major mega-corps able to afford interstellar travel on a regular basis, or if you can travel to Alpha Centauri like I can travel to Canada.

I was thinking the jump system is fairly low power realitive to their tech level.

[Caiaphas]

The question that immediately comes to mind is "where is this story happening"? If it's happening in the Local Cluster, then you can very easily look up starmaps and actually plot out what routes are available to ships in your universe and therefore what systems would become trade hubs, strategic chokepoints, so on and so forth.

Which brings me to another point that I feel needs addressing. How much power does your FTL system require, and, as a corollary, what kind of power generation is available to the peoples of this universe? If you can figure that out, you can figure out if you're dealing with only governments and major mega-corps able to afford interstellar travel on a regular basis, or if you can travel to Alpha Centauri like I can travel to Canada.

I was thinking the jump system is fairly low power realitive to their tech level.

Okay, that's one question answered.

But again, do you know where your story is taking place? If it's someplace like a globular cluster, then travel between star systems should be fairly easy, and you should be able to jump to whatever system you want without too much trouble (pending the actual details of the stellar population of said cluster). If it's someplace like the Local Bubble, well, might be a little more trouble getting around.

Another consideration: since the ship needs to be on a line between the "home" star and the "target" star, how easy is it to travel between stellar systems that are out of the plane of the solar system you're in? Those orbits take a lot of delta-v to get into, so if they have anything less than a torchship, those systems are going to be sparsely traveled.

[Rhadamantus]

The question that immediately comes to mind is "where is this story happening"? If it's happening in the Local Cluster, then you can very easily look up starmaps and actually plot out what routes are available to ships in your universe and therefore what systems would become trade hubs, strategic chokepoints, so on and so forth.

Which brings me to another point that I feel needs addressing. How much power does your FTL system require, and, as a corollary, what kind of power generation is available to the peoples of this universe? If you can figure that out, you can figure out if you're dealing with only governments and major mega-corps able to afford interstellar travel on a regular basis, or if you can travel to Alpha Centauri like I can travel to Canada.

I was thinking the jump system is fairly low power realitive to their tech level.

Okay, that's one question answered.

But again, do you know where your story is taking place? If it's someplace like a globular cluster, then travel between star systems should be fairly easy, and you should be able to jump to whatever system you want without too much trouble (pending the actual details of the stellar population of said cluster). If it's someplace like the Local Bubble, well, might be a little more trouble getting around.

Another consideration: since the ship needs to be on a line between the "home" star and the "target" star, how easy is it to travel between stellar systems that are out of the plane of the solar system you're in? Those orbits take a lot of delta-v to get into, so if they have anything less than a torchship, those systems are going to be sparsely traveled.

I was imagining this takes place in the local bubble, and with torchships (something like 12000g for a civilian ship.) This of course makes non-planar travel very easy.

[Caiaphas]

I was thinking the jump system is fairly low power realitive to their tech level.

Okay, that's one question answered.

But again, do you know where your story is taking place? If it's someplace like a globular cluster, then travel between star systems should be fairly easy, and you should be able to jump to whatever system you want without too much trouble (pending the actual details of the stellar population of said cluster). If it's someplace like the Local Bubble, well, might be a little more trouble getting around.

Another consideration: since the ship needs to be on a line between the "home" star and the "target" star, how easy is it to travel between stellar systems that are out of the plane of the solar system you're in? Those orbits take a lot of delta-v to get into, so if they have anything less than a torchship, those systems are going to be sparsely traveled.

I was imagining this takes place in the local bubble, and with torchships (something like 12000g for a civilian ship.) This of course makes non-planar travel very easy.

In that case, it's a comparatively simple matter to look up starmaps of the Local Bubble (this is a decent starting point: http://www.projectrho.com/public_html/s ... pindex.php) and calculate the distance a starship can jump, especially since you've already decided on a mathematical basis for your FTL drive's capabilities. As an example of how your results might affect the astropolitical landscape and economic development of your universe, and therefore the kind of setting you'll be playing around in, say that there's a particularly high-mass star in the Local Bubble (damned if I know if there's one off of the top of my head), which can be jumped to from virtually any system in the LB, or from any star in the LB. That place is going to be a natural travel nexus, and so its local economy is going to be very much based off of servicing the crews of the ships that pass through.

Also, I've noticed a vague variable in your original equations; does mstar represent the local star's mass, or the target star's mass, or some weird average of both?

Sidenote: I can very, very highly recommend the Atomic Rockets website I linked above. Top-notch stuff and cutting-edge rocket science for storytellers, and they have an entire section on torchships that you should definitely read.

[Rhadamantus]

Okay, that's one question answered.

But again, do you know where your story is taking place? If it's someplace like a globular cluster, then travel between star systems should be fairly easy, and you should be able to jump to whatever system you want without too much trouble (pending the actual details of the stellar population of said cluster). If it's someplace like the Local Bubble, well, might be a little more trouble getting around.

Another consideration: since the ship needs to be on a line between the "home" star and the "target" star, how easy is it to travel between stellar systems that are out of the plane of the solar system you're in? Those orbits take a lot of delta-v to get into, so if they have anything less than a torchship, those systems are going to be sparsely traveled.

I was imagining this takes place in the local bubble, and with torchships (something like 12000g for a civilian ship.) This of course makes non-planar travel very easy.

In that case, it's a comparatively simple matter to look up starmaps of the Local Bubble (this is a decent starting point: http://www.projectrho.com/public_html/s ... pindex.php) and calculate the distance a starship can jump, especially since you've already decided on a mathematical basis for your FTL drive's capabilities. As an example of how your results might affect the astropolitical landscape and economic development of your universe, and therefore the kind of setting you'll be playing around in, say that there's a particularly high-mass star in the Local Bubble (damned if I know if there's one off of the top of my head), which can be jumped to from virtually any system in the LB, or from any star in the LB. That place is going to be a natural travel nexus, and so its local economy is going to be very much based off of servicing the crews of the ships that pass through.

Also, I've noticed a vague variable in your original equations; does mstar represent the local star's mass, or the target star's mass, or some weird average of both?

Sidenote: I can very, very highly recommend the Atomic Rockets website I linked above. Top-notch stuff and cutting-edge rocket science for storytellers, and they have an entire section on torchships that you should definitely read.

1. The mass of the originating star. I think Vega fits the bill, as do Sirius, Capella, and Altair. Achenar is a bit further, but has 800+ ly range.
2. I know of atomic rockets.

[Loren Pechtel]

Some red dwarf star gets picked as a prison planet. It's a virtually escape-proof prison.

Given the torch drive it's not truly one-way, ships can return the slow way, plodding along just under lightspeed to the nearest star they can jump from. That's how the prison construction crew gets home. The resupply freighters do not have life support so nobody can hitchhike.