Jump vector question

[captainjack23]

The teleporter thing probably came from whatever piece of fiction inspired the addition of teleportation to the game, and really, it helps both suppress and enhance different types of "stupid teleportation tricks".

Niven was the first place I recall explicit issues due to momentum conservation being discussed in SF. One of his solutions was that in a big system, the excess energy was shunted to an energy sink, separate from the teleporter/destination.

 

[kristof65]

I've used SSOM in play. It's not bad with a sci-calc to hand.

Even less so with a pre-done spreadsheet on hand. Plug the numbers in, get your answer. If you're really gung ho, you can make one up for each system to account for all of those variables. Hmmm, that's a project I may have to tackle for my most visited campaign worlds.

I've got the SSOM myself, a quick glance didn't reveal what I was looking for - which makes sense now, as I really didn't know what was looking for.

In thinking about this, I've realized you can have some really interesting situations to make various worlds/systems unique. Frex, Earth sits a mere 6,000,000 miles or so outside Sol's 100d limit. If the orbit was just a little more elipitical, you could have a situation where we spent part of the year being within Sol's 100d limit, and part of it outside. Depending on how far in/out that swing is, could mean vast differences in travel time before reaching a jump point.

 

[Gee4orce]

Never really understood why it's a 100 diameter limit anyway, as I thought it was the MASS of the star that was supposed to effect Jump drive.

You could have two stars with the same mass - one a bloated old red giant and another a compact main sequence star, but the giant would need a vastly greater jump point distance.

 

[GypsyComet]

Never really understood why it's a 100 diameter limit anyway, as I thought it was the MASS of the star that was supposed to effect Jump drive.

You could have two stars with the same mass - one a bloated old red giant and another a compact main sequence star, but the giant would need a vastly greater jump point distance.

Because the math is simpler, and this is a game.

 

[EDG]

Because the math is simpler, and this is a game.

It's not simpler actually. You still have to look up a table either way, and figure out 100x whatever value is shown there - whether that's mass or radius doesn't matter in terms of how quick it is to calculate.

"This is a game" - as if it's an excuse that things have to be less realistic or easier - is a cop-out answer too. Plenty of games have complex elements in them and they do fine.

Either way, there's no physical basis for using the star's radius (or multiples thereof) at all. An object's radius is the specific distance from its centre of mass where its surface happens to be - beyond that there's nothing special about it. Surface gravity is just the gravity at that distance from the centre of mass of the object.

It would make much more sense to use the gravity (and therefore the mass) as the determinant - have it as the limit beyond which the gravity drops below a certain absolute value. As I said, you still have to look it up anyway so it's no more complex than using the diameter - but this way a white dwarf has roughly the same jump limit as a solar-mass star, and a red giant most likely will have its limit inside it rather than thousands of AU beyond its surface (and beyond any remaining planetary system).

 

[kristof65]

...and a red giant most likely will have its limit inside it rather than thousands of AU beyond its surface (and beyond any remaining planetary system).

Isn't that what would make it more complex? Now you have to have a second table showing the safe distance to jump in to that solar system based on temp.

I agree with you, that it should be based on mass. But then again, m-drive should be based on the ships mass, power plant on the megawatts required and J-drive size based upon a combination of mass and boundry volume, rather than d-tons.

It's pretty easy to tear the game apart for stuff like this, especially with over 30 years of scientific advances since it was first released. All in all, there are just some things you have to take with a grain of salt.

 

[EDG]

...and a red giant most likely will have its limit inside it rather than thousands of AU beyond its surface (and beyond any remaining planetary system).

Isn't that what would make it more complex? Now you have to have a second table showing the safe distance to jump in to that solar system based on temp.

No, it'd be based entirely on mass. For a red giant you could just assume it has a mass of 2 or 3 Sols and leave it at that - precalculate its gravity, and show the limit determined from that in a table. So you just have one table to look up.

Heck, just break it down as one value for each type of star (O V, B V, A V, F V, G V, K V, M V, BD, Red giant, Supergiant, White Dwarf, Neutron Star), based on their average mass. That'd make it even simpler.

 

[Rikki Tikki Traveller]

Wouldn't THAT make a wonderful plot hook though... It would also explain some Amber and Red Zones...

I have used Mass since the very beginning (1977) and ignored the radius thing except as an approximation for Earthlike worlds.

Use the cube-root of the mass (gravity gradient) and it keeps things separated nicely with decent travel distances.

Guess what? It never caused a problem in any game. I just told them how far away they were, and off they flew.

In CT, LBB1-3, there was not info to calculate mass, so the only thing they could use was planetery diameter. It wasn't until later that scientist and smarty-pants figured out that stellar 100D limits might be beyond the planetary orbits.

Guarenteed that MWM never thought about that when setting up the idea of a 100D limit for jumping.