Jump Shadow

[sudnadja]

The jump shadow effect is more significant than one would immediately suspect. This graphic represents a ship launching from Terra where it is right now, accelerating to 100 diameters in the direction opposite from the sun. It's presumed that a jump cannot be made through tidal force stronger than what earth's is at 100 earth diameters, this comes out to be for the sun about 126.9 solar radii. This actually blocks out a significant portion of the sky - Midway, Loki, Junction and Ember are all shadowed.

Note that if you used the 100 diameter rule for the Sun rather than the tidal gradient, the effect would be even more pronounced.

 

[AnotherDilbert]

Yes, absolutely, but since we are lazy (at least I am) we don't bother doing that for every jump. We even use a 2-D map for simplicity...

Obviously the direction that is shadowed would shift with the time o year, hence the planets orbit around the star.

 

[sudnadja]

Yes, absolutely, but since we are lazy (at least I am) we don't bother doing that for every jump. We even use a 2-D map for simplicity...

Obviously the direction that is shadowed would shift with the time o year, hence the planets orbit around the star.

The direction of the shadow would also and perhaps more importantly shift by the path the players choose to take the ship.

Say the players are leaving from Terra (as is positioned right now, September 10, 2017) intending to jump for Junction, they head off (in galactic cartesian coordinate direction) toward -1,0,0, exactly away from the core. They don't actually get clear of the sun's jump shadow until they've made 5000 earth diameters distance away from the earth. The jump shadow of the earth (the green cone in this plot) is insignificant compared to the sun's jump shadow.

I think it can make a more interesting game - if your choice is to jump to Barnard or Junction, Barnard is a much better choice as it is not shadowed and all your players have to do is get clear of the 100 diameter limit. They could make Junction, but then they'd be hanging around in real space a lot longer, prone to pirate attack or what have you.

 

[Supplement Four]

Why can't the ship travel through N-Space around the sphere created by 100 diam of Sol to a point where it can jump in any direction it wants?

Yes, we're talking longer treks in normal space before jump.





For gaming purposes, the SOM has a quick chart to roll upon to figure planetary masking. It would be easy to do the same and add a system's star(s) effect.

I like the idea of masking, if its easy to track and use in a game. I like how it makes space travel more like ocean voyages, with different seasons. Can't go to that sea because is frozen or because it's storm season. Likewise, can't go in that direction because its is masked.

Think of what this would do to Traveller star systems. More of the solar system would be used. When's the last time your Traveller PCs went to a base in the system that wasn't on the main world? There would be a lot more N-Space travel, which means more chances for piracy and eating up costly consumables. Even the Power Plant fuel that we normally don't even concern ourselves with.

Think of trade in the subsector--how some worlds would be in the masked travel area of their trading partners for a time.

Lots of interesting implications.

 

[sudnadja]

Why can't the ship travel through N-Space around the sphere created by 100 diam of Sol to a point where it can jump in any direction it wants?

Yes, we're talking longer treks in normal space before jump.

It can travel through n-space, that was the point of me mentioning just how far they would have to travel in my example. 5000 diameters rather than the optimal 100

However, the Sun's mask is huge:

(this using the tidal version of jump limits, planet orbits are plotted to scale) - anywhere around earth's orbital path a large portion of the sky will be blocked and you can't get to a point where you can jump in any direction you want. If you get far enough away from the sun (dozens of AU) you can get to the point where the mask / shadow is fairly small, though.

For gaming purposes, the SOM has a quick chart to roll upon to figure planetary masking. It would be easy to do the same and add a system's star(s) effect.

I like the idea of masking, if its easy to track and use in a game. I like how it makes space travel more like ocean voyages, with different seasons. Can't go to that sea because is frozen or because it's storm season. Likewise, can't go in that direction because its is masked.

Think of what this would do to Traveller star systems. More of the solar system would be used. When's the last time your Traveller PCs went to a base in the system that wasn't on the main world? There would be a lot more N-Space travel, which means more chances for piracy and eating up costly consumables. Even the Power Plant fuel that we normally don't even concern ourselves with.

Think of trade in the subsector--how some worlds would be in the masked travel area of their trading partners for a time.

Lots of interesting implications.

I thought of that too - passenger liners would have seasons. There would certainly be more bookkeeping but it's doable. You'd need orbital elements for everything, but that's something that's pretty easy to write code for.



You would definitely need a particular type of player, but one of the complaints that I have had with traveller is that it makes 11,000 worlds, which should be vast beyond belief, seem like 11,000 midwest towns all within walking distance from each other. I hope it starts to drift a bit more toward realistic astronomy and the implications of that.

 

[ShawnDriscoll]

It's never been an issue for me.

 

[Supplement Four]

I've had some games, back when I was using Heaven & Earth, where I detailed each and every system the players visited, and I would figure which worlds were completely masked by the system's star or stars.

I figured it out to the orbit, and when that fell within the habitable zone, it made for interesting space terrain--especially when the world's orbit was elliptical, giving it a period of time where the distance to outside the star's jump mask was shorter than usual.

 

[sudnadja]

I've had some games, back when I was using Heaven & Earth, where I detailed each and every system the players visited, and I would figure which worlds were completely masked by the system's star or stars.

I figured it out to the orbit, and when that fell within the habitable zone, it made for interesting space terrain--especially when the world's orbit was elliptical, giving it a period of time where the distance to outside the star's jump mask was shorter than usual.

and in modern times, there's no real reason that a full system can't be updated, including orbits, on every jump-in or out.

 

[GrayPennell]

I like this idea to, This would also complicate naval strategy. More operations would be moved into the far orbits and our favorite modular cutters would be super busy as Lightering ships taking cargo from the far orbits to the near orbits.