On 29Jun2020 0141, Thomas Jones-Low wrote:
>     My seven count is (in no specific order):  Ancients / Droyne,
> Vilani, Zhodani, Vargr, Solomani, K'kree, and Hiver. There are, that I
> know of, three instances of reverse engineering the jump drive:
> Genoee, Aslan, and one group in the Island Cluster. Everyone else was
> simply given the whole kit.
>
>     I've see it argued that the Vilani, Zhodani, Vargr, and Solomani
> invention was reverse engineering an Ancients device rather than true
> first invention. But, unlike the Aslan, have managed to hide the
> evidence better.
The conspiracy theorists like this, but there the evidence in the case
of the Zhodani and Vilani is "They're on worlds with Ancient ruins! They
must've found one in them!". For Vargr it's "They're an Ancient uplift
project, there must be ruins and they must've found one in them!". For
Terrans it's "The Ancients visited Terra, so they must have left some
ruins in the system, and the Terrans much have found a drive in them!".

So basically it's complete supposition, especially in the case of the
Vargr and Terrans. For the Vargr, a better case would be that as with
the Aslan they reverse engineered a drive from a crashed/stranded scout
or merchant (examination of an original Vargr drive, if one can be had
would prove/disprove this), in this case Zhodani, but there's no canon
textual support for that either. For the Terrans there's nothing. No
Ancient artefacts ever found, and a drive that was known to be somewhat
different from the Vilani version (which was, IIRC, later reverse
engineered to get J2, and then improved on to get J3).

>
>     The initial Hiver jump drive was an interesting setup. It would
> melt itself into slag after a few jumps. It was only sometime later
> they managed to buy/steal a more conventional, longer lasting, design.
>
>     This leave the K'kree. Has anyone really understood how their
> Drive actually works?

The same way as everyone else's, so far as I know.
>>
>> Though for jump entry, there seems to still be a lot of discussion as
>> to whether the sun constitutes a 100D limit or is not relevant - it
>> is convenient to ignore the sun, but its just another body in space
>> with gravity and mass so I'm not sure why it would be ignored.
>>
>     As Robert Boleyn pointed out the 1977 version of the Traveller
> rules includes the sun. T5 re-affirms this by stating any object
> larger than your ship may cause jump failures. The 100D limit on a
> Tigress-class Dreadnought is 12km.

I tend to ignore stars for reasons of laziness, but they've been there
in the rules since forever.

>
>
>     For an extended treatise on this I refer you to GT:Far Trader, pg.
> 58-63 and a discussion of the effects Jump Masking on interstellar trade.
>
>     One reason people feel they can ignore it is for most stars (GKM
> class main sequence stars) the 100D limit of the star is inside the
> habitable zone. Make the 100D limit on the main world and you're free
> to go. Even with the A and F class main sequence stars, the time
> required to get to the 100D limit of the star and the world are not
> that much different. A few hours with a 1G or 2G drive. It adds a lot
> of calculations that makes no difference. Rather the Pilot and
> Astrogator would know about the 100D limit on the star and plot a
> course accordingly. But the Players don't need to be aware if that
> detail.
Well, aside from jump shadowing, though that's not obviously in CT.

>
>     There are stars where this starts to make a huge difference. The
> Type II and Type Ia / Ib giant stars. The time from the habitable zone
> to the 100D limit on the star is measured in months. The fact these
> star's won't have habitable planets is another discussion entirely.
FWIW, Book 6 - Scouts doesn't allow random placement of Type Ia/Ib
stars. It also doesn't allow worlds with breathable atmospheres or
populations in the 100s of millions or more around stars large than Type
V dwarfs. So CT's extended system generation rules took that into account.

For the biggest Type IIs, yes it would take almost three months at 1G,
less than two months at 2G+. Turnover velocity would be 8-9% of light
speed. For smaller, hotter Type IIs reaching the 100D limit takes a
little less than a day at 1G.

>     One system that explicitly mentions the Jump Capacitors is High
> Guard in relation to the Black Globe generators. And you can use that
> power for maneuver drive, agility, weapons, or powering the jump. But
> the Jump Capacitors won't hold a charge for long (1 or 2 turns).
>
>     The only other place I've seen this discussed is in GT:Starships,
> which uses GURPS Vehicles as a base, one of the most detailed vehicle
> design systems ever produced. Here all of the energy weapons have
> large capacitors to allow reducing the size of the main power plant,
> and the jump drive has it's own set of capacitors, as does the
> Maneuver drive, and the Black Globe will feed the power grid on the ship.
>
>     The only group of people I've seen interested in doing power
> management at this level are Star Fleet Battles players.

FF&S for TNE also discusses black globes, jump drive capacitors, and
powering the ship from a black globe's absorbed energy. It also
discusses using a black globe as a solar power collector, and what
happens when a large mass interpenetrates with the surface of a black
globe (nothing good).

--
Rupert Boleyn <xxxxxx@gmail.com>