168 Hours plus or minus 10 percent

[TheEngineer]

Aramis gets a skill check in library use

And, errrr, did I miss something or why is it about jump masking now ???

 

[Whipsnade]

Originally posted by TheEngineer:
And, errrr, did I miss something or why is it about jump masking now ???

TheEngineer,

Because if you know the duration of your jump beforehand, you can use that knowledge to avoid 100D limits and reduce the chance of jump masking.

Arguing for knowing jump duration prior to jump initiation is way to nibble away at jump masking and thus nibble away at GT which is incorrectly seen as the 'father' of jump masking.

There's another game being played here.


Have fun,
Bill

 

[atpollard]

OK, I’ll play along.
I assume that “jump masking” refers to the fact that any ship in jump space which attempts to exit from jump within about 100 diameters of a major mass precipitates out of jump space at the 100 diameter limit. On that subject, the article on Jumpspace by Mark Miller in the JTAS No. 24 (which I quoted in my initial post) also states that:

“The perturbing effects of gravity preclude a ship from exiting jump space within the same distance. When ships are directed to exit jump space within a gravity field, they are precipitated out of jump space at the edge of the field instead.”

That sounds clear to me. It appears to be a game mechanic designed to prevent a catastrophic misjump where a ship reenters normal space inside a planet or to allow a warship/weapon to appear too close to a world for the defenders to respond, but you will have to ask Mr. Miller what his intentions were.

Jump masking is also completely unrelated to this topic. To restate my premise:

Have you ever had one of those moments when everything suddenly makes sense. I was re-reading the article on Jumpspace by Mark Miller in the JTAS No. 24 and thinking about all of the debate on the inaccuracy of Jumps given the Time uncertainty inherent in a Jump (if you don’t know WHEN you will emerge from a jump then you don’t know WHERE the target world will be when you emerge). Four sentences from the article caught my attention:

</font><blockquote>quote:</font><hr />“Jump takes 168 hours (+/- 10%) to complete. This time is related to the nature of the alternate space being traveled in, and to the energy applied. Where time is a variable in travel in normal space, energy consumption is a variable in alternate space; time is a constant.”

“The exact time of emergence is usually predicted by the ship’s computer and the bridge is well manned for the event.”

What if the time required for any particular Jump is a constant that is calculated just prior to the jump. The exact value for the constant “TIME” varies from 151.2 hours to 184.8 hours for all possible jumps (excluding misjumps), but the time for any particular jump is known with great precision. I find nothing in CT or the article to suggest that this is not exactly what Mr. Miller had in mind when he wrote the article.

With this understanding, virtually all of the controversy evaporates and peace is restored to the Imperium. </font>[/QUOTE]

I am still convinced that both the LENGTH and DURATION of a jump are determined prior to entering jump space. Just as the distance between the point of departure and the point of arrival will be different for every jump (both worlds are moving) so too the time spent in jump space will be different for every jump. The fact that the game requires a roll to determine the time does not, in itself, prove that the time is a variable and unknown quantity – it just proves that all jumps are not the exact same duration. The JTAS article clearly implies that a jump is a highly precise (if not well understood) process and it clearly states that time is a constant in jump space and the exact time a ship departs from jump space is known to the crew.

[EDIT] If the jump duration is known with the same precision as the jump distance (one part in ten billion), then the time error is a tiny fraction of a second. In fact, if the time error is one part in ten million (1000 times greater than the distance error) then the time window is still only 1 second. If the time error is one part in ten thousand (1 million times greater than the distance error) then the time window is only 1 minute. If the time error is one part in ten (1 billion times greater than the distance error) then the time window is 16.8 hours. It seems illogical to assume that jump distance is calculated with 1 billion times greater precision than jump duration without a VERY clear cannon reference to this fact.

What I have requested is as follows:

Is there anything in any other published source which specifically contradicts this interpretation?

Unless someone can find a passage which EXPLICITLY states that the duration of a jump is unknown before a ship enters jump space, there is no reason to believe that the jump rules and description are broken.

With all due respect to your passion, Bill, and with complete disregard of the fate of GURPS Traveller, your statements that I am wrong are unsupported. To your statement “There is no indication in canon that jump duration is known before jump initiation.” I would point to every story reference of ships exiting jump space at the 100 diameter limit as one piece of evidence. The JTAS 24 clearly states that the exact time a ship departs from jump space is known to the crew. Where is there any evidence that the exact time a ship departs from jump space is NOT known before the jump?

At this point, the entire debate on the jump rules being broken appears to be based entirely on the fact that some people want it to be broken. WHERE’S THE BEEF?

 

[aramis]

TE:

Bill is under the mistaken assumption that GT is canonical to the rest of the OTU. And in his convincedness, is not being rational about the evidence otherwise.

It's not in canon anywhere until GT, and it's not in T20 which postdates GT. And Hunter ALSO asked MWM. Got a different answer. MWM isn't consistent. Big surprise... not.

I'm citing stuff in print in canonical rulesets. GT isn't one of those; it's an ATU.

Now, as to not being able to tell how long before hand; all that matters is not being able to change it after one knows. Canon speaks to neither.

 

[Malenfant]

Just throwing out a random suggestion, call it crazy....

but given that Marc is vaguely contactable, why not just ask him again (or more likely get robject to ask him, since he seems to be in reasonably regular communication with him about T5) and get a final answer from him? If he can make up his mind about it himself, that is (the fact that the designer of the game can't figure out a straight answer himself is really promising... ).

So pull together everything that's ever been said about the subject from all available sources (yes, even GT) and then ask him "so, what's the final verdict here". And that will hopefully end the matter without everyone tearing out eachothers throats.

Like I said, just a crazy idea...

 

[atpollard]

Originally posted by Malenfant:
Like I said, just a crazy idea...

Bleeding heart pacifist. Whatever happened to "God, Guts and Glory"?

 

[TheEngineer]

Hi !

[QUOTE}]
Jump masking is also completely unrelated to this topic.
[/QUOTE]
I think so, too

[QUOTE}]
Where is there any evidence that the exact time a ship departs from jump space is NOT known before the jump?
[QUOTE}]

Did You take a look at my last posts ?
So again (quote from Jumpsapce article):
[QUOTE}]
...
The duration of a jump is fixed at the
instant that jump begins, and depends on
the specific jump space entered, the
energy input into the system, and on
other factors. In most cases, jump will
last a week.
...
[QUOTE}]

Honestly I don't know how to express it more explicitly as the source does.

Regards,

TE

P.S.
Somehow this reminds me off a comedy video where Mr. Bush asks "Who is the new leader of China" and Mrs. Rice answers "Hu is the new leader of China !"...

 

[Andrew Boulton]

I've always assumed the jump exit time wasn't known until an hour or so before you reenter real space, but I've seen nothing that says it isn't known as soon as you enter jump.

 

[Hal]

Ok - riddle me this:

Two ship within 2 km of each other, agree to jump at the same time for the same destination (system wise) and the same general ballpark of the jump destination (ie roughly the same patch of space within the star system).

Per the rules, unless they are both coordinating via one ship doing the plots for all ships, it is entirely possible for one ship to arrive 1 day sooner than the other. If the "conditions" of the jump are identical for both ships - why isn't the duration identical for both ships?

 

[Andrew Boulton]

Slightly different input by the Astrogators, and different computers/software.

 

[atpollard]

Originally posted by TheEngineer:
The duration of a jump is fixed at the instant that jump begins, and depends on the specific jump space entered, the energy input into the system, and on other factors. In most cases, jump will last a week.

Hi, TE

I have read you posts and am considering them very carefully. I was hoping to gather a body of evidence against my interpretation and then admit that I was wrong or show that my interpretation could still be correct, rather than address each specific reference.

In response to the above quote, it can also mean that ALL of the parameters of a jump are fixed "at the instant that jump begins". No one would argue that the distance of the jump is NOT fixed at the instant that jump begins – you cannot decide two days into the jump that you changed your mind and want to jump two parsecs instead of one. In the same way, the TIME that the jump will take is unalterable from the instant that the jump begins. What is the point of Mark Miller stating that a Jump is accurate to within 3000 kilometers if the time is so inaccurate that the world could be millions of kilometers from the target point when you emerge? Don’t you want to see some pretty strong evidence before you blindly accept anybody’s claim that Mark Miller and every version of Traveller is wrong and needs to be fixed.

You earlier suggested that if the time could be known before the jump, then a smart captain would plot several jumps and select the jump with the best time. Perhaps he does. Plotting the jump could easily include adjusting all of the variables to determine the shortest and safest path from point A to point B. The variables of the jump can be changed prior to opening the rift into the specific jump space, but once that jump space is entered, the variables are fixed and unalterable. The roll for duration represents the final result of a long process.

I believe that your first piece of evidence was the task list from MT that listed calculating the length of the jump as the LAST step in the sequence. That is the strongest evidence presented so far against the jump time being known prior to jump. Had the calculation of jump duration been listed as a separate step BEFORE entering jump space, my premise would have been proven. Had the calculation of jump duration been listed as a separate step AFTER entering jump space, my premise would have been shot down. Instead, it is listed in the past tense at the end of the sequence and could be interpreted as “Duration is not known until shortly before the jump ends” or it can be interpreted as “the players did not need this information until the end of the process, so they could move on with the game”. Would you be comfortable with all of the consequences of jump time uncertainty based exclusively on that one ambiguous line in a single task list?

Aramis’ recollection of MTJ MTQ&A synchronized jumps could offer a valuable glimpse into this issue. If two ships can use the exact same plot to achieve the exact same jump time, then the time clearly is both known and fixed before the jump. The extent to which two ships using the exact same plot arrive at different times, is the variability of the actual jump which may not be known in advance. The difference between the synchronized plot times and the unsynchronized plot times (+/- 16.8 hours) would represent the time difference based on the specific plot (which would be known prior to jump). We would need the exact wording of the Q&A to use this as hard data. Most of the rest of what Aramis has posted shows how non-specific cannon is about jump – the vast majority just says a jump takes about a week and leaves it at that.

My problem with admitting that my interpretation is wrong, is that if Traveller has always assumed jump time uncertainty as a basic cornerstone of space travel in the Official Traveller Universe, why are we having so much trouble locating text which unquestionably proves me wrong?

Thank you for your time and effort in presenting quotes from actual material (which can be discussed), rather than just stating opinions.

 

[Malenfant]

Originally posted by atpollard:
</font><blockquote>quote:</font><hr />Originally posted by TheEngineer:
[qb]The duration of a jump is fixed at the instant that jump begins, and depends on the specific jump space entered, the energy input into the system, and on other factors. In most cases, jump will last a week.

Hi, TE

In response to the above quote, it can also mean that ALL of the parameters of a jump are fixed "at the instant that jump begins".</font>[/QUOTE]That quote is pretty unambiguous - you're reading more into it than it actually says. It says that jump duration is fixed when the jump begins - not that anything else is fixed as well. If people do insist on bickering over rules minutiae here, then surely it makes more sense to bicker over what is actually said in the rules, and not bicker based on extrapolations made from that. It says nothing about any other aspect of jump being fixed (unless there's something else in the article that the quote comes from that does mention that) - if that makes no sense, well, welcome to Traveller .

What is the point of Mark Miller stating that a Jump is accurate to within 3000 kilometers if the time is so inaccurate that the world could be millions of kilometers from the target point when you emerge?

Because Marc has a history of making flawed, poorly thought-out game design decisions that turn out to make little or no sense in practice when people actually consider their consequences later on? This is one of the main reasons why so much of Traveller needs "fixing", after all.

Don’t you want to see some pretty strong evidence before you blindly accept anybody’s claim that Mark Miller and every version of Traveller is wrong and needs to be fixed.

I don't need any more, personally . I've seen enough from the issues with world design (never mind realism, the star tables have modifiers that are actually biased in favour of habitable worlds orbiting white dwarfs and subdwarfs - that's just bad design), and enough from all the other contradictions that pervade Traveller.

My problem with admitting that my interpretation is wrong, is that if Traveller has always assumed jump time uncertainty as a basic cornerstone of space travel in the Official Traveller Universe, why are we having so much trouble locating text which unquestionably proves me wrong?

Probably because there's a lot to wade through, and because some people think that what Marc says is The Law, and others thing what MT says is The Law, and so on.

Again, if people insist that Marc is the only one who can make a final decision on this, then just ask him about it and get an answer and get it all over with. If he's even capable of giving a straight answer, that is.

 

[atpollard]

The duration of a jump is fixed at the instant that jump begins, and depends on the specific jump space entered, the energy input into the system, and on other factors. In most cases, jump will last a week.

Originally posted by atpollard:
In response to the above quote, it can also mean that ALL of the parameters of a jump are fixed "at the instant that jump begins".

Originally posted by Malenfant:
That quote is pretty unambiguous - you're reading more into it than it actually says. It says that jump duration is fixed when the jump begins - not that anything else is fixed as well. If people do insist on bickering over rules minutiae here, then surely it makes more sense to bicker over what is actually said in the rules, and not bicker based on extrapolations made from that. It says nothing about any other aspect of jump being fixed (unless there's something else in the article that the quote comes from that does mention that) - if that makes no sense, well, welcome to Traveller .

With all due respect, there are only three factors in a jump which affect the game:

The jump distance: The fact that a ship cannot alter course mid jump is well documented in any and every version of the game, so the jump vector (bearing and distance) “is fixed when the jump begins”. Do you believe that a ship can change it’s destination mid jump?

The energy required for the jump: Although the different rule systems disagree in game mechanics on the required fuel for a jump, all versions of Traveller require that a ship have enough fuel for the jump before entering the jump. There are no instances of falling out of jump after a half parsec because the ship ran out of fuel mid-jump, so the required jump fuel (energy) “is fixed when the jump begins”. Do you believe that it is possible to turn off the jump drive mid jump to exit jump space early?

The jump duration: I agree with you that the jump duration is fixed when the jump begins. The EXACT duration is also known prior to exiting jump space. I propose that duration is known prior to entering jump space and is used to accurately select a course that will deliver the ship to the correct LOCATION and TIME to arrive at the desired location relative to the target world. Since Distance and Energy were both fixed when the jump begins, the quote from Mr. Miller indicates that the last unknown, Time, is also fixed when the jump begins.

HENCE my statement: [it can also mean that ALL of the parameters of a jump are fixed "at the instant that jump begins"].

 

[TheEngineer]

Hi !

So we are somehow sure now about the time frame where people know, how long the jump would take

Just one remark:
The distance is not fixed, because objects on the jump plot may cause the ship to be kicked out of jump space quite before they reach the target.
Well, at least one could say, that maximum distance is indeed fixed.

Regards,

TE

 

[atpollard]

Originally posted by TheEngineer:
Hi !
So we are somehow sure now about the time frame where people know, how long the jump would take

You posted a quote yourself that says that the duration is fixed at the start of the jump. The only question is did the computer have time at the start of the jump to align the destination and time so the ship exits where the crew wants relative to the target world? I found nothing that says aligning time and distance is not possible. Bill found nothing that says aligning time and distance is possible. Decide which makes more sense to you.

Just one remark:
The distance is not fixed, because objects on the jump plot may cause the ship to be kicked out of jump space quite before they reach the target.
Well, at least one could say, that maximum distance is indeed fixed.
Regards,
TE

Management regrets that it can enter into no discussion on jump masking at this time.
Management also regrets that it will NEVER speculate on the effects (if any) that jump masking has on jump duration.

 

[Malenfant]

Originally posted by atpollard:
Management also regrets that it will NEVER speculate on the effects (if any) that jump masking has on jump duration.

[/QB]

I think it's already been established that it doesn't have any effect - the jump takes the same total amount of time as it would have taken without the jump masking, because jumpspace is magical like that.

I would hope that in T5 (if it ever gets published), Marc actually properly thinks about jump and how it works and comes up with something that makes sense this time. Either that or he should think about the consequences of his design decisions more fully - if his intent really is for fleets of ships to be unable to come out of jump at the same time then that should be made loud and clear and militaries in the setting will have to deal with everything that falls out from that. But then I guess that some people will still claim that CT will still take precedence over that if they don't like it...

 

[atpollard]

Malenfant,

A brief clarification is required.

I was actually speaking only for myself and trying to make a joke. I do not speak for any form of Traveller in any official capacity.

 

[Malenfant]

Oh I know you were joking. I was just pointing out that it really does have no effect on jump duration, which illustrates how silly jumpspace is. I'm sure Marc would claim the intent is that it's non-intuitive because it's a different kind of space, yadda yadda, but in practice it is a royal pain in the arse in gameplay and just makes no damn sense at all.

 

[atpollard]

I spent some time trying to imagine an alternate universe in which time is a constant and distance varies based on energy (the basic description from the JTAS article) but it just gives me a headache.

(Although to be completely honest, I have a little trouble with the concept that light is both a particle and a wave, too – it just doesn’t keep me up at nights).

 

[rancke]

Originally posted by atpollard:
I assume that “jump masking” refers to the fact that any ship in jump space which attempts to exit from jump within about 100 diameters of a major mass precipitates out of jump space at the 100 diameter limit.

No, that's jump shadowing. That's been established since the year dot and I think it's one of the few Traveller 'facts' that has never been the subject of a canon debate .

Basically, if you aim for a spot that's inside a jump limit (like, for instance Regina, which is always inside Assiniboia's jump limit (since it orbits at 55 diameters)) then you get precipitated out at the jump limit. The spot you were aiming for is shadowed by the body that creates the limit.

Jump masking is when you jump from one spot outside any jump limit to another spot outside any jump limit, but where a direct line between those two spots intersect a jump limit. From one side of a sun to another, for instance. Until GT no published material ever mentioned the 'fact' that if you did so, you would precipitate out at that intervening jump limit (and it would take 7 days even if the jump was interrupted a fraction of a percent of the distance of the plotted jump). No description of jump procedures mentioned this possibility, no color text anywhere mentioned an instance, no adventure used it as a plot device. You got into your ship, you aimed for your destination, and you arrived 7 days later. End of story.

atpollard uoting from MM's article: </font><blockquote>quote:</font><hr />“Jump takes 168 hours (+/- 10%) to complete. This time is related to the nature of the alternate space being traveled in, and to the energy applied. Where time is a variable in travel in normal space, energy consumption is a variable in alternate space; time is a constant.”

“The exact time of emergence is usually predicted by the ship’s computer and the bridge is well manned for the event.”

</font>[/QUOTE]The time of emergence is predicted, not determined. There is a mention somewhere (sorry, I can't give you a reference right now) about how people begin to suspect that they've misjumped as the predicted time of emergences is passed. Not that they know instantly when the calculated moment of emergence is past.

What if the time required for any particular Jump is a constant that is calculated just prior to the jump. The exact value for the constant “TIME” varies from 151.2 hours to 184.8 hours for all possible jumps (excluding misjumps)

From 151 hours to 185 hours.


Hans