Andrew Boulton
The Adminator
I use det-lasers as mines. A fairly small number can make a large area dangerous, and with the right IFF codes friendly ships are safe.
What does 'Commerce Raiding' entail?
- Thread starter Seriayne
- Start date
HG_B,
It's short for "detonation laser", which is another term for "bomb-pumped laser".
You pop a nuke which also happens to be sitting in the middle of a bunch of "laser tubes" which, in the microsecond before they're destroyed, collimate a portion of the bomb's energy into several very powerful x-ray laser beams.
I think it's worth noting that the idea was first broached by Edward "I'm really not Dr. Strangelove, honest" Teller.
Anyway, the idea has been borrowed by any number of sci-fi writers every since and, in the case of Traveller, det-laser warheads have been the standard missile payload since TNE when GDW finally decided to try and explain why missiles still existed in a setting with light-second ranged lasers.
Regards,
Bill
Thanks, I'm used to seeing the item termed as bomb-pumped.
Yes, that would be nasty but detectable. However, detection isn't equal to nullification.
Theophilus
SOC-13
In TNE the Det laser armed missile is a sub-micro sized target and is very difficult to detect. A merchant ship with minimal sensors would have almost no chance detecting a few of these left in orbit.
So the question becomes, do I take my 5000 ton Hercules class freighter into to the planet if there is a chance someones dropped a few Laser/mines, or orbiting bolt's, Or do I ignore the system and disrupt commerce?
Which is, of course, the whole point of commerce raiding.
Imagine the disruption a few missile/mines would cause if they reached Efate, or Regina, or Porozolo. Just one heavy merchant lost could cause disruption far beyond any cost for having one stealthed scout drop some missiles on a ballistic trajectory insystem.
So the question becomes, do I take my 5000 ton Hercules class freighter into to the planet if there is a chance someones dropped a few Laser/mines, or orbiting bolt's, Or do I ignore the system and disrupt commerce?
Which is, of course, the whole point of commerce raiding.
Imagine the disruption a few missile/mines would cause if they reached Efate, or Regina, or Porozolo. Just one heavy merchant lost could cause disruption far beyond any cost for having one stealthed scout drop some missiles on a ballistic trajectory insystem.
That's why I believe Efate and Regina and Porozlo will have their jump limits heavily guarded.
Detection is a matter of how easy it is to detect something coupled with how long you have to detect it. A ballistic missile will have a low signature, but either a low velocity, giving defenses more time to detect it, or a high velocity, giving it a vey limited time in range of the jump limit.
Hans
Theophilus
SOC-13
Please define "jump limit"? My understanding is that at 100 diameters a ship is pulled from jump space by gravity, whether they want to be or not. But the "jump limit" is anywhere in the system, so I could come out of Jump space in the Oort Cloud/Kuiper Belt or even farther out if I choose to exit jump space there. While our star Sol would pull me out of jumpspace between Mars and Terra, the Earths gravity pulls me out of jump at what is it? around 36 hexes? 34? something like that if I recall. Therefore the space to be patrolled is HUGE. How many ships would it take to cover the entire solar system?
That's the jump limit. Also known as the 100 diameter limit. That's where merchants will arrive if they're headed for the world that generates the gravity that causes the limit.
It's not neccessary to defend the entire system. Just the part of it where merchant ships congregate. In other words, at the mainworld jump limit and inwards of that. The attacker can jump in anywhere he wants and send in his missiles on ballistic courses. But the time it takes for the missile to reach the jump limit depends on its velocity and the time it stays in range of the jump limit also depends on its velocity. If it comes in slow, it takes longer from deployment until it's useful, and the defenders have longer to detect it. If it comes in fast, it stays in useful range for a shorter time.
Hans
Every space-borne body has a jump limit; it only affects jumping vessels smaller than itself. Stellar jump limits are big; some star's limits extend well past their ecospheres.
Note that, in many people's house rules, the jump limit is defined by gravity or gravitational gradient (which are two different things); making such changes affects the distances drastically, but the term "jump limit" can still be used for those thresholds, and they make no difference in how a jump limit affects a ship... just where it does.
In one official ATU, GTIW, the jump limit is the required destination, as under that particular ATU, one can only exit jump at the jump limit.
In theory, you can be dropped out of jump by an oort cloud object between your jump entry and exit points. It's a low enough chance that it's a deus ex-machina
Theophilus,
Your understanding is incorrect. Gravity has nothing to do with the 100D limit. It's dimensionally based and nothing more.
If you want to quibble, talk with Mr. Miller. He's the one who said gravity is not involved.
No. Jump exit points are anywhere in the system. 100D jump limits exist anywhere a body large enough to express one exist.
And, because you're taking more time to travel from your exit point to the port, you're giving someone a more potential opportunities to attack you. Not certainties, potentialities. Potentials have a way of adding up, sadly.
Wrong. Earth orbits outside of Sol's 100D limit even after taking into account the perigee. Even Earth's 100D limit is outside of Sol's 100D limit.
You don't need to cover the entire system, you only need to cover those bits where ships need to go.
Willie Sutton robbed banks because that's where the money is. Commerce raiders and escorts are going to operate around ports because that's where the shipping is.
You could leave jump out past Pluto but, if you still need to touchdown in Earth, you're still going to approach Earth one way or another. The longer you spend in normal space, the more opportunities you have to be attacked.
Regards,
Bill
Wil,
While an otherwise fine product, GT:ISW is fatally flawed in both that regard and in regard to deep space jumps. Jump was deliberately simplified for design, deadline, and word count reasons. The authors could have spent paragraphs explaining jump operations or spent paragraphs explaining the setting. They chose the latter.
Thirty plus years and several other official settings and versions all say something different. Mr. Miller's own jump space essay says something different. All the rest of GURPS: Traveller says something different. GT:ISW is the outlier here, not the norm.
Personal TUs are irrelevant to this conversation and, whichever way a personal TU handles jump limits, shipping is still going to "congregate" around fuel sources unless the TU in question does away with jump fuel requirements.
Hitting the 100D limit in order to exit jump is not a requirement. In fact, given the fact that planets move and given jump drive's temporal uncertainty, hitting a planetary 100D limit can in some situations be impossible.
Regards,
Bill
True, but it's still the most likely outcome by far, although the exact details depend on size and velocity of the target world. Say you're aiming for a world that moves 200 planetary diameters in 30 hours. What you do is aim for the place where that world will be in 168 hours. If you arrive any time between 15 hours early and 15 hours late, you'll be precipitated out somewhere alone the jump limit. Only if you're very early or very late will you break out further away than that. And if we assume jump variation is distributed along a bell curve (as T20 implies it is), those occurences are rare enough to be Referee's Choice Only.
Hans
Evil Steve
SOC-10
Steve,
The essay was originally published in issue #24 of GDW's JTAS magazine.
Regards,
Bill
From JTAS #24, pg. 34. article titled Jumpspace by Marc Miller:
"Entering jump is possible anywhere, but the perturbing effects of gravity make it impractical to begin a jump within a gravity field of more than certain specific limits based on size, density, and distance. The general rule of thumb is a distance of at least 100 diameters out ..."
So...
HG_B,
So what?
When Mr. Miller wrote that 25 years ago, people immediately began attempts to quantify the 100D limit. For the next quarter century gravity, sizes, distances, and densities were all juggled with varying degrees of "success" to explain 100D. Gravity gradients such as found in 2300AD were proposed, tidal force measurements were proposed, and many other things were proposed. All of those explanations began with the sentence you quoted...
... and Mr. Miller gently dismissed each and every one of them.
He may have written "... the perturbing effects of gravity make it impractical to begin a jump within a gravity field of more than certain specific limits based on size, density, and distance..." but he has also stopped anyone from explaining canonically just how a gravity field of more than certain specific limits based on size, density, and distance actually makes it impractical to enter jump or even prevents exits from jump.
All he cares to state is that the 100D limit is enough of a rule of thumb to go by and that any body "big" or 'dense" enough can exert a 100D limit. Nothing more. We're left to ponder whether huge balloons, gas clouds, nebulae, and even the mass of the Milky Way are enough to make jump entry impractical.
Gravity plays some role in the 100D limit. How gravity plays that role, however, is unknown and will forever remain unknown. Gravity's role cannot be discerned and will never be discerned. Because we cannot explain or quantify gravity's actual role, we can also claim that snakes, and snails, and puppy dog tails play a role in the 100D limit with a level of certainty equal to that of gravity's role.
And that is why I say gravity plays no role in the 100D limit.
Regards,
Bill
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If you have two worlds with the same diameter but different density, you will have different gravitational effects at the same distance from the two bodies. So if the gravity was really a factor, the jump limit would not be at the same distance. Since Marc Miller has stated that the jump limit is at the same distance, regardless of the density of the world, gravity can not really be a factor, no matter what Miller claims. Even Miller can't change the rules of logic.
Bill is quite right. Regardless of what Miller claims, he also insists jump distance is a function of the size of the world, nothing else. He can have it one way or he can have it the other way, but he can't have it both ways at the same time.
Well, he can and he does, but only by insisting on ignoring logic and common sense.
Hans
HG_B,
No it doesn't. Did you read my post #37?
Mr. Miller claims a gravity field has something to do with the 100D limit and then wholly ignores gravity fields when calculating the 100D limit. What's more, he has said no to repeated suggestions of how gravity could be used to calculate the 100D limit.
The density of a body effects the gravitational field it exerts and, according to the fluff text Mr. Miller wrote, should then effect the 100D limit it creates. However, when we examine the rule Mr. Miller also wrote, the 100D limit is based solely on a body's dimensions.
According to the rule, a balloon inflated to 1km in diameter has the same 100D limit as a sphere of lead 1km in diameter even though the gravitational field both produce are greatly different. That's why I wrote about "... huge balloons, gas clouds, nebulae, and even the mass of the Milky Way... in Post #37.
Gravity has no effect on the 100D limit because the rules do not take gravity into account when calculating the 100D limit. In that, gravity's role is the same as the snakes and snails and puppy dog tails I wrote about early, both are of no consequence because both are ignored in the rules.
Regards,
Bill
