I've stated my opinion (I was going to say "logic," but that stopped applying pages ago); I hope you enjoy my take on it, and do what makes sense for your table.
1g Ships and Size:7 worlds...
- Thread starter infojunky
- Start date
- Status
I think our disagreement is how and whether Striker applies. I say no, while you say yes. So let's go with what makes us happy for our own games.
AnotherDilbert
SOC-14 1K
Agreed, the argument was never about how you play Traveller, or how I play Traveller. It was about RAW pedantry. Or originally what MWM himself said, probably outside of the game, long ago...I think our disagreement is how and whether Striker applies. I say no, while you say yes. So let's go with what makes us happy for our own games.
Spinward Flow
SOC-14 5K
Didn't have to.
What forum is this thread posted in?
Hint: Classic Traveller
I was under the impression that dragging other editions into specific edition topics is frowned upon by the site moderators, enough so that people who do it can be awarded account strike penalty infractions for their trouble.
I accept your forceful admission that you can find no such reference to cite supporting your assertion ... because if you could find any that support your claims that prove the positive, you wouldn't be so furiously attempting to place the burden on me to prove the negative.
Correct. UP is not the "only direction" available ... but it IS the direction you need to go in order to reach orbit from the surface.
Show me the vector pointing UP in this context (hint: it's not the curvature of the planetary surface!).
Spoiler Alert: there isn't enough of one to gain altitude and reach orbit.
Your starship may be a "fast ground vehicle" ... but without enough "force vector pointing UP" ... You Are Not Going To Space Today™.
This is not a Christopher Columbus style problem where you can "go east by sailing west" ... or in this context, accelerating UP by accelerating DOWN through the planet.
If you don't like that answer ... simply change the Gravitational Constant of the (Your Traveller) Universe.
Problem solved!
How extraordinary!
Your 1G maneuver drive outputs 1G and your streamlined hull ALSO outputs 1G to counteract the 1G of gravity!
So in an atmosphere (regardless of density or altitude) ... your 1G maneuver drive is really a 2G maneuver drive!
How ... convenient ...
No wonder you refuse to accept that 1-1=0 ...
{ points ... laughs ... walks away }
That's five assumptions in a row with zero citations of RAW to support or back up those assumptions.
Zaphod Beeblebrox: "How many are there?"
Ford Prefect: "None."
Zaphod: "Did you count them!?"
Ford: "Twice."
I can't.
I just can't ...
LBB2.77, p25-29 ... Starship Combat chapter
LBB2.81, p26-30 and p36-37 ... Starship Combat chapter
Here's a snippet from LBB2.77, p25 which explains the vector movement system better than the editing of LBB2.81 managed.
Again, I am embarrassed that I am compelled by need to point out something so obvious and fundamentally BASIC.
LBB2.81 did not change any of the purpose or content of this text from LBB2.77, just reformatted it with a new layout on the pages that was ultimately more confusing and less helpful in promoting understanding.
If you want to be excessively pedantic about things, you can point out that even the text I'm citing doesn't use the word "rockets" (Aha! GOTCHA!) while completely ignoring the fact that both rockets AND maneuver drives (of every variety) move around using vector math as is presented here.
mike wightman
SOC-14 10K
Correct, I am not seeking to say how things work in anyone else's universe, but how I interpret the rules and fill in the missing pieces for MTU.
mike wightman
SOC-14 10K
And you said you were done lol.Didn't have to.
What forum is this thread posted in?
Hint: Classic Traveller
I was under the impression that dragging other editions into specific edition topics is frowned upon by the site moderators, enough so that people who do it can be awarded account strike penalty infractions for their trouble.
I accept your forceful admission that you can find no such reference to cite supporting your assertion ... because if you could find any that support your claims that prove the positive, you wouldn't be so furiously attempting to place the burden on me to prove the negative.
Correct. UP is not the "only direction" available ... but it IS the direction you need to go in order to reach orbit from the surface.
Show me the vector pointing UP in this context (hint: it's not the curvature of the planetary surface!).
Spoiler Alert: there isn't enough of one to gain altitude and reach orbit.
Your starship may be a "fast ground vehicle" ... but without enough "force vector pointing UP" ... You Are Not Going To Space Today™.
This is not a Christopher Columbus style problem where you can "go east by sailing west" ... or in this context, accelerating UP by accelerating DOWN through the planet.
If you don't like that answer ... simply change the Gravitational Constant of the (Your Traveller) Universe.
Problem solved!
How extraordinary!
Your 1G maneuver drive outputs 1G and your streamlined hull ALSO outputs 1G to counteract the 1G of gravity!
So in an atmosphere (regardless of density or altitude) ... your 1G maneuver drive is really a 2G maneuver drive!
How ... convenient ...
No wonder you refuse to accept that 1-1=0 ...
{ points ... laughs ... walks away }
That's five assumptions in a row with zero citations of RAW to support or back up those assumptions.
Zaphod Beeblebrox: "How many are there?"
Ford Prefect: "None."
Zaphod: "Did you count them!?"
Ford: "Twice."
I can't.
I just can't ...
LBB2.77, p25-29 ... Starship Combat chapter
LBB2.81, p26-30 and p36-37 ... Starship Combat chapter
Here's a snippet from LBB2.77, p25 which explains the vector movement system better than the editing of LBB2.81 managed.
Again, I am embarrassed that I am compelled by need to point out something so obvious and fundamentally BASIC.
LBB2.81 did not change any of the purpose or content of this text from LBB2.77, just reformatted it with a new layout on the pages that was ultimately more confusing and less helpful in promoting understanding.
If you want to be excessively pedantic about things, you can point out that even the text I'm citing doesn't use the word "rockets" (Aha! GOTCHA!) while completely ignoring the fact that both rockets AND maneuver drives (of every variety) move around using vector math as is presented here.
Rockets don't fly straight up to achieve orbit, they follow a curved path so they have sufficient horizontal velocity to stay in orbit, which according to your understanding they can not do.
You appear to have such a fundamental lack of basic physics I don't know what to say.
Aircraft fly because their overall lift cancels their weight. 1-1=0, now add 1g of thrust 0+1=1 understand yet? See where you are going wrong? Understand basic physics yet - oh that's right, there is no such thing as a lift force, a drag force or anything other than m-drive force in your Traveller universe.
You have yet to provide a quote to back up your suppositions, and have yet to tell me what you think a vector represents.
Hint - it isn't a force. It is projected future displacement. I may have to explain the difference to you.
I still get a kick out of the rules-as-written glitch that allows VTOL for 1G ships on a 1G world because of the sequence in which movement, thrust and gravity vectors are applied. (First turn movement puts the first-turn vector midpoint above the world's 1G band, so only the 1/2G band applies when the rules say it's time to calculate the effect).
Physics doesn't work that way.
The rules themselves do.
The question then is whether to treat the rules as mistaken, or to use a combination of handwaving, technobabble, and aerodynamics to explain the glitch away.
I just think it's amusing.
Physics doesn't work that way.
The rules themselves do.
The question then is whether to treat the rules as mistaken, or to use a combination of handwaving, technobabble, and aerodynamics to explain the glitch away.
I just think it's amusing.
AnotherDilbert
SOC-14 1K
YOUR game works that way, not necessarily Traveller in general. As you have stated you had to assume extra "magic" lift to make it work.
You can't claim physics work that way on Traveller spacecraft in general, without your additional assumptions.
Striker says spacecraft flies on their M-drive thrust alone, and can't take off if thrust is less than weight, just like LBB2 space combat. You don't have to use that, but you can't say someone else is wrong when they do.
Your house rules doesn't apply to my game, or RAW.
AnotherDilbert
SOC-14 1K
The rules don't either.
Gravity applies to all turns, even the first when the movement vector is [0,0].
At least in RAW.
Please, enlighten me, show how to arrange these vectors from LBB2'77 in a way so that the ship escapes the gravity well:
Last edited:
Spinward Flow
SOC-14 5K
I've done NOTHING BUT provide quotes.
You are just determined to refuse accept any of them as being valid or germane to the subject of discussion.
LBB2.77, p25 (snippet) (AGAIN)
The arrangement of those vectors with respect to the planet look an awful lot like the vector arrangement shown in Figure B that I've now cited TWICE from LBB2.77, p25.
Coincidence?
I think not ...
Captain_Ahab
SOC-9
Aircraft fly because aerodynamic surfaces deflect flow downwards, which causes induced drag.
You don't get lift for free just because your ship is streamlined.
so even if 1-1=0, you don't have thrust left over to add to it
profile drag + induced drag will equal thrust at the ship's top speed in atmosphere ( I'll ignore skin friction drag here )
you don't know how much drag or lift you get, but that's okay, because you also don't know how much thrust you have because you have no idea how much your ship masses
lift decreases with altitude, although speed increases, but will it increase enough?
personally, I doubt it
I'll let you run the numbers
mike wightman
SOC-14 10K
When planes fly their weight and lift cancel - same way ships float, But different
You are adding all the "forces" to the start point. That is not the way the rules work.
What are the forces on a ship sitting on the ground? Its weight due to gravity and the reaction force (Newton's third law)
Future position is to stay still because thee is no force to cause movement (Newton's first law).
Vectors in LBB2 are not force arrows they are displacement arrows, future position determined by the summation of forces.
You plot the displacement that will be caused by the drive, then you add the gravity effect, which would have to be at least the 0.5g band since you are effectively adding 50mm to determine the mid point, to the head of that vector arrow.
(I don't think this should work which is one of the reasons for having ships IMTU fly.)
You then draw the vector. Which is 50mm straight up. Take off aerobraking and the total vector is 25mm.
By the way what causes aerobraking? So we can assume drag exists but not lift...
You are adding all the "forces" to the start point. That is not the way the rules work.
What are the forces on a ship sitting on the ground? Its weight due to gravity and the reaction force (Newton's third law)
Future position is to stay still because thee is no force to cause movement (Newton's first law).
Vectors in LBB2 are not force arrows they are displacement arrows, future position determined by the summation of forces.
You plot the displacement that will be caused by the drive, then you add the gravity effect, which would have to be at least the 0.5g band since you are effectively adding 50mm to determine the mid point, to the head of that vector arrow.
(I don't think this should work which is one of the reasons for having ships IMTU fly.)
You then draw the vector. Which is 50mm straight up. Take off aerobraking and the total vector is 25mm.
By the way what causes aerobraking? So we can assume drag exists but not lift...
AnotherDilbert
SOC-14 1K
There is no such vector specified in LBB2, by RAW.
Sure we can add it, if you stay on the ground the entire turn, but not if we try to take off.
There is only one movement phase, you only move once, adding all the vectors.
Yes, force vectors that causes acceleration (F = ma), that integrated over the turn is a velocity vector showing distance travelled per turn. Does that make any difference whatsoever to LBB2 RAW?
You can assume anything you want, but RAW specifies aerobraking, not aerodynamic lift.
Yes, if we are flying perfectly level, and lift is adequate. It's not automatic, it's a happy coincidence arranged by the pilot. If lift in not equal to weight, the aircraft will ascend or descend.
Wasn't there an alternate "crunchy" acceleration rule in '77 that applied half the acceleration in the first turn, then the full vector in the following turn? In other words, the vector you see in the normal simplified rules is (approximately) what you'd get for accelerating at twice the maneuver rating for half the turn, then coasting the remainder of the turn.
AnotherDilbert
SOC-14 1K
I can rearrange them sequentially, if you think it makes the slightest difference to the maths:
Addition is commutative.
Last edited:
AnotherDilbert
SOC-14 1K
The default simple method add all the acceleration as a single impulse at the start of the turn. You gain your new velocity instantly.
The "crunchy" simulated applying the acceleration evenly over the turn, with constant acceleration the added velocity over the turn is half the added velocity at the end of the turn.
mike wightman
SOC-14 10K
Not quite.
How do planes fly upside down? (intended as rhetorical for the pedantic)
It's also a case of angle of attack, pressure, fluid flow rates. I remember teaching this once according to the A level text and a student said "You are wrong"
He was in the RAF Air Cadets and his flying instructor had explained how planes fly and how to trip up your physics teacher
I started to argue with him but then when he told me about the RAF pilot who had told him this I realised my simplistic knowledge was lacking.
So I read text books on aero-engineering and the physics of flight, watched a lot of youtube video - including the ones that do the maths.
Last edited:
mike wightman
SOC-14 10K
A ship on the ground has no vector because it is not moving and has no potential to move in the future because the resultant force on the ship is zero. There is no vector to draw.
The "vectors" that you are plotting are not "vectors" they are forces, the resultant of which is then applied to the current vector in order to determine future position.
Vector movement in Traveller has you drawing displacement vectors, not force vectors.
Yes it makes a difference because the final displacement "vector" that is actually drawn on the surface does not represent force, or energy, or velocity. It shows displacement only.
So aerobraking exists because the rules say so, but lift doesn't?
So in level flight lift and weight cancel out yes? And if you apply a 1g continuous thrust to an object with balanced forces what happens?
Spinward Flow
SOC-14 5K
Wikipedia Link: Whataboutism
mike wightman
SOC-14 10K
Still wrong
The thrust vector should be plotted to a position 100mm above the planet surface, the midpoint of which places it in the 0.5g band of all planet sizes 8-10. So your gravity vector is only 50mm downwards, and subtract the 25mm for air resistance - which can only cause drag and not lift in YTU.
Overall result is a vector arrow drawn upwards with a length of 25mm.
- Status
Similar threads
