Armour... Hull.... Mass??

I haven't seen this asked or answered anywhere else, but I have noticed that the latter Vasari Armour techs and one artifact  decrease the 'mass' of a ship or its hull. Now, having some idea of basic physics, does this effect how much a grav well affects your speed/acceleration when travelling through it? Or the depth you can jump within a grav well?  

17,636 views 29 replies
Reply #1 Top

Not really sure what it does to be honest. May even give an increase in maneuverability in addition to what you have, but it is all pure speculation.

Reply #2 Top

Maybe one of the modders could answer your question.  In practice, I don't "feel" any difference after researching this tech, so it's not a major effect.

Reply #3 Top

Yea agreed, it mustn't be. Interesting tho.

Reply #4 Top

I'm pretty sure it slightly top speed/acceleration/turning, but not enough to be noticable unless you mod it to change the mass a lot.

Reply #5 Top

Here is what I found in the "ResearchSubject_SpeedBoostArmor.entity -

 

***

researchModifier
    modifierType "MassReduction"
    baseValue 0.000000
    perLevelValue 0.040000
artifactPicture ""

***

 

 

That's the only info I have found so far.  Anyone know what the properties of the "massReduction" value is?

Reply #6 Top

It probably decreases the mass value.  Jack it up to 500% or so and see what the effects are.

Reply #7 Top

Its a percentage. In other words about 4% of mass removed or reduce mass to 96%.

The issue is what is the game effect and I believe kyogre12 hit the nail on the head. It works similar to TECs Maneuvering Thrusters Research only it does it by a change in mass vs a change in power of vector change. Doesn't have a huge effect on gameplay.

Reply #8 Top

I'm not sure if it does anything in expansion pacts but mechanic is there and it is used to great effect in some of the mods out there.

Reply #9 Top

A 100% mass reduction causes ships to move VERY SLOWLY for some reason. Divide by 0 much? Interestingly enough, a 90% mass reduction has the same effect, so maybe the game reduces ship speed to a minimum value when it gets too high. A -90% reduction causes the ships to move at a slower rate, but still fairly quickly when you zoom in. A -900% reduction slows them to a crawl when zoomed in, but they still looked faster than with a 90% reduction. Tested with a custom research and a custom Scout, Light and Colony frigate, all with 2000 mass. The Scout and Light one actually had slightly above-average thrust values.

Looks like there are some hardcoded limits that prevent me from generating any blatantly obvious changes, and I don't want to make "ship races" with a stopwatch atm.

 

I think the Telekinetic Push ability (ApplyImpulseFromSpawner action) applies a set "momentum" to the target ship, which is then divided by the ships' mass to yield the speed of the "push". This would mean that the Vasari tech actually makes their SC weaker against TK Push, though of course not by much. (Actually, an 8% push range increase in TK push should be noticeable, right?)

I never noticed this in the normal game, but if you make TK Push affect frigates/caps, you will notice that a frigate (mass 2000) barely budges while any SC (mass 150) is sent flying. Caps (and envoy cruisers for some reason) have 10k mass, so they won't move at all. A -1 million impulse every 0.5 seconds provides a steady "pull" on 2k mass frigates (tested with custom gravity vortex ability)

Magnetise also uses the impulse line, but it doesn't matter if your SC are destroyed 0.05 seconds earlier, does it?

 

Edit: Ran another test with 90% mass reduction: The ships "stutter" when turning, but linear movement appeared normal over small distances. (might be because the ship didn't get to accelerate to 10x normal speed before arriving, it was flying about 10 shiplengths only)

Another test with 90% reduction had the ship stutter once more. The ship made a huge arching turn way outside the marked gravwell, seemed to stop once it was back at the edge of it, then turned towards its destination and flew normally across the gravwell (desert planet) I also noticed one of my constructors overshoot its destination while going to an asteroid, fly outside the gravwell by a further gravwell radius, and fail to return even by the time my test ship had completed its journey.

With -900% reduction the ship still turned at a "normal" rate, and traveled the entire gravwell at a speed I would also consider normal, though possibly slower than without the research. Then again, in space max speed shouldn't be limited by anything except the speed of light, so maybe mass only affects acceleration rates.

 

Conclusion for now: Players: Don't care about it. Modders: Don't fiddle with ship mass, or at least keep it within a +/-50% margin.

Reply #10 Top

Then again, in space max speed shouldn't be limited by anything except the speed of light, so maybe mass only affects acceleration rates.
End of quote

Relativistically speaking as v -> c, p (momentum) -> infinity...your limiting factor (practically speaking) is the amount of thrust you have, not the speed of light (you can think of it as your mass increasing if you want, and therefore with a constant force your acceleration will decrease until it is essentially zero)...

I believe that Photoloss has determined the only imortance of mass, and that is whenever an impulse is applied to a ship (such as TK)...it is possible that gravity wells would affect more massive ships, but I honestly don't know how gravity was programmed...nice to know how mass works at the extremes, should be useful for the modders out there :-)

Reply #11 Top

Quoting Seleuceia, reply 10

Relativistically speaking as v -> c, p (momentum) -> infinity...your limiting factor (practically speaking) is the amount of thrust you have, not the speed of light (you can think of it as your mass increasing if you want, and therefore with a constant force your acceleration will decrease until it is essentially zero)...
End of Seleuceia's quote

I am aware of relativistic effects, but the difference between 0.99c and c is negligible anyway, and you should be able to reach 0.99c rather comfortably. (Mass gain until then is about 7*original mass or so)

The problem is that sins ships move considerably slower than 0.9c if the planet sizes are even close to accurate. Even if we assume a logarithmic scale on gravwells, ships close to the planet should be glowing blurs, not drift about like blimps.

The only times you'd want to be much slower than c is atmospheric reentry, which doesn't exist in sins, and if you want to turn around. However, if you're sitting in a Pirate Cutthroat with a juicy colony frigate half a gravwell in front of you, why wouldn't you be flying at full thrust all the way? Or if you have an Orkulus in your back, the first thing you'd do is engines to max!!!, then make sure you don't fly to a Vasari planet by accident.

I would also assume that mass affects thrust rates, but I doubt the effect will make a difference. Maybe I'll make some tests with 50% mass reduction and standard massive-arching-turn situations.

 

Gravwells shouldn't affect more massive ships differently, Gravity is proportional to the mass of the affected object :grin:

The manual does mention an effect of "gravity" though, in that ships near the edge of the gravwell supposedly move slower. I have asked about this before, but have never gotten any confirmation.

Reply #12 Top

Quoting Photoloss, reply 11

I am aware of relativistic effects, but the difference between 0.99c and c is negligible anyway, and you should be able to reach 0.99c rather comfortably. (Mass gain until then is about 7*original mass or so)
End of Photoloss's quote

1% of 3x10^8 m/s is still 3000 km every second... it's negligible compared to c, but in absolute terms, it's a large difference in velocity.

Reply #13 Top

But you're either zooming at the equivalent of 25 earth diameters a second anyway, or using a logarithmic scale that compounds that 1% into nothingness.

Give any ship a 1% max speed increase/decrease and try to see the difference. You don't.

Reply #14 Top
Quoting Photoloss, reply 13

Give any ship a 1% max speed increase/decrease and try to see the difference. You don't.

End of Photoloss's quote

You won't notice it in the game, but realistically it would it make a huge difference...as InfiniteVoid noted the absolute difference is still rather large, likely enough to render ballistic and missile weapons useless...if the two ships were not accelerating and they were moving in the same direction, then they'd be in the same inertial reference frame and therefore the only thing that matters is the absolute difference in their velocity...

Likewise, the difference between .99c and .999c even would be very significant in combat...imagine a ship fleeing from a stationary beam defense platform...if the ship is traveling at .99c, then the energy pulse will gain on it at a rate of 3000 km/s...if however it travels at .999c then the beam only gains on it at 300 km/s, giving the ship ten times more time to phase jump or deviate course to avoid the beam...sure, 300 km/s is very fast, but distances in space are huge and laser/beam pulses may not even last more than a fraction of a second anyway...each "9" you tack on to your speed after the decimal increases the time you have by a factor of 10...

From a combat perspective, the difference between .99c and c is immense...as you have stated earlier, at .99c your "mass" is increased by a factor of 7.08...at .999c that factor becomes 22.4, and at .9999c that factor is 70.7...the energy requirements to get even most of that extra 1% are asinine...however, as shown in the previous example an additional .009c increase in speed gave a substantial advantage in being able to avoid weapons traveling at the speed of light...

Even if a ship can travel at .99c, energy weapons like lasers and beams are still going to be able to shoot it down (we can hit fast moving aircraft now with ballistics that travel far less than 3000 km/s)...however, if you have engines 223 times more powerful, then you could travel at .99999c....this gives you more time by a factor of 1000 to react to energy weapons (net gain would be 3 km/s)...basically, a less than 1% change can mean the difference between easy escape and total annihilation...

The mathematics that apply here are similar to shield mitigation in that each additional % point becomes more and more powerful...

Quoting Photoloss, reply 11

Gravwells shouldn't affect more massive ships differently, Gravity is proportional to the mass of the affected object 
.
End of Photoloss's quote

This is not true...while gravitational acceleration is independent of mass, gravitational force is not, and it is the force (not acceleration) that matters here...the thrust of each ship is different and would be determined by engine design, not mass of the ship...so, smaller ships with more thrust per unit mass would be affected less by a gravity well...in sins, this would mean that capital ships are going to be a lot more vulnerable in large gravity wells like stars and gas giants since not only do they move slower, but small, faster ships will have an even greater speed advantage...

 

Reply #15 Top

You cannot dodge laser beams. They can miss if you swerve randomly after the beam is fired, or was off-target in the first place, but you cannot actively evade them as by the time you know of the beams' existence it has reached you.

Ships apparently need to stop dead to phase jump, so you don't have 10x the time to jump away either.

For physical weapons you might have a point, but only for unaccelerated projectiles and missiles whom you out-thrust outright or if you have very powerful computers (information spreads at the speed of light at most, so you'd only have a very short time from the light reaching you to being hit, though it's possible in theory) Of course anything flying at nonrelativistic scales is essentially screwed if ships really fly at 0.9c.

This is not true...while gravitational acceleration is independent of mass, gravitational force is not, and it is the force (not acceleration) that matters here...the thrust of each ship is different and would be determined by engine design, not mass of the ship...so, smaller ships with more thrust per unit mass would be affected less by a gravity well...in sins, this would mean that capital ships are going to be a lot more vulnerable in large gravity wells like stars and gas giants since not only do they move slower, but small, faster ships will have an even greater speed advantage...
End of quote

Would be nice if you had a link to verify this. I end up with a ratio of total accelerations of (k*a-g)/(a-g), where k is the ratio of thrust accelerations, a the thrust-based acceleration of 1 ship, and g is the gravitational acceleration (assumed to be constant and the same for both ships, which it is if they're at the same position).

Interestingly this changes with g (i.e. for different distances from the same central mass) but doesn't depend on the masses of the ships.

You also assume smaller ships would have a greater thrust acceleration, but that isn't necessarily correct. It greatly depends on the available technology and other factors, so we can't assume any relation between engine thrust and ship size. (as an example, any reactor needs a certain minimum size to function, so a larger ship might have access to a far more potent energy source)

Reply #16 Top

This is not true...while gravitational acceleration is independent of mass, gravitational force is not, and it is the force (not acceleration) that matters here...the thrust of each ship is different and would be determined by engine design, not mass of the ship...so, smaller ships with more thrust per unit mass would be affected less by a gravity well...in sins, this would mean that capital ships are going to be a lot more vulnerable in large gravity wells like stars and gas giants since not only do they move slower, but small, faster ships will have an even greater speed advantage...

Would be nice if you had a link to verify this. I end up with a ratio of total accelerations of (k*a-g)/(a-g), where k is the ratio of thrust accelerations, a the thrust-based acceleration of 1 ship, and g is the gravitational acceleration (assumed to be constant and the same for both ships, which it is if they're at the same position).
End of quote

I'm not going to get into the rest of this discussion, but he is referring (I assume) to Newton's Law of Gravitation:

F=G*M1*M2/r^2

Where F is the magnitude of the force due to gravity, G is the gravitational constant (approximately 6.67*10^-11), M1 and M2 are the masses of the two objects in question, and r is the distance between their respective centers of gravity. Assuming two ships are located at the same distance away from a planet, the heavier one would feel more force (and exert a greater force on the planet, but unless the ship is huge it's pretty negligible).

Techinically Relativity is more accurate, but for most intents and purposes Newton's method is good enough.

Reply #17 Top

Quoting kyogre12, reply 16

I'm not going to get into the rest of this discussion, but he is referring (I assume) to Newton's Law of Gravitation:

F=G*M1*M2/r^2

Where F is the magnitude of the force due to gravity, G is the gravitational constant (approximately 6.67*10^-11), M1 and M2 are the masses of the two objects in question, and r is the distance between their respective centers of gravity. Assuming two ships are located at the same distance away from a planet, the heavier one would feel more force (and exert a greater force on the planet, but unless the ship is huge it's pretty negligible).

Techinically Relativity is more accurate, but for most intents and purposes Newton's method is good enough.
End of kyogre12's quote

Assuming no other forces affect the ship we can say m*a=F+G where m is the ship's mass, a is the total acceleration, F is the constant thrust force, and G is the force of gravity. As the ships' mass is constant we can simply divide by it, thus a=F/m+g (g=gravitational acceleration): F/m is a constant, which I called thrust acceleration. As you should be able to see the acceleration caused by gravity is the same regardless of ship mass.

Assuming no loss of mass isn't a given for spaceships, but sins ships don't appear to be using significant amounts of propellant, though they're losing huge amounts of energy if they're using ion drives.

Reply #18 Top

Quoting Photoloss, reply 15
but you cannot actively evade them as by the time you know of the beams' existence it has reached you.
End of Photoloss's quote

You are correct in that you cannot actively dodge due to information being limited by c, but the same also applies to the enemy: they cannot accurately predict where you are going to go either...even if the enemy knows for sure you will arc 180 degrees and even if they know the radius of that arc, there are still an infinite number of similar arc trajectories you can take in a 3D environment...point being, faster ships could actually dodge laser pulses while slower ones can't...basically, if you are able to go fast enough (still sub-light), no weapon can dependably hit you, even if it travels at the speed of light...

Quoting Photoloss, reply 15
Ships apparently need to stop dead to phase jump, so you don't have 10x the time to jump away either.
End of Photoloss's quote

In reality, there is no such thing as a dead stop since all velocities must be related to another object (the only velocity that is constant from all perspectives is c)...therefore, a space ship could enter phase space at any time and at any "velocity"...

Let's go with your equation...

a=F/m+g

g is constant for all ships....however, F/m is NOT...F/m is determined by the ship and engine design, and therefore is not constant across all ships (only constant for ships of the same model, such as all LFs)...therefore, the net acceleration for ships of different engine designs will not be the same unless by pure coincidence they have the same thrust per unit mass...

It would seem that the ships in sins with smaller masses tend to have faster acceleration (especially SC, scouts, and LFs)...from a relativistic perspective, maximum velocity would also be indicative of thrust per unit mass...so, in sins, ships with less mass tend to have more efficient engine designs...

Obviously there will be some optimal size for a ship...I doubt you are going to make a ship the size of a thimble that can approach near light speeds...however, diminishing returns suggests that bigger engines, while yielding more thrust, will likely start yielding less thrust per unit mass...

Reply #19 Top

Quoting Seleuceia, reply 18


You are correct in that you cannot actively dodge due to information being limited by c, but the same also applies to the enemy: they cannot accurately predict where you are going to go either...even if the enemy knows for sure you will arc 180 degrees and even if they know the radius of that arc, there are still an infinite number of similar arc trajectories you can take in a 3D environment...point being, faster ships could actually dodge laser pulses while slower ones can't...basically, if you are able to go fast enough (still sub-light), no weapon can dependably hit you, even if it travels at the speed of light...
End of Seleuceia's quote

There will be an accuracy difference for hitting a ship at 0.9c or 0.99c, but that would require the ship to make a turn, which is hard when flying at 0.9c. A standard "assume enemy is flying a straight line, SPRAY AND PRAY!!!" approach won't be much less effective than trying to maximise your chance to hit by considering all trajectories.


In reality, there is no such thing as a dead stop since all velocities must be related to another object (the only velocity that is constant from all perspectives is c)...therefore, a space ship could enter phase space at any time and at any "velocity"...
End of quote

Yet sins ships must remain stationary relative to their host gravwell when charging up a phase jump. That's the frame of reference I was using, which is identical to the player's frame of reference.


Let's go with your equation...

a=F/m+g

g is constant for all ships....however, F/m is NOT...F/m is determined by the ship and engine design, and therefore is not constant across all ships (only constant for ships of the same model, such as all LFs)...therefore, the net acceleration for ships of different engine designs will not be the same unless by pure coincidence they have the same thrust per unit mass...
End of quote

F/m is constant once you choose your ship design. Because the value is different from ship to ship you will notice different behavior between them within one gravwell, but a smaller/larger gravwell doesn't put any ship at an advantage/disadvantage by default. A Star gravwell is much bigger, but the smallest accessible radius (the edge of the star) is further away from the gravwell center than the outer radius of an asteroid gravwell.

The main point is, the effect depends on the ships' relative thrusts, not their masses.


It would seem that the ships in sins with smaller masses tend to have faster acceleration (especially SC, scouts, and LFs)...from a relativistic perspective, maximum velocity would also be indicative of thrust per unit mass...so, in sins, ships with less mass tend to have more efficient engine designs...

Obviously there will be some optimal size for a ship...I doubt you are going to make a ship the size of a thimble that can approach near light speeds...however, diminishing returns suggests that bigger engines, while yielding more thrust, will likely start yielding less thrust per unit mass...
End of quote

Like I said, we can't say anything about engine technology in sins. Scouts in particular will be much faster because they have less weapon systems, and thus more room for engines. Again, you could build a huge but agile ship or a small, slow juggernaut. In sins smaller ships will be more agile, but that isn't due to a physical law, instead it's based on the actual use of different designs. If someone had a use for a huge ship packed with mostly engines they could build it. Noone does, because smaller scouts get the job done.

Reply #20 Top
Quoting Photoloss, reply 19

Yet sins ships must remain stationary relative to their host gravwell when charging up a phase jump. That's the frame of reference I was using, which is identical to the player's frame of reference.

End of Photoloss's quote

Well yes that is how things happen in sins...but as you noted earlier no ship in sins travels even remotely close to the speed of light, making this discussion pointless if it is only in the confines of the game...if we are going to approach this from a realistic perspective then there is no such thing as stationary and no need for a ship to change acceleration before jumping...from a combat perspective, being able to phase jump at any time would obviously be very important...

Quoting Photoloss, reply 19

but that would require the ship to make a turn, which is hard when flying at 0.9c.

End of Photoloss's quote

At .9c turning probably wouldn't be too bad if you already have the tech to get to that speed...start getting to .99999c (which is the number I used earlier) and the impulse needed to change your velocity vector would be pretty high due to relativistic momentum...from an engineering perspective, what propulsion you have that gets you up to .9c is probably not for maneuvering, so yes turning would be a bitch...

However, a laser pulse is more or less a one-dimensional line (relative to the size of a ship) so while it may be difficult to change your vector, moving even a few meters sideways likely would be enough to dodge...if you account for laser dispersion, well then the diameter of the beam will be greater (perhaps much greater) but the intensity will then be lower (and therefore much less damaging)...regardless of how you approach it, the faster speed buys you time (either to turn or to "wait-out" the laser as it diverges)...

As you have noted, random firing is not much worse than attempting to calculate trajectories...that is why my original example was a 1D situation where a ship is being pursued (which means accuracy is more or less irrelevant) because it seems this would be the only situation where hitting the target is likely...the point was to show that differences in ship propulsion can mean the difference between getting hit, or not getting hit...in essence, a slow ship (say .99c) likely would be hit while a fast ship (say .99999c) would likely be able to dodge or phase jump...

Quoting Photoloss, reply 19

The main point is, the effect depends on the ships' relative thrusts, not their masses.

End of Photoloss's quote

If a scout (m=10,000 kg) has a thrust of 1,000,000 N and a capital ship (m=1,000,000 kg) has a thrust of 50,000,000 N, the ratio of the thrusts is 1:50, favoring the capital ship...however, the constant F/m would be 100 N/kg for the scout while for the cap it would be 50 N/kg...the ratio of relative thrusts (1:50) is not inherently equal to the ratio of relative masses (1:100) or thrust per unit mass (2:1), which is what I am been trying to say...

Again, let's use this equation, this time with gravity acting against the ship (say it's fleeing from a planet)...

a=F/m-g

Let's use the above two ships...let's compare four situations: empty space, small gravity well, large gravity well, and a super large gravity well...lets say that g=10 N/kg for the small gravity well and 40 N/kg for the large gravity well...for the super large, let g=60 N/kg

In empty space, the ratio of the scout and capital ship acceleration (F/m) would be 100:50, or 2:1...

In the small gravity well, the ratio would be (100-10) : (50-10) or 9:4...

In the large gravity well, the ratio would be (100-40) : (50-40) or 6:1...

In a super large gravity well, the ratio would be (100-60) : (50-60), or 40 to -10...by this point, the scout ship can easily escape the gravity well while the capital ship can't at all...of course this is an extreme situation but it goes to show that the ships are affected very differently by an actual gravitational field...

By this point I'm not really sure what you are trying to get it...if you are saying that the absolute difference in acceleration is independent of the gravity well then yes, you are correct...the absolute difference in all 4 examples was and would always be 50 N/kg...however, this symmetry is not really important...what matters is that a ship with high thrust/mass will feel less affected by a gravitational field than a ship with low thrust/mass...assuming smaller ships have higher thrust/mass, large gravity wells will widen the gap of speed difference between small and large ships...

Reply #21 Top

Well yes that is how things happen in sins...but as you noted earlier no ship in sins travels even remotely close to the speed of light, making this discussion pointless if it is only in the confines of the game...if we are going to approach this from a realistic perspective then there is no such thing as stationary and no need for a ship to change acceleration before jumping...from a combat perspective, being able to phase jump at any time would obviously be very important...
End of quote

As you still need to escape a small remnant of gravity when phase jumping, being stationary relative to the central mass might simplify calculations. If you significantly change your position after initiating the jump you might end up killing yourself.

At .9c turning probably wouldn't be too bad if you already have the tech to get to that speed...
End of quote

We already have the technology to accelerate a satellite to 0.9c. It just takes a while. And turning the thing when it's using an ion drive will take even longer.

As you have noted, random firing is not much worse than attempting to calculate trajectories...that is why my original example was a 1D situation where a ship is being pursued (which means accuracy is more or less irrelevant) because it seems this would be the only situation where hitting the target is likely...the point was to show that differences in ship propulsion can mean the difference between getting hit, or not getting hit...in essence, a slow ship (say .99c) likely would be hit while a fast ship (say .99999c) would likely be able to dodge or phase jump...
End of quote

The problem, as I said, is that you can't do much while "running away". Your 1D example works if you can phase jump at full speed, but if you have to slow down to a set velocity relative to the planet you'll still get hit, as it'll take much longer to slow down. A 3D approach will give you a "statistical advantage" in that the space you can reach with a higher velocity is greater, thus as you said either accuracy goes down or the laser disperses. However, the most likely trajectory for your ship still is the straight line, which comes back to the problem of whether you can phase jump while moving or not.

In empty space, the ratio of the scout and capital ship acceleration (F/m) would be 100:50, or 2:1...


In the small gravity well, the ratio would be (100-10) : (50-10) or 9:4...

In the large gravity well, the ratio would be (100-40) : (50-40) or 6:1...

In a super large gravity well, the ratio would be (100-60) : (50-60), or 40 to -10

End of quote

 

You assume the Scout ship is faster to begin with. If we accept that then:

F/m is constant once you choose your ship design. Because the value is different from ship to ship you will notice different behavior between them within one gravwell, but a smaller/larger gravwell doesn't put any ship at an advantage/disadvantage by default. A Star gravwell is much bigger, but the smallest accessible radius (the edge of the star) is further away from the gravwell center than the outer radius of an asteroid gravwell.
End of quote

To clarify, I meant thrust accelerations in this line:

The main point is, the effect depends on the ships' relative thrusts, not their masses.
End of quote
It is ships of equal accelerations, not of equal thrust forces, that will be equal in calculations. Your example already gives the Scout an advantage of 2:1 on its acceleration, so I would definitely expect it to outperform the capship, as it already does so in a linear race.

assuming smaller ships have higher thrust/mass, large gravity wells will widen the gap of speed difference between small and large ships...
End of quote

This is your one and only point, and it lies beyond physics. No physical law states that smaller ships will have greater thrust acceleration. It depends on engineering and available technology, which we don't know enough about to conclude anything.

Reply #22 Top
Quoting Photoloss, reply 21

As you still need to escape a small remnant of gravity when phase jumping, being stationary relative to the central mass might simplify calculations. If you significantly change your position after initiating the jump you might end up killing yourself

End of Photoloss's quote

? If you are travelling at .9c, you will travel 2.7 million km in just 10s...let's assume you are flying by a planet like earth, same mass and distance from the sun ((Me = 5.97E24 kg and r=150 million km)...Newton's law of gravitation tells us that at 2.7 million km from earth, the gravitational acceleration between your ship and earth will be g=.000055...the gravitational acceleration due to the sun (which has mass of about 1.99E30 kg) will be about g=.00590 (at r=150 million km)...basically, the sun will have more affect on your ship than the gravity well of the planet...

Let's consider the possibility that a changing gravitational acceleration (due to you moving) causes your jump calculations to be way off...consider the following situation where a ship moving at .9c starts at earth and moves for 10s directly away from both the sun and the earth...its distance from earth is 2.7 million km and its distance from the sun is about 150 million km...now, let's say it takes 1s for the computer to make jump calculations upon knowing the current gravitational field and the destination...in that one second, the distance between the ship and the sun/earth changes by 270,000 km...g between the earth and the ship changes from .000055 to .000045...g between the ship and the sun changes from .00590 to .00588...obviously the field due to earth changes more, but the change in g due to the sun is still about .4%...If a changing gravitational field affects jump calculations, .4% could arguably be statistically significant (especially from an astronomical perspective)...

The question then becomes, does a change in g actually prevent you from jumping?  If you are in the same IRF as the earth, you cannot guarantee being in the same IRF as the sun since the sun is moving on its own and planetary orbits are not perfect...therefore, ideal conditions are practically impossible...asteroids prove this point even more since there are many large bodies with different IRFs (yet ships can still jump away from asteroids)...with this in mind, we know that ships don't need a perfectly constant g in order to phase jump...then we must ask, what gravitational field change is allowable before jump calculations become inaccurate?

Because moving phase missiles can perform phase jumps regardless of trajectory or nearby mass, we can assume that moderate changes in g do not prevent one from phase jumping...let's say you make the argument that PMs don't always successfully jump all the way through a shield, indicating that a changing g may still matter...since PMs are no more effective in empty space, we can assume that changing gravitational fields do not affect the success of a PM's phase jump (rather, it is probably the PM design or shield design)...what is important here is that phase jumping is still possible despite A) a large body of mass being near by and B) the gravitational acceleration not being constant...phase missiles support both of these statements while subverters (which are actual ships, not some small short-jump missile) unquestionably support the first statement...

We also know that ships can jump regardless of whether nearby ships are moving or not...what the exact mass of a spaceship would be is unknown, but lets say its around 200,000 tons for a large ship (I looked up the Starship Enterprise and it apparently weighs 190,000 tons)...that is 1.82E8 kg...for a ship weighing that much and that is 1km away, the gravitational acceleration on you would be .0000012, which is 1/50 of the gravity pull that earth had in the previous example...consider that there could be dozens or even hundreds of nearby ships that all moving at various speeds, and it becomes apparent that moving nearby ships could be more gravitational influential (both in g's magnitude and rate of change)...yet, we know that nearby ships have no affect what so ever on phase jumping ability, so somehow I don't think the gravitational changes you have put forward will prevent a ship from jumping...

The only logical reason that a ship needs to be far from a planet before jumping is that the presence of nearby mass greatly affects the accuracy of long distance phase jumps...however, this is the presence of mass and not because any gravitational acceleration is changing...furthermore, at 2.7 million km from earth, it has been shown that the sun's mass has stronger gravitational pull which means that ultimately, ships don't need ideal circumstances in order to jump (otherwise jumps within a gravity well wouldn't even be possible)...

Quoting Photoloss, reply 21

This is your one and only point, and it lies beyond physics. No physical law states that smaller ships will have greater thrust acceleration. It depends on engineering and available technology, which we don't know enough about to conclude anything.

End of Photoloss's quote

This whole thread started because someone wanted to know how "mass" of a ship affects gameplay...I proposed the possibility that "gravity" in the game actually took into account the mass of each ship, and therefore reducing the mass of a ship would make it more maneuverable relative to other ships when in large gravity wells...My "one and only point" is that larger ships are more affected by gravity wells than smaller ships in the game of sins...in general, larger ships in sins have both smaller accelerations and smaller max linear velocities, so we can assume in the game of sins that smaller ships have greater thrust per unit mass...

I've shown that when the force vectors of thrust and gravity are summed, the mass of the ship heavily influences the net force...since in sins, bigger ships have more mass and less thrust per unit mass, in theory their net acceleration when exiting gravity wells should be reduced by a greater proportion than that of a smaller ship...I've shown this mathematically with a series of examples...the original question here is how mass affects gameplay, and if the physics engine in sins actually uses laws of gravitation, then armor techs that reduce mass will help your bigger ships escape/maneuver in stars and gas giants...

 

 

 

 

Reply #23 Top

On the phase jumping issue:

Ships in sins move to the edge of the "no jump zone", slow down until motionless relative to the host planet, turn to face their jump target, then "charge up the jump drive", sitting perfectly still. Then, they suddenly zoom off at incredible speeds. Once the ships arrive, they are once again perfectly motionless relative to the new planet (which is also motionless relative to the old planet ofc)

All ships do this, even when under heavy fire. Even a scout chased by 200 fighter squads will slow to a halt and let itself be pummeled to oblivion. This suggests phase jumping while moving is impossible with sins jump drives, as even the slightest chance of survival (otherwise getting ripped to shreds in the jump) is better than certain destruction by the fighter cloud.

Ships in sins also stop, turn and channel even when moving outside the "no jump zone" the entire time, suggesting it isn't possible to "channel in advance" either (either you simply have to be still when jumping for whatever reason, or you can't create the "entry point" far away from the ship, or both.)

Subverters also face their target, then channel (for 1.5s) while perfectly still, then teleport. They also arrive perfectly motionless, but of course they are channeling the Distortion Field at the time.

Phase Missiles must be using a different way of teleporting, as according to the artifact descriptions and jump efficiency techs phase drives are very large machines that require enormous amounts of energy.

The Skirantra Microphasing Aura, the Phasic Trap and the Antorak Phase Out Hull must also be using a different approach, as they don't even affect their host body. They don't require facing the target either, nor do they require caster or target to be stationary. Interestingly enough, Microphased SC maintain their momentum iirc while Phase Out Hull slows the target to a stop. Phasic Trap I don't know, but I would guess the SC lose their momentum.

Mines and Jikara Cloaking don't allow any movement. For the Jikara this means moving within phase space isn't trivial, and doesn't correspond with moving in realspace.

 

From this I conclude that while there are ways of phase jumping while moving, these aren't simple and definitely not included in normal jump drives. Only capships and hangars (which are larger than most ships) can do it, and they use an entire ability slot for it.

I for one imagine phase jumping as creating a "portal" at your location, and another one at your exit point, both having to be as still as possible relative to their host planets. Phase Lanes would be planets moving in a way that allows the ship to pass these portals despite their movement relative to each other. Phase Stabilisers work by creating a permanent, stable exit portal and providing a strong signal of its location. This is only my theory though. (I do faintly recall a line in the manual about "punching a hole into phase space" though)

 

This whole thread started because someone wanted to know how "mass" of a ship affects gameplay...I proposed the possibility that "gravity" in the game actually took into account the mass of each ship, and therefore reducing the mass of a ship would make it more maneuverable relative to other ships when in large gravity wells...My "one and only point" is that larger ships are more affected by gravity wells than smaller ships in the game of sins...in general, larger ships in sins have both smaller accelerations and smaller max linear velocities, so we can assume in the game of sins that smaller ships have greater thrust per unit mass...

I've shown that when the force vectors of thrust and gravity are summed, the mass of the ship heavily influences the net force...since in sins, bigger ships have more mass and less thrust per unit mass, in theory their net acceleration when exiting gravity wells should be reduced by a greater proportion than that of a smaller ship...I've shown this mathematically with a series of examples...the original question here is how mass affects gameplay, and if the physics engine in sins actually uses laws of gravitation, then armor techs that reduce mass will help your bigger ships escape/maneuver in stars and gas giants...
End of quote

Neither of us actually considered a change of mass of the ship. You proved that changes in the value of gravitational acceleration shift the ratio of accelerations between the ships, on which I agree. Your conclusion considering stars/gas giants is wrong, however, as you are also further away from them, meaning the gravitational acceleration could very well be equal to that around an asteroid. In fact, I think the edge of the "no jump zone" should have the same value of g across all planets, as it is the only parameter that even warrants a circular/spherical zone around the planet.

If we do consider the mass reduction implemented in sins (a % reduction to all ships) we get what looks like a 1/x function, where x is the % mass reduction. The ratio becomes infinite as the acceleration you divide by approaches g.

For x=1 (ships have no mass) the ratio of accelerations would be the same as without gravity. Impossible and duh.

For x=0 (original mass) the faster ship has a greater advantage than without gravity.

For a mass reduction (x going from 0 to 1) the ratio becomes smaller, meaning the faster ship loses its advantage!

For a mass increase (x negative) the faster ship gains an even greater advantage, to the point where the slower one is hopelessly drawn towards to planet while the faster ship can still escape. Eventually the faster ship will fall too until...

As x becomes (negatively) infinite the ratio becomes 1 (you basically get g/g, as with infinite mass both ships have 0 thrust acceleration, both ships fall towards the planet like unpowered rocks)

 

Note that the base in .entity files is a given mass and acceleration, not a force, though these aren't constant during gameplay (changed by research and Distort Gravity mainly)

Forces/impulses are used in various buffs though (TK push, Magnetise, anything that spawns ships), where in fact, as I stated before you (Seleuceia) even joined this topic, a mass reduction spells the doom of your ship. Which is very interesting since I made a custom race with access to both mass reduction tech and a "gravity vortex" ability based on TK push. That vortex now sounds like the ultimate counter in mirror matches.

Reply #24 Top

Quoting Photoloss, reply 23
 

From this I conclude that while there are ways of phase jumping while moving, these aren't simple and definitely not included in normal jump drives. Only capships and hangars (which are larger than most ships) can do it, and they use an entire ability slot for it.

End of Photoloss's quote

You can conclude what you like from the game, but I am approaching this from a realistic point of view and applying it to sins...while it is clearly obvious when playing that ships must always stop moving before phase jumping, there is really no good explanation for this that holds up under physics...

If you assume this is because you cannot experience a changing g, well I have shown that there is absolutely no way to avoid a changing g no matter what you are doing...moons, other planets, the central star(s), other asteroids, and nearby ships will make it virtually impossible to obtain a constant gravitational acceleration regardless of what you try to do...if you can't jump out of a changing gravitational field, then even jumping away from earth with one moon would be almost impossible...try jumping from a planet with multiple moons, from the edge of an asteroid belt, or from a planet close to a binary star, and you might as well just forget you even have a jump drive...

In sins some of these factors (like moons, binary stars, etc...) are conveniently missing...nevertheless, other factors that are present (like ships and asteroids) are still statistically relevant and unavoidable even if the nearby planet is the main gravitational influencer...

Let's assume that your velocity vector must match the nearby planet before jumping...regardless of which planet you jump to, you always end up with the same velocity vector as the destination planet...this makes absolutely no sense since the two vectors will rarely if ever be the same...again, we have another situation that doesn't hold up to physics...even if you suppose that phase space travel does not mean your velocity vector will be preserved (real space and phase space don't match up, basically), we have no real physical reason to suggest that it must always match the destination planet...if portals (like stargates) were used, that would be one thing, but ships do not require any portal device at the destination...

If you are far enough away from a planet (indicated by the edge of the gravity well) to phase jump, any possible changes in g are going to be small no matter how fast you are moving...if you think these changes are significant, then all other sources of gravity I've mentioned earlier will also be significant and will render phase jumping impossible...

Supposing that phase jumping is actually possible, there is no reason supported by physics that states you need to be "standing still" relative to your nearest planet in order to phase jump...so why do ships have to stop before phase jumping?  Because it makes good game balance...it is an attribute of the game that simply cannot be explained away with scientific mojo or hand waving...

Because mass (and gravity) distort space, there is at least some physical explanation for why you may need to be a certain distance away from a planet before plotting long distance jumps (this also would explain why you can only jump to other systems via star gravity wells)...however, an inaccurate jump is a lot different than being shredded to pieces as you suggest...subverters and PMs can perform phase jumps despite a constantly changing gravitational field (due to ships, debris, asteroids, etc.) and a nearby large mass...this only suggests that gravity makes jumps inaccurate, not dangerous...while the technology (since it doesn't exist) is not fully understood, there is nothing to contradict the idea (yet) that the mere presence of mass affects jump accuracy...in fact, physics seems to support the notion...

Quoting Photoloss, reply 23
 

Phase Lanes would be planets moving in a way that allows the ship to pass these portals despite their movement relative to each other.

End of Photoloss's quote

The entire concept of phase lanes as portrayed in the game is nonsensical...planets are moving in ellipses around a star, meaning that the very location and vector of the phase lane would be constantly changing...if we assume mass somehow affects phase jumping, it is reasonable to assume that such phase lanes exist in order to avoid traveling through massive entities like stars or other planets...

Basically, we reach a paradox...if phase lanes are meant to avoid mass en route, then they would constantly be changing during the course of a game...furthermore, some planets would temporarily cease to be connected as gas giants or stars came between them...if phase lanes are not dependent on mass en route, then there is absolutely no reason for them to exist--you should be able to jump between any two planets at any given time...either way, sins is not supported by physics...phase lanes exist because of the gameplay necessity to have choke points...

That phase lanes can be easily bypassed by kosturas and phase stabilizers further suggests that mass doesn't actually prevent phase jumping, it just makes it less accurate (further supported by technologies/pacts that reduce the jump radius)...

Some things (like a need to be outside a gravity well) at least have decent physical support and nothing to contradict them...other things (like phase lanes or the need to be in the same IRF as nearby masses) either don't have physical support or are directly contradicted by something else (like the fact that nearby ships/asteroids can be moving relative to you before you jump)...

Following the notion that the accuracy of phase jumping is affected by mass (or the curvature of space, or whatever), that a changing gravitational field would affect accuracy may seem like a logical jump...yet this just yields another paradox...if it does matter, then ships would rarely ever be able to jump from a gravity well due previously mentioned reasons...if it does not matter, then ships shouldn't need to be in the same IRF as a nearby planet...again, we have another gameplay mechanic justified by gameplay balance, not physics...

Quoting Photoloss, reply 23
 

I for one imagine phase jumping as creating a "portal" at your location, and another one at your exit point, both having to be as still as possible relative to their host planets. Phase Lanes would be planets moving in a way that allows the ship to pass these portals despite their movement relative to each other. Phase Stabilisers work by creating a permanent, stable exit portal and providing a strong signal of its location. This is only my theory though. (I do faintly recall a line in the manual about "punching a hole into phase space" though)

End of Photoloss's quote

Phase jumping via observation does seem to suggest the creation of a "portal" into phase space...however, no matching portal appears at the destination...ever...the ship simply appears there...therefore, since there is no need for a pair of portals, why only certain routes can be taken makes no sense unless objects of mass (stars, planets) prevent certain routes...even then, it seems reasonable that you could often take a detour in phase space "around" the "roadblock" instead of having to travel to another gravity well, in which case you could travel between any two planets (at least in the same system) regardless of what faction you are...

I'm going to go with the assumption that the accuracy of your jump is affected by mass en route as well as nearby mass...phase stabilizers, marauders, and kosturas increase accuracy due to a signal as you suggest, allowing more risky jumps...IIRC phase stabilizers on starbases don't work at stars, supporting the relation between mass and jump accuracy (though this could also be unintentional such as the SB trade port bug at stars)...however, subverters and PMs both show that jumping near a mass and in a constantly changing gravitational field is still possible and not dangerous...neither of these entities are ever destroyed accidentally when performing in-grav well jumps (PMs sometimes just fail to bypass the shield and end up doing normal damage, so even they make "safe" jumps all the time)...

Ultimately, we have a paradox in sins in regards to a changing gravitational field and phase lanes...if you don't assume some things were done entirely for gameplay purposes, then you can't conclude anything from phase jumping systems since the entire game mechanic is incoherent and contradicts itself...

Quoting Photoloss, reply 23
 

For a mass reduction (x going from 0 to 1) the ratio becomes smaller, meaning the faster ship loses its advantage!

End of Photoloss's quote

I'm going to assume by faster you mean higher thrust per unit mass ration...with that in mind, this is a very true statement but it is not what matters...what does matter is what advantage/disadvantage you gain relative to the enemy, not to your other ships with the same mass reduction...a reduction in mass should give all your ships some boost compared to the enemy, and while this may be convenient for some ships, it is really important for high value ships like caps...

My belief regarding gravity in sins has been that every gravity well applies a vector via a dot product to the ships acceleration and velocity...since ships don't naturally drift towards the planet, it would seem the gravity vector actually applies a percent change on the ship's characteristics...from both previous readings and past experience I think ships are affected differently depending on whether they are moving towards or away from the planet...however, I don't think distance from the planet center seems to matter...from a programming stand point, it is doubtful that actual laws of gravitation were due to the computation intensity of such a design...however, this doesn't mean the programmers didn't take into account mass...regardless of what actual physics states, they could have designed it so that gravity affects more massive ships differently...

Ultimately, all I really want to know is how the gravity mechanism works in sins, because if it does take into account the actual mass of the ship, that would have implications for modders aside from thrust-applying abilities like TK...

Quoting Photoloss, reply 23
 

Your conclusion considering stars/gas giants is wrong, however, as you are also further away from them, meaning the gravitational acceleration could very well be equal to that around an asteroid. 

End of Photoloss's quote

This statement just confuses me...sure, in theory from a macro point of view you can always find some radii for any two gravity wells that will give you the same g, but I don't see why this matters...

Your ships can be anywhere in the gravity well except inside the planet itself or very close to the surface...ultimately, there comes a point where no matter how close you are to the asteroid, you won't be able to experience the high g-values you would if you were in the gravity well of a gas giant...when it comes to maneuverability, the more massive ships with presumably lower thrust/mass ratios (in sins this would be the acceleration in the entity file) are going to have more problems in high gravity environments...

Even if gravity in sins simply slowed all ships down the same, that is going to hurt capital ships since it will take them longer to get in and out of the fray...sure, it hurts all ships, but no one cares about LFs and HCs, they care about caps...what I care about is knowing how gravity affects ships...if the gravity mechanism in the game takes into account a ships mass in anyway, I would like to know about it for modding purposes...

Reply #25 Top

Even if gravity in sins simply slowed all ships down the same, that is going to hurt capital ships since it will take them longer to get in and out of the fray...sure, it hurts all ships, but no one cares about LFs and HCs, they care about caps...what I care about is knowing how gravity affects ships...if the gravity mechanism in the game takes into account a ships mass in anyway, I would like to know about it for modding purposes...
End of quote

According to my tests the differences weren't too great, and large mass changes in either direction seemed to cause illogical problems. I mean, if your cap has 100 Assailants in its back, how will it help if you can reach the gravwell edge 1.5s earlier? Unless they've all got Charged Missiles active they'll shred the cap before it jumps. And I doubt the enemy player will have calculated the exact number of Assailants needed to kill your cap before it escapes, thus the minimal change of this "breakpoint" won't help you.

The mess I saw with 90% reduction definitely didn't look like it would help you in any way, unless you need to clear a minefield with some Carriers.

Your ships can be anywhere in the gravity well except inside the planet itself or very close to the surface...ultimately, there comes a point where no matter how close you are to the asteroid, you won't be able to experience the high g-values you would if you were in the gravity well of a gas giant...when it comes to maneuverability, the more massive ships with presumably lower thrust/mass ratios (in sins this would be the acceleration in the entity file) are going to have more problems in high gravity environments...
End of quote

True on the high-gravity environments, but what exactly are you doing close to a gas giant's surface? At least in regular sins where the things aren't colonisable.

Since stars/planets in sins don't have a mass we can only go with RL counterparts. Then, however, since sins ships can easily escape from the surface of a star, we must assume the effect is completely negligible for all planets: If you say the faster ship accelerates with 4g and the slower one with 2g you get a 3:1 ratio of accelerations at original mass. If you have the slow ship accelerate with 50g and the faster one with 100g you get a ratio of 2,02:1.

 

On phase jumping: I think Phase Space isn't part of the "normal" 4D universe, but either consists of additional dimensions, or lies in a "parallel universe" of sorts. The reason for this being that if phase jumps took place in realspace (via spacetime warping etc) they could be aborted mid-jump, and wouldn't include the limits present in sins (phase lanes, needing tech to jump between stars...) It also makes Phase Out Hull seem much more gratifying if you actually get your enemies stuck in another dimension.

Of course, since we know nothing about the geometry of phase space, there might be obstacles with no counterparts in realspace. Phase lanes could be stationary (or at least permanent) in it, and you'd want to remain stationary as you open the portal infront of you. ("portal" as in, entry point into phase space, a hole between the universes/dimensions)

Compare it to the "Warp" of the WH40k universe, rather than the "bend spacetime very very much, then fly normally" version of FTL travel.

 

I think we need to stop this though, as we don't have any official sources (and definitely noone who hacked the actual formulae used in sins), and we either have inconsistencies in our theories or rely on vague, far-fetched concepts to hide them. Mainly concerning phase space, as the "bend spacetime" approach clearly opposes key parts of sins gameplay, and my "Warp" approach can neither be proven nor disproven, as I can just say "Warp geometry demands it".