Newtonian Aurora

[backstab]

My hope is for realistic game, not reality.  Newtonian is fine for me.  I don't expect Steve to come up with a game capable of modeling all the physics we have available.  If projectiles cross each other at 1+ c, that is fine with me.  The game doesn't need to shift reference for most.  Honestly, most people don't know the math, and I doubt those that do want to spend their free game time worrying about it (I sure don't).  If it was going to be that complicated, we would be harping on Steve to figure in the change in relative size of an object travelling at high velocities just to see if it affects whether we hit the target or not.

If you really want that level of difficulty it takes 9-12yrs at a good institution or two (and a passable doctoral thesis), and then you can deal with these problems regularly - and get paid for it.

I don't expect this level of detail.  Just a good 'realistic feel' with no outright violations (other than FTL travel) of reality.  (I'm sorry if guidance systems on projectiles undergoing 1/4 million G accel felt like a violation for me.)


To me the comm issue is less of a hurdle.  I did a fair amount of time in the military and lack of comm is a common problem.  That is what all the training and SOPs are for.  To keep everyone on the same sheet of music without having to check in with each other every few seconds.


Lag time for a non self guided munition would be a problem.  But I really forsee most of the missiles having some onboard guidance systems.  Only time will tell how this game will play out, but I forsee most missile exchanges occuring at very long range with the opponents dropping ordinance and then beginning evasive manuvering to try and run the opposing missile over its delta-v budget so that it will be impossible for it to make intercept.  Groups of ships will likely release missiles from vastly different locations and speeds to bracket a target to make it more difficult for a ship to break away from inbound ordinance.  In this environment, interplanetary range duels will be quite possible.  I forsee the side best able to put missiles on a target from one AU+ to be the winners in this kind of duel.

But as I said, time will see (and I truly can't wait to try it out for myself).

Well said procyon !
People are taking this waaaay to seriously ... its only a game

[UnLimiTeD]

+1, procyon.

I believe most of those issues could be solved with entirely unrealistic, but reasonable soft cap borders, like making ships use more fuel above a certain treshhold, say, 10% and 30% of c, and have kinetic weapon projectiles have less acceleration based on how much % of c, rounded down, the firing ship has.
At 0.6 c, the railgun would only accelerate the projectile with 40% it's speed.
Those should be reasonably graspable, make no difference in early game, which is where most people start out, and it could be pretty consistent over the gameplay as well.

[fcharton]

have kinetic weapon projectiles have less acceleration based on how much % of c, rounded down, the firing ship has.

This would probably work, and would amount to using (special) relativistic formulae for projectiles.

making ships use more fuel above a certain treshhold, say, 10% and 30% of c

This sounds strange. . .  The whole point of Newtonian Aurora is that fuel is not spent to move but to accelerate (ie change speed and/or direction of movement).  A ship that doesn't accelerate, no matter her speed, will not use fuel.

Francois

[fcharton]

My hope is for realistic game, not reality.

I believe this is the heart of the matter. The problem, to me, is that, if we define "reality" as "what we experience and feel as being real", space movement and combat is highly unreal. We all know that movement uses fuel. For cars, tanks, planes or ships, double the fuel tank and you'll more or less double the range. On contrast, changing course uses only a fraction of the fuel consumed to move.

Unfortunately, this "reality" doesn't work in space, where fuel is spent to change course or speed. This means a lot of concepts we take for granted, in our "blue water navy" vision of space combat (as depicted in Honorverse, and similar works) do not work in "real physical space".

Take range, for instance. In most modern naval wargames (and current Aurora), a sound tactics for missile equipped ships is to close on the enemy, fire missiles and move out of range. In a Newtonian setting, this doesn't work: an enemy missiles, pointed at you (and with some onboard homing system) will probably catch you anyway, so long its speed is greater than yours. To evade pursuit, you should rather close on the missile, change course, and hope that you can outfuel it. To earthbound tacticians, this is is extremely unrealistic.

I think other examples could be produced, notably about dogfights, where high speed, which entails higher fuel cost for course change, might be less decisive than we use to think.

Overall, I think it is less about the game "looking real" (the more science you put in it, the less it will, to us earthbound humans, at least), than about keeping the maths reasonable for the programmer (it won't make a huge difference for the players, anyway).

Francois

[procyon]

Unfortunately, this "reality" doesn't work in space, where fuel is spent to change course or speed. This means a lot of concepts we take for granted, in our "blue water navy" vision of space combat (as depicted in Honorverse, and similar works) do not work in "real physical space".

Agreed.

Take range, for instance. In most modern naval wargames (and current Aurora), a sound tactics for missile equipped ships is to close on the enemy, fire missiles and move out of range. In a Newtonian setting, this doesn't work: an enemy missiles, pointed at you (and with some onboard homing system) will probably catch you anyway, so long its speed is greater than yours. To evade pursuit, you should rather close on the missile, change course, and hope that you can outfuel it. To earthbound tacticians, this is is extremely unrealistic.

Not necessarily agreed.  Hopefully this game will help refine just what tactics work.  I personally see turning into an attacker as helping him to bracket you with missiles/projectiles and reducing your manuever options.  But I could prove wrong and look forward to finding out.

Overall, I think it is less about the game "looking real" (the more science you put in it, the less it will, to us earthbound humans, at least), than about keeping the maths reasonable for the programmer (it won't make a huge difference for the players, anyway).

Disagee on the first point, agree on the second.
Steve is doing this without pay, and sharing it with us.  Whatever makes this easier for him - I see as a good thing.

But on the case of it 'looking real', I disagree.  

It would appear to me that Steve and all of the people commenting on this are trying to make it as 'real' in a Newtonian sense as possible, without making Steve generate code that would make NASA envious.  There are 48 pages in this thread alone showing that people have a pretty good grasp of what this should be like.  The discussions of required fuel per degree for course changes, viability of guidance systems on rail gun projectiles, exhaust velocities and rates of consumption, etc, etc, - prove to me at least - that the group following this and looking forward to it have a very good grasp of what happens outside the Earth's atmosphere.

People don't play Aurora looking for an 'easy' game.  They play it for the level of detail and 'reality'.

[procyon]

like making ships use more fuel above a certain treshhold, say, 10% and 30% of c,

This sounds strange. . .  The whole point of Newtonian Aurora is that fuel is not spent to move but to accelerate (ie change speed and/or direction of movement).  A ship that doesn't accelerate, no matter her speed, will not use fuel.

I'm not sure I really agree with the % 's he is proposing, but the idea is actually sound.

I don't think UnLimiTeD is suggesting you need fuel to coast, but relative speed will affect fuel use to effect a certain level of delta V.

It has to do with the increasing mass of a body as you increase its kinetic speed, per E=mc2.  The energy of movement will increase the apparent mass of the ship, and hence the fuel required to accelerate it.  It makes no difference in continuing at a given speed, but changing it will be affected by its current velocity in a given frame of reference.

Hopefully we don't have a lot of objects moving at such high relativistic velocities that it would make a large differece, but I will have to admit that I don't know what a drive in game will be capable of.


EDIT

As a short note, effects below .1c really should be ok without worrying about Lorenz.  It only amounts to about 0.5% at this range.  If we only fudge half a percent, I am not to worried.

At .5c, it amounts to around 15%.  This could be sticky to ignore, but I really don't expect to see many objects passing this limit.  Of course, I could be wrong. 

[UnLimiTeD]

Yup, that's what I meant.
The aim was essentially to discourage those high speeds, even with high tech games, to the point that a hardcap set at, like, 90% lightspeed (as in current Aurora) would not be noticed by anyone that isn't die-hard trying.
I chose 10% as the first threshold because it's a nice, even number, easy to memorize and to calculate with, and a point where not too many distortions should take place.

[bean]

I doubt that ships, even given infinite delta-V, would routinely get above about .1 c, anyway.  It simply takes too long to accelerate.  At 10 m/s2, a ship will put on 864 km/s/day.  To get to c, assuming constant acceleration, would take about 347 days.  To get to .1 c, then, takes 34.7 days.  During that time, a ship will cover 149808 light-seconds, or over 300 AU, which is about 8 times the semi-major axis of pluto's orbit.  Very rarely will it make sense to spend that much time and fuel building speed for a jump, and going faster is highly impractical.

[fcharton]

10 m/s2 (around 1G) is a very low acceleration value.

A ship travelling at 1000 km/s (not a crazy speed, at this average, she'd need about 2 months to travel from the Sun to Neptune), with a 10 m/s2 acceleration, would turn arctan(10/1e6), or 5.7e-4 degree, per second. A 45° course change would take almost a full day. Even at 100 km/s, a ship could turn about 20°/hour, and a right angle turn would take 4.5 hours.

At such rates, and unless they move at very low speeds (a few km/s, which means outer planets are hardly reachable, since intra system jumps are not possible), ships become little more than projectiles, and firing a missile in the general direction of something not right ahead becomes a very costly exercise.

So, if you want ships a bit more maneuverable (and space combat possible), you need much higher acceleration rates, which, again, make relativistic speeds feasible.

On the other hand, one could argue that such high speeds are not desirable (for ships and missiles) because of the lack of maneuverability they entail. But you'd still need a lot more acceleration than a few G (more in the hundreds than the tenth, in fact) as soon as you want to travel further than the inner planets and have more maneuverability than a modern day supertanker...

Francois

[procyon]

10 m/s2 (around 1G) is a very low acceleration value.

A ship travelling at 1000 km/s (not a crazy speed, at this average, she'd need about 2 months to travel from the Sun to Neptune), with a 10 m/s2 acceleration, would turn arctan(10/1e6), or 5.7e-4 degree, per second. A 45° course change would take almost a full day. Even at 100 km/s, a ship could turn about 20°/hour, and a right angle turn would take 4.5 hours.

No arguement there.  Now actually turning the ship would be fairly easy.  It will rotate on its axis fairly well and this is why I don't mind Steve's decision to ignore facing.  Effecting a course change will take time. 

I don't know what others forsee, but I expect combats to occur at ranges measured in AU, not km.  Weapons will take many hours/days to reach targets, during which a great deal of time will be spent maneuvering to ascertain just what the incoming weapon is capable of (assuming you can see it), while manuevering your own ships and weapons to begin denying your target any movement options that won't put it in danger.

At such rates, and unless they move at very low speeds (a few km/s, which means outer planets are hardly reachable, since intra system jumps are not possible), ships become little more than projectiles, and firing a missile in the general direction of something not right ahead becomes a very costly exercise.

Again, no large arguement.  Ship deployment will be critical.  The 'Empire State Formation' of old will be a death trap.  You won't be able to keep all your eggs in one basket.  It will limit your attack options too severely and leave you vulnerable to a single nuke leaking past your defenses and taking out a whole fleet..

So, if you want ships a bit more maneuverable (and space combat possible), you need much higher acceleration rates, which, again, make relativistic speeds feasible.

Not sure I agree.  Required fuel will probably make getting much past .1c impractical.  Not impossible, but you may not see that ship again as it sails off into the 'long dark'.  Weapons may push the limit, but I am willing to overlook the physics violations on 'expedible munitions' to ease the coding burden.

On the other hand, one could argue that such high speeds are not desirable (for ships and missiles) because of the lack of maneuverability they entail. But you'd still need a lot more acceleration than a few G (more in the hundreds than the tenth, in fact) as soon as you want to travel further than the inner planets and have more maneuverability than a modern day supertanker...

High G weapons, ok.  High G crewed ships, not so much - unless we posit some huge medical/genetic developments, or an alien race adapted to ultra G environments. 

People don't do so well at high G.  10 G for short periods will render most unconcious.  More than a few minutes is generally associated with high morbidity/mortality rates. 

At 100 Gs most critters we know of get kind of 'squishy' as my 7 y/o says.

As I said, I forsee a lot of combat involving ships jumping in at trans-Neptune orbits, orienting on a target, releasing self guiding ordinance, and then reversing course and jumping out before a return strike occurs.  The real battle will involve having a well deployed fleet that can intercept/eliminate incoming weapons, and then be prepared to deal with the 'follow on ships' that come in a week or two later to assess the results.
Out system 'defense bases' or 'patrols' with (probably two stage) missiles that may have a chance to intercept an 'interloper' may become vital designs to prevent a holocaust.

Even extended durations at 2 G will do horrible things to you.  The blood vessels in your brain have poor ability to withstand this (hence 'shaken baby syndrome' I get to see far to often) and strokes will occur regularly if you keep up 2 Gs for days on end.

This is why I see most combat occuring at long range.  At shorter ranges you simply can't dodge bullets (no matter how cool I think the 'Matrix" is).  Ships will start disappearing too quickly.  A few railgun armed ships should be able to shred dozens of targets before the opposing weapons even reach them.  Of course, the opponents incoming ordinance will doom those ships also.  I kind of forsee 'close combat' to be a form of mutually assured destruction.  The weapons are just to powerful for a ship to survive.

Which sadly enough, is very 'realistic'......

[UnLimiTeD]

Well, at some point midgame, I see 'Cyborg Crews' as relatively realistic. But I obviously agree with you.

[fcharton]

Now actually turning the ship would be fairly easy.  It will rotate on its axis fairly well and this is why I don't mind Steve's decision to ignore facing.  Effecting a course change will take time.  

Yes, unfortunately, for a moving ship, this change of facing would only be useful for energy weapons, and work at very short range.

I don't know what others forsee, but I expect combats to occur at ranges measured in AU, not km.

Only if you can detect your target that far away. I believe this more or less limits this very long range hit and run strategy to attacks on planets and moons. For anything smaller and less predictable, you'll need to close in and detect, then align, then fire. Also, unless you put very long "warp delays", you will always be able to warp out of long range battles.

As I said, I forsee a lot of combat involving ships jumping in at trans-Neptune orbits, orienting on a target, This is why I see most combat occuring at long range.  At shorter ranges you simply can't dodge bullets (no matter how cool I think the 'Matrix" is).  Ships will start disappearing too quickly.  A few railgun armed ships should be able to shred dozens of targets before the opposing weapons even reach them.  Of course, the opponents incoming ordinance will doom those ships also.  I kind of forsee 'close combat' to be a form of mutually assured destruction.  The weapons are just to powerful for a ship to survive.

I think there would be two different styles of battle.
- attacks on planets/moons/orbital installations
Those happen as you suggest. Attacker warps in very far, aligns, shoots, and warps out. Counter fire is pretty much limited to antimissile and point defense. Antimissile tactics is relatively straightforward : move heads on, not necessarily fast, forcing the incoming missile to try to dodge, and use up its delta-v reserve. The further away you detect the enemy, the more delta-v you can force him to use. Point defense are like now, a last ditch attempt.

- ship to ship battles
detection and movement to align would force this to happen at shorter range, but I agree with you, close range is mutually assured destruction. Yet, against incoming missiles, dodging is possible, especially if you are close range (but not too close!), this is because the delta-v cost of a course change is proportional to the angle (its tangent, in fact), and the closer you are, the larger the angle.
This brings back an interesting question about light speed and detection: the cability of a missile to change course and hit an eviding target will depend on its correct evaluation of its future course. Taking information propagation delays into account would probably introduce another interesting twist. The further away you are, the less precise your assessment of future enemy position is, and the faster you move, the less time you have to react. Like a weird OODA loop...

Francois

[procyon]

......??

Looking forward to the responses.  Most folks don't talk about Minkowski space unless they know something about physics. 

I think perhaps the text on your last post got dropped.

[fcharton]

As for high-G acceleration, I thought I had read previously that Trans Newtonian elements would become some sort of "anti-gravity magic dust". Now, if we consider the (very relativistic) idea that acceleration and gravity are two aspects of the same phenomenon (local space time curvature or something), and that TN-elements can offset gravity, we might have a tech-line for high-G acceleration...

Francois

[procyon]

As for high-G acceleration, I thought I had read previously that Trans Newtonian elements would become some sort of "anti-gravity magic dust". Now, if we consider the (very relativistic) idea that acceleration and gravity are two aspects of the same phenomenon (local space time curvature or something), and that TN-elements can offset gravity, we might have a tech-line for high-G acceleration...

Don't know what place the TN materials will play, but I do expect to see some form of tech to allow high G maneuvers.  Whether you call it 'gravatic dampening', 'cyborg crews (ala my Nemesis Camp)', etc, I do expect it to make an appearance to allow for a more 'dynamic' style of play.

Yes, unfortunately, for a moving ship, this change of facing would only be useful for energy weapons, and work at very short range.

It is hard for me to think of a rail gun as an 'energy weapon', - but yes I agree - I expect direct fire weapons at very high velocity will dominate in close.

Only if you can detect your target that far away. I believe this more or less limits this very long range hit and run strategy to attacks on planets and moons. For anything smaller and less predictable, you'll need to close in and detect, then align, then fire. Also, unless you put very long "warp delays", you will always be able to warp out of long range battles.

This is where my lack of familiarity with the prior versions of Aurora will get me for some time.  I really have no idea what is possible in the game as it stands.  Some may have different ideas on what will be necessary to win.  I see only one path, the same as it has been since people figured out how to throw a weapon.  He who can strike farthest - wins.  With the weapons discussed, nearly any hit will be fatal to a ship.  It will all boil down to who can see farthest - ie sensor tech.  

A hunter that can't see the deer goes home hungry.  A deer that can't see the hunter is DEAD.

EDIT

As a side note, that is why I see the out system attack as the norm.  So long as you arrive pointed toward the primary, everything 'in system' will be a viable target - more or less.

I think there would be two different styles of battle.
- attacks on planets/moons/orbital installations
Those happen as you suggest. Attacker warps in very far, aligns, shoots, and warps out. Counter fire is pretty much limited to antimissile and point defense. Antimissile tactics is relatively straightforward : move heads on, not necessarily fast, forcing the incoming missile to try to dodge, and use up its delta-v reserve. The further away you detect the enemy, the more delta-v you can force him to use. Point defense are like now, a last ditch attempt.

To this I would add the one thing I see 'fighters' as useful for.  It sounds like they are cheap(er) and fast to produce, requiring less sophisticated facilties.  A squadron with rail guns would be able to more rapidly deploy to intercept incoming ordinance, creating multiple interception points.  Reusable AAMs as it were.

- ship to ship battles
Yet, against incoming missiles, dodging is possible, especially if you are close range (but not too close!), this is because the delta-v cost of a course change is proportional to the angle (its tangent, in fact), and the closer you are, the larger the angle.

Will wait to see how it works.  I forsee bracketing targets with ordinance to reduce maneuver options, but only 'in game' play will see if this is workable.  

EDIT

And the bracketing would occur on the approach (which probably took awhile).  Intentional 'overshots' just to get inbounds closing from multiple angles should prove devastating if the coding will support it.  If you back away from recent launches, you will connect with the earlier ones...

This brings back an interesting question about light speed and detection: the cability of a missile to change course and hit an eviding target will depend on its correct evaluation of its future course. Taking information propagation delays into account would probably introduce another interesting twist. The further away you are, the less precise your assessment of future enemy position is, and the faster you move, the less time you have to react. Like a weird OODA loop...

Steve has had enough headaches trying to just get the missiles to hit a target with the current coding (as I understand).  Tracking system delays on targeting data is one hurdle that I don't want to drop on him (or the processor).  In reality it is a problem.  In the game ?