In-lore reason for shapes of many ships in Elite

[Khazid]

No, there is no stress, because the rest of ship does not have any resistance (there is no difference in momentum of thrusters and lets say a tip of the ship for example). The force in zero G/ vacuum is not "transmitted" from thrusters to the rest of the object, it is simply applied to the whole object. It is Physics 101.

This is plain wrong. Inertia resists any change of speed, be it in the presence of gravity, or vacuum, or anywhere. The bigger the mass, the greater the inertia. Thrusters only apply force on a surface of the ship. If force is too great, and the mass of the whole object is sufficient, the object will break.

Imagine the following in space:

You have a 100kg anvil tied on a very long hair. Pulling the hair too fast will only make the hair break, and anvil will change speed only slightly. The force of tension exceeds the break poing of hair, but for the tiny fructure of time the hair held together, it managed to change the speed of the anvil.

Example number 2:
Try to hit that oversized anvil with your fist as hard as you can. By the quoted logic the anvil should fly off at the speed of your fist. But would you dare doing that? No, your instincts are more true than your concious thinking. Your instincts tell you your hand will brake and the anvil, once more will only change speed slightly. The more the mass of it, the less its acceleration, because F=m*a...

So an anaconda with oversized thrusters will change speed upon boost, only it will be speeding debris after that. Engineering wise thrusters in more than one place on a ship are required, to share the thrust power on more surface. Turning around an axis for a long ship is very tricky, and thrusters along the ship would need to be electronically calculating how to apply thrust along the surface of the ship. Which is the case on python and anaconda and most big ships if you notice up close.

Engineering wise this might be the best space shape for best turning rate:

http://mimg.ugo.com/201011/6/4/7/132746/cuts/hitchhikers-guide_786_poster.jpg

I 'd totally fly that...

 

[sgtprobe]

No, the physic in zero G and vacuum does not work like you describe. You cannot hold a stick in one end and start spinning it around. Also, you cannot stop it abruptly and change direction.
If you apply force in the Space (zero G, vacuum) tangential to the center of gravity on any part of any object, you only change the rotation momentum and object, regardless of shape, will start to rotate around his center of gravity. If you apply force in line with the center of gravity, the object (regardless of shape) will start to move in vector of this force. No more, no less.

And because of the First law of physic (action and reaction) when you apply for example the tangential force and make the object to rotate around the center of gravity, you cannot stop him any other way than apply same force in the opposite direction. But the slowing down and eventual change of the rotation will not be abrupt. BTW, this is the reason, why you cannot easily use the simple screwdriver in space if you are freely floating in space.

Structural integrity in space is a problem only when it comes to centrifugal force, because when object is rotating, there is a virtual gravity gradient between the center of gravity and outer part of the ship.

I hope that I described it right, english is not my native language.

Well, the laws of physics are pretty simple in this case. In the stick example you can stop it abruptly (more or less), it depends on the force applied to counter the rotation, of course. And yes, I'm aware the difficulty of spinning around holding a stick in one end in zero G environment because of the law of motion. More of a point to demonstrate structural integrity vs inertia/mass and that it doesn't matter if you are in vacuum or atmosphere.

But now you are talking about zero G environment, which mix things up a bit. But mass/inertia is the same regardless though!

Structural integrity isn't always a problem in centrifugal cases either. Take the ISS space station as an example, if you would to apply force in centre of structure and accelerate in one direction with too much force, the outer parts of the structure would, because of inertia and mass, be in under lot more stress than the centre of the structure. And if the acceleration would be to powerfull/fast it would break appart. Apply 1 (or whatever) G acceleration in one vector for a while and then accelerate 4 G the opposite direction, and parts would fly everywhere pretty soon. Of course, the ISS isn't designed for that kind of operation anyway, but as a thought experiment it works.

Nothing wrong with your English at all, I understand it perfectly.

ps.
I'm not a native English speaker either
ds.

 

[PavelKCZ]

This is plain wrong. Inertia resists any change of speed, be it in the presence of gravity, or vacuum, or anywhere. The bigger the mass, the greater the inertia. Thrusters only apply force on a surface of the ship. If force is too great, and the mass of the whole object is sufficient, the object will break.

Hmm, either it is a problem that I am tired (here is 23:49) or I should return my 30 years old university diplom.

Let's suppose that the whole ship (including thrusters) is not moving at all. So the inertia dictates to stay and do not move at all. When you apply force to the thrusters, you are pushing the whole ship (including the thrusters) away from the material going outside from the thrusters (the burned fuel). Because the thrusters are attached to the rest of ship and there is no gradient of resistance between thrusters and the rest of ship, the whole mass of the ship will slowly start to accelerate. Where is the force which can break the ship ? The thrusters are trying to move the whole body and because there was no inertia difference at the beginning (before we applied the force) there is no difference during the application of thruster force.

Same thing is with the deceleration. The ship move as a whole with velocity v and we apply the force (from deceleration thrusters) opposite to the vector of movement. The whole ship will gradually slow down and there is no structural stress on outer parts of the ship, because there is no resistance.
Of course, this is valid only if we apply the force more or less in the center of gravity. If we do not apply the force at the center of gravity, the ship will start to rotate, not move.

 

[Darth Ender]

I dont apply logic to elite as they seem to be at war with eachother. This is a result of continuing the canon from a game that released in the 80's and the sci-fi of that era being shoe-horned into the sci fi of today.

As far as planetary landings : I dont see how any of them would survive re-entry - shields seem to allow air (low denity gasses) to pass through so they should be ineffective against protecting against the friction of re-entry and if not, then it seems unlikely that they'd be able to explain how thrusters work while shields are up (in space or otherwise). Turning off shields to land on a planet is an option but the ships dont seem designed to take heat ....with so many exposed subsystems and edges and lack of any kind of heat shield or aerodynamic concern to reduce heat buildup.... no I dont think they were designed to go in shieldless. Not really designed to go down at all, at least intact.

when it comes to space combat games, it's best to not think too hard about the "Sci fi" of it. Because in reality, space flight would be immensely boring and space combat would be even more so and totally not something that would look like a WW1 dogfight.

 

[Khazid]

Heh, its late indeed. I do not think I can explain it without another example.

Shoot a bullet towards a heavy wooden block. Yes, the block will move, but the bullet will pass through and destroy it, even if the bullet was touching the block from the start.
Mass resists changes of speed. It is why the block of wood will not gain the speed of bullet, but will break instead. Even if the materials were the same (wooden bullet? bone ?)
damage will happen on both items.

So thrusters attached on one side of a space ship, if they push too hard, they could make the ship crumble from the back towards the front. The problem can be less if multiple thrusters are attached along the ship length (imagining an anaconda) so that force is not applied only to the back of the ship, but equally pulls the ship, splitting the needed force for acceleration, without putting too much tense on one point.

No matter how dense a material, it has some elasticity, and a tension it can handle. If materials had no inertia, thus no resistance in change of speed, you 'd be right.

I hope its more clear.

 

[Trafalgar Law]

I dont apply logic to elite as they seem to be at war with eachother. This is a result of continuing the canon from a game that released in the 80's and the sci-fi of that era being shoe-horned into the sci fi of today.

As far as planetary landings : I dont see how any of them would survive re-entry - shields seem to allow air (low denity gasses) to pass through so they should be ineffective against protecting against the friction of re-entry and if not, then it seems unlikely that they'd be able to explain how thrusters work while shields are up (in space or otherwise). Turning off shields to land on a planet is an option but the ships dont seem designed to take heat ....with so many exposed subsystems and edges and lack of any kind of heat shield or aerodynamic concern to reduce heat buildup.... no I dont think they were designed to go in shieldless. Not really designed to go down at all, at least intact.

when it comes to space combat games, it's best to not think too hard about the "Sci fi" of it. Because in reality, space flight would be immensely boring and space combat would be even more so and totally not something that would look like a WW1 dogfight.

In Frontier: Elite2, you had to buy special Atmospheric shields to survive re-entry. I'm expecting something similar for Elite: Dangerous.

 

[sgtprobe]

Hmm, either it is a problem that I am tired (here is 23:49) or I should return my 30 years old university diplom.

Let's suppose that the whole ship (including thrusters) is not moving at all. So the inertia dictates to stay and do not move at all. When you apply force to the thrusters, you are pushing the whole ship (including the thrusters) away from the material going outside from the thrusters (the burned fuel). Because the thrusters are attached to the rest of ship and there is no gradient of resistance between thrusters and the rest of ship, the whole mass of the ship will slowly start to accelerate. Where is the force which can break the ship ? The thrusters are trying to move the whole body and because there was no inertia difference at the beginning (before we applied the force) there is no difference during the application of thruster force.

Same thing is with the deceleration. The ship move as a whole with velocity v and we apply the force (from deceleration thrusters) opposite to the vector of movement. The whole ship will gradually slow down and there is no structural stress on outer parts of the ship, because there is no resistance.
Of course, this is valid only if we apply the force more or less in the center of gravity. If we do not apply the force at the center of gravity, the ship will start to rotate, not move.

Imagine the engine module as being very powerfull and able to apply too much force on structure, what would happen? If the engines apply more force than the integrity of the structure of the ship can withstand, they would force their way in to the ship from behind, or at the very least break, becaus the intertia of the ship is too big to accelerate with the force from the engines.

Or imagine a long ship with very powerful rear mounted thrust vectoring engines, changing the direction of the ship from behind too fast.

 

[DrakeAurum]

Hmm, either it is a problem that I am tired (here is 23:49) or I should return my 30 years old university diplom.

Let's suppose that the whole ship (including thrusters) is not moving at all. So the inertia dictates to stay and do not move at all. When you apply force to the thrusters, you are pushing the whole ship (including the thrusters) away from the material going outside from the thrusters (the burned fuel). Because the thrusters are attached to the rest of ship and there is no gradient of resistance between thrusters and the rest of ship, the whole mass of the ship will slowly start to accelerate. Where is the force which can break the ship ? The thrusters are trying to move the whole body and because there was no inertia difference at the beginning (before we applied the force) there is no difference during the application of thruster force.

The thrusters are attached to the ship, but they're still individual, small points of thrust, which transmit their acceleration to the rest of the ship. Yes, the more rigid the structure, the easier it is to transmit that force, but no material is infinitely rigid.

Try this thought experiment: Take a thin sheet of plasticine, and lay it across the tines of a garden fork, then swing it briskly around in a full circle a few times. The tines of the fork represent the ship's thrusters, delivering acceleration to the ship (the plasticine) at regular intervals across its body. After a few swings, take a look at the plasticine, and you'll find that it's sagging through between the tines, because although the thrust is being applied evenly across its surface, it is not being applied uniformly.

Now, obviously a ship's hull is a lot more rigid than plasticine, but it's not infinitely more rigid, and it will experience stress due to acceleration.

And this is only if that force is applied perfectly symmetrically relative to the ship's centre of mass. If that force is applied unevenly (such as when rotating, and especially when both rotating and accelerating), then the change of momentum is applied unevenly across the ship's structure, and that can cause all sorts of stresses.

EDIT: Also, what Khazid said.

 

[Apos]

I dont apply logic to elite as they seem to be at war with eachother. This is a result of continuing the canon from a game that released in the 80's and the sci-fi of that era being shoe-horned into the sci fi of today.

As far as planetary landings : I dont see how any of them would survive re-entry - shields seem to allow air (low denity gasses) to pass through so they should be ineffective against protecting against the friction of re-entry and if not, then it seems unlikely that they'd be able to explain how thrusters work while shields are up (in space or otherwise). Turning off shields to land on a planet is an option but the ships dont seem designed to take heat ....with so many exposed subsystems and edges and lack of any kind of heat shield or aerodynamic concern to reduce heat buildup.... no I dont think they were designed to go in shieldless. Not really designed to go down at all, at least intact.

when it comes to space combat games, it's best to not think too hard about the "Sci fi" of it. Because in reality, space flight would be immensely boring and space combat would be even more so and totally not something that would look like a WW1 dogfight.

Ships can survive being a few Ls away from 30.000 K stars.

Reentry heat won't get even near that.

Heat is really the last of the problems a ship in ED would have,unless the atmosphere pressure is like 500,1000,+++. In fact, there is only one problem that a ship would have and that's whether it has the power to get back out again, which would be a different requirement for each planet with different gravitational pull.

 

[Karakhian]

I think its because its a make do future, things havent gone perfectly over the last 1,000 years and its back to basics rather than perfecting life. Knockbacks, setbacks and rebuilding has given us an industrial age future.

I love the ship design, dthey looked like they were knocked together in dirty factorys on the cheap with manual labour from bits lying around. Which is a nice theme. What I think looks out of place is the super sleek outfits we wear. I think more like a han solo look would match, clothes we stole from some drunk in an alley.

There's a really nice bit in an early newsletter with explanations of what the flight suit is, the Remlok helmet for emergencies and concept sketches of clothes worn over the flight suit - which might be more the kind of style that comes somewhere near what you're talking about - though it still has the advanced emergency flight suit underneath:

http://us2.campaign-archive2.com/?u=dcbf6b86b4b0c7d1c21b73b1e&id=f703580f39#2

And here's the concept sketches:

 

[Frenotx]

Hmm, either it is a problem that I am tired (here is 23:49) or I should return my 30 years old university diplom.

Let's suppose that the whole ship (including thrusters) is not moving at all. So the inertia dictates to stay and do not move at all. When you apply force to the thrusters, you are pushing the whole ship (including the thrusters) away from the material going outside from the thrusters (the burned fuel). Because the thrusters are attached to the rest of ship and there is no gradient of resistance between thrusters and the rest of ship, the whole mass of the ship will slowly start to accelerate. Where is the force which can break the ship ? The thrusters are trying to move the whole body and because there was no inertia difference at the beginning (before we applied the force) there is no difference during the application of thruster force.

Same thing is with the deceleration. The ship move as a whole with velocity v and we apply the force (from deceleration thrusters) opposite to the vector of movement. The whole ship will gradually slow down and there is no structural stress on outer parts of the ship, because there is no resistance.
Of course, this is valid only if we apply the force more or less in the center of gravity. If we do not apply the force at the center of gravity, the ship will start to rotate, not move.

Nothing is a true, perfect, rigid body. Those are just something we make up to simplify physics / engineering problems when that level of detail is sufficient. With the logic that you're using, it would be impossible for a round of ammunition to pierce a ship's hull. A shell hitting a ship I'd applying force to the ship, just like a very small, very strong, very short-burning thruster. With the physics you're proposing, the impact force would be asked to the entire ship at once, and just push it away.

What actually happens is the inertia of the ship is vastly higher than the inertia / structural integrity of the point of impact + shell, so the ship mostly holds still, and the bit of hull the shell hit gets sheared off, and accelerated.

Since even rigid material (metal etc.) are still "soft", deformable bodies, for the sake of visualizing the effect in question, you CAN pretend the ships are made of rubber. If you've got a long skinny rod of rubber and apply a force to a single point on it, you'd expect it to bend, right? Well a metal rod will behave the same way- it just takes more force to get it to deform, and it generally tends to simply break before it has bent enough to notice with the naked eye. This video may help some: http://www.youtube.com/watch?v=Do1lm9IevYE&t=5m3s

 

[FrankusSupremus]

It was explained on this forum by someone that all the ships have big engines at the back and fly "forward" plane style because they require equally balanced thrust in space. Kind of like the real life Space Shuttle, which looks just like a plane. With that level of technology, there's only so many shapes you can have that make sense around this engine concept and also are usable in combat. If there was some superior type of movement available, they could probably come up with different basic shapes. Simpler designs are better for mass production as well, as mentioned here.