[Physics 'n stuff]

14 hours ago, Veld said:

As a sidenote one thing I actually missed was when he hits about 5k km/h his thrust goes down. Perhaps the velocity cap but couldn't spot a distinct pattern.

I think it's because near planets, even in space, the atmosphere density is slighlty increasing. From how i see it in the video, it would impact your ship in 2 ways :

- 1) atsmosphere density creates a friction force probably proportionial to the velocity or square velocity so it will slow you. But you can't notice it because the atmospheric density meter precision is not enough to see it. I guess the force equation is something like : F=C(d).v or F=C(d).v² where F is the friction force, C a friction coefficient depending of the atmospheric density d (C being an increasing function of d) and v is your ship velocity. In space, i guess C(d) is very small but as you have a high velocity, the force is huge and slows you down very fast. That would explain why around 1.37, you have a high g value (i agree with you on the fact that it only shows the absolute value of g so always a positive value) but you are slowing down very fast. By doing so, if space has an atmosphere density then it creates a threshold for the velocity a ship can reach and then the maximum velocity you can reach is :

vmax=sqrt((m.g+F)/C) where vmax is the maximum velocity you may reach in a given direction, m is the mass of your ship, g is the intensity of the gravity field in that direction, F is the maximum thrust of your ship in that direction and C is the friction coefficient I mentionned before (I took the F= C.v² equation for the friction force). Of course this equation is for a given point in space as i expect g and C values depend on your position. This value can also be softcaped meaning there is a maximum value and so classical mechanic is no longer valid once you reached it.

- 2) atmosphere density impact the yeld of space engines meaning the higher the density the less space thrust you get from space engines. And it's the contrary for atmospheric engines. The higher the density the higher atmospheric thrust you get from atmospheric engines. From the video, around 2.45, you can see that space thrust is higly diminishing when the atmospheric density is greater than 0,01. And when it reaches a certain threshold (which i guess is 0,1 from the video) you have no longer space thrust. At 2.44, you can also see that atmospheric thrust is no longer 0 while the density meter still indicates a 0,00 density meaning the threshold for atmospheric engines is smaller than 0,01.

[Physics 'n stuff]

Just now, CoreVamore said:

There is nothing wrong with having things floating around, assuming you and your corp have the ability to pay for the fuel/energy that powers the anti-grav units, that is really the big logistics issue

 

I don't have anything against floating constructs but it should require something (energy, anti-gravity generators like you said it or something else). What i meant was that static core units should'nt be some magical stuff that let you built floating structures (and so defying the laws that apply to dynamic core units) without any other requirement.

[Physics 'n stuff]

43 minutes ago, Felonu said:

Actually it seems like the antigravity units will be needed by the new flight mechanisms they mentioned in the recent news release . 

Yeah i read that after posting. 

43 minutes ago, Felonu said:

 Also, if static constructs by definition don’t have velocity, then gravity can’t move the construct.  This would mean that antigravity units would be more of a rp device on these structures than a necessity.

True but I hope it doesn't work that way because it would mean that you could build anything anywhere floating around. So in this case, a space station would be a piece of cake to build which i think should be something hard enough to achieve because it is useful in many ways.

And well, i liked the idea of playing with gravity.

I'll try to test it tomorrow if i success to build a functionnal ship.

[Physics 'n stuff]

4 hours ago, Veld said:

Interesting. But JC said that they would add planet spin. I'll look into it. But may I ask how do you know that anti gravity generators will be applied in this way? Source please?

Planet spin will not affect the gravity field. About the use of anti-gravity generators, in my opinion, they use it to solve the problem of space stations. Indeed as it is a building, it will require a static core unit as said in this video where JC also says "don't use that[speaking of the static core units] if you want to build anything that moves" so the velocity of constructions made with a static core unit will be zero from how i understand it. Then a problem arises. How can you make space stations (created from static core units) that requires velocity to stay on a given altitude in presence of a gravity field when by definition, you stated contructions made by these units will have no velocity. The solution is anti-gravity generators.

 

Also do not forget that even if NQ's function shows g as a scalar, it is a 3 dimensional vector. And in the video where you gathered the data, the ship acceleration is given as a scalar so the value only represents the acceleration in a given direction (the one of the ship i presume). Same goes for speed. So whenever the pilot is changing direction, both speed and acceleration are fluctuating. So i don't really know if the data you gathered can be used given the fact you don't really know what the pilot is doing.

[Physics 'n stuff]

1 hour ago, Veld said:

is the equation for the acceleration in real life (G=gravitational constant, M=mass of planet, r=radius from core). But at NQ they don't have time to be thinking about the average density of a planet for it's mass or the gravitational constant. What they do is simplify the right hand side of the expression (GM/r^2) to other values to make it have the same dimension. Instead of GM the constant of proportionality is gr0^2. Which gives the same dimension of ms^-2.

To be a bit more accurate, NQ's definition of g is g(r0) from your equation. In NQ's equation, r is reffered as x.

 

On 02/04/2018 at 11:33 PM, Veld said:

Antigravity presented in the context of JC’s ‘orange line’ seems like it is supposed to hold objects in ‘stasis’ around a point. However, if this point moves the object in stasis will jiggle about accordingly. So it is unclear as to what the practical applications of such a generator are. Perhaps just to stop slow moving objects. Most likely just a concept he was playing around with that won’t make it to release.

The point is to make the gravity field being zero in some points. Then in these points you will no longer "feel" the gravity field and if your velocity is null then you will stay on these points and so you are able to have an orbital "floating" station without needing it to have a velocity (as it's supposed to be built using static cores in the game) on the orbit of a planet. But by doing this you have to put your object very accurately otherwise it will oscillate indefinitely around the point (depending how far you placed the object from the equilibrium point supposing that the gravity field is the only force). So i guess they will likely introduce some friction (or anything that dissipates energy) to stabilize the position.

[Physics 'n stuff]

The function seems to describe the variation of the gravity field (unit : m.s-2, just like g) created by an object located at x=0 (probably a planet). x is the radius distance between the planet core and the position where you are.

r0 is probably the radius of the planet which creates this field and h the altitude from the sea level of this planet. So r0+h is the distance from the core of the planet and from the graphic, in this case, it values something around 32 (kilometers i guess). In the exponential term, s is a term that indicates how large is the well. a indicates how deep is the well.

So by choosing ro+h you can set where you want your gravity well to be, choose s to set how large it is and a to set how deep it is. If you want to have anti-gravity (so that the function is negative somewhere), you have to choose a wisely. If you choose a=0, then you have the standard field of gravity (the green curve).

 

I hope it will help some of you to understand but it's mostly maths and does not have much to do whith physics. To sum up, by adding a gaussian function to the standard gravity field you are able to create a given area where g is negative (=anti-gravity). The only trick is that you want it to be on a specific location and that's why you use a gaussian function (it does not have much effect at distances greater than a few s).

 

N.B : english is not my mother tongue so you may have some difficulties to understand what i meant only due to my poor english skills

[Delete item is a good thing ?]

On 19/03/2018 at 5:34 PM, CalenLoki said:

I'm against deleting things. DU claim to follow some rules of physics, and conservation of mass is one of the main ones.

Destroying (devices, blueprints) OK, you can smash that computer. But the "scrap" should remain, littering the area surrounding cities, factories and bases.

And you can't really destroy dirt.

 

But dumping in space should be a thing. If you want to spend time and fuel to shoot all that dirt up there.

Well to be exact, mass conservation is not a rule of physics. Nuclear reactions are based on the fact that some mass is lost in the process (it is converted into energy : that's how nuclear plants works). Energy is the only thing which is conservative.

 

But i agree with you. I am against the idea of being able to delete "material" things. It would distord the economy. Even dirt can contribute to the economy because it may cost you (you will have to manage it) or be an income (some people may want to buy it !). Of course, as it has been stated before, i don't think it will have a big effect on the beginning of the game (there will be plenty of land to put it on : the world will seem infinite) but later on as some people may do not want you to trash dirt on their land, it will cost you (either by owning land where you would store dirt or paying people to accept it on their land for exemple).

 

To broaden the topic, i think this possibility need to be linked with waste management. In a game, generally, when something is useless to you (which is what waste is), you can delete it and the problem is solved. But as DU aims to reproduce a civilization development and i think civilizations are human organizations managing all the problems humanity have to face in order to survive and/or achieve goals (waste is one of these problems : just think about nuclear waste), deleting shouldn't be possible for material components ; we can already recycle constructions with a 100% efficiency (if i'm not mistaken) which is already a very convenient feature not accessible in reality.