Guide / Tutorial DCello's Science Guide to the Galaxy

[Frank]

After 3 and a half hours of intense formatting, editing, and image attachment wrestling, the Guide is complete!
(this version, for now, at least)

I recommend that everyone who read it or skimmed through to skim through it once more (and for those who didn't to do it!). I believe it is much more handsome now, way easier to read and to navigate. As always, comments are appreciated.



Thank you.

I considered it for the briefest of times, but quickly discarded it as that would defeat the purpose of doing a "realistic" guide -- as the game is based on our real galaxy, I had to work within our dimension's constraints.

I tried to skim as many of the concepts as I could before my brain started to overheat and I could see sparks. I'll dive back into it after I've repaired the integrity of my skull.

Please please! if there are any physicists who want to argue about these speculations, don't take it to PM. It'll be more fun for us to watch the battles. The only comment I can make is about the fun quote for the sensor section. If I were you I would have used "My universe is my eyes and my ears. Anything else is just hearsay."

 

[curses]

I considered it for the briefest of times, but quickly discarded it as that would defeat the purpose of doing a "realistic" guide -- as the game is based on our real galaxy, I had to work within our dimension's constraints.

Fair enough (-:

For me it's the easiest way to accept the things I experience in game than waving my hands about alternate dimensions and negative energy densities. I'm still to convince anyone else of this though, heh. Each to their own...

Some of the "physics" answers I see on this forum really make my stomach turn sometimes. So much so that I've given up correcting anyone anymore. This kind of thing is much needed here, thank you!

+1 to that, so true (-:

 

[DCello]

Very nice read. Sweet balance between spoonfuls of science, prose stuffings, humour, images and quotes. Thank you for this!

Great to hear it! Thank you!

Yep, they indeed are.

Already added them to the guide and fixed the squaremeter typo in the meantime

I tried to skim as many of the concepts as I could before my brain started to overheat and I could see sparks. I'll dive back into it after I've repaired the integrity of my skull.

Please please! if there are any physicists who want to argue about these speculations, don't take it to PM. It'll be more fun for us to watch the battles. The only comment I can make is about the fun quote for the sensor section. If I were you I would have used "My universe is my eyes and my ears. Anything else is just hearsay."

Heh, I did not remembered that one =P I'll reflect about if I should change it or not =P

Do come back! Brain is gain... I mean, brain overheating means you're on the right track!

 

[Baron von Schnellenstein]

Thanks DCello (and your erstwhile editor) for taking the time to put this material together in a fashion that is digestible and enjoyable to us who are not theoretical physicists.

I got through most of this quite intact and was pleased to learn something about plasma weapons. My brain _did_ start to hurt around the topic of causality and why it is impossible to see things before they happen... Which brings me to a quote from a former R&D Manager I had: "You know you've had too much caffeine when you start seeing things before they happen!"

Now, whilst I should have a bex and a lie down after causality, I ought to go and play some E : D

Again, thanks heaps

 

[Huros]

You can come out now Dr. Sheldon Cooper B.S M.S M.A Ph.D Sc.D.....

 

[Brad Avidro]

Chapter III

---

---Sound-

Sound exists in space. It just doesn’t usually travel.

View attachment 11567

Sound is a wave. A wave is a specific frequency of electromagnetic radiation. The reason why space seems – well, sounds – soundless is because the sound waves travel via vibration through molecules in viscous materials (in our case, air) or solid materials or any kind of material actually, and there’s a lack of them in vacuum. However, if the sound waves hit something like a spaceship, sound *would* be heard inside the ship. Basically, what would happen is: any sound coming from something that is attached to the ship or hitting it would be heard – that includes engines, weapons, hits on the hull, among others, but pretty much everything else (ship explosions, etc) would not. In some special cases, you may even hear sound from far away sources if the wave is a special kind of wave and it hits the hull, making it vibrate and transmitting that to the air inside the ship. But most of the time, things far away would look (sound?) silent.

Spoiler

It is actually possible to hear the sound made by planets if you have a special instrument that detects the electromagnetic vibrations.
[video=youtube;-MmWeZHsQzs]https://www.youtube.com/watch?v=-MmWeZHsQzs[/video]

In the game, I have a nice theory that could explain the presence of all sounds: Your ship computer simulates sounds outside of the cockpit. That would make sense tactically (you can hear people firing at you and locate ships by their engines, for example), and it also makes for great gameplay, so what the hell. As an added bonus that I’m pretty sure even ED didn’t thought of as anything else but “immersion-adding”, the canopy blowing out actually supports that theory: when your canopy blows out, everything mutes as if you are in a vacuum.





All the best!

Thank you! excellent read. I like to think for sound, the ships would have ears. Electromagnetic sensors mounted either side near the front, coupled with piezo speakers on the inside of the cockpit/cabin/bridge giving a stereoscopic sound effect to the pilot/crew. +1 from me

 

[DannyLeigh]

"In Newtonian physics (also known as “the physics you learned in school” or “Classical Physics/Mechanics”), gravity is generated by mass. Rotation accelerates an object towards the centre of that mass, therefore creating gravity"

Umm.... No. Not this.

Rotation has nothing to do with Newtonian gravity. If anything, the centripetal force caused by the rotation of a planet will counteract the force of gravity felt by a small body on the surface, but for Earth at least, the effect is small. Conversely, the rotation of a docking cylinder causes a small "gravitational" force for ships on the platforms. This is because the space station is "inside out" as compared to a planet. Note that the centre of mass of the station is towards the centre of the cylindar, but the force is pushing you against the outside wall because the centrapetal force exceeds the gravitational force for something tiny like an Orbis Station. In the habitation rings, the increased radius causes increased angular velocity, and so a greater "gravitational" force. That's why they have the big fancy hoops.

 

[Monk]

"In Newtonian physics (also known as “the physics you learned in school” or “Classical Physics/Mechanics”), gravity is generated by mass. Rotation accelerates an object towards the centre of that mass, therefore creating gravity"

Umm.... No. Not this.

Rotation has nothing to do with Newtonian gravity. If anything, the centripetal force caused by the rotation of a planet will counteract the force of gravity felt by a small body on the surface, but for Earth at least, the effect is small. Conversely, the rotation of a docking cylinder causes a small "gravitational" force for ships on the platforms. This is because the space station is "inside out" as compared to a planet. Note that the centre of mass of the station is towards the centre of the cylindar, but the force is pushing you against the outside wall because the centrapetal force exceeds the gravitational force for something tiny like an Orbis Station. In the habitation rings, the increased radius causes increased angular velocity, and so a greater "gravitational" force. That's why they have the big fancy hoops.

He has it right in the original writing, though it could be clearer I suppose. When on the inside of a spinning object...the change in velocity vector by the circular surface curving towards/around the center is what creates a force, normal to the surface you are standing on towards the center of the rotating object. The floor pushes against you while your body wants to continue in a vector away from the center. Not sure if I'm explaining this well...I teach better in person

In the image below, you can see the your velocity is tangential to the surface. You don't feel this b/c it is a constant value. You do feel, however, the force exerted upon you as the ring curves around, or as it changes the direction of your velocity. A change in direction or magnitude of velocity must be caused by some force/acceleration. There is no gravity here, except for the inconsequential amount coming from the objects involved.

Spoiler

 

[DCello]

"In Newtonian physics (also known as “the physics you learned in school” or “Classical Physics/Mechanics”), gravity is generated by mass. Rotation accelerates an object towards the centre of that mass, therefore creating gravity"

Umm.... No. Not this.

Rotation has nothing to do with Newtonian gravity. If anything, the centripetal force caused by the rotation of a planet will counteract the force of gravity felt by a small body on the surface, but for Earth at least, the effect is small. Conversely, the rotation of a docking cylinder causes a small "gravitational" force for ships on the platforms. This is because the space station is "inside out" as compared to a planet. Note that the centre of mass of the station is towards the centre of the cylindar, but the force is pushing you against the outside wall because the centrapetal force exceeds the gravitational force for something tiny like an Orbis Station. In the habitation rings, the increased radius causes increased angular velocity, and so a greater "gravitational" force. That's why they have the big fancy hoops.

He has it right in the original writing, though it could be clearer I suppose. When on the inside of a spinning object...the change in velocity vector by the circular surface curving towards/around the center is what creates a force, normal to the surface you are standing on towards the center of the rotating object. The floor pushes against you while your body wants to continue in a vector away from the center. Not sure if I'm explaining this well...I teach better in person

In the image below, you can see the your velocity is tangential to the surface. You don't feel this b/c it is a constant value. You do feel, however, the force exerted upon you as the ring curves around, or as it changes the direction of your velocity. A change in direction or magnitude of velocity must be caused by some force/acceleration. There is no gravity here, except for the inconsequential amount coming from the objects involved.

Spoiler

Exactly as Monk said. If you read carefully, you'll see the context of the piece was not about gravity per se, but the differences between the effects of their models in spacetime.

But I'll make sure to modify that part a bit to make it clearer just in case more people like you don't understand the context either.

 

[reload]

Excellent piece - not much new to me personally but very concisely put, and bound to be useful to a lot of people!

 

[Karaaz]

Great read, thanks for taking the time to write this up.

On the subject of atmospheric entry and flight, I like to think the ships we fly in-game aren't built for this. Seeing as how minerals are mined and refined in space and there are giant production facilities also in space, we can safely assume ships are built in space. When those ships are built and used in space, it seems impractical at best to build them to be capable of atmospheric flight.

 

[Monk]

Great read, thanks for taking the time to write this up.

On the subject of atmospheric entry and flight, I like to think the ships we fly in-game aren't built for this. Seeing as how minerals are mined and refined in space and there are giant production facilities also in space, we can safely assume ships are built in space. When those ships are built and used in space, it seems impractical at best to build them to be capable of atmospheric flight.

Yeah, several of the ships have no aerodynamic chops at all. The Clipper? hahah fat chance...or how about a flying t6...no way!

Even the ones that appear to have wings would drop like a rock in earth flight. The Eagle...that can't fly in the familiar sense. Now, what DCello suggest is that a sort of one wing body could be formed using the shield, which at high enough velocities could fly. Of course, you would need to switch to some sort of VTOL to complete docking with a terran station.

 

[Loomis]

@Monk - if even a puny Sidey can accelerate to many times the speed of light, I would think its engines would have no problem fending off a bit of planet-side gravity without needing to worry about generating enough forward velocity over an aerofoil to generate lift. Wings are so last-millenia....

My reading of the "science-bit" about atmospheric flight was about how do you achieve scary velocities without melting yourself.

 

[Monk]

@Monk - if even a puny Sidey can accelerate to many times the speed of light, I would think its engines would have no problem fending off a bit of planet-side gravity without needing to worry about generating enough forward velocity over an aerofoil to generate lift. Wings are so last-millenia....

My reading of the "science-bit" about atmospheric flight was about how do you achieve scary velocities without melting yourself.

Well, your maximum thrust is limited by your thrusters' available power. The part that accelerates said sidey is not reliant on any normal propulsion. In both supercruise and hyperdrive, you are moving at relativistic speed but the space around you is whipping by at superluminal speeds.

You are right though, with sufficient thrust you should be able to produce lift on any surface.

I'd be interested to know what the acceleration is like on each of the ships. That way I could figure out the force output and then we could figure out if the ships could physically leave the gravity well. Without enough force, you'd run out of fuel before you could escape. Also, your escape could be interminably slow if the force isn't enough.

 

[DCello]

I'd be interested to know what the acceleration is like on each of the ships. That way I could figure out the force output and then we could figure out if the ships could physically leave the gravity well. Without enough force, you'd run out of fuel before you could escape. Also, your escape could be interminably slow if the force isn't enough.

On the wiki, there are figures for hull mass of every ship. I do not know how accurate are they, but if they are, we could do a couple of equations for fun. We would need to figure out what the speed indicator measurement is, which could be done by setting a ship at a constant velocity with no acceleration and calculate the time it takes to approach a station or other relatively stable body. Then we would have speed, mass, and could apply that to an Earthly environment. I'm not home, so I won't be able to gather the speed test today.

Btw, given how we have things like rotational correction and flight assist that automatically activate the thrusters in small amounts, I think it would be feasible that they could also double as a VTOL system -- I tested it while researching for the Guide in stations by standing motionless with my ship, and I noticed the craft didn't bulged one centimetre -- at 0.1g, a ship should fall at least a meter in a second or two. That allows us to deduce that the ship is kept aloft by thrusters.

 

[Monk]

Yeah, edshipyard.com is a good resource for the numbers. I can't be bothered (and I'm at work) to measure the time it takes for each ship to hit some speed.

I also wonder if the ships have an acceleration curve or if it is just linear up to top speed. If linear we could just pick any speed, say 100 m/s, and time how long it takes for each craft to get there. If there is a curve to acceleration, we'd just need to calculate average acceleration to each ships top (boost or no boost?) speed.

 

[Loomis]

Small point - there's supposed to be atmosphere in the coriolis stations, as well as an equivalent gravitational replacement with the centripetal force, and the ships seem to have no problem flying in there (on thrusters, or otherwise)

 

[Midgardsormr]

First things first: the FSD is *not* an Alcubierre Drive.​

Maybe I've completely misunderstood the descriptions I've read of the Alcubierre drive, then, because what you went on to describe sounded very much like one.

 

[DCello]

Yeah, edshipyard.com is a good resource for the numbers. I can't be bothered (and I'm at work) to measure the time it takes for each ship to hit some speed.

I also wonder if the ships have an acceleration curve or if it is just linear up to top speed. If linear we could just pick any speed, say 100 m/s, and time how long it takes for each craft to get there. If there is a curve to acceleration, we'd just need to calculate average acceleration to each ships top (boost or no boost?) speed.

I'm pretty sure it's linear, by what I remember in-game.

Maybe I've completely misunderstood the descriptions I've read of the Alcubierre drive, then, because what you went on to describe sounded very much like one.

You clearly did.
I made sure to show the explanation of the drives to a handful of different people before posting to make sure it was both easy to understand and clear what the differences were. Given you were the only one so far who did not understood, I can only recommend you read it again (and again, and again, and again) as many times as necessary until you do.

 

[Monk]

Small point - there's supposed to be atmosphere in the coriolis stations, as well as an equivalent gravitational replacement with the centripetal force, and the ships seem to have no problem flying in there (on thrusters, or otherwise)

.1g is low enough to not need atmospheric flight to stay aloft. Therefore the presence of atmosphere inside the station is irrelevant since you don't need it for lift and you won't be going fast enough for drag to be of issue. On a planet with significantly more gravity you need to either use lift to stay up or strong enough thrust to facilitate VTOL. Being able to cruise in using flight/lift would have significantly lower fuel use than using thrusters all the way down.