Page 1 of 1

STL -- a space game

Posted: Sat May 30, 2015 2:54 pm
by Squirrelocrat
Hey Hey,

I've just started work on a relativistically correct space game that I'd like to share. But first -- some introductions: I'm new here, my name's Jeff, and I recently got my B.S. in Physics. All I want to do now is make science games! To that end I've started building a game I'm calling STL Slower Than Light. The latest prototype is on gamejolt at ... ght/69890/

Eventually I want to challenge the player with managing a colonial empire in a relativistically correct galaxy. Is it even reasonable to think of an empire as united when its colonies are hundreds of light-years apart?

But the current prototype is all about navigation and making use of the relativistic rocket equations. At this point in my life I know enough about physics to know that I've probably made more than a few mathematical errors already. Particularly when it comes to Special Relativity -- I once calculated a value for gamma that was less than one...on a midterm....I mean c'mon :) So I could use all the eyes I can get.

Thank you for your time and your help,

Re: STL -- a space game

Posted: Tue Jun 02, 2015 6:02 pm
by testtubegames
Welcome to the forums, Jeff / Squirrelocrat. Sounds like you're working on some cool stuff!

First off, I love the pun-of-a-name (I've spent maaaany an hour on FTL). *And* the fact that you're making a relativistic game... something I think there should be more of in this world.

I took a first peek at your prototype, and things seem to at least be working qualitatively (I didn't check the math or anything). Just a few things that occur to me that I thought I'd note:
-The systems for moving around are pretty counter intuitive to a new user -- which is fine for a prototype of course, but just be aware it took me about 10 minutes to really understand how/what I was supposed to do.
-I'd love to be able to see the times on the different planets/stars a lot more easily. Right now you have to hover over them to see how their clocks are ticking, which can be tough to do since they are moving across the screen.
-At the moment, using Velocity Raptor lingo at least, you're displaying 'Measured' relativity instead of 'Seen' relativity. Which is completely fine (and a lot easier!), but just be aware that in the future that could lead to some problems for your game. The main one that occurs to me is that you can see time move backwards on distant objects, so if civilizations/starfleets are developing there, you'd have some non-causality to deal with. Also the faster-than-light transmission of information would tip players off to information they shouldn't necessarily have yet. I imagine you've thought of ways around this, of course, but it stands out to me as something to mention. You could always shift to 'Seen' instead, or find some other 'fog-of-war' solution

Thanks for sharing your in-progress game with us! I'll be interested to see how it develops.

Re: STL -- a space game

Posted: Wed Jun 03, 2015 12:06 am
by Squirrelocrat
Thanks for the great feedback! And yeah I'm not calculating what the player would actually see quite yet. Mostly because I'd have to deal with light aberration and I loathe angles haha.

To be honest I've thought more about the backwards moving time than the player controls. So at some point I'm going to have to rethink and rebuild how the player actually moves around. As for the time issues, the problem is especially bad because if you're accelerating away from a distant star during the last leg of your journey then you're watching time go backwards after it just shot way forward when you accelerated towards it during the first leg. You end your journey in the star's reference frame and you have information about the star's future. But as far as I can tell (hope), once the star is at rest the information you saw is never further into the future than the star's time + the distance between you and the star. If and when I find my line of reasoning to be wrong, then I may have to artificially block information because a wizard did it. And that would make me sad :(

You may not be able to affect something you've already seen but you could arrive at a colony with information about distant colonies that will take years for the locals to get. That could get interesting.

Re: STL -- a space game

Posted: Wed Jun 03, 2015 3:47 pm
by testtubegames
I think your reasoning is right -- that however far in advance you see a star's clock while you're moving towards it, you'll never be able to reach it at an earlier time. And when you fly away from a star, you'll never be able to see it at an earlier time than it was when you were there.

Though, the captain of your spaceship wouldn't really have any future information about the stars... since the light hasn't had a chance to reach her. And I don't think you could arrive at a new colony with any extra information, because all info (presumably...) travels at light speed, and you're traveling slower than that. So you wouldn't be able to report any novel information (assuming they could learn the same thing with their telescopes).

Re: STL -- a space game

Posted: Thu Jun 04, 2015 5:34 pm
by A Random Player
I'm thinking that the best option would be a switch to 'Seen' view (include aberration, I KNOW I hate it too). Otherwise you'd run into the issue of, essentially, prescience ( :lol: ). What's with the issue of
Here's a simple way to view the issue of future seeing (ignore all the sign errors in the input boxes).
Red refers to the "at rest" reference frame, the one the colony is in. Recall that the horizontal line in your reference frame (blue) is what you can see in measured. Notice how you can see the future events which you normally wouldn't have been able to see.
STL MinkDiag 1.png
Diagram 1
STL MinkDiag 1.png (31.53 KiB) Viewed 16976 times
STL MinkDiag 2.png
Diagram 2
STL MinkDiag 2.png (38.66 KiB) Viewed 16976 times
I'm thinking that in measured you can accelerate arbitrarily fast to arbitrarily close to c for a very short time and act based on the events that you saw in the "future". I'm not quite sure if by accelerating "arbitrarily fast" you'd necessarily reach the destination, but I doubt it, since you always can reduce the time-scale. This result may violate causality... so I'd definitely recommend Seen.
***Edit: Actually it seems you can only "peek" at events not in your future light cone. This means you can peek forward somewhat, but cannot influence these events. Interesting (and confusing)...***

Note that you can't see into the future if you limit one's view to a past light cone (Seen):
STL MinkDiag with light cone.gif
Diagram with Light Cone
STL MinkDiag with light cone.gif (68.68 KiB) Viewed 16976 times
Here's a simple VR experiment:

Code: Select all

[Example, [o,o,o,o,o,o,o,o,o,o,o,o,o,o,o;o,o,o,o,o,o,o,o,o,o,o,o,o,o,o;o,o,o,o,o,o,o,o,o,b1-2.2-2,o,o,o,o,x;o,o,o,o,o,o,o,o,o,o,o,o,o,t-4-0,o;o,o,o,o,o,o,o,o,o,o,o,o,o,o,o;o,o,o,o,o,o,o,o,o,o,o,o,o,o,o;o,o,o,o,o,o,o,o,o,o,o,o,o,o,o;o,o,o,o,o,o,o,o,o,o,o,o,o,o,o;o,o,o,o,o,o,o,o,o,o,o,o,o,o,o;;]]
Note how in measured you can peek into the future by moving toward the apparatus, but time always goes forward in seen.

Interestingly, I had also been thinking about a game with finite-light, but was experimenting with an aether (the universe if the Michelson–Morley experiment gave a positive result) and potential superluminal motion.

Edit 2 (continuing from my previous edit). Actually, it seems that while you can't influence events that you "peek" at, you may be use these events to influence other events farther away. For example, you peek at an event 4 ly away and 3 years in the future, then travel in the opposite direction at .5c for 4 years and warn them of the event? But with measured they would already have been able to see this event... Really just throwing this out there.

Re: STL -- a space game

Posted: Thu Jul 27, 2017 5:59 am
by Bockman
Nice little game you made there Jeff.