## Physics and geometry (of spacetime) in games?

A forum set up for physics questions from students in the courses PHYS1121, 1131, 1221 and 1331 at the University of New South Wales. It is intended for questions that cannot readily be answered in class,
either because they fall outside the main syllabus and therefore would be distraction (however interesting) or for other reasons.

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Hon yu
Posts: 4
Joined: Sat Mar 31, 2012 12:28 am

### Physics and geometry (of spacetime) in games?

Sometimes when I came across games of this type, it makes me tried to interpret the physics in those imaginary worlds
http://jayisgames.com/games/time-4-more-cat/

(front bit posted later due to character limit 1023, my original post have 2000+ characters)
Back to main topic:
What I'm interested in this particular example given above are the following:
1. In the cat's reference frame, what is the rough trajectory of the people around it? (seemed partially answered in 2.)
2. What is the motion of the cat in the other peoples' reference frame? (It is hinted at the ending that in the game the people are actually constantly in motion as in daily routine, despite what the screen shows, which suggest that is the cat's view of the world around it)

Please inform me if this turned out to violate the rules here, cause I'm really unsure whether it is a physics question or not, seeing that science fiction are becoming more and more closely related to physics nowadays
joe
Posts: 755
Joined: Fri Aug 29, 2003 11:57 am
Location: Sydney

### Re: Physics and geometry (of spacetime) in games?

Sorry, this link took me to an advertisement. What are the rules?

Joe
Hon yu
Posts: 4
Joined: Sat Mar 31, 2012 12:28 am

### Re: Physics and geometry (of spacetime) in games?

Video-ed the tutorial of the game, note the white words appeared on the screen (I hope the link works)

The main theme is other objects move only when you (the cat) move

@rules: As this is a physics forum (and is one made by uni), I am worried if this considered as a physics question
joe
Posts: 755
Joined: Fri Aug 29, 2003 11:57 am
Location: Sydney

### Re: Physics and geometry (of spacetime) in games?

There must be an algorithm behind the responses of objects in that game. So, in a sense, the objects have behaviours that may be described by laws. (I don't know whether it is deterministic or not, but that doesn't affect this argument.)

So there is an analogy - very distant, analogy - with physics: behaviour described by and probably predictable from laws.

Some theoretical physicists spend time thinking about behaviour subject to other laws (what if the universe had 2+1 dimensions, or 11+1?). For the rest of us to take them seriously, however, the laws of these hypothetical universes must have some relation to ours. The game doesn't.

I expect that some games would be made by people with training in physics. There is another distant connection.

Please don't think that playing such games has anything to do with physics!

Joe

PS It doesn't look like an interesting game.
Hon yu
Posts: 4
Joined: Sat Mar 31, 2012 12:28 am

### Re: Physics and geometry (of spacetime) in games?

Well, the main reason I found theoretical physics interesting is its close relationship in realising science fiction concepts

(Front bit part 1 of 2)
These time travel themed games always cause me to be curious about the nature of time

From what I learnt throughout real life and on the internet, "time is nature's way to prevent everything from happening at once"

1.Time seemed to have a direction, we remember the past but not the future
2.In relativity time and space are considered as one single entity-spacetime. Due to the constant speed of light for all reference frames, spacetime can be deformed by mass-energy (I don't understand much about the details however)

3.The irreversiblity of time seemed to be related to entropy and second law of thermodynamics, that entropy (disorder/energy per degrees of freedom) of an isolated system tends to
increase. This raised the question why the universe started as a highly ordered st
(2nd bit cut due to 1023 limit, will be posted later)
joe
Posts: 755
Joined: Fri Aug 29, 2003 11:57 am
Location: Sydney

### Re: Physics and geometry (of spacetime) in games?

Yes, time has a direction.

One 'arrow' comes from the second law of thermo, which is related to why we remember only the past.

Another comes from cosmology: the universe is expanding on one direction of time.

However, the game that launched this thread doesn't seem to have any of this - or indeed any physics - in it.

Joe