• NOW LIVE! Into the Woods--new character species, eerie monsters, and haunting villains to populate the woodlands of your D&D games.

Faster than light travel or "jumping"

bolen said:
A cool topic (let a physicist highjack it)

A fun idea for you to play with is no matter what FTL drive you have you are violating relativity (ie getting information or you to travel outside your light cone.) If you accept that you basically have a time machine. Obviously there are tons of plot threads here.

Solutions for stable transversable wormholes do exist in Einstein's Theory of Gravity (General Relativity). But the throat needs be made of negative mater (This is not anti-mater). Negative matter would repel and not attract ordinary matter. Here’s the problem: although as a theorist I can invent such a beastie, it don’t mean that it exists in our world. Now there are a few possibilities that you could use from quantum field theory but again that is highly theoretical.

If you want my personal opinion wormholes do exist but only at the Plank level (about 10^-34 meters) as part of spacetime foam. But wormholes of this size aren’t a lot of use for spaceships

(end highjack)
And what's your take on String Theory (aka the One Theory to Rule Them All -- Big and Small)?
 

log in or register to remove this ad


Finster said:
I have never heard this term before. Can you explain so that us lower life forms can understand? ;)

That's because it only exists in the minds of physicists. The problem with making a tranversable wormhole (one you can go down) in that all the calculations show it tends to try to collaspe on itself. You need something to hold it apart. That is what the negative matter (or more preciely negative energy density) does. You can easily write this on paper but as far as building it in the lab or even imagining it being built in the lab is beyond what anyone knows how to do. The basic idea is that this negative energy density would repel (ie bend space in the oposite direction) then ordinary matter would.

There is good physics being done here but I am not sure that it is anything other then playing with math.
 


Ranger REG said:
And what's your take on String Theory (aka the One Theory to Rule Them All -- Big and Small)?

short answer It is overhyped and going in the wrong direction

Long answer We have a good model of three forces of nature (except gravity) at low energies (lower then a couple of TeV) String theory tries the same approaches that worked for the standard model but instead of particles (1 d objects) it uses strings (2 D objects). Unfortunately it has to invent other dimensions the latest is 12 spatial dimensions with 1 time. It seems to have all the ingredients needed for a final theory

Except
- It has no testable predictions
- You end up with hundreds of free parameters
- It is not clear why one should begin with flat spacetime at the fundamental plank length
- Many other more technical questions

I work in Loop quantum gravity in this we do not try to unite the forces we just try to understand how to create a quantum theory of gravity. In some ways it is less ambitious then strings but I think we are on more solid mathematical ground.

By the way if I had posted the above on a physics board the moderators would have closed the thread. I am not being very diplomatic (but neither are the string people)
 

In a short lived D20 Future game, I used a combination of unmanned drones with FTL drives and jump gates that travelled from one specific point to another. I had decided that true FTL travel was somehow harmful to conscious beings, so all exploration was either done by slow cryo-sleep ships or unmanned drones. Once a suitable location for a jump gate was mapped by a drone (is there something worth jumping to in this system?), a second drone would tug a jumpgate to the new locale.

Travel between jump gates was instantaneous, and safe. Travelling FTL was dangerous and slow(er). It made it so known space grew slowly at first, but increased in size exponentially as drones could start progressively further from Earth due to Jump Gates.
 

I think the problem with calling negative mass "just playing with math" is that it comes directly from the math whereas any attempts to challenge its existence come from inventing new maths derived from...ether, right? That is, the current most persistent mathematics of GR supports negative mass as an existing notion and most mathematics being developed to counter that existence are still working against the more proven models?

Anyways, as far as I know no one's actually performed any legit looking for it really have they? I mean, it's not like it would be something that you'd point Hubble at and go, "Gosh! There it is, the Negative Matter Dog Star!" And then, even if you were to observe it, doing something with engineering with it would be another thing entirely.

It's really too bad physics is at its coolest when it's not doing it's job and adequately explaining the universe :D

Oh yeah, and my physics fu is very weak. I'm just repeating arguments I've overheard and possibly misunderstood or represented. Present all the damning counterevidenciary formulas you want, and it won't make a dent in my thick undereducated skull. :cool:


And on topic: I'm a long time fan of Traveller, and a Bujold fanatic. I like jump drives and jump points. No matter how unscientific they may be, they're excellent means for plot device and motion.
 

I guess I have been lucky. In my twenty years of playing or GMing Traveller (sporadically) I have never sat at a table with anyone who cared if the science behind the concepts was valid. We just played an imaginary game and had fun.

I do have to say the geek in me has found this thread interesting though. BTW, about 4 years ago Scientific American reported how oranges and apples may be successfully teleported (they were teleported successfully, they just did not arrive in a recognizable form, applesauce was close) once they figure out how to account for the atmosphere surrounding the objects to be teleported within the teleportation chamber.

I also recommend subscribing to this magazine if you run a science based game. It even helped me tremendously with GMing Deckers in Shadowrun with articles on hacking systems and building firewalls. It often touches on the possibilities of genetics and cybernetics, which helps with games using those ideas.

Plus it is just a good magazine. Just not as thoroughly peer reviewed as Science and other heavy hitters of the Scientific community. However, you can understand most of what they say in Scientific American.
 

Scientific American is a wonderful magazine. As for as being peer reviewed, it is not a journal. No one is going to put research in there. The purpose of this magazine is to be a newspaper for science. and it is one of the best out there. (although I think the technical level has gone down a bit. The math puzzles are wonderful.

Not sure if I believe you about this teleportation. There are experiments which "teleport" atoms using something called entangled states in quantum mechanics?

Sorry If I am highjacking this thread but I really think that one of my jobs as a physicist is to show that my subject is as cool as any science fiction idea (and often even weirder)
 

James Heard said:
I think the problem with calling negative mass "just playing with math" is that it comes directly from the math whereas any attempts to challenge its existence come from inventing new maths derived from...ether, right? That is, the current most persistent mathematics of GR supports negative mass as an existing notion and most mathematics being developed to counter that existence are still working against the more proven models?

Anyways, as far as I know no one's actually performed any legit looking for it really have they? I mean, it's not like it would be something that you'd point Hubble at and go, "Gosh! There it is, the Negative Matter Dog Star!" And then, even if you were to observe it, doing something with engineering with it would be another thing entirely.


What I mean by playing with math is just because something is a solution to an equation does not mean that nature has to obey it.

As far as the laws of nature are I dont think there is a reason why there are not green people, but I personally have never seen one (except once but I was very drunk) :p
 

Into the Woods

Remove ads

Top