Do MGT Traveller ships have anti-gravity for lift?

[AnotherDilbert]

My basic assumption was that we can choose the density of the hydrogen atmosphere by choosing the altitude at which we are skimming. 40 km/s is a rather absurd speed, but I hoped that by choosing a very low density we could still get a reasonable flow over the hull and into the scopes. Perhaps such a low density will yield insufficient fuel?

40 km/s may sound absurd, but it's about how fast the Galileo orbiter was going when it was deorbited into Jupiter's atmosphere (I think it was going more like 50 km/s actually). And that pretty much just 'fell in', it just picked up that speed from Jupiter's gravity as it dove in on its final orbit.

I meant that I agree that we are talking about that speeds that large and the drag would be rather high (the absurd part).

But with a very low atmospheric density the energy transfer would still be manageable?

An icy moon or asteroid is perhaps better, but probably takes more time?

"More time" is probably infinitely preferable over "very likely ship destruction" and "wrestling with a huge gravity well". And most gas giants have icy moons anyway. [/quote]Isn't is a bit early to talk about "most GGs"? We have only seen three with moons and all.

If it takes a few hours it's fast enough, if it takes a few days it's probably usable, but if it takes a few weeks too slow.

 

[fusor]

But with a very low atmospheric density the energy transfer would still be manageable?

It'd still cause drag. And even low atmospheric density can heat things up pretty drastically.

Isn't is a bit early to talk about "most GGs"? We have only seen three with moons and all.

Nope. We've seen four with moons. We've seen thousands more outside the solar system that could easily have moons (no reason to believe that they wouldn't exist outside the solar system). While the specifics of the gas giant's location would affect its evolution (whether it's in the inner system, outer system, migrated, too hot, cryogenically cold, etc), physically speaking a gas giant is a gas giant is a gas giant, no matter where you go, and if they're in the outer system then there's no reason to believe that they wouldn't have icy moons of their own.

 

[Reynard]

A few of us have given 'clear' answers based on what is known which, for Mongoose Traveller, is sketchy. HG2e states "Maneuver drives use gravitic technology that pushes the ship
through space – it is these that give a ship its Thrust score." Traveller2e Core is also sketchy with Spacecraft Operation - Landing (page143) "Ships have landing gear allowing them to touch down 'in the wild'...", "They can also land on bodies of water." Pretty much that's it. Lots of speculation if Mongoose 2e is your only source. I'm probably biased because I know the other editions and what they say. Gravitic could be production of gravitons pushing the ship along or 'grabbing' the ambient gravity in a star system. There is anti-grav technology acknowledged especially for vehicles, drones and certain equipment plus, of course, gravity plates and inertial compensators. If the gravitic M-drive is thrust only and no separate (or possibly integral) lifter system, wilderness landings would be problematic unless the quoted descriptors are actually hinting at VTOL landing.

Personally, Traveller ships are like so many popular science fiction vessels so they use AG systems as an extension of their gravitic drive for maneuvering and TOL. Better than describing the ship angles in and plows through the forest until coming to a rest.

 

[AnotherDilbert]

I fundamentally agree here. Which is why I started the thread in the first place.

This shown how difficult it is to discuss on a forum like this. To a large extent we have probably talked past each other.

I'm not dismissing you argument, but I place much greater emphasis on the rules, I think you place greater emphasis on the illustrations than I do.

I find an argument based on an "artists impression" made by an artist rather than an aerospace engineer to be rather flimsy. If we required all illustrations to be a perfect demonstration of the physics we would have rather few illustrations.

Effect of Gravity
When fighting in the presence of a significant gravity field that field acts as an additional “thrust” on the craft fighting within it.

MgT1 HG, p86. To me this is rather conclusive, because if the craft had anti-grav this would not happen.


Since we choose different basis to argue from, it's not very surprising that we come to different conclusions. If I haven't misunderstood you completely.

 

[AnotherDilbert]

It'd still cause drag. And even low atmospheric density can heat things up pretty drastically.

There must be some density between "interplanetary space" and 1 kPa where even a badly streamlined spaceship at that speed would heat up, but not melt?

Nope. We've seen four with moons. We've seen thousands more outside the solar system that could easily have moons (no reason to believe that they wouldn't exist outside the solar system).

Before we have studied a few dozen star systems in detail I'm hesitant to completely accept our current theories of the development of planetary systems.

 

[fusor]

Nope. We've seen four with moons. We've seen thousands more outside the solar system that could easily have moons (no reason to believe that they wouldn't exist outside the solar system).

Before we have studied a few dozen star systems in detail I'm hesitant to completely accept our current theories of the development of planetary systems.

Are you seriously arguing that we know nothing about how the universe works outside our own solar system? Do you honestly believe that we have to see things with our own eyes before we accept that they're real? Do you have any understanding of science at all? It's one thing to be skeptical (of course we don't know everything about how the universe works), but we know that the same things can happen out there that happen in our own system.

Why do you think that the processes would be so different as to not allow moons to be created in the next star system over? Sure, things can happen to strip moons from their primaries or destroy them after they form, but in most cases there will be moons in other systems. They're as natural a side-effect of planet formation as planets are from star formation - and we know that a lot of stars have planets. We've seen systems very different from our own and also very similar. The laws of physics are the same in all of them. (and don't trot out the 'we didn't know about hot jupiters' argument. We did. They were theorised many years before they were first discovered. It didn't "totally throw out our theories of planet formation", it just meant that they could be adjusted).

You're basically suggesting the same thing as "we know that gas and dust can accumulate into boulders and then into moons and planets and stars in our system, but we don't know that happens anywhere else". Yes, we do. We know because we see stars and planets out there. And there's no reason to think that moons or anything else can't exist.

 

[AnotherDilbert]

Nope. We've seen four with moons. We've seen thousands more outside the solar system that could easily have moons (no reason to believe that they wouldn't exist outside the solar system).

Before we have studied a few dozen star systems in detail I'm hesitant to completely accept our current theories of the development of planetary systems.

Are you seriously arguing that we know nothing about how the universe works outside our own solar system? Do you honestly believe that we have to see things with our own eyes before we accept that they're real? Do you have any understanding of science at all?

I'm seriously arguing that we don't know EVERYTHING about how planetary systems in general evolve.
I will not completely accept any theory that is not tested on any data other than the calibration data.

 

[fusor]

I'm seriously arguing that we don't know EVERYTHING about how planetary systems in general evolve.

Sure. But to claim that means that we have no reason to believe that moons exist outside our own solar system is just ridiculous.

 

[-Daniel-]

ok so the conversation has left the topic, I am cool with that, but did we get a final answer from Mongoose on the question or are we leaving it to each GM and their game to do what they want?

 

[AnotherDilbert]

ok so the conversation has left the topic, I am cool with that, but did we get a final answer from Mongoose on the question or are we leaving it to each GM and their game to do what they want?

No clear answer in MgT2, or directly from Mongoose.
Every Referee is always free to do everything as he pleases?

 

[-Daniel-]

ok so the conversation has left the topic, I am cool with that, but did we get a final answer from Mongoose on the question or are we leaving it to each GM and their game to do what they want?

No clear answer in MgT2, or directly from Mongoose.

Too bad, I like clear answers. Oh well, back to the moon conversation then. :mrgreen:

 

[fusor]

ok so the conversation has left the topic, I am cool with that, but did we get a final answer from Mongoose on the question or are we leaving it to each GM and their game to do what they want?

I don't think we've had a final answer from Mongoose about anything raised on these boards so far because of HG 2e. So I wouldn't hold your breath waiting.

 

[-Daniel-]

ok so the conversation has left the topic, I am cool with that, but did we get a final answer from Mongoose on the question or are we leaving it to each GM and their game to do what they want?

I don't think we've had a final answer from Mongoose about anything raised on these boards so far because of HG 2e. So I wouldn't hold your breath waiting.

To be fair, there is one in the "High Guard is Here! " thread right now. :wink:

But I get the feeling that if Matt were going to way in on this one, he would have done so by now. :mrgreen:

 

[AnotherDilbert]

Sure. But to claim that means that we have no reason to believe that moons exist outside our own solar system is just ridiculous.

I'm not questioning the potential existence of extra-solar planets or moons.

And most gas giants have icy moons anyway.

That is a specific claim that I question is conclusively proved.

 

[AnotherDilbert]

Haven't we all got trapped in:

 

[-Daniel-]

Haven't we all got trapped in:

LOL, I have that cartoon up on my board to remind me that I am not the Internet Police. It is not my job to correct all of their errors. I did so because I have been known to get trapped in that mode and in each case all it did for me was made me look dumb. :mrgreen:

 

[fusor]

That is a specific claim that I question is conclusively proved.

So cite a reason why you have a doubt about it. We have absolutely zero reason to doubt that moons exist outside our solar system. We know that stars and planets exist out there and they formed exactly the same way our own system did (and we know the planets are there, they're not "potential"). Why do you think the formation process magically stops at moons?

And more to the point, what do you even know about how stars, planets, and moons form in the first place, if anything, for you to have such doubts about their existence or the veracity of the data that we have on them?

 

[fusor]

LOL, I have that cartoon up on my board to remind me that I am not the Internet Police. It is not my job to correct all of their errors. I did so because I have been known to get trapped in that mode and in each case all it did for me was made me look dumb. :mrgreen:

But it'd still be so much better if people stopped making stupid, ill-informed, and/or ignorant statements.

 

[phavoc]

ok so the conversation has left the topic, I am cool with that, but did we get a final answer from Mongoose on the question or are we leaving it to each GM and their game to do what they want?

Conversations ALWAYS leave the topic... it's the internet!

But yeah, that's the way it's looking.

Which for me at least is kind of frustrating. I like open systems, but there's a limit to how much loosey-goosey you should expect. The whole point in purchasing a set of rules is to have a pre-defined universe to game in. If all you are getting is guidelines then at what point do you draw a line? I don't believe in the idea of gaming systems ruled by fiat by a referee for everything. BOTH the player and the ref need to have a good understanding of how things work. The ref so he can design the scenarios and populate the universe, and the player so he knows what he can reasonably do.

It's like if you had a game and the idea of a gravitational constant wasn't defined. Sure, you could have gravity sometimes here, or sometimes there. Or sometimes it's 2X and other times it's .2X. And all in the same room... It doesn't work very well for anyone. Hence you have a defined rule about gravity - at least IN the room. IF they can figure how to open the door, well, that's a whole other room to define.

 

[AnotherDilbert]

That is a specific claim that I question is conclusively proved.

So cite a reason why you have a doubt about it.

What reason would I have for believing in a hypothesis that cannot (with current technology) be tested?

Again, I do not doubt the existence of planets.

I doubt that more than 50% of all GGs within 500 Pc from Sol have at least one moon with large masses of easily accessible water or water ice that can be mined for hydrogen. How do you suggest that we test that hypothesis (with current technology)?