Why hydrogen?
- Thread starter Klaus Kipling
- Start date
far-trader
Mongoose
EDG said:
Both why as fuel and why as bubble actually, the way I read it.
far-trader said:
Well fuel is obvious - you need hydrogen for the fusion reactors. There's arguments for other hydrogen-containing compounds (e.g. methane, ammonia, some kind of wacky clathrate, etc) having greater hydrogen density per cubic metre.
But I thought he was more specifically asking about why it's used in the jump bubble.
(one possible reason is the Lanthanum jump grid - it turns out Lanthanum can actually retain hydrogen in its lattice structure, like Palladium can - so you can charge up the grid with hydrogen, and then you can do some jiggerypokery (run a current through it?) to it to release it all to make the jump bubble. But I don't think anyone knew about that property in 1977, so I think it's coincidental that this metal was the one that happened to be used here).
Supergamera
Mongoose
Why use H2 as fuel?
The game reason - it limits the ranges of ships but doesn't tie them to an actual fuel facility, gives an advantage to non-jump ships in battle, and makes Gas Giants places where things happen.
H2 vs Antimatter - Fusion was going to be The Next Big Thing, but still seems as far away today as it was in the 70's. An open market in Antimatter fuel just seems to be asking for trouble, but in a galaxy with relativistic drives maybe it would seem perfectly reasonable.
H2 as J-Drive Feed - the "bubble" formed during Jump requires an actual mass for it to be created; this is implied here and there in canon, and I think the MGT book may state this outright. Maybe the opening to J-Space, prior to actual Jump, is not much larger than a proton, and hydrogen is the only material that can fit through the opening.
Although jumps without mass feed appear in a couple in places in canon (Annic Nova and HG), they seem to have been retconned as generally a Very Bad Thing.
The game reason - it limits the ranges of ships but doesn't tie them to an actual fuel facility, gives an advantage to non-jump ships in battle, and makes Gas Giants places where things happen.
H2 vs Antimatter - Fusion was going to be The Next Big Thing, but still seems as far away today as it was in the 70's. An open market in Antimatter fuel just seems to be asking for trouble, but in a galaxy with relativistic drives maybe it would seem perfectly reasonable.
H2 as J-Drive Feed - the "bubble" formed during Jump requires an actual mass for it to be created; this is implied here and there in canon, and I think the MGT book may state this outright. Maybe the opening to J-Space, prior to actual Jump, is not much larger than a proton, and hydrogen is the only material that can fit through the opening.
Although jumps without mass feed appear in a couple in places in canon (Annic Nova and HG), they seem to have been retconned as generally a Very Bad Thing.
Rikki Tikki Traveller
Cosmic Mongoose
The Jump Bubble is what keeps your ship safe while in that special pocket universe called Hyperspace.
No Jump Bubble and your ship's hull is exposed to Hyperspace and it is destroyed.
No Jump Bubble and your ship's hull is exposed to Hyperspace and it is destroyed.
Klaus Kipling
Mongoose
It just struck me as potentially telling that h2 was the basis of the dTon, and that vast amounts of it were required for the jump drive. This implies that hydrogen is necessary for the jump drive, as other elements have been posited for use as fusion fuel in a power plant. There is also the fact that unrefined fuel can cause misjumps, implying that if anything other than hydrogen gets in the jump bubble then it causes problems.
I was just speculating what other special properties hydrogen might have beyond its use as fuel.
It would make sense for most starship power plants to use h2 for fusion if it already has to carry loads of h2 for forming the jump bubble. There might actually be more practical forms of fusion fuel, given the difficulties of storing h2, and if another element could be used to create a jump bubble then it may be more practical to use that.
The clincher for me is that all ships are expressed in dTons of liquid hydrogen, implying that it is absolutely crucial for jump drives. However, it surely has to do more than just inflate?
I was just speculating what other special properties hydrogen might have beyond its use as fuel.
It would make sense for most starship power plants to use h2 for fusion if it already has to carry loads of h2 for forming the jump bubble. There might actually be more practical forms of fusion fuel, given the difficulties of storing h2, and if another element could be used to create a jump bubble then it may be more practical to use that.
The clincher for me is that all ships are expressed in dTons of liquid hydrogen, implying that it is absolutely crucial for jump drives. However, it surely has to do more than just inflate?
far-trader
Mongoose
Well, I think Hydrogen makes for a good plasma, so maybe that's what actually keeps jump-space at bay.
Ok misunderstanding, it's mostly used to inflate the jump bubble, not to generate power, so it's 'fuel' in the sense that it's used up, but not burned to generate power so I suppose not really 'fuel' as such. In any case, hydrogen for power plant fuel would have to be deuterium or tritium, not just any old hydrogen.
My point still holds though, you claim that water isn't viable because most planets don't have any, actually most of them do in the form of ice but how many have free unbound hydrogen knocking about though? Apart from gas giant skimming, cracking water is pretty much the only viable way to get Hydrogen in the rest of our solar system.
I'm guessing the reason hydrogen is used is that you need a plasma to inflate the jump bubble. Hydrogen becomes a plasma much more easily than any other element - it requires a lot less heat and so is less of a threat to the hull than anything else would be.
Simon Hibbs
My point still holds though, you claim that water isn't viable because most planets don't have any, actually most of them do in the form of ice but how many have free unbound hydrogen knocking about though? Apart from gas giant skimming, cracking water is pretty much the only viable way to get Hydrogen in the rest of our solar system.
I'm guessing the reason hydrogen is used is that you need a plasma to inflate the jump bubble. Hydrogen becomes a plasma much more easily than any other element - it requires a lot less heat and so is less of a threat to the hull than anything else would be.
Simon Hibbs
Rikki Tikki Traveller said:
So the reason that Hydrogen is used is because it is a commonly available material which can be stored in at least a reasonably stable and compact form, released in the timescales required for the transition into jump and, most importantly is not annihilated by contact with J-space.
We can probably speculate as to what it is about hydrogen that gives it that last, vital quality. Perhaps it's its low boiling point: other gases would liquefy and collapse the bubble. Perhaps it's its density: J-Space ignores light stuff.
That it's the gas which forms the bubble implies that the bubble might be spherical, though ISTR some discussion about the gas "clinging" to the ship, so it forms a layer around the ship a couple of metre thick, rather than a void in J-space at the centre of which the ship sits. There's no reason for gases to behave like Boyle predicted, after all.
Rikki Tikki Traveller
Cosmic Mongoose
Oh no, I figure H2 is annihilated by Jumpspace. But, if you make a big enough bubble, it takes a while, so you can protect your ship during transit. If the hull was exposed directly to Jump Space, then it would deteriorate and hull breaches are no fun in space and less fun in Jump Space.
Just my thoughts of course.
Just my thoughts of course.
Rikki Tikki Traveller said:
I'm thinking that there's a statement in the Player's Guide PDF that if you go outside in J-space you're dead. rrNProc expunge dead no save no fate point. Dead. That seems like a fairly sudden thing to me. the hydrogen 'bubble' must be a bit more durable for some reason (I like the "plasma" idea) even if the crystaliron hulls might survive such destructive wear and tear for a whole week.
It might even be that the hydrogen plasma skin has to be constantly replenished over the course of the week in J-space, though that would start to make the concept of storing the hydrogen in a more compact form than L-hyd more attractive, since you have the time to crack it out of whatever you're storing it as.
far-trader
Mongoose
Shiloh said:
It would also invalidate drop tank usage. No idea if drop tanks are in the basic rules but they will (or should) be in the coming High Guard.
It can't just be a skin of hydrogen though. Presumably there's some kind of pressure pushing it outwards, to counter whatever jumpspace is made of trying to push its way in to contact the ship?
Seems to me that there's a volume of hydrogen around the ship, not just the skin of a bubble.
Seems to me that there's a volume of hydrogen around the ship, not just the skin of a bubble.
EDG said:
Sorry, my lack of clarity. I was referring to the idea that there's a "coating" of hydrogen (or its plasma or whatever) that mostly follows the contours of the hull, rather than there being a "balloon" of hydrogen pushing out equally in a sphere.
I don't think it's valid to assume that J-space is "made" of anything, or that it exerts any mechanical forces... Could just be the Lanthanum grid keeping the plasma in place, and the plasma supporting some kind of energy field that's the real protection.
Perhaps you could think of the hydrogen-plasma sheath as a bit like the shockwave that mostly protects the Shuttle's refractory tiles on re-entry.
Maybe the immediate death upon exposure to J-space is actually death from superheated hydrogen plasma...
Hi all,
I just looked this thread over and have a few thoughs as a "johnny come lately"
1: volume of water vs h2..
I find the entire discussion of this facet very "one item in a vaccume"
You must remember that it is not "just" fuel storage... If you store h2 in water(or other mediums) you have to strip out the h2 before you can use it. So you have to enlarge your engineering section with hardware to accomplish that task and..
Soon you end up with much more metal than you need to build a loss triple(or more) the savings you gained in storing water vs h2.
from Classic (LBB) Traveller, jump has always been represented as ripping open the fabric of normal space and tumbling into jump space with the jump field creating a "bubble" of normal space around the ship. In more than one published reference(which I would provide except that I am far away from my documents at this time) there is enough space between the ship's hull and the edge of the bubble for crew in vacc suits to work outside the ship. The major hazard with this is accidentally coming in contact with jump space by slipping/falling/tumbling into and through the bubble. This leads to Jump Madness and has not been cured or amealiorated so far.
Marc
I just looked this thread over and have a few thoughs as a "johnny come lately"
1: volume of water vs h2..
I find the entire discussion of this facet very "one item in a vaccume"
You must remember that it is not "just" fuel storage... If you store h2 in water(or other mediums) you have to strip out the h2 before you can use it. So you have to enlarge your engineering section with hardware to accomplish that task and..
Soon you end up with much more metal than you need to build a loss triple(or more) the savings you gained in storing water vs h2.
from Classic (LBB) Traveller, jump has always been represented as ripping open the fabric of normal space and tumbling into jump space with the jump field creating a "bubble" of normal space around the ship. In more than one published reference(which I would provide except that I am far away from my documents at this time) there is enough space between the ship's hull and the edge of the bubble for crew in vacc suits to work outside the ship. The major hazard with this is accidentally coming in contact with jump space by slipping/falling/tumbling into and through the bubble. This leads to Jump Madness and has not been cured or amealiorated so far.
Marc
Rikki Tikki Traveller
Cosmic Mongoose
The description in Mongooses CRB is a bit different. Now Jump Space is more like a pocket of hyperspace and there is no mention of enough area around the ship for a person (not that it isn't there, but we cannot assume that it is there in the new rules). HG will hopefully clarify this issue too.
Understood about the "pocket"
However, the points on not being forced to to install a fuel puriification plant on even the smallest ship in order to tank water instead of H2 is still valid as is the additional point that doing so would require something that LBB ignored...Energy loss.
It takes energy to crack both ammonia and water to get at the stored H2 and that energy is a loss.
There are additional reasons for H2 over other "storage mediums" that go back to the 26 file cabinet days before the go was given to Traveller at GDW..
But these are good enough for me as far as this forum goes
Marc
However, the points on not being forced to to install a fuel puriification plant on even the smallest ship in order to tank water instead of H2 is still valid as is the additional point that doing so would require something that LBB ignored...Energy loss.
It takes energy to crack both ammonia and water to get at the stored H2 and that energy is a loss.
There are additional reasons for H2 over other "storage mediums" that go back to the 26 file cabinet days before the go was given to Traveller at GDW..
But these are good enough for me as far as this forum goes
Marc
Klaus Kipling
Mongoose
simonh said:
Sorry to back track a little, but this point implies something quite interesting.
That J-fuel is regular, run of the mill H2, and P-fuel is deuterium or tritium. Therefore, starships might need 2 different types of fuel. I know it is probably simpler just to lump it together, but this opens up some interesting possibilities.
'Regular' hydrogen is easier to find and skim than the other isotopes, so a ship with fuel scoops and maybe purification, it can jump to it's hearts content, but the P-plant needs more specialist fuel that is much harder to find in the wild so the ship has to return to a civilised port to refuel this reliably.
For most vessels this won't matter, as they'll jump from port to port, but it makes exploring more interesting, and makes the giant fuel tanks in the new scout make more sense.
Rikki Tikki Traveller
Cosmic Mongoose
I always considered that the Purification Plant did that for you as part of "refining" the fuel.
IMHO:
Refined fuel has a higher concentration of Deuterium and Tritium, as well as all impurities removed, allowing it to be used in the PP (and Jump Engines).
Unrefined fuel is "raw" hydrogen, without enrichment that can cause problems with the PP. This in turn causes a slight increase in the chance of a mis-jump. Irregardless of a H2 bubble or not, there is certainly SOME power pulse required to open the hole to Jump Space. Any hickups in the PP at that time is why the mis-jump chance increases.
IMTU:
If you use water/ammonia or anything else, it must be run through the Purification Plant ONCE to remove the impurities and AGAIN to "refine" it for use by the PP (and Jump Drive).
Standard wilderness refueling procedures IMTU have you run the hoses from the GG/lake/ice sheet through the Purification Plant and then into the fuel tanks. At that time it is unrefined fuel. THEN, after you take off if desired, it is run through the Purification Plant AGAIN to "refine" it.
That is why all of the ship designs have Purification Plants. Can't do wilderness refueling without it.
For Non-Jump ships, the "hickups" in the PP are not as big a deal, but it adds to your annual maintenance costs as all the lines and nozzles and stuff have to cleaned out; similar to a car running on bad gas, it needs to be cleaned out more often.
IMHO:
Refined fuel has a higher concentration of Deuterium and Tritium, as well as all impurities removed, allowing it to be used in the PP (and Jump Engines).
Unrefined fuel is "raw" hydrogen, without enrichment that can cause problems with the PP. This in turn causes a slight increase in the chance of a mis-jump. Irregardless of a H2 bubble or not, there is certainly SOME power pulse required to open the hole to Jump Space. Any hickups in the PP at that time is why the mis-jump chance increases.
IMTU:
If you use water/ammonia or anything else, it must be run through the Purification Plant ONCE to remove the impurities and AGAIN to "refine" it for use by the PP (and Jump Drive).
Standard wilderness refueling procedures IMTU have you run the hoses from the GG/lake/ice sheet through the Purification Plant and then into the fuel tanks. At that time it is unrefined fuel. THEN, after you take off if desired, it is run through the Purification Plant AGAIN to "refine" it.
That is why all of the ship designs have Purification Plants. Can't do wilderness refueling without it.
For Non-Jump ships, the "hickups" in the PP are not as big a deal, but it adds to your annual maintenance costs as all the lines and nozzles and stuff have to cleaned out; similar to a car running on bad gas, it needs to be cleaned out more often.
