AnotherDilbert
Emperor Mongoose
Except that you will not be getting that very often, since it's much more profitable for freighters to have purifiers onboard and buy unrefined.PsiTraveller said:
Setting up a skimming operation in a system
- Thread starter PsiTraveller
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AnotherDilbert
Emperor Mongoose
Skimming at a distant gas giant and selling at the starport is generally quite an expensive operation in my experience, because of the distances involved. Note that it can easily take a week for a low acceleration craft to get to the starport.
Skimming a local ocean is much cheaper, if allowed.
Edit:
I once made an attempt at estimating the cost of skimming: http://forum.mongoosepublishing.com/viewtopic.php?p=899759#p899759
Skimming a local ocean is much cheaper, if allowed.
Edit:
I once made an attempt at estimating the cost of skimming: http://forum.mongoosepublishing.com/viewtopic.php?p=899759#p899759
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Anonymous
Guest
AnotherDilbert said:
Atlas notes they export food, import tech to maintain space-tech, resident humans considered honorable by Aslan, and 1/3 pop Hkaaiheir.
I think it's a mix of imported SDBs and the Aslan not harrassing them. Or maybe there's an Aslan cruiser in the system, but that's pretty rare.
edit: I actually don't understand this world. How is it "non-aligned"? I bet the census is out of date and when I get there it'll be an Aslan restaurant, or a client state.
PsiTraveller
Cosmic Mongoose
Well I like the J3 route of Tyohk or Vorito, Byrni, Tech-World, Acrid as having the best starports along the route if you are heading towards Fist at J3, coming in that way from the Imperium.
Byrni is also the closest to the 90 Billion people market of Browne and a jumping off point for any expeditions that way as well. So justifying an economic interest in Byrni is easy. Cheaper ships will buy unrefined, which the drones could collect as well. Risking someone elses drones and not having to make a piloting roll in a gas giant is an option for smaller ships as well.
Byrni is also the closest to the 90 Billion people market of Browne and a jumping off point for any expeditions that way as well. So justifying an economic interest in Byrni is easy. Cheaper ships will buy unrefined, which the drones could collect as well. Risking someone elses drones and not having to make a piloting roll in a gas giant is an option for smaller ships as well.
AnotherDilbert said:
I had forgotten that thread. In hindsight I should have said that it would be much cheaper to build a pipeline.
You have to wonder if a planet would allow wholesale reduction of its water sources on a large-scale basis. For a world-spanning ocean it isn't a lot, but we also have to remember that this water is leaving the biosphere permanently. Over time it will have an impact - even with the normal amount of loss a planet experiences. Frontier worlds won't have an issue, but older more populated and busy ones would.
Anyone want to do the math on how much water Sylea would have lost over say 10 centuries of trade? Would it really be that much?
AnotherDilbert
Emperor Mongoose
How about Terra:phavoc said:
http://www.travellerrpg.com/CotI/Di...539255&highlight=current+sea+level#post539255AnotherDilbert said:
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Anonymous
Guest
AnotherDilbert said:
They fuse regular hydrogen? it doesn't require deuterium or tritium?
AnotherDilbert
Emperor Mongoose
That is, as far as I know, undefined.Moppy said:
Given that we can skim any old H source, and that refined fuel is just as big as unrefined fuel, it is generally assumed, at least by me, that "fuel" is all H isotopes mixed as usual.
It is quite possible that we only burn ²H and ³H, and use the rest as coolant. We do know that Traveller spacecraft fusion power plants use huge amounts of fuel for the energy produced.
AnotherDilbert said:
That's because of melting ice caps. At some point they will freeze again and the water will withdraw. Yes, I understand that it takes time, but some planets may actually look in to the future and decide that it's better to no use a resource up like that. Humans do, on occassion, think to the future. The Great Lakes in the US have water restrictions on them due to overuse. Too much water is flowing out or being used by the surrounding states, so they created a compact to change things up and each state is restricted on how much water they may draw.
Jupiter is probably not a good example to cite. it's more than 1300 times the size of earth. But I see your point - it would take some time. But if you think about it in centuries, it's actually quite a bit and could have ramifications that are serious. I just think long term well-settled planets would start placing restrictions, especially if their hydrography was more limited than Earth. A planet with far shallower seas would feel the effect earlier than Earth would.
AnotherDilbert
Emperor Mongoose
Not as far as I know. The Arctic polar cap does not matter since it is already floating in the sea. The permanent massive ice caps on land is basically Antartica and Greenland and they are not melting appreciably as far as can be measured.phavoc said:
Current sea level change, which is quite small, has probably been constant for at least a century. As to why, I don't think anyone has a good grip of the complex processes running the oceans and atmosphere.
Jupiter is an example of a gas giant with, for human purposes, functionally infinite supply of hydrogen.phavoc said:
If you don't like the last calculation, how about this:
AnotherDilbert said:
The top mm of ocean contains tens of billions of Dt of water. It will take skimming trillions of Dt for anyone to notice...
DickTurpin
Banded Mongoose
AnotherDilbert said:
True, but. . .
AnotherDilbert said:
Quite wrong, in spite of what certain ill-informed nation leaders might say: https://www.factcheck.org/2018/01/ice-caps-record-low-not-high/
AnotherDilbert said:
You may want to go back and look at the science books. Remember the ice age that got mentioned? And the fact that seas covered far more of the planet than they used to? Planetary environments can change over time due to many things.
AnotherDilbert said:
A valid point. But the discussion was based upon planetary water being used, not the near infinite supply gas giants would offer. There's no argument there.
AnotherDilbert said:
I will take your math as correct. Though I don't agree that nobody would ever notice. For a planet with 70% hydrography yeah, you may be right. At least for the oceans. Though I will tell you that people do notice a change in the Aral sea. Water was diverted upstream and it has essentially dried up. Now, for the sake of the discussion, if the major starport for a planet happened to be on a large body of water like the Aral sea, it would be no big deal. But over a large period of time skimming the water there would have an impact. Using all water sources your point stands for any planet with a large hydrographic percentage. But local conditions, or say shallow seas that weren't recharged through a lot of rainfall or river flow, then that water use would make a difference.
Aside from that we've already got documented lowering of other bodies of water due to changes in weather conditions and usage by people. The point is sustainability. And I'm sure some planets will have Green or environmentalist parties that may say nyet to local water being used for fuel, hence the need to replace it with fuel from a gas giant (where the supplies are essentially unlimited).
Condottiere
Emperor Mongoose
Asteroid ice mining becomes viable.
At some point, colonists are going to run out of water on the Moon and Mars.
At some point, colonists are going to run out of water on the Moon and Mars.
AnotherDilbert
Emperor Mongoose
Melting ice caps would certainly affect sea levels, and if we want to change sea levels by many metres that would have to be the primary cause. But a change of a few mm can have many causes, as far as I know. E.g. thermal expansion of the water mass.phavoc said:
The change in the Aral sea is slightly more than a millimetre or two, I believe in the range of tens of metres.phavoc said:
AnotherDilbert said:
Yes. Both points I made go back to the original point - that some places will prohibit local fuel skimming while others won't. and for those that won't allow for it you have to find alternate fuel sources. In this case a local gas giant. Though if a system is lacking in water and gas giants then you'd have to hope for ice.
AnotherDilbert
Emperor Mongoose
Yes, as I said the ice caps are not melting appreciably. Note that the estimated melting rates are not much bigger than the estimated error-bars. Its easy to throw around numbers gigatonnes of ice, but that is a still a very small fraction of existing ice.DickTurpin said:
If we take another random estimate (with more visible error bars):
leading to a sea level change of a few mm over a period of decades:
Source:
http://www.antarcticglaciers.org/2018/06/mass-balance-antarctic-ice-sheet-1992-2017/
I have no idea who they are or how accurate their quoted science is. The link was more or less randomly chosen by Duckduckgo.
Another paper by Nasa claims that Antarctica is gaining ice:
https://www.nasa.gov/feature/goddar...ns-of-antarctic-ice-sheet-greater-than-losses
I believe the point here is that different teams of scientists come up with different estimates, all with fairly large error-bars. To claim certainty, or that one team is correct and the other teams are all incorrect, is rather difficult.
It does show that the naked numbers provided by factcheck.org was used misleadingly to create the impression that the ice caps are melting quickly, which they are not. What they failed to mention is that the Antarctic ice cap is in the region of 26500 trillion tonnes of ice, a few billion tonnes here and there is just a rounding error.
AnotherDilbert
Emperor Mongoose
Oh, yes, I will certainly not claim that politics are always rational.phavoc said:
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Anonymous
Guest
AnotherDilbert said:
That's not true, because much of that artic ice is freshwater (from the sky, to the land, to ice, to breaking and floating off) and therefore there's a density difference.
When freshwater ice melts in salt water, the water level will rise.
AnotherDilbert
Emperor Mongoose
No, one tonne of ice displaces exactly one tonne of water. Since ice as you say has lower density it will float and the rest will stick out of the water.Moppy said:
When the ice melts one tonne of ice turns into one tonne of seawater and the sea level is unchanged.
OK, I can agree that salinity changes can minutely change the density of the seawater, so can theoretically change sea levels a tiny amount, but that is practically close to zero.
