Detecting Weapons' Fire

[Galadrion]

lolz. Fair enough.

Isn't that kind of the opposite of what "or" means?

That depends on which case of "or" you are using: "exclusive or" ("one - and only one - out of this list") or "Inclusive or" ("at least one of this list of options applies"). Same word, but different logical operations.

 

[swordtart]

Which broadcast your location.

You can make them directional and hope there are no sensors in that direction.

Because you are using the environment as a heat sink, in space that is not possible.

The heat has to go somewhere, and 2% of a terra watt is pretty easy to detect.

Again you are hoping that the system does not have sensors throughout the system, which is unlikely by the 57th century

In which case it radiates the heat.

The parabolic reflector gets hot, so radiates heat.

Ever put your hand round the back of a fridge? The heat has to go somewhere. Your are missing the fact that your ship is a closed system.

All of which requires significat mass of the ship given over to whatever internal heat sink you use, eventually your ship melts or you have to eject the heat sink or radiate the heat to space.

Reflecting heat will heat up the reflector, phase changes involve heat transfer, cooling the reflector means you are ejecting hot hydrogen into space, you can't transfer heat from cold to hot.

That is possible, but in the 57th century every system with a starport will have system wide sensors.

Agreed.

it is not a single degree, space is ~3K a ship is ~300K.

Until MgT defines its EP I have no idea, but previous editions had numbers, and then there is the conversion of power plant energy to kinetic energy of the shi...

Even if it does what happens to the heat generated after jump emergence?


Room temperature superconductors are akin to perpetual motion , unlikely to be physically possible, as to running circuits close to the hull to reduce theri temperature - where does the waste heat from the circuit go? It is radiated into space and you are a beacon again

How much ice does a Traveller starship carry as a heat sink? heat sinks are physically possible, but they will take up a significant amount of payload.

That is edition specific.

It isn't. Unless your crew enjoys an ambient temperature of 3K.

Traveller ships are not built with these mechanisms in mind, they could be but the deckplans of the type A would have to change

Regardless, in the 57th century I expect a network of sensors throughout any system with an Imperial starport.

Easily detectable - check the signal strength from Voyager.

Using CT numbers 1EP is 250MW, I have yet to see a MgT definition.

See previous answer. 250MJ per second.

it is a 300K object against a 3K background...

The laws of thermodynamics are yet to be challenged (successfully)

We have no idea of how much fusion fuel is being used in a free trader, the mechanisms we know are not modeled in Traveller.

If you are going to take every statement I make out of context and agree in one place but then ignore that in the next line of your argument then there is no point discussing it further. I did begin to , but frankly it is pointless.

This reminds me of a conversation once I had with a CT traveller player back in the 80's who used to bang on about how he had calculated that the gauss rifle had a recoil force of 20 tons and would kill you if you fired it. We pointed out that surely couldn't be true, but he trotted out his maths... supersonic projectile... 4mm calibre... probable length... material... density etc... equal and opposite reaction etc. and everyone agreed that it must be right. I pointed out that a conventional rifle had a much heavier bullet that also travelled supersonically but didn't kill you when you fired it. His argument was detailed and persuasive, but he failed to reference it to real life experience. That isn't you is it Steve?

You clearly have fixed ideas on how the game universe should work. I don't agree with your assumptions and I think you are misrepresenting my argument in order to dismantle it word by word rather than consider it holistically.

I specifically disagree with your assumptions about the ubiquity of sensors. We were talking about a shop detecting another ship, not system wide sensor network. Sensor networks also have issues with communications speeds which make them useless for detecting where a ship is now (vs there might have been one there n minutes ago). Space combat takes place at speeds that makes your position only 6 minutes ago a historic artifact, not useful targeting information so relayed sensor information is not going to help you.

I also disagree with your assertion regarding the thermal energy generated by space ships as they are not compatible with the fuel available, nor are they compatible with lived experience. We have had manned space flight for decades and astronauts are not routinely cooked during even long term missions. It is therefore not a given that they need to be in the future.

Voyager is not detectable thermally according to my information (even by the James Webb telescope). It is actively beaming signals to us so detecting it is less challenging but that is also using radio waves not IR.

With respect to thermal separation, Thermos flasks enable you to hold hot liquid without burning your hands. You only need a few mm of vacuum to drop 100 degrees. Dewar flasks hold liquid gases with far greater temperature differentials quite happily for extended periods. We don't need to alter ship deck plans to accommodate this as the tonnage doesn't include the hull itself unless you fit special options. Any default cooling and thermal interfacing could be in all the grey (or brown) bits round the outside of the bits we actually bother to map.

You keep mentioning the "laws of thermodynamics" but never actually state what laws you say I am breaking. I suspect that is because nothing I said is breaking them. They are quite simple and easy to navigate but also apply to ideal systems in thermal equilibrium. No engineering solution has ever been an ideal system as they are not in thermal equilibrium and you need to consider time (rather than just the start and end state).

CT had some yampy numbers but as is was a 1970's game based on 1950's science fiction filled with space magic* written by someone who was not necessarily up with current physics theory, we can forgive it for being a bit off on the science. Most of us who played it in the 80s were not physicists either (and those that were up to date on the latest physics theories were still thinking in 1980's physics) and we didn't have the internet to find facts and counter opinions instantaneously. We do not need to perpetuate Olde Lore into new editions (or we may as well just play the old versions) especially as Olde Lore changed between edition.

I am happy with my arguments and conclusions. I'd like there to be more data but there isn't. I'll leave them here for the consideration of the wider community.

*Gravitics adds a massive dose of "dunno" and could be used to solve almost any problem including deflecting IR (and even potentially pushing heat up hill).

 

[Sigtrygg]

If you are going to take every statement I make out of context and agree in one place but then ignore that in the next line of your argument then there is no point discussing it further. I did begin to , but frankly it is pointless.

I am sorry you feel that way, it is not my intent to cause you upset. When presented with a wall of text I read it through then reply point by point, that way the context is preserved. The accusation it is out of context is difficult for me to parse since I am replying as you make your points.

This reminds me of a conversation once I had with a CT traveller player back in the 80's who used to bang on about how he had calculated that the gauss rifle had a recoil force of 20 tons and would kill you if you fired it. We pointed out that surely couldn't be true, but he trotted out his maths... supersonic projectile... 4mm calibre... probable length... material... density etc... equal and opposite reaction etc. and everyone agreed that it must be right. I pointed out that a conventional rifle had a much heavier bullet that also travelled supersonically but didn't kill you when you fired it. His argument was detailed and persuasive, but he failed to reference it to real life experience. That isn't you is it Steve?

A fascinating anecdote. Simple momentum or kinetic energy calculation would prove Steve wrong. And Newton's third law.

You clearly have fixed ideas on how the game universe should work.

Not at all, I run games in many different settings with some different technologies, but I do consider the Third Imperium universe to follow the laws of thermodynamics, with the caveat that there has to be magic space technology to deal with the waste heat.

I don't agree with your assumptions and I think you are misrepresenting my argument in order to dismantle it word by word rather than consider it holistically.

You don't agree with the laws of thermodynamics? Again I reply point by point so that there can be no ambiguity.

I specifically disagree with your assumptions about the ubiquity of sensors.

So in a thousand year old empire with trivial space travel you don't think there will be sensors out at the jump boundary and beyond to monitor shipping?

We were talking about a shop detecting another ship, not system wide sensor network.

Which is where I agree with you in part. It would be possible to have directional radiators up to a point (although I have read articels by others that dismiss such ideas) that a target vessel that is in front of you would have a hard time detecting, but how do you know which way to point your ship if you don't know where the enemy is either? Traveller ships don't even have radiators - hence my adoption of a magic gravitcs based heat sink.

Sensor networks also have issues with communications speeds which make them useless for detecting where a ship is now (vs there might have been one there n minutes ago).

The closest sensor picks up the ship, it transmits that data to the network, the network then models the movement of the ship in real time. It is possible for a hostile to spoof this by maneuvering, but that would be flagged as a hostile action... CJ Cherryh's Alliance universe describes this "longscan" nicely.

Space combat takes place at speeds that makes your position only 6 minutes ago a historic artifact, not useful targeting information so relayed sensor information is not going to help you.

Your speed isn't important, your ability to accelerate is.
At the ranges over which ship combat takes place sensor and comms lag is not worth modelling.
Very long range is 50,000km, it takes a laser or near c particle beam 0.17 seconds to travel from the firing ship to the target ship, the target has 0.17 seconds worth of acceleration to change its predicted position to avoid being hit. Then we have to take into account the targetting system. An active sensor takes 0.34 seconds to make the trip, so you have a bit longer to accelerate to avoid being hit, 0.17 seconds for the sensor return plus the 0.17 seconds for the laser, this is fundamentally the lag that makes hitting a target ship an uncertain task. If you are using a passive sensor for your targeting fire control solution then you know where the target was 0.17seconds ago, you have to send your lightspeed laser to where you are predicting the target to be in the fraction of a second it takes the laser to cross the space. Only the target ship's acceleration matters, can it accelerate in such a way that its future position is uncertain. Note that I am assuming microsecond computing time, and microsecond computer controlled adjustment of the lase emitter array/mirror whatever.
Having a human in the loop requires two lots of reaction and thinking time - computers shoot the weapons, human reactions are not fast enough.

I also disagree with your assertion regarding the thermal energy generated by space ships as they are not compatible with the fuel available, nor are they compatible with lived experience. We have had manned space flight for decades and astronauts are not routinely cooked during even long term missions. It is therefore not a given that they need to be in the future.

Real world spacecraft have to have massive radiators to prevent overheating. Look at the ISS, look at why the shuttle had to open its payload bay doors...
Real world spacecraft are not generating the power needed to move tons of spacecraft at multi g acceleration for months at a time, real world spacecraft do not have fusion reactors generating MW to TW of power...

Voyager is not detectable thermally according to my information (even by the James Webb telescope). It is actively beaming signals to us so detecting it is less challenging but that is also using radio waves not IR.

I didn't say it was,but we can detect its feeble radio emission... it's all energy, but perhaps I need to go into more specifics, my bad.

With respect to thermal separation, Thermos flasks enable you to hold hot liquid without burning your hands. You only need a few mm of vacuum to drop 100 degrees. Dewar flasks hold liquid gases with far greater temperature differentials quite happily for extended periods. We don't need to alter ship deck plans to accommodate this as the tonnage doesn't include the hull itself unless you fit special options. Any default cooling and thermal interfacing could be in all the grey (or brown) bits round the outside of the bits we actually bother to map.

Your ship is the thermos flask/dewar vessel, and inside you have a furnace getting hotter and hotter and hotter. Your ship is not just containing the heat it starts with, it is generating more heat every passing second.

You keep mentioning the "laws of thermodynamics" but never actually state what laws you say I am breaking. I suspect that is because nothing I said is breaking them. They are quite simple and easy to navigate but also apply to ideal systems in thermal equilibrium. No engineering solution has ever been an ideal system as they are not in thermal equilibrium and you need to consider time (rather than just the start and end state).

Sorry I was assuming you were familiar with the four laws of thermodynamics, I can go into more details no problem at all.

CT had some yampy numbers but as is was a 1970's game based on 1950's science fiction filled with space magic* written by someone who was not necessarily up with current physics theory, we can forgive it for being a bit off on the science. Most of us who played it in the 80s were not physicists either (and those that were up to date on the latest physics theories were still thinking in 1980's physics) and we didn't have the internet to find facts and counter opinions instantaneously. We do not need to perpetuate Olde Lore into new editions (or we may as well just play the old versions) especially as Olde Lore changed between edition.

The laws of thermodynamics have not changed since the 80s, in order to accelerate a spacecraft at multiple g you need a lot of energy, in order to power all the electrical systems on board a ship you need a lot of energy. Energy transfers generate waste heat, you have to reduce that waste heat or the inside of your ship gets hotter and hotter until electronics overheats and the crew dies of heat exhaustion.

I am happy with my arguments and conclusions. I'd like there to be more data but there isn't. I'll leave them here for the consideration of the wider community.

*Gravitics adds a massive dose of "dunno" and could be used to solve almost any problem including deflecting IR (and even potentially pushing heat up hill).

Space magic can be used to explain the lack of radiators in Traveller, gravitics are the current go to (in the past people suggested waste heat was removed by the jump drive into jump space but there is a massive flaw in that idea - spaceships don't have jump drives) and are a convenient handwavium technology to allow us to break physics as and when we need to.

 

[MasterGwydion]

So in a thousand year old empire with trivial space travel you don't think there will be sensors out at the jump boundary and beyond to monitor shipping?

Maybe at a Class A starport, but not at anything less than that.

Class B has low, medium, and high orbit satellites. Class A has "more satellites", whatever that means, but that would likely be where your "extended sensor net" is potentially added.

 

[swordtart]

I am sorry you feel that way, it is not my intent to cause you upset. When presented with a wall of text I read it through then reply point by point, that way the context is preserved. The accusation it is out of context is difficult for me to parse since I am replying as you make your points.

But you recognise I hope that not every sentence on a structured argument needs to be self contained because otherwise we will reach heat death of the universe before we can reach a conclusion.

Not at all, I run games in many different settings with some different technologies, but I do consider the Third Imperium universe to follow the laws of thermodynamics, with the caveat that there has to be magic space technology to deal with the waste heat

CRB does not exclusively rely on third imperium setting details.

You don't agree with the laws of thermodynamics? Again I reply point by point so that there can be no ambiguity.

I don't agree with your assumptions about the applicability of the four laws to my argument. The laws apply within a framework of constraints.

So in a thousand year old empire with trivial space travel you don't think there will be sensors out at the jump boundary and beyond to monitor shipping?

This is setting specific and not therefore admissable as an argument in ALL settings.

Which is where I agree with you in part. It would be possible to have directional radiators up to a point (although I have read articels by others that dismiss such ideas) that a target vessel that is in front of you would have a hard time detecting, but how do you know which way to point your ship if you don't know where the enemy is either? Traveller ships don't even have radiators - hence my adoption of a magic gravitcs based heat sink.

If thermal sensors exist and can detect ships then ships they must by definition radiate. A thing that radiates is a radiator.

The closest sensor picks up the ship, it transmits that data to the network, the network then models the movement of the ship in real time. It is possible for a hostile to spoof this by maneuvering, but that would be flagged as a hostile action... CJ Cherryh's Alliance universe describes this "longscan" nicely.

I work with sensor nets and there is always delay and any delay introduces inaccuracy, especially if there is relaying involved as the processing adds in extra delay.

Your speed isn't important, your ability to accelerate is.
At the ranges over which ship combat takes place sensor and comms lag is not worth modelling.
Very long range is 50,000km, it takes a laser or near c particle beam 0.17 seconds to travel from the firing ship to the target ship, the target has 0.17 seconds worth of acceleration to change its predicted position to avoid being hit. Then we have to take into account the targetting system. An active sensor takes 0.34 seconds to make the trip, so you have a bit longer to accelerate to avoid being hit, 0.17 seconds for the sensor return plus the 0.17 seconds for the laser, this is fundamentally the lag that makes hitting a target ship an uncertain task. If you are using a passive sensor for your targeting fire control solution then you know where the target was 0.17seconds ago, you have to send your lightspeed laser to where you are predicting the target to be in the fraction of a second it takes the laser to cross the space. Only the target ship's acceleration matters, can it accelerate in such a way that its future position is uncertain. Note that I am assuming microsecond computing time, and microsecond computer controlled adjustment of the lase emitter array/mirror whatever.
Having a human in the loop requires two lots of reaction and thinking time - computers shoot the weapons, human reactions are not fast enough.

Agreed, targeting from the ship might be that quick but my point was about relayed information. Your point about speed vs. delta vee is well made. I was conflating my reservations about intercept so I accept the refutation of this point.

I would ask you to consider however that a single position will not give you any velocity information. You need two before you can predict where something will be. Any positional inaccuracy will roll onto your velocity prediction and will be a double whammy as your start point will also be incorrect and it might take several such readings before you get decent trending. Only if your positioning is accurate to the metre and your timing is equally accurate will you be able to put the beam on target. With a single ship you do not even have a position, simply a line of bearing and whilst fire along that LOB will eventually hit a stationary target anywhere along that LOB, if the target is further along it than you thought its velocity (rather than it's delta vee) will be relevant to whether it is still there when the beam arrives.

Real world spacecraft have to have massive radiators to prevent overheating. Look at the ISS, look at why the shuttle had to open its payload bay doors...
Real world spacecraft are not generating the power needed to move tons of spacecraft at multi g acceleration for months at a time, real world spacecraft do not have fusion reactors generating MW to TW of power...

Your argument implies you are willing to accept time as a factor of the heat issue.

I will remind you I am talking about a short term solution that needs only last a few hours,l as by that time the ship will be far from the emergence point. I am choosing to assume that any radiator system can dump all heat accumulated prior to emergence along the way (as it doesn't need to mask it's signature before then).

I didn't say it was,but we can detect its feeble radio emission... it's all energy, but perhaps I need to go into more specifics, my bad.

Your ship is the thermos flask/dewar vessel, and inside you have a furnace getting hotter and hotter and hotter. Your ship is not just containing the heat it starts with, it is generating more heat every passing second.

Ok. Think on this. Put a thermos of hot soup in a good quality cool box. Put the cool box in a deep freeze for half an hour. When you take it out the interior of the cool box will not be at the temperature of the soup. Neither will it be the temperature of the deep freeze. You will not have shattered the laws of thermodynamics

If you can accept that then you can accept similar principles for our spacecraft. The only parameters are the specific insulation coefficients and the time. Those are all dependent on technology and circumstance not changing fundamental principles in physics.

You mentioned the heat out the back of the fridge. You will agree that the heat of the door is close to ambient. The middle is a few degrees above freezing, the ice box a few degrees below and the heat pump significantly above ambient.

This means that the interior heat is being transferred to the exterior. Heat moving from cold to hot which breaks the second law! But if course it doesn't as the law does not apply to this aspect. Heat doesn't flow from cold to hot in a system in thermal equilibrium, this system is being pumped and so heat moving from cold to hot is perfectly acceptable.

If you put a thermal camera in front of the fridge you will see the heat glow out the back because of convection. Eliminate that and you would see all the radiated heat instead where it bounced off the wall behind the fridge. Move that wall to space distances and the fridge would not be visible. Direct that radiation at a suitable target ballute and your sensor would see the ballute instead of the fridge and finding the fridge would become much more difficult.

Sorry I was assuming you were familiar with the four laws of thermodynamics, I can go into more details no problem at all.

Not about the wording of the laws merely about their specific applicability to the specific arguments.

The laws of thermodynamics have not changed since the 80s, in order to accelerate a spacecraft at multiple g you need a lot of energy, in order to power all the electrical systems on board a ship you need a lot of energy. Energy transfers generate waste heat, you have to reduce that waste heat or the inside of your ship gets hotter and hotter until electronics overheats and the crew dies of heat exhaustion.

Laws of thermodynamics makes no assumptions about the amount of waste heat or the efficiency of energy transfer. Those are all assumptions specific to your setting that have inescapable consequences from the laws, but the laws do not lead inescapably to that conclusion if the setting chooses to assume greater efficiency than the present (or that existed in the 1980s).

Space magic can be used to explain the lack of radiators in Traveller, gravitics are the current go to (in the past people suggested waste heat was removed by the jump drive into jump space but there is a massive flaw in that idea - spaceships don't have jump drives) and are a convenient handwavium technology to allow us to break physics as and when we need to.

Not just when we need to, but also when we can't be bothered sadly, even when that means it breaks the rules along the way.

 

[swordtart]

...

It is gravitic and EM, but the EM is states as only being detectable to the same range as the gravitic flash. So, the range of detection for the gravitic flash is what you need to know.
View attachment 6602

Hmm, I had assumed it was thermal. If it is gravitic then you need a densitometer. That means TL 12 sensors at MCr4.3 minimum and the max range (which cannot be extended) is 10,000 km (though at least the time to sensor will be short).

That changes things massively. Extensive sensor nets capable of detecting jump flash become very expensive to implement and maintain, and detection from sensors on planet or near orbit is not possible.

An 8000km planet requires over 25,000 sensors just to cover the 100D shell. That is over GCr100 in capital costs and MCr100 in maintenance costs for just the sensors. If you want coverage for the normal range of variance in jump you'll need a few more layers (each requiring more sensors). That is pretty unsustainable for all but the most wealthy systems. To catch ships that chose to jump in at the 1000D limit and creep in under stealth would require over 500 million sensors. That would cost 2 TCr in annual maintenance alone - though you might be able to get a bulk discount

 

[Sigtrygg]

But you recognise I hope that not every sentence on a structured argument needs to be self contained because otherwise we will reach heat death of the universe before we can reach a conclusion.

I agree, the internet and forums are a lousy way to debate and discuss, face to face is much better.

CRB does not exclusively rely on third imperium setting details.

After the first two paragraphs the rest of the book focuses on how the Third Imperium does things. You have to try very hard to adapt the rules to a different setting.

I don't agree with your assumptions about the applicability of the four laws to my argument. The laws apply within a framework of constraints.

This is where I disagree, the laws of thermodynamics are foundational to out understanding of the universe, In order to step away from their constraints you need space magic technology. I suppose it is how far you want to move along the science fiction to science fantasy scale.

Many sci fi franchises are better described as space fantasy, possibly soft science fiction, but the more laws of physics you break the further away from fiction and into the realm of technomagic we find outselves.

This is setting specific and not therefore admissable as an argument in ALL settings.

Yes, within the setting thermodynamics are ignored, but to be science fiction you need handwavium to explain how you are doing it. It is an oversight of many sci fi franchises.

Traveller has many fictional technologies, and then plops psionics on top. Nowhere in the rules is heat management ever rationalised which is why I subsume it within gravitc tech, which is the is magical of the lot - well, apart from psionics where thermodynamics suddenly matters if you teleport.

If thermal sensors exist and can detect ships then ships they must by definition radiate. A thing that radiates is a radiator.

Yes.

I work with sensor nets and there is always delay and any delay introduces inaccuracy, especially if there is relaying involved as the processing adds in extra delay.

Real world computers are not as fast as TL8+ computers and electronics are they? Don't real world computers also get very hot and require lots of cooling?

Agreed, targeting from the ship might be that quick but my point was about relayed information. Your point about speed vs. delta vee is well made. I was conflating my reservations about intercept so I accept the refutation of this point.

I agree with you about signal processing delay, just how fast to Traveller computers and electronics process data? The lag in the electronics introduces the wiggle room to make weapon fire a task rather than an automatic hit - although "realistically" within a certain range a laser can not miss.

Your argument implies you are willing to accept time as a factor of the heat issue.

Yes, time is a factor. You could have an internal heat management system that can manage emissions for the short term

I will remind you I am talking about a short term solution that needs only last a few hours,l as by that time the ship will be far from the emergence point. I am choosing to assume that any radiator system can dump all heat accumulated prior to emergence along the way (as it doesn't need to mask it's signature before then).

but where is this heat management system? Traveller ships don't have huge radiators (the only mention in CT is in the AHL supplement) which is why I have gone the route of gravitics being able to radiate energy. Could a ship dump waste heat in jump space? Interesting question to think about.

Ok. Think on this. Put a thermos of hot soup in a good quality cool box. Put the cool box in a deep freeze for half an hour. When you take it out the interior of the cool box will not be at the temperature of the soup. Neither will it be the temperature of the deep freeze. You will not have shattered the laws of thermodynamics

The thermos of hot soup is not generating more and more heat every second.

Now put a thermit reaction inside your thermos that generates more and more heat every second... The ship is a closed system, to lose waste heat it has to remove something from this closed system.

How hot is the back of the deep freese?

If you can accept that then you can accept similar principles for our spacecraft. The only parameters are the specific insulation coefficients and the time. Those are all dependent on technology and circumstance not changing fundamental principles in physics.

No, because it is fundamentally the wrong model. The ship is a closed system.

You mentioned the heat out the back of the fridge. You will agree that the heat of the door is close to ambient. The middle is a few degrees above freezing, the ice box a few degrees below and the heat pump significantly above ambient.

To cool the contents of the fridge the heat has to be moved, which is why the back of the fridge gets hot. Work generates heat.

This means that the interior heat is being transferred to the exterior. Heat moving from cold to hot which breaks the second law! But if course it doesn't as the law does not apply to this aspect. Heat doesn't flow from cold to hot in a system in thermal equilibrium, this system is being pumped and so heat moving from cold to hot is perfectly acceptable.

No it doesn't because you are not considering the whole system. The interior heat is moved to the exterior by doing work, that work generates waste heat. Which requires power, which is why you need to provide electricity to the fridge.

What is actually happening in a fridge is the heat inside the fridge is transferred to a coolant - hot to cold so no 2nd law violation - the coolant then dumps that heat thanks to radiation, conduction, and convection round the back of the fridge, which is another reason why the back of your fridge gets hot - hot coolant dumping heat into surroundings is again hot to cold so again no violation of 2nd law.

If you put a thermal camera in front of the fridge you will see the heat glow out the back because of convection. Eliminate that and you would see all the radiated heat instead where it bounced off the wall behind the fridge. Move that wall to space distances and the fridge would not be visible. Direct that radiation at a suitable target ballute and your sensor would see the ballute instead of the fridge and finding the fridge would become much more difficult.

You don't need a thermal camera, just put your hand on the back of your fridge, it is hot to the touch. it is dumping the heat externally to the fridge, it is using the environment as a heat sink.

How do you accelarate the ballute to match the movement of your ship?

Not about the wording of the laws merely about their specific applicability to the specific arguments.

You are ignoring the whole system, you are taking bits out of context rather than considering the whole cycle.

Laws of thermodynamics makes no assumptions about the amount of waste heat or the efficiency of energy transfer. Those are all assumptions specific to your setting that have inescapable consequences from the laws, but the laws do not lead inescapably to that conclusion if the setting chooses to assume greater efficiency than the present (or that existed in the 1980s).

All energy must be accounted for is an assumption (1st law)... energy transfer can never be 100% efficient (2nd law)... you can never achieve absolute zero (3rd law)... temperature is an emergent property (zeroth law)

The setting doesn't define how much energy is transferred to the maneuver drive in real world units, and makes assumptions that heat is managed magically. I do not find that satisfactory hence my desire for an in universe explanation for how heat is managed. In the absence of an official pronouncement I will stick with gravitics.

Not just when we need to, but also when we can't be bothered sadly, even when that means it breaks the rules along the way.

Science fiction is all about bending and breaking rules, new discoveries are only made by scientists not tied to dogma, all I want from a given setting is consistency.

 

[MasterGwydion]

Guys? A fridge isn't a closed system. You put electricity in and get heat out. Starship is not a closed system. You put fuel in and get heat and electricity out.

A closed system, you have no input and no output. In both of your examples above you have inputs and outputs.

Plus - Traveller as a universe, matter and energy are interchangeable. (at TL-19+ anyhow) It is likely that way in Our universe too. Once we develop the technology to do E=mc2 level efficiency, then thermodynamics go out the window, since no system can be a closed system. In modern thermodynamics, they seem to consider a "closed-system" to be matter only while ignoring energy. So, the Laws of Thermodynamics are not wrong, they are just incomplete. Eventually someone will figure that math out.

 

[Condottiere]

1. Where does the exhaust go after the fusion reactors takes it apart?

2. More importantly, where does the exhaust go after the chemical power plant burns it?

3. You could transfer heat to the exhaust, as it exits the spacecraft tailpipe.

4. Or for a more closed system, transfer the heat to water, until it turns to steam.

5. Direct it through steam turbines to create electricity.

6. Let the steam cool off in radiators, and let it collect in water tanks.

7. Rinse, and repeat.

8. Seems somewhat closed.

9, And after kickstarting it, perhaps perpetual power points.

 

[Sigtrygg]

1. Where does the exhaust go after the fusion reactors takes it apart?

The hot plasma is ejected, giving away your location...

2. More importantly, where does the exhaust go after the chemical power plant burns it?

Into the CO ₂ scrubber and water reclamation, assuming complete combustion of a hydrocarbon fuel

3. You could transfer heat to the exhaust, as it exits the spacecraft tailpipe.

You can't move the relatively cold waste heat into the hot exhaust, you could heat up a coolant with the waste heat and inject that. But where is your coolant system accounted for...

4. Or for a more closed system, transfer the heat to water, until it turns to steam.

Which increases in pressure and blows up, and once again where are your steam pressure vessels accounted for?

5. Direct it through steam turbines to create electricity.

Where does the steam go after the turbine? Where does the waste heat not radiating from the hot pipework and the turbine go?

6. Let the steam cool off in radiators, and let it collect in water tanks.

And the radiators radiate to space... giving away your location.

7. Rinse, and repeat.

Yup, there is no stealth in space.

8. Seems somewhat closed.

Only because you are boiling the inside of your ship...

9, And after kickstarting it, perhaps perpetual power points.

And there we have it, the ultimate rejection of the laws of thermodynamics

 

[swordtart]

I agree, the internet and forums are a lousy way to debate and discuss, face to face is much better.

After the first two paragraphs the rest of the book focuses on how the Third Imperium does things. You have to try very hard to adapt the rules to a different setting.

This is where I disagree, the laws of thermodynamics are foundational to out understanding of the universe, In order to step away from their constraints you need space magic technology. I suppose it is how far you want to move along the science fiction to science fantasy scale.

The constraints still exist. Thermodynamic equilibrium. We agree it is radiating. If it is radiating then it is not an isolated system. Closed systems can still transfer energy beyond the boundary.

Many sci fi franchises are better described as space fantasy, possibly soft science fiction, but the more laws of physics you break the further away from fiction and into the realm of technomagic we find outselves.

Yes, within the setting thermodynamics are ignored, but to be science fiction you need handwavium to explain how you are doing it. It is an oversight of many sci fi franchises.

Traveller has many fictional technologies, and then plops psionics on top. Nowhere in the rules is heat management ever rationalised which is why I subsume it within gravitc tech, which is the is magical of the lot - well, apart from psionics where thermodynamics suddenly matters if you teleport.

Nowhere is heat management identified as an issue that needs rationalisation. The rules tell us ships emit thermal radiation enough to be detected. You could choose to read that as it is not sufficiently significant that space heat sinks are required..

Yes.

Real world computers are not as fast as TL8+ computers and electronics are they? Don't real world computers also get very hot and require lots of cooling?

Computers will advance but the speed of light won't. Computers will be more heat efficient along with everything else. Not 100% but maybe within a few decimal places of that, but this is a side issue as waste heat is waste heat.

I agree with you about signal processing delay, just how fast to Traveller computers and electronics process data? The lag in the electronics introduces the wiggle room to make weapon fire a task rather than an automatic hit - although "realistically" within a certain range a laser can not miss.

Yes, time is a factor. You could have an internal heat management system that can manage emissions for the short term

but where is this heat management system? Traveller ships don't have huge radiators (the only mention in CT is in the AHL supplement) which is why I have gone the route of gravitics being able to radiate energy. Could a ship dump waste heat in jump space? Interesting question to think about.

Traveller doesn't mention bras either, but that is a George Lucas argument to say they don't exist.

The thermos of hot soup is not generating more and more heat every second.

So the soup is even hotter than when you started.

Now put a thermit reaction inside your thermos that generates more and more heat every second... The ship is a closed system, to lose waste heat it has to remove something from this closed system.

Ok this is probably the nub of the disagreement. According to my textbook there are three types of system.

Isolated systems do not pass energy or matter beyond the boundary of the system into the environment. No real system (unless you consider the entire universe) meets this definition.

Closed systems do not pass matter beyond the boundary, but they do pass energy. Ships radiate energy in lots of ways (thermal, EM, gravitic etc.) so a ship could be this. So to lose waste heat it just needs to pass energy to the environment as permitted (and indeed required) by thermodynamic definition of a closed system.

The final type is an open system. Do M-Drives emit gravitons and are they considered matter? More significantly what happens to the products of fusion. Once "hydrogen" is converted to Helium do we keep going or do we eject Helium to space to allow new hydrogen in. Even if we "burn" the Helium there comes a point where the reactions become too inefficient (Lithium?), at that point we need to take them out If excessive heat build up is an issue, then a good way to help regulate it is ejecting hot fusion products but that probably makes more sense when you think no-one looking (or maybe in jump space to clear as much as possible before emergence).

How hot is the back of the deep freese?

Less hot than the soup. I am not sure what this question is expressing.

No, because it is fundamentally the wrong model. The ship is a closed system.
To cool the contents of the fridge the heat has to be moved, which is why the back of the fridge gets hot. Work generates heat.

The interior cool box is no less a closed system than the ship. I choose to define the boundary of the system as the cool box and the interior of the freezer is the environment. If you insist I include the exterior of the freezer then I can include the entire planet and that is exactly the same situation as a ship in space but there will just be too many factors to make any headway.

No it doesn't because you are not considering the whole system.

That is the thing with closed systems in thermodynamics, you can put the boundary wherever it is mathematically convenient.

The interior heat is moved to the exterior by doing work, that work generates waste heat. Which requires power, which is why you need to provide electricity to the fridge.

But the generator could be inside the fridge as well. We have battery fridges.

What is actually happening in a fridge is the heat inside the fridge is transferred to a coolant - hot to cold so no 2nd law violation - the coolant then dumps that heat thanks to radiation, conduction, and convection round the back of the fridge, which is another reason why the back of your fridge gets hot - hot coolant dumping heat into surroundings is again hot to cold so again no violation of 2nd law.

Yes, that is what I said. I was hoping you would see the similarity to putting a coolant in thermal contact with the exterior of the ship separated from the rest of the ship by vacuum and materials of low thermal conductivity. That coolant would be pumped round the back of the ship to be radiated out the back.

You don't need a thermal camera, just put your hand on the back of your fridge, it is hot to the touch. it is dumping the heat externally to the fridge, it is using the environment as a heat sink.

And you can put your hand on the front of the fridge and it won't be hot to the touch because it is using the environment as a heat sink. It gets to use convection as well as radiation but otherwise it is just like the ship.

How do you accelarate the ballute to match the movement of your ship?

It will inherit the velocity of the ship and if you don't accelerate it will remain in the same relative position to you. If you accelerate, as long as it remains behind you your directed energy will still hit it and still a decoy. If you have to turn and are unable to direct energy toward it anymore you will need to drop another ballute, but you might just choose to coast instead as by that time your opponent may well have lost your track.

You are ignoring the whole system, you are taking bits out of context rather than considering the whole cycle.

Define whole system? Like a ship considered isolated from its environment, but that still interacts with it?

All energy must be accounted for is an assumption (1st law)...

So the energy required to convert hydrogen int fuseable matter (D or T). The energy radiated as EM or thermal. The energy required to maintain the plasma (heat used for this is not waste heat it is required) and heat the fuel to fusion temperatures. The energy required to maintain the magnetic containment, and run the electronics. The energy required to run the gravitics for the m-drive. The energy required to recycle water, air etc. All these mechanisms take energy out of the system. They are all doing work and waste heat is the energy left when all energy required for the work has been taken out. Some work is done to the system and some work is done by the system.

energy transfer can never be 100% efficient (2nd law)...

No but as long as it is 99.99999999999999999999999999999999999999999999999999999999999% then we are good.

you can never achieve absolute zero (3rd law)... temperature is an emergent property (zeroth law)

We don't need to cool the exterior of the ship below the ambient temperature of space as then it would appear as a negative.

The setting doesn't define how much energy is transferred to the maneuver drive in real world units, and makes assumptions that heat is managed magically. I do not find that satisfactory hence my desire for an in universe explanation for how heat is managed. In the absence of an official pronouncement I will stick with gravitics.

Science fiction is all about bending and breaking rules, new discoveries are only made by scientists not tied to dogma, all I want from a given setting is consistency.

Guys? A fridge isn't a closed system. You put electricity in and get heat out. Starship is not a closed system. You put fuel in and get heat and electricity out.

Thermodynamically closed is different. You can move energy across the boundary freely. Closed is not the same as Isolated.

A closed system, you have no input and no output. In both of your examples above you have inputs and outputs.

That is an isolated system.

Plus - Traveller as a universe, matter and energy are interchangeable. (at TL-19+ anyhow) It is likely that way in Our universe too. Once we develop the technology to do E=mc2 level efficiency, then thermodynamics go out the window, since no system can be a closed system. In modern thermodynamics, they seem to consider a "closed-system" to be matter only while ignoring energy. So, the Laws of Thermodynamics are not wrong, they are just incomplete. Eventually someone will figure that math out.

Thermodynamics existed before and after Einstein it already allows for fusion. Fuel is just potential energy as it isn't really destroyed, the atoms are just joined up differently releasing nuclear bond energy. If the matter were actually converted to energy (and the hydrogen vanished) it is not fusion.

 

[MasterGwydion]

Thermodynamics existed before and after Einstein it already allows for fusion. Fuel is just potential energy as it isn't really destroyed, the atoms are just joined up differently releasing nuclear bond energy. If the matter were actually converted to energy (and the hydrogen vanished) it is not fusion.

No. This would be something far beyond fusion.

 

[swordtart]

No. This would be something far beyond fusion.

Agreed but conversion of matter to energy still does not require matter to pass the boundary so it is a still a thermodynamically closed system.

EDIT: Ignore me, I am an idiot

 

[MasterGwydion]

Agreed but conversion of matter to energy still does not require matter to pass the boundary so it is a still a thermodynamically closed system.

Under this, it would be matter converted to energy, then the energy passes the boundary. In this fictional 100% matter to energy conversion thingie. You would actually be losing matter within the "closed system". Matter would not cross the boundary, but it would still be "lost" within the "closed system"

 

[swordtart]

Under this, it would be matter converted to energy, then the energy passes the boundary. In this fictional 100% matter to energy conversion thingie. You would actually be losing matter within the "closed system". Matter would not cross the boundary, but it would still be "lost" within the "closed system"

No you are quite correct. I was talking cobblers. Apologies, thermodynamics was 39 years ago

 

[Sigtrygg]

The constraints still exist. Thermodynamic equilibrium. We agree it is radiating. If it is radiating then it is not an isolated system. Closed systems can still transfer energy beyond the boundary.

The ship and its contents are a closed system because they can only interact with the environment energetically buy radiating EM or by opening a door and throwing something out.

Nowhere is heat management identified as an issue that needs rationalisation. The rules tell us ships emit thermal radiation enough to be detected. You could choose to read that as it is not sufficiently significant that space heat sinks are required..

So we agree there is no stealth in space... without space magic.

Computers will advance but the speed of light won't. Computers will be more heat efficient along with everything else. Not 100% but maybe within a few decimal places of that, but this is a side issue as waste heat is waste heat.

How thermally efficient is the most efficient computer today? Currently they all have a thermal efficiency of 0% - all of the electrical energy input into a computer becomes heat, fortunately they get so hot that that heat can be repurposed. What breakthroughs will allow electronic computers to become more efficient?

Traveller doesn't mention bras either, but that is a George Lucas argument to say they don't exist.

Ha ha, then how did he explain Leia's slave girl costume...

The interior cool box is no less a closed system than the ship. I choose to define the boundary of the system as the cool box and the interior of the freezer is the environment. If you insist I include the exterior of the freezer then I can include the entire planet and that is exactly the same situation as a ship in space but there will just be too many factors to make any headway.

The cool box does not contain a furnace, a starship does. You are setting the conditions inside the thermos, and inside the cool box, as a fixed temperature. A starship is not going to remain at a fixed temperature as it has a fusion reactor and all of those systems on board turning electricity into heat.
Why bring up a planet? A starship is not transferring heat to a planet unless it is within its atmosphere. on it surface or whatever.

Your analogy, the model you are using, is flawed.

That is the thing with closed systems in thermodynamics, you can put the boundary wherever it is mathematically convenient.

True, but then we are discussing a hypothetical engineering problem, ie waste heat management of a ship, and not a spherical chicken.

But the generator could be inside the fridge as well. We have battery fridges.

What happens to a battery inside a freezer? Or the battery on a Tesla in cold conditions...

Yes, that is what I said. I was hoping you would see the similarity to putting a coolant in thermal contact with the exterior of the ship separated from the rest of the ship by vacuum and materials of low thermal conductivity. That coolant would be pumped round the back of the ship to be radiated out the back.

I agree, but others don't. The folks at Atomic Rockets don't think this would work.

And you can put your hand on the front of the fridge and it won't be hot to the touch because it is using the environment as a heat sink. It gets to use convection as well as radiation but otherwise it is just like the ship.

The front of the fridge is the same temperature as the room it is in...

It will inherit the velocity of the ship and if you don't accelerate it will remain in the same relative position to you. If you accelerate, as long as it remains behind you your directed energy will still hit it and still a decoy. If you have to turn and are unable to direct energy toward it anymore you will need to drop another ballute, but you might just choose to coast instead as by that time your opponent may well have lost your track.

So we need a mechanism to store them, launch them, and track them.

Define whole system? Like a ship considered isolated from its environment, but that still interacts with it?

The whole system being the fridge and its environment.

So the energy required to convert hydrogen int fuseable matter (D or T). The energy radiated as EM or thermal. The energy required to maintain the plasma (heat used for this is not waste heat it is required) and heat the fuel to fusion temperatures. The energy required to maintain the magnetic containment, and run the electronics. The energy required to run the gravitics for the m-drive. The energy required to recycle water, air etc. All these mechanisms take energy out of the system. They are all doing work and waste heat is the energy left when all energy required for the work has been taken out. Some work is done to the system and some work is done by the system.

You transfer energy, you move it from energy store to energy store to use the up to date language, back in my day we called it something else

No but as long as it is 99.99999999999999999999999999999999999999999999999999999999999% then we are good.

Which requires space magic.

We don't need to cool the exterior of the ship below the ambient temperature of space as then it would appear as a negative.

I was just restating the four laws as basic assumptions.

Fun discussion, thanks for sticking with it.

 

[Condottiere]

No concealed weapons.

 

[swordtart]

The ship and its contents are a closed system because they can only interact with the environment energetically buy radiating EM or by opening a door and throwing something out.

Good we agree. We can both those and we can get rid of waste heat by either method. Now it just a question of amounts.

So we agree there is no stealth in space... without space magic.

I am still loath to agree we need space magic, we have managed up until now in the discussion with accepted real physics. I agree that there is no mechanism to hide the thermal signature from all aspects indefinitely. As I believe we have agreed that thermal energy can be redistributed, I am hoping we can agree that we could make a ship stealthy from some directions at the expense of being vastly more detectable in others i.e. if we halve the the thermal signature to the front the thermal signature to the rear would more than double as it would be the sum of the thermal energy from the front plus some arbitrary additional energy that was generated by the movement mechanism.

Then the only question is how long that can be maintained and for how much of the ship). As that is a matter of degree then it is a matter for referee judgement (and we may be able to home in on some credible numbers with some of the facts we do have)

How thermally efficient is the most efficient computer today? Currently they all have a thermal efficiency of 0% - all of the electrical energy input into a computer becomes heat, fortunately they get so hot that that heat can be repurposed. What breakthroughs will allow electronic computers to become more efficient?

I am not sure, super conductivity, optical computers or subatomic computer gates, really really small dense chips so the power pathways are short and resistance is reduced. Sub nano mechanical computers. All waste heat comes from electrical resistance conventionally so lowering resistance reduces the energy required to run them and thus the energy that ends up as waste heat. Handily the cooler we get them the less resistance they have so running coolant through them as a minor part of the thermal energy redistribution could be enough to make their waste heat negligible compared to the other heat sources (like the flesh bags). Maybe that waste heat can be used leveraged for state changes in memory materials (like flipping magnetic cores). We may need the same space magic that allows you to put a computer in your skull as those getting hot would be an equally severe issue but it is less objectionable for small heat generators.

Ha ha, then how did he explain Leia's slave girl costume...

Lots of stuff to unpack there and nothing particularly edifying

The cool box does not contain a furnace, a starship does. You are setting the conditions inside the thermos, and inside the cool box, as a fixed temperature. A starship is not going to remain at a fixed temperature as it has a fusion reactor and all of those systems on board turning electricity into heat.

Thus is probably where we will not meet and just have to wave politely from either ends of the pitch. I don't think this is problem as it is just a question of assumptions rather than a disagreement on understanding of fundamental principles.

I don't think it is necessary to have a lot of waste heat. I am willing to allow the energy conversion to be really efficient. I am happier handwaving that as technological progress vs inventing space magic. If we assume we need terawatts it is harder, but there is no requirement that it needs to be terawatts.

We used to have gas lamps that generated loads of heat. We now use high efficiency LEDs and the light to input power ratio is a fraction. This might reasonably continue and the 1 power unit could be kilowatts rather than terra watts. Lighting each DTon of a ship with a 1W of super efficient future LEDs doesn't sound unreasonable. Artificial gravity might not use much power as we only need to accelerate to 10 N/kg energy is force x distance so we could come up with some numbers. We had a magnetic hold open device that drew close to zero power unless you tried to move it, so many gravity plates could draw no power unless something was sitting on it and then ramp up the power the further the object were away from it (need some radar sensor and calibration so it didn't go mental trying to attract the ceiling. We don't need to waste power on heating as we will likely need to remove heat rather than add it.

We should able to work out the theoretical energy required to move a ship (once we determine its mass). We just need to assign an efficiency to the M-Drive to come up with the "actual" value.

The problem is just how much energy fusion of 1 Dton of hydrogen produces and that is a given in the rules. We do know however that as TL increases the amount of power per DTon of plant (and by extension of fuel) increases. That allows that if a TL15 plant converts 100% of the hydrogen to useful energy the TL8 plant only manages 50%. Unconverted hydrogen is not waste heat though so I can live with that. There may also be a lot of the energy driving the magnetic bottle (or the LIF lasers) so not all power need end up available for use of other systems. TL15 doesn't need to be 100% efficient at conversion either so the theoretical gigawatts could end up in megawatts (maybe if you squint at it hard enough) - this is the bit that really irritates me.

I have no doubt that the fuel requirement was just made up on the spot, but once you use the word fusion it suddenly becomes something tangible with an actual energy. We could probably get the required energy down pretty low. The energy from the M-drive could be considered entirely ejected as G-waves (whatever they are). But the m-drive requirement for a 1G ship is 1/2 that of life support requirement, which even in the inefficient 60's was tiny. The ISS only uses 100kW (no artifical gravity of course, but even if it was all life support for a 70 DTon vessel). Y

HG allows thermal signature to be detected at 5M km. I am not sure how many nanowatts per metre are required to be detectable, but if the entire ships energy was spread out over the surface of a 5M km sphere you can continuously radiate a lot without putting much into a 1 m sensor.

Incidentally it allows jump flash to be detected beyond 5M km having completely forgotten that densitometers have a max range of 10,000 km and apparently jump flash can only be seen at the range of densitometers. Gotta love consistency.

Why bring up a planet? A starship is not transferring heat to a planet unless it is within its atmosphere. on it surface or whatever.

It was attempt to put the fridge in the same closed system floating in free space like the space ship. It also generates waste heat and receives energy from an external source like the fridge.

Your analogy, the model you are using, is flawed.

Quite possibly I am trying to understand how badly and whether it is less flawed than pure space magic.

True, but then we are discussing a hypothetical engineering problem, ie waste heat management of a ship, and not a spherical chicken.

I'll stop playing if you are mean.

What happens to a battery inside a freezer? Or the battery on a Tesla in cold conditions...

I didn't mean inside the cold compartment. Just as a self contained part of the system rather than considering an external power supply.

I agree, but others don't. The folks at Atomic Rockets don't think this would work.

True but are they scientists or authors? There are plenty of people with opinions, not all of them are worth anything.

The front of the fridge is the same temperature as the room it is in...

Yeah so we probably do agree that we can have at least part of the ship thermally stealthed.

So we need a mechanism to store them, launch them, and track them.

It would be part of a stealth suite, not default kit. But a mylar balute inflated by a small self contained gas cylinder could be an alternative sand caster round. Tracking will be easy if you have illuminated it with your own thermal emission, it is an active sesnor at that point. Since the object it for it to been seen instead of you it could also broadcast EM to make it easier to track by both you and your opponent.

The whole system being the fridge and its environment. You transfer energy, you move it from energy store to energy store to use the up to date language, back in my day we called it something else.

Yeah I wanted to be sure we were not talking at cross purposes and heat generation meant it was acting as an electric heater.

Which requires space magic.

Maybe to get to 99.9 recurring. But to get to 0.0000001 can be done with baler twine and chewing gum. I am hoping to meet somewhere in the middle.

I was just restating the four laws as basic assumptions.

Fair enough, always good to restate the opening argument to bring us back to the topic.

Fun discussion, thanks for sticking with it.

Yeah I am not sure I can get past the mind boggling energy potential of fusing 1Dton of hydrogen. I am not sure we need that much, but if you accept that then you are tacitly accepting that any you didn't need must be waste.

Maybe it is 0.99 DTon of fuel tank and only 0.01 DTon of actual fuel

 

[swordtart]

We should able to work out the theoretical energy required to move a ship (once we determine its mass). We just need to assign an efficiency to the M-Drive to come up with the "actual" value.

Ok as we have the power for the life support of the ISS, lets see how much power if required to move it at 1G. Assuming 14 days of constant 1G acceleration/deceleration per month on average (so discounting the 2 jumps). Also assume 1Don = 1 Tonne. That is a total of 1.25 Million seconds (rounding to nearest quarter). Kinetic energy is 1/2 MV**2 and final speed (if just accelerating for 14 days) it roughly 12.5 Million m/s. Energy is 1/2 * 66000 * (12,500,00)**2.

That is 5 E+18 J or 4 e+12 Watts. which in this case equates to 6.6 power units. A power unit from this single example is 0.61 e+12 W.

If we assume all going out the back as radiation (equal and opposite and all that) then actually we could consider that all of this energy will turn into waste heat behind the ship as the gravimetric waves collapse. That actually means that we could often ignore this for detection as it would only appear to a ship less than 10,000 km astern.

I confess that is more than I expected and it totally dwarfs the life support energy requirement if we consider the ISS. Unfortunately according to Traveller we need to expend twice that on life support, which seems a hell of a lot for not much effect.

At this point the rest of it is hardly worth discussing. 20% is so entirely arbitrary a number and it results in a ridiculous power consumption that has no outlet other than as waste heat.

Annoying.

 

[Condottiere]

Primitive hulls only exude one power point per hundred tonnes.

Rules allow halving that, without shutting off basic services.

Extreme external temperature require more climate control.