Far Trader cargo/Freight manifest questions

[BetterThanLife]

Originally posted by rancke:
</font><blockquote>quote:</font><hr />Originally posted by Bhoins:
[qb]Obviously you aren't going to be quieter than the background. It was a flaw discovered in both the Ohio Class Submarines and the Predator RPV. You match the background. As for being a Becon in space just because you are there? IR signatures are masked today. Even the lowly tech 7-8 soldier has IR masking. (The BDU uniform has IR masking characteristics.) Will it make you invisible? Absolutely not. But it does cut your signature down. In a Technology where Chameleon Armor is available I don't see how it would be difficult to hide your IR signature.

The background is 4 degrees Kelvin. The interior of your ship had better be about 300 degrees higher. Unless you come up with some place to put the heat (like a subspace heat sink) there's really no way to mask a spaceship.</font>[/QUOTE]I have been thinking about your concept of thermals to detect a starship. The physics don't work. While Thermal radiation is detected in the Infra Red Spectrum it is radiated by increasing the Kinetic energy of the molucles around the source of heat. Since there are very, very few molucles in a vaccuum a vaccuum would be a very good heat insulator. You can't see stars on thermals. The only heavenly body you can see on thermals is the sun and that is probably just an image of where it is heating the atmosphere. (And that works by refraction not radiant heat.) I think thermals, like sonar, would be totally useless in space. Besides Optical sensors to detect something as small as a starship have a definite finite range much shorter than other light speed sensors. (Even if you used optics similar to the Hubble and all the space that would take up.) After all they can't make out details on Mars with Hubble. You can only see one man made structure from the moon. (And that is a mere 384,000 KM and the Great wall of china is quite a bit bigger than a starship as well. (With a nice contrasting background.) It sin't trying to hide.

Camoflague does work, you don't need a cloaking device.

 

[Anthony]

Um..I don't know where to start, the errors are so vast.

Thermal radiation is in no way dependent on an atmosphere.

 

[RainOfSteel]

Originally posted by Bhoins:
I have been thinking about your concept of thermals to detect a starship. The physics don't work. While Thermal radiation is detected in the Infra Red Spectrum it is radiated by increasing the Kinetic energy of the molucles around the source of heat. Since there are very, very few molucles in a vaccuum a vaccuum would be a very good heat insulator. You can't see stars on thermals. The only heavenly body you can see on thermals is the sun and that is probably just an image of where it is heating the atmosphere. (And that works by refraction not radiant heat.) I think thermals, like sonar, would be totally useless in space. Besides Optical sensors to detect something as small as a starship have a definite finite range much shorter than other light speed sensors. (Even if you used optics similar to the Hubble and all the space that would take up.) After all they can't make out details on Mars with Hubble. You can only see one man made structure from the moon. (And that is a mere 384,000 KM and the Great wall of china is quite a bit bigger than a starship as well. (With a nice contrasting background.) It sin't trying to hide.

Camoflague does work, you don't need a cloaking device.

It's true that space in general is a high quality (but not perfect) vacuum that does make an excellent thermal insulator. However, Infrared Radiation is an electromagetic emission, energy carryied away as photons, that drains away heat.

Apollo 13 got quite cold over a period of just a day or two, and that with the Sun shining on them most of the way. They were radiating their own Infrared energy away, and the Sun's energy and the heat of three bodies could not keep up with that loss.

Also, even my best vacuum thermos' lose or gain heat over time.

Further, the fusion generator of a starship is going to be radiating neutrions for Neutrino Detectors to pick up. IMO, stopping the fusion power plant is not a casual operation. IMTU, it requires great energy input to start up a fusion power plant.

 

[BetterThanLife]

Well I know that the transfer of heat is the molecules speeding up and bumping into each other. At least that seems to be what I remember from Physics.

I do admit I never took thermodynamics and my physics is limited to basic physics in College many years ago. (For this kind of stuff anyway, get me into Aerodynamics and that is a different story.

Now if I remember it wrong or if that is too simplistic then straighten me out please. How is heat transferred?
(And why don't stars show up in Thermo sights?)

Originally posted by Anthony:
Um..I don't know where to start, the errors are so vast.

Thermal radiation is in no way dependent on an atmosphere.

 

[BetterThanLife]

I didn't say heat wouldn't be lost, I said that the heat signature would be difficult to detect at range. As for Neutrino detectors that is a horse of a different color. Detecting a Fusion plant, that happens to be in the direction of the systems star should be nearly impossible. Otherwise you are looking for a needle in a haystack once you get to reasonable ranges. The good thing about a Neutrino Sensor is that it is an FTL sensor. Given that Neutrino's don't slow down or decay, go out in all directions and would disperse with range, there would definitely be a finite range at which a Neutrino Detector would work well. It is certainly less than starsystem range. Pinpointing a target using a Neutrino Sensor at over a Light second or two would be tough. The good thing is if you are patient and the target is moving you could, in theory triangulate, of course you moving, them moving, random neutrinos from other directions would make the targeting solution rough. Not saying it is impossible but rough. What is the actual speed of a Neutrino? How far will it actually go?

I guess you could always mount a battery for silent running, like a WWII Submarine.

Originally posted by RainOfSteel:
</font><blockquote>quote:</font><hr />Originally posted by Bhoins:
I have been thinking about your concept of thermals to detect a starship. The physics don't work. While Thermal radiation is detected in the Infra Red Spectrum it is radiated by increasing the Kinetic energy of the molucles around the source of heat. Since there are very, very few molucles in a vaccuum a vaccuum would be a very good heat insulator. You can't see stars on thermals. The only heavenly body you can see on thermals is the sun and that is probably just an image of where it is heating the atmosphere. (And that works by refraction not radiant heat.) I think thermals, like sonar, would be totally useless in space. Besides Optical sensors to detect something as small as a starship have a definite finite range much shorter than other light speed sensors. (Even if you used optics similar to the Hubble and all the space that would take up.) After all they can't make out details on Mars with Hubble. You can only see one man made structure from the moon. (And that is a mere 384,000 KM and the Great wall of china is quite a bit bigger than a starship as well. (With a nice contrasting background.) It sin't trying to hide.

Camoflague does work, you don't need a cloaking device.

It's true that space in general is a high quality (but not perfect) vacuum that does make an excellent thermal insulator. However, Infrared Radiation is an electromagetic emission, energy carryied away as photons, that drains away heat.

Apollo 13 got quite cold over a period of just a day or two, and that with the Sun shining on them most of the way. They were radiating their own Infrared energy away, and the Sun's energy and the heat of three bodies could not keep up with that loss.

Also, even my best vacuum thermos' lose or gain heat over time.

Further, the fusion generator of a starship is going to be radiating neutrions for Neutrino Detectors to pick up. IMO, stopping the fusion power plant is not a casual operation. IMTU, it requires great energy input to start up a fusion power plant. </font>[/QUOTE]

 

[Anthony]

Originally posted by Bhoins:
Well I know that the transfer of heat is the molecules speeding up and bumping into each other.

Heat is transferred in several ways. What you describe is conduction. Thermal radiation, however, is a different method of heat transfer, and is dependent on the temperature and albedo of the heat source.

(And why don't stars show up in Thermo sights?)

Because typical thermo sights aren't sensitive enough. The world is actually quite bright in thermo; stars are about as visible as they would be to normal vision during daytime.

 

[mike wightman]

A thermal immager would work on Hubble, but inside the atmosphere all it would pick up is the air.
As for neutrino sensors, they are another magic technoogy. If you want to keep Traveller Sci-Fi rather than Sci-Fantasy then limit the number of magic tech.
In the real world a neutrino detector is a spherical cavern, deep underground, filled with several thousands of gallons of water and lined with scintilation detectors. Quite how you reduce that to the size of a "matchbox" is beyond me. Perhaps it uses midi-chlorians in its construction

 

[Straybow]

Hubble does a large percentage of its imaging in the IR band. IR penetrates interstellar dust clouds that are opaque to visible light, hence all those really nifty nebula pictures. Narrow band imaging helps to pick out objects in particular temperature range, such as starships.

Yes, heat and IR are not the same thing. Heat is molecular or particle energy in excess of quantum oscillations. Heat is also the average kinetic energy of gas molecules. Conduction and convection are the means of mechanical heat energy transfer between material objects. Electromagnetic energy is the way molecular and particle energy is released, without transfering to any specific material object: radiant energy.

Blah, blah, blah... you can skip down a bit if you don't want a technical discussion.

The electromagnetic spectrum is a continuum, photons with differing intrinsic energies expressed as wavelength. Blue light is the same stuff as yellow or red light, except blue light is around 400 nm and red light is around 700 nm. Ultra- (above) violet is outside the sensitivity of our eyes, with wavelengths shorter than 400 nm. Infra- (below) red is outside human vision with wavelengths longer than 700 nm.

Microwaves are longer wavelengths still (1000 nm = 1 µm). Microwaves and everything with longer wavelengths are radio waves. Gamma rays and X-rays are shorter (higher energy) than UV.

As Anthony said, thermal radiation is dependent on the temperature of the source and its albedo or emissivity. The visible layer of the sun (the chromosphere) is at 6000°K, which is very bright in radiation from the visible spectrum on down through IR and radio. Any object heated to 6000° would have the same wavelength distribution of emitted energy.

A halogen lamp filament is about 2500°K, which still is very bright in the visible spectrum. An electric heater element is at 1000°K, and glows a dim orange.

Your body is at 310°K and emits no noticible visible light, but still emits plenty of IR photons. BDUs and M-1s can be "invisible" because they attempt to match the IR levels of the stuff around them (the ground and foliage, typically at 280-300°K).

aragraph: Here comes the particularly relevant part:

Your ship's hull will have an intrinsic temperature of 100-200°K long after you've shut down engines and coasted for weeks, crew stuffed in vacc suits and wrapped up in metalized thermal blankets. Unless you cover the entire hull with some powerful, expensive, and no doubt delicate, supercooling sheath you will stand out from the general background like a proverbial IR lightbulb.

By the way, buying or even stealing whatever materials are needed to do that, in enough quantity to conceal a whole starship, is probably a really quick way to get the undivided attention of various enforcement personnel.

 

[Straybow]

Back to the original topic, apart from GT and T20 of which I know squat, transport/cargo has to be per parsec, I don't really understand why that is hard to "get" from Book 2.

"Differences in starship jump drive have no specific effect on passage prices." That means the prices are the same.

"That is to say, a starship with a jump drive of 3 charges the same passage price as a starship with a jump drive of 1." That means the prices are the same.

"The difference is that a jump-3 ship can reach a destination in one jump that would take the jump-1 ship three separate jumps..." The difference for one jump-3 vs 3×jump-1 is not price, only time.

Either that means one high/mid/low passage ticket or cargo charge is good for any destination, however far (or at least up to 6 parsecs),
Or that means that each parsec covered costs the 10k, 8k, or 1k ticket price or 1k cargo charge. That is what a jump-1 will charge, simply by refusing to sell passage beyond the immediate destination. Which means passage and cargo charges must be per parsec.

It may also mean they weren't thinking clearly when devising the rules, nor when explaining them. Of course it is your rules IYTU. If you want to play it per jump, go ahead and shoot yourself in the economic foot.
__________________________________________________
Granted, there are 12 pages to sift through here. Maybe I missed it. There was a page of comments about excessive stateroom size and support but I don't recall anybody mentioning the economic cost of the 20 dton bridge. I'm fairly sure that was the first ship stat to go out the proverbial window when my brothers and I got into CT 25 years ago.

Why the heck does a 100 dton Scout (clearly stated as being operable by a one-man crew) need 1250 ft² or more of bridge space, about the size of the Star Trek set?

The 4 seat cockpit of an airliner would be about 2 dtons, and that's all you'd need for a Scout or Free Trader. Maybe so for somewhat larger ships, too. LBB2 says it's for guidance radars and comm, too, but that can fit in the few ft³ of a 20th century jet fighter's nosecone.

Liberating the majority of that space for cargo/passengers makes the smaller ships far more economically viable. Even a LBB2 Scout with 40 ton fuel tankage and only 3 tons cargo can do serious trading with an additional 18 tons of cargo.

:alpha: Instead of being 20 dtons for everything and scaled linearly below 100, at the most scale the 20 dtons linearly for everything under 1000, ie, 2%. Really I don't think more than 1% should be necessary apart from a 2 ton minimum for starships and a 1 ton minimum (2 seat cockpit with lots of instrument space) for small craft.

Unless you want an Olympic gymnastics mat in the bridge so you can practice your floor routine.

 

[BetterThanLife]

Actually Chameleon Armor would accomplish the same thing in space as it would on the ground. Put the same coating on a Starship and it would be very, very tough to spot.

Originally posted by Straybow:

Here comes the particularly relevant part:

Your ship's hull will have an intrinsic temperature of 100-200°K long after you've shut down engines and coasted for weeks, crew stuffed in vacc suits and wrapped up in metalized thermal blankets. Unless you cover the entire hull with some powerful, expensive, and no doubt delicate, supercooling sheath you will stand out from the general background like a proverbial IR lightbulb.

By the way, buying or even stealing whatever materials are needed to do that, in enough quantity to conceal a whole starship, is probably a really quick way to get the undivided attention of various enforcement personnel. [/QB]

 

[BetterThanLife]

I think that quote was covered on either page one or two of this thread.

And the economic implications of the per jump regardless of distance pricing. Especially since you can't design a starship under any of the rule sets that, with a higher than jump-1 drive, can break even with a bank note and the "typical" two jumps per month cycle of a starship.

Originally posted by Straybow:
[QB] Back to the original topic, apart from GT and T20 of which I know squat, transport/cargo has to be per parsec, I don't really understand why that is hard to "get" from Book 2.

"Differences in starship jump drive have no specific effect on passage prices." That means the prices are the same.

"That is to say, a starship with a jump drive of 3 charges the same passage price as a starship with a jump drive of 1." That means the prices are the same.

"The difference is that a jump-3 ship can reach a destination in one jump that would take the jump-1 ship three separate jumps..." The difference for one jump-3 vs 3×jump-1 is not price, only time.

Either that means one high/mid/low passage ticket or cargo charge is good for any destination, however far (or at least up to 6 parsecs),
Or that means that each parsec covered costs the 10k, 8k, or 1k ticket price or 1k cargo charge. That is what a jump-1 will charge, simply by refusing to sell passage beyond the immediate destination.

It may also mean they weren't thinking clearly when devising the rules, nor when explaining them. Of course it is your rules IYTU. If you want to play it per jump, go ahead and shoot yourself in the economic foot.

 

[Anthony]

Originally posted by Bhoins:
Actually Chameleon Armor would accomplish the same thing in space as it would on the ground. Put the same coating on a Starship and it would be very, very tough to spot.

Uh...no. Changing the color of an object doesn't really help in a significant way with its IR signature. Basically, any ship _has_ to emit a certain amount of energy; it just has some choice about how it emits that energy. The minimum amount of energy is generally sufficient to allow detecting it at quite long ranges.

 

[mike wightman]

The chameleon option extends to mimicking the IR background as well. This is the closest thing in T20 to the EMM packages in MT/TNE/T4 and GT, and its not officialy mentioned as a starship armour add on (but then, it doesn't say you cann't

)

 

[Anthony]

Ah, ok, than it's a 'magic surface'.

Honestly, something like that might be possible for atmospheric work, particularly on the ground. It won't work in vacuum.

 

[rancke]

Originally posted by Sigg Oddra:
The chameleon option extends to mimicking the IR background as well. This is the closest thing in T20 to the EMM packages in MT/TNE/T4 and GT, and its not officialy mentioned as a starship armour add on (but then, it doesn't say you cann't

)

No one has claimed that IR masking isn't possible in a planetary environment, although you might want to read the description about how a chameleon suit accomplishes that. What we're saying is that it can't be done in deep space.


Hans

 

[mike wightman]

I agree, the chameleon option for personal and vehicle armour as presented in T20 is only for atmospheric use. By the way, T20 doesn't actually explain it, the Mercenary version relies on chill cans to mask the heat radiator fins doesn't it?
The problem is T20 going back to a CT version of ships which lack the options given in every later incarnation . So instead of calling it a chameleon option how about calling it an EMM package?

 

[rancke]

Originally posted by Sigg Oddra:
I agree, the chameleon option for personal and vehicle armour as presented in T20 is only for atmospheric use. By the way, T20 doesn't actually explain it, the Mercenary version relies on chill cans to mask the heat radiator fins doesn't it?
The problem is T20 going back to a CT version of ships which lack the options given in every later incarnation . So instead of calling it a chameleon option how about calling it an EMM package?

Let me put it another way.

You see...

The thing is...

What you fail to take into account...

Hmm... there really isn't another way to put it. A spaceship in deep space is an IR beacon that can be detected from far, far away. Period.


Hans

 

[mike wightman]

Hmm... there really isn't another way to put it. A spaceship in deep space is an IR beacon that can be detected from far, far away. Period.

True enough in the real world, but not in the Traveller universe

 

[flykiller]

</font><blockquote>quote:</font><hr />Hmm... there really isn't another way to put it. A spaceship in deep space is an IR beacon that can be detected from far, far away. Period.

True enough in the real world, but not in the Traveller universe</font>[/QUOTE]now that is a good answer.

 

[TheEngineer]

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