SciFi movies and pathetic misconceptions of tech failing for the story line.

[tggzzz]

Its incredibly hard to make a story flow if you are going to be accurate. Its would be tool long, and too complex. You just have to give the author some licence.

Consider an accurate movie rendition of some space manoeuver:

Ensign X: Initiating Womble manoeuver.
Crew sits there flapping their hands over panels with random lit symbols on them.
Time passes
Ensign X breaks wind.
More time passes.
Ensign X: Well, that's the end of my shift, can I get anyone anything before I turn in?
Ensign Y: Nah, all good, thanks!
More time passes.
Ensign Y sneezes.
Several more hours pass.
Ensign Y leaves at the end of the shift.
Several more hours pass. Ensign X returns for their next shift.
Ensign X: How's it going?
Ensign Z: So far so good, another two days to go.
Ensign X: Yup.
More time passes.

Not exactly riveting viewing is it?  I mean, it's cheap to produce and all, but I don't think it'll hold onto its audience.

Cue Joe Haldeman's "The Forever War"

[AVGresponding]

Plot line: a group of random political prisoners steal the most powerful fighter spaceship in the galaxy. Later they find an omniscient computer. Each episode they still manage to get themselves into scrapes with vastly inferior opposition forces.

You're not watching it for the sophisticated plot, you're watching it for Paul Darrow and, for a lighter note, Michael Keating.  It also contains a lot of things that later became common in other series like longer story arcs rather than one-episode set pieces, the creators of several later series were big fans of Blake's 7.

Surely you mean Jacqueline Pearce or Glynis Barber.

Shameful! No mention of Sally Knyvette!

I should probably not mention I had a cat called Soolin...

[coppice]

Plot line: a group of random political prisoners steal the most powerful fighter spaceship in the galaxy. Later they find an omniscient computer. Each episode they still manage to get themselves into scrapes with vastly inferior opposition forces.

You're not watching it for the sophisticated plot, you're watching it for Paul Darrow and, for a lighter note, Michael Keating.  It also contains a lot of things that later became common in other series like longer story arcs rather than one-episode set pieces, the creators of several later series were big fans of Blake's 7.

Terry Wogan was such a big fan he started a charity to raise funds to send the cast to acting school.

[coppercone2]

Cue Joe Haldeman's "The Forever War"

That author IMO was very interested in statistics, the basis for making his world believable was kind of like demographic statistics and stuff. He reminds me of particle accelerator analysis people

Battlestar galactica new one basically had no motion of the big ships but it remained interesting.

The movie battleship is based on a board game but it was made interesting

Maybe its only as boring as your captain

If space combat is boring and dismal it means your shield generators and armor are too weak. But Haldman inadvertently went into that when he was attempting to show progress, because the boring combat stuff is when the ship is built like the moon lander, out of paper thin aluminum.. I think once you start rolling 12 foot thick steel things get more interesting... oragami shop vs pipe works


so
1) did you develop a good power distribution system for the 100 TW reactor on board?
2) did you manage to weld up that heavy steel?


Even more interesting if someone develops some kind of field that diffracts light and spreads out laser beams, then you need to get closer and use mass. Like say a wall of some kind of exotic particle wall (gripped by EM) that act as a diffuser barrier 2 miles away for the 10TW laser beam that is going to hit the ship. Like if it just happens to make a prism made of exotic matter assimilate in the path of the laser cannon. Plasma wave guide things or something, not really sure what it would be, but its scifi

[David Hess]

1) did you develop a good power distribution system for the 100 TW reactor on board?

Even more important than the power distribution and reactor is how did you cool it?

http://www.projectrho.com/public_html/rocket/heatrad.php

And I am quite sure that you are going to make things infinitely worse by insisting on your precious nuclear power reactors and megawatt laser cannons. Human bodies only make enough waste heat to kill everybody, reactors and lasers can make the entire freaking ship glow white-hot and vaporize.

[tggzzz]

Plot line: a group of random political prisoners steal the most powerful fighter spaceship in the galaxy. Later they find an omniscient computer. Each episode they still manage to get themselves into scrapes with vastly inferior opposition forces.

You're not watching it for the sophisticated plot, you're watching it for Paul Darrow and, for a lighter note, Michael Keating.  It also contains a lot of things that later became common in other series like longer story arcs rather than one-episode set pieces, the creators of several later series were big fans of Blake's 7.

Surely you mean Jacqueline Pearce or Glynis Barber.

Shameful! No mention of Sally Knyvette!

I should probably not mention I had a cat called Soolin...

FTFY 

Jacqueline Pierce embraced and even revealed in the reactions of young males to the character. Sally Knyvette grew to hate her "housewife" character.

Then there's Jan Chappell.

[coppercone2]

1) did you develop a good power distribution system for the 100 TW reactor on board?

Even more important than the power distribution and reactor is how did you cool it?

http://www.projectrho.com/public_html/rocket/heatrad.php

And I am quite sure that you are going to make things infinitely worse by insisting on your precious nuclear power reactors and megawatt laser cannons. Human bodies only make enough waste heat to kill everybody, reactors and lasers can make the entire freaking ship glow white-hot and vaporize.

something quantum radiators

freeze ray related technology. I see the acoustic cooling being inspiration for whatever. Assumes ideal known radiator is highly inefficient antenna with bad VSWR. Because it kind of is, like a jumbled antenna pile or something, it radiates a little slowly and resonates internally or something. If heat is motion like a wave, and its stored, that would imply like a resonator behavior with decay due to leakage from antenna effectsish, like a LC super conductor that radiates at some frequencies.

[David Hess]

1) did you develop a good power distribution system for the 100 TW reactor on board?

Even more important than the power distribution and reactor is how did you cool it?

http://www.projectrho.com/public_html/rocket/heatrad.php

And I am quite sure that you are going to make things infinitely worse by insisting on your precious nuclear power reactors and megawatt laser cannons. Human bodies only make enough waste heat to kill everybody, reactors and lasers can make the entire freaking ship glow white-hot and vaporize.

something quantum radiators

freeze ray related technology. I see the acoustic cooling being inspiration for whatever. Assumes ideal known radiator is highly inefficient antenna with bad VSWR. Because it kind of is, like a jumbled antenna pile or something, it radiates a little slowly and resonates internally or something. If heat is motion like a wave, and its stored, that would imply like a resonator behavior with decay due to leakage from antenna effectsish, like a LC super conductor that radiates at some frequencies.

Or use a blackbody radiator.  The solution does not require handwavium.

The design of Discovery in 2001 originally included radiators, and the mounts were left on the model after the radiators were removed by Kubrick.  Niven's and Pournelle's stories sometimes included heat management.

[tggzzz]

B5 Rulez. Hope there's good news later today, and that the WGA strike doesn't get in the way.

It seems it can't get in the way 

"New Babylon 5 animated movie is coming, creator confirms. J Michael Straczynski said the project is "already finished" and coming "very soon"."
https://www.radiotimes.com/tv/sci-fi/babylon-5-animated-movie-confirmed-newsupdate/ and probably elsewhere.

[AVGresponding]

Jacqueline Pierce embraced and even revealed in the reactions of young males to the character. Sally Knyvette grew to hate her "housewife" character.

Then there's Jan Chappell.

Not quite sure what you mean by "housewife character". She had great wardrobe, had plenty of attitude, and kicked ass when required?

[tggzzz]

Jacqueline Pierce embraced and even revealed in the reactions of young males to the character. Sally Knyvette grew to hate her "housewife" character.

Then there's Jan Chappell.

Not quite sure what you mean by "housewife character". She had great wardrobe, had plenty of attitude, and kicked ass when required?

https://en.m.wikipedia.org/wiki/Sally_Knyvette#Television_career  She later complained of her Blake's 7 role that Jenna had "started off as this really exciting, intergalactic space pirate, but then she became a sort of housewife on the Liberator".

I remember her character becoming boring.  But I agree about the, um, wardrobe.

[coppercone2]

1) did you develop a good power distribution system for the 100 TW reactor on board?

Even more important than the power distribution and reactor is how did you cool it?

http://www.projectrho.com/public_html/rocket/heatrad.php

And I am quite sure that you are going to make things infinitely worse by insisting on your precious nuclear power reactors and megawatt laser cannons. Human bodies only make enough waste heat to kill everybody, reactors and lasers can make the entire freaking ship glow white-hot and vaporize.

something quantum radiators

freeze ray related technology. I see the acoustic cooling being inspiration for whatever. Assumes ideal known radiator is highly inefficient antenna with bad VSWR. Because it kind of is, like a jumbled antenna pile or something, it radiates a little slowly and resonates internally or something. If heat is motion like a wave, and its stored, that would imply like a resonator behavior with decay due to leakage from antenna effectsish, like a LC super conductor that radiates at some frequencies.

Or use a blackbody radiator.  The solution does not require handwavium.

The design of Discovery in 2001 originally included radiators, and the mounts were left on the model after the radiators were removed by Kubrick.  Niven's and Pournelle's stories sometimes included heat management.

Eventually you will need a better radiator because its going to look ridiculous because scifi designers don't have the time to do thermal analysis for space x, but I see your point that it should be a more prominent feature.

And I am not sure its pure handwavium, the idea of phonons (not photons, the heat one) and stuff is pretty profound. I think they bring thermal superconductors into play, but its not going to decrease radiator sizes. The reply to this one is interesting about sapphire second sound
https://physics.stackexchange.com/questions/130869/thermal-superconductivity

https://arxiv.org/abs/1211.3633

[coppercone2]

Interesting idea for heat control too is to juggle it, like heat up objects to as hot as they get, then jetison them from the ship but keep it on a tether or some how control it, that way you can radiate alot more energy because you have a giant surface area. Like if the enterprize had a deck of cards that got to white hot and then jetison them and make it orbit the ship with a tractor beam.. then at least if there is a material with insane thermal mass, it could be used this way, that the ship enters some kind of cooling state eventually but does not look absurd with the amount of radiators attached to it.

Otherwise, space peacocks.

[David Hess]

Eventually you will need a better radiator because its going to look ridiculous because scifi designers don't have the time to do thermal analysis for space x, but I see your point that it should be a more prominent feature.

Sure they do:

P = A * ε * σ * T4

    P = the power of waste heat the radiator can get rid of (watts)
    σ = 5.670373×10-8 = Stefan-Boltzmann constant (W m-2K-4)
    ε = emissivity of radiator (theoretical maximum is 1.0 for a perfect black body, real world radiator will be less. Should be at least 0.8 or above to be worth-while)
    A = area of radiator (m2)
    T = temperature of radiator, this assumes temperature of space is zero degrees (degrees K)
    x4 = raise x to the fourth power, i.e, x * x * x * x

[coppercone2]

[AVGresponding]

Eventually you will need a better radiator because its going to look ridiculous because scifi designers don't have the time to do thermal analysis for space x, but I see your point that it should be a more prominent feature.

Sure they do:

P = A * ε * σ * T4

    P = the power of waste heat the radiator can get rid of (watts)
    σ = 5.670373×10-8 = Stefan-Boltzmann constant (W m-2K-4)
    ε = emissivity of radiator (theoretical maximum is 1.0 for a perfect black body, real world radiator will be less. Should be at least 0.8 or above to be worth-while)
    A = area of radiator (m2)
    T = temperature of radiator, this assumes temperature of space is zero degrees (degrees K)
    x4 = raise x to the fourth power, i.e, x * x * x * x

Modern materials reach 99.9%, though I expect you'd want to factor in contamination and damage over time. The (average) temperature of (interstellar) space is 2.7°K. Why not recycle some waste heat into electricity?

[David Hess]

Modern materials reach 99.9%, though I expect you'd want to factor in contamination and damage over time.

Since practical emissivities only make a proportional difference in size, emissivity can be ignored unless it is terrible.  There is just not much to be gained with "perfect" emissivity.

This reminds me of current efforts to make more efficient electric motors and motor controllers for electric vehicles.  Both are already pretty efficient, so there is not much to be gained there.

Why not recycle some waste heat into electricity?

Project Rho discusses that.  It results in a greater volume of lower temperature heat, so now the radiator is less effective to the 4th power, and must be even larger, to the 4th power.

Niven might have recognized the problem, and the solution, but only briefly refers to it.  In his stories, spacecraft have storage systems and radiators for handling heat, but also concentrate it, adding even more heat and reducing efficiency, but this reduces the size of the radiators because they can operate at a higher temperature, taking advantage of that 4th power.

[5U4GB]

Even more important than the power distribution and reactor is how did you cool it?

http://www.projectrho.com/public_html/rocket/heatrad.php

That looks like a SF project, but something very similar was going to be built by NASA until they cancelled it like almost everything else they do that's cool (sigh), look up the Jupiter Icy Moons Orbiter.  That would have been an amazing craft...

[AVGresponding]

Modern materials reach 99.9%, though I expect you'd want to factor in contamination and damage over time.

Since practical emissivities only make a proportional difference in size, emissivity can be ignored unless it is terrible.  There is just not much to be gained with "perfect" emissivity.

This reminds me of current efforts to make more efficient electric motors and motor controllers for electric vehicles.  Both are already pretty efficient, so there is not much to be gained there.

Why not recycle some waste heat into electricity?

Project Rho discusses that.  It results in a greater volume of lower temperature heat, so now the radiator is less effective to the 4th power, and must be even larger, to the 4th power.

Niven might have recognized the problem, and the solution, but only briefly refers to it.  In his stories, spacecraft have storage systems and radiators for handling heat, but also concentrate it, adding even more heat and reducing efficiency, but this reduces the size of the radiators because they can operate at a higher temperature, taking advantage of that 4th power.

After a quick skim, the immediate problem I see with the argument is the misunderstanding of how the second law applies, generally, and specifically in relation to thermo-electric modules.

"What's the problem? Well, the general problem is that pesky Second Law of Thermodynamics. In this context, it tells you that it is impossible to destroy heat, the best you can do is move it around. So using a thermocouple to convert heat into electricity is impossible.

The specific problem is that a thermocouple does NOT convert heat into electricity. It converts a heat gradient into electricity. The original heat is still there. In fact, the conversion process adds even more waste heat to the original total.

As an analogy, think about a hydroelectric dam. The water in the reservoir is at a higher gravity gradient than the water downstream. The hydroelectric dam converts the gravity gradient into electricity. But the water is still there after passing through. The dam does not convert water into electricity, if it did the water would disappear. In the same way a thermocouple does not convert heat into electricity, the heat is still there."

Ok, firstly "the conversion process adds even more waste heat to the original total" implies the creation of energy, which as we know, is impossible. Using their analogy, this would equate to the generation of extra water during the operation of the dam, a clear nonsense idea.

The use of a "hydroelectric dam" as an example is telling; the use of the term "gravity gradient" here is misleading, in the context of use. A dam converts potential energy into kinetic energy by flowing H₂O molecules with high potential energy down the gravity gradient, through a turbine where this potential energy is converted into kinetic and then electrical energy (with some losses, inevitably ending up as waste heat), and for the purposes of this argument you may consider the molecules of H₂O to be the equivalent of the photons that carry waste heat away from a radiator.
The water indeed does not disappear, but it does lose potential energy, just as thermal energy is converted into kinetic energy in a steam turbine, or electrical energy in a thermoelectric module. TEMs are pretty inefficient, 6% or so for commercially available stuff, NASA are achieving on the order of 20% in their most advanced TEGs. The cold side of your TEM is the radiator, the photons of waste heat don't disappear, nor are they destroyed; they radiate out into their environment, with even local space (within the solar system) being cold enough and large enough to be effectively an infinite heatsink.

The heat is not "destroyed"; there is a flow of high energy photons from the hot side to the cold side, and as they drop to a lower energy level, this causes electrical current to flow, as the photons give up their energy. Yes, you need a thermal gradient for this to happen, just as you need the gravity gradient to create a difference in potential energy for a hydroelectric dam to work.

[BrianHG]

TEMs are pretty inefficient, 6% or so for commercially available stuff, NASA are achieving on the order of 20% in their most advanced TEGs.

Do you have your acronyms backwards?  Maybe something has changed in the last 5 years or so...

TEGs, like the ones on the Voyager space probes, which operate on the Seebeck effect, can only achieve maximum 6% efficiency in the best of cases.

The latest tech Stirling generators which use a magnet piston floating in helium as a lubricant can achieve 20% efficiency under optimum circumstances.  However, this tech is not usually labeled today as TEG.  It is possible to get even better efficiency with a normal Stirling engine, however, you will now have moving and rotating components which will wear out needing maintenance every few years.

[AVGresponding]

TEMs are pretty inefficient, 6% or so for commercially available stuff, NASA are achieving on the order of 20% in their most advanced TEGs.

Do you have your acronyms backwards?  Maybe something has changed in the last 5 years or so...

TEGs, like the ones on the Voyager space probes, which operate on the Seebeck effect, can only achieve maximum 6% efficiency in the best of cases.

The latest tech Stirling generators which use a magnet piston floating in helium as a lubricant can achieve 20% efficiency under optimum circumstances.  However, this tech is not usually labeled today as TEG.  It is possible to get even better efficiency with a normal Stirling engine, however, you will now have moving and rotating components which will wear out needing maintenance every few years.

Yes, I could have been more clear in explaining the difference between a TEM and the general TEG term, thanks. I think it depends who you ask as to whether Stirling engines are labelled (correctly or otherwise) as TEGs (in this specific context), I would tend to agree it's perhaps not the most accurate way to do it. I suppose it's an easy/lazy oversimplification since they effectively turn heat into electricity.

[coppercone2]

This reminds me of current efforts to make more efficient electric motors and motor controllers for electric vehicles.  Both are already pretty efficient, so there is not much to be gained there.

Just don't underestimate how many of those things there are out there. The number of motors working vs small efficiency gain = HUGE

Smaller motors in weirder form factors are the future I think. I think that is where the 'wow' is going to come from if we see what motors look like in 100 years. Gearbox elimination/reduction too.

I can imagine something like instead of a motor attached to the shaft its gonna be like a sleeve that you put over a shaft that bolts onto something one day. Like slip this 2 inch thick piece of steel over the shaft and connect some wires to it and it is a car. Or just like bearings that are actually motors. It's gotta go some where eventually that is cool.

Maybe we will see the procedure being instead of replacing the belt and motor bearings, it will just be like 'replace this small integrated car propulsion ASIC the size of a large ball bearing with a 300A plug on it'.

[BrianHG]

TEMs are pretty inefficient, 6% or so for commercially available stuff, NASA are achieving on the order of 20% in their most advanced TEGs.

Do you have your acronyms backwards?  Maybe something has changed in the last 5 years or so...

TEGs, like the ones on the Voyager space probes, which operate on the Seebeck effect, can only achieve maximum 6% efficiency in the best of cases.

The latest tech Stirling generators which use a magnet piston floating in helium as a lubricant can achieve 20% efficiency under optimum circumstances.  However, this tech is not usually labeled today as TEG.  It is possible to get even better efficiency with a normal Stirling engine, however, you will now have moving and rotating components which will wear out needing maintenance every few years.

Yes, I could have been more clear in explaining the difference between a TEM and the general TEG term, thanks. I think it depends who you ask as to whether Stirling engines are labelled (correctly or otherwise) as TEGs (in this specific context), I would tend to agree it's perhaps not the most accurate way to do it. I suppose it's an easy/lazy oversimplification since they effectively turn heat into electricity.

The Seebeck effect turns a difference in temperature directly into electricity.  The Sterling engine turns a difference in temperature to expand and compress a gas.  That change in density of the gas is used to move a piston or turbine.  This is basically a thermal motor/engine.  That engine's motion is used to move a magnet or coil to generate electricity like any conventional alternator.

[David Hess]

Smaller motors in weirder form factors are the future I think. I think that is where the 'wow' is going to come from if we see what motors look like in 100 years. Gearbox elimination/reduction too.

Getting higher power density is a different matter.  And there higher efficiency is required because it becomes more difficult to remove waste heat.

This would matter for an aircraft, but not so much in a traction application.

[coppice]

This reminds me of current efforts to make more efficient electric motors and motor controllers for electric vehicles.  Both are already pretty efficient, so there is not much to be gained there.

I think they are mostly trying to make electric motors for cars more efficient to simplify the cooling requirements in a confined space. Even if you have 99.9% efficiency, moving to 99.99% would eliminate 90% of your waste heat. The efficiency of current electric cars varies quite a bit, but I don't think that has a lot to do with the motor efficiency.