Why CRT in sci fi deep space ships actualy make sense

Interstellar travelers get to use whatever kind of display they want.

A key technology for space colonization is advanced manufacturing that lets a small population be self-sufficient. An outpost on the moon can probably be supplied from Earth but even to colonize Mars you would need an advanced industrial base even when the population is 10,000 so you need something similar to Eric Drexler's assemblers even if it is based on different principles. (The existence of life proves that something like this is feasible... Even if you can't assemble molecules with little robot arms or mills it is definitely possible to build arbitrary complex things by composing a set of building blocks.)

The most feasible path to interstellar travel seems to be to use deuterium-deuterium fusion to be self-sufficient off comets between the stars. Recent discoveries about artificial magnetospheres make this seem more feasible than it did 30 years ago because we know think it is possible to slow down using the interstellar medium which greatly conserves fuel.

Interstellar travelers might take 10,000 years to get to the next star but might have a comfortable lifestyle the whole time. If they found a Pluto-sized world floating between the stars they could even establish a colony and build some more ships. The big contradiction is that people like that might not really care to visit star systems at all, which I think is part of the resolution of the 'Fermi Paradox'.

But yeah, there is something sexy about the bridge in Silent Running or the old Battlestar Galactica although it seemed they had a flat screen TV in Star Trek.

> we know think it is possible to slow down using the interstellar medium which greatly conserves fuel.

Where can I learn more about this?

See

https://en.wikipedia.org/wiki/Magnetic_sail

and

https://www.centauri-dreams.org/2017/12/29/the-plasma-magnet...

The solar sail lobby thinks that magsailers overstate the potential of mag sails in the solar system (the very high solar wind velocities they quote happen only rarely) but the "interstellar brake" is model-changing. In some ways they are like

https://en.wikipedia.org/wiki/Bussard_ramjet

but only for stopping and not requiring impossible H-H fusion.

Several years ago, I read about Americans capturing Soviet-era jet fighters. They were analyzing it and finding all sorts of deficiencies compared to their own fighters, but noted its vacuum tube electronics were resistant to EMPs.

> Perhaps the most stunning discovery was the fact that most of the MiG-25’s avionics were based on vacuum tubes—not solid state electronics. This was considered woefully outdated for a top-of-the-line military jet in the 1970s, but the vintage system had its advantages. The vacuum tubes were more temperature-tolerant than modern avionics were, which allowed the MiG to fly without weighty environmental controls in the avionics bay. Plus, the tubes allowed for quick and easy maintenance at Russia’s primitive airfields, and the antiquated system would better withstand the circuit-frying power of an electromagnetic pulse created by a nuclear blast.

Yea, just look at how much redundancy in satellites and space probes we need to operate within the range of Sun's heliosphere. Outer space outside it would be even more killer to current electronics. Even if we switch to silicon carbide (which could possibly still remain harder to manufacture process) stuff it still would be a factor to consider.

> Even if we switch to silicon carbide (which could possibly still remain harder to manufacture process)

In the 1980s I got a copy of the latest Cricklewood Electronics catalogue that had a whole page devoted to these newfangled SiC blue LEDs. Blue! Actually properly blue, too!

They were 40 quid each, and indeed the text box where it gave the price said something like "£40 - yes, really, yes these are one of the most expensive components we have ever stocked".

The inventor of the blue LED came to our school for a talk like 5 years ago. IIRC he won a Nobel prize?

He got the Nobel Prize because the blue LED + phosphor enabled the use of cheap, energy-efficient LEDs for general illumination, whereas previously LEDs had been used mostly for indicator lights.

And for the past 10 years, almost every cheap electronic device has been permanently glowing blue because of them.

EDIT: aren't modern blue LEDs based on GaN?

Yah, the first ones were a very different shade of blue and really expensive.

Silicon Carbide LEDs were the first true blue (not blue-violet) ones, but they were horribly inefficient.

Doped GaN made blue LEDs viable, and LEDs in general more available.

sounds like the [possibly-apocryphal] store of the invention of red-black trees

during the space race, the Americans threw more computing power at the problem

the Soviets didn't have the computers to use, so they threw math at it

sometimes simplest is bestest!

> Plus, the tubes allowed for quick and easy maintenance at Russia’s primitive airfields,

I don't buy the maintenance angle.

Modern solid-state avionics are swappable LRUs. Like lego, you plug and unplug them. Just as easy as tubes, in fact the exact and precise same. Plus you can drop them and they don't shatter.

Techs aren't out in the field desoldering surface-mount components and swapping capacitors, the are unplugging and plugging modules the same as unplugging and plugging in a vacuum tube.

I also don't buy the EMP angle. The metal that aircraft avionic components are encased in also serves as EMP shielding. Not that that matters, the effects of thermonuclear EMP effects are so poorly understood that anyone claiming to be able to predict them is a liar. An EMP in the upper atmosphere may fry well-shielded components 1 meter away from unshielded components if the unshielded components are disconnected and at a different angle to the blast than the shielded ones, and vice-versa. Every real-world analysis of EMP effects is punctuated by how seemingly random the effects are.

An analysis of the effects of STARFISH PRIME on the streetlights of Honolulu notes how random and unpredictable the outages were, and this is on unshielded long-wire circuits (ideal for soaking up EMP radiation).

Did High Altitude EMP Cause the Hawaiian Streetlight Incident? http://ece-research.unm.edu/summa/notes/SDAN/0031.pdf

USSR was using tubes because it was technologically far behind the West (it was still producing cars that were between 30 to even 50 years behind the West) and was under heavy sanctions. Soviet bloc made chips were actually less reliable and that's one of reasons why commie bloc TTL based computers were so unstable as they had either to import components from the West (see story of Karpiński and his K-202 architecture) if they wanted components that they were allowed to order them in the 1st place or smuggle them (which would not work for large scale) or use inferior in quality components produced within the bloc. Vacuum tubes were much harder to fuck up while production – hence more reliable than commie bloc TTL or LSI. How do I know? I am from one of countries that been in that bloc.

This is exaggeration and oversimplification. From American/German high quality tubes.

I've deal with old soviet tubes. They where extremely specific, You even couldn't just place new tube into device, but need to make some manipulations with it before turn on (run it in special device on low currents).

And unfortunately, soviet tubes unreliable, many (not all), work very few hours. So MiG-25’s where for soviets, like SR-71 for US - very expensive in making and in support.

For example, known fact, MiG-25’s could for tiny time make more than 2.5Machs, but after this 100% engines go to landfill.

One key flaw to this idea is simply mass. The best CRTs we ever made were probably the Trinitron tubes, which are notoriously hefty. A good living room TV set weighs 100-200 pounds!

The CRT itself is heavy, it's all glass and metal. Then you have to consider all the electronics required to drive it. Transformers and coils are very dense.

Whereas an LCD panel on its own is a very thin sheet of glass and some plastics. It's all driven digitally, so your entire control system is one fat chip.

Multiply this weight by the number of screens in a starship (hundreds? Thousands?) and you've got a problem. This extra mass significantly affects maneuverability and acceleration. You'd have to reduce mass elsewhere in the ship, most likely by reducing passenger count.

And good luck if you have to transport these things from a planetary surface. CRTs are inherently fragile and don't handle high acceleration well.

Magentic interference is also a likely concern. Every screen in the engine room would turn into a colorful mess any time the reactor is running. You'd have to invest even more mass into magnetic shielding.

All in all, I find this unlikely. Mass is too important in space travel. As other commenters mention, once you have the ability to produce ICs outside of earth, it's not that far of a leap to produce LCDs.

LCDs are simply better in every way that matters. Even refresh rate is arguably unimportant today, and will likely be solved entirely by the time we're thinking about interstellar travel.

> you solved problem of easy production of electricity

Sure, but you may not have solved the problem of how to get the heat out of your spaceship. Since your only option is radiative heat transfer (no convection/conduction…), you're stuck with really fat radiators. So you really don't want to waste power into heat.

https://en.wikipedia.org/wiki/External_Active_Thermal_Contro...

FTL travel is a fictional concept. It is a really useful fictional concept because it lets characters outside of each other’s light cones interact, but involves ignoring the laws of physics as we know them. So, if we are to have FTL travel, that’s fine, but we can’t really discuss the engineering aspects of CRT vs LCD if we don’t know how to you’ve bent the laws of physics.

If we suppose FTl travel is possible, 1 and 2 don’t really apply, the colonists can instead just get resupplies from Earth. In fact it will be very convenient, because FTL travel allows the traveler to go back in time, your spare monitor will arrive before you order it. The only downside is the sense of impending doom if you suddenly get a large shipment of splints and bandages from Earth.

3 seems unlikely to matter, humans are bad at quick precise movements compared to machines. By the time space colonization is possible, the (as RTS players would call it) “micro” at least of space combat will be handled by AIs. This seems independent of FTL, although we don’t know what the side effects of allowing FTL signal propagation inside a CPU could be. Really good branch prediction I guess, if we can just send a “which way did it go” bit back in time.

4 relies on point 0 I guess so we can toss that out.

5, if we’re moving humans we’ll have to come up with shielding anyway.

—-

If we don’t suppose FTL travel, then I think a colony will inherently need to include somehow the ability to make advanced computers.

There’s no practical way of returning resources from a space colony many light years from Earth. So, the colonists must be heading out there in their own self interest. Nobody is going to pay you to mine rocks on Alpha Centauri if it takes years to get anything back, you must have set out because you are interested in living there. So, the quality of life must not be much, much worse than Earth. Fairly up to date manufacturing will be table stakes for most colonists I think.

> because FTL travel allows the traveler to go back in time

I'm actually curious, has FTL ever been observed in reality, even for just individual particles? My personal belief is that backwards time travel is impossible because the universe changes in-place, but I haven't actually done any research on the subject so I could be totally wrong.

Information has not been observed to travel faster than light. What I mean by “FTL travel allows the traveler to go back in time” is, if one were to abuse the equations to get a traveler that is moving faster than light, some times would also end up looking negative.

But these are nonsense quantities that come about from abusing the equations, I mention it not because I think it is a practical concern but to highlight that we can’t just say “assuming FTL” without also being charged with ancillary crimes against the laws of physics!

> FTL travel allows the traveler to go back in time

People regularly say this, and I've yet to find a convincing argument for it.

The "backwards time travel" argument presupposes that an object is actually moving through space at a speed faster than light - i.e. with an imaginary Lorentz factor (1/sqrt(1-(v^2/c^2))) and all the shenanigans that entails. That presupposition ignores hypothetical approaches like wormholes and Alcubierre drives that outright shorten the distance to be traversed and thus don't entail actually moving at such speeds (and therefore keeping the Lorentz factor right around its normal happy 1).

Put differently: such an argument presupposes that a light cone is actually cone-shaped, whereas wormholes and Alcubierre drives throw a wrench in that, producing all sorts of lumpiness that keeps events within the same (really weird looking) light cone despite taking place at long distances.

CRT monitors are especially prone to electromagnetic interference. Even if you could control for that within your vessel there are all manner of things that could interfere with it from the outside.

''Humans, your puny CRT monitors are no match for our degaussing coil!''

I can't even begin to fathom the sheer joy and satisfaction of a ship-wide ZZZZZZZNNNNNNNNNNNNNGGGGG.

If you postulate a species that has solved item #0 (faster than light travel or very near light speed travel) then you have also postulated a species that is likely technically advanced enough that #1-5 no longer matter (i.e., they have found technical advancements that make the other points no longer relevant).

I.e., #1 -- ease of manufacture. A FTL species likely also has some technology similar to Star Trek's "replicators" -- and once said species is capable of assembling products by positioning individual raw atoms, difficulty of manufacture of a product onboard a space ship fades away and becomes little more than a raw supplies (you need the input raw materials) problem.

I.e., an "atomic" (as in placement of individual atoms) 3D printer allows for most anything to be assembled (provided one has the CAD files for the 3D printer and the required atomic materials).

> Good luck producing LCD array with same level of tech in some remote colony light years from advanced foundries.

Any colony that can manufacture integrated circuits can easily manufacture LCD panels.

The ability to manufacture integrated circuits will likely be seen as important as the ability to manufacture oxygen in any colony, so there will probably be an LCD "printer" as part of their standard list of abilities.

This person made a simple passive LCD at home: https://www.youtube.com/watch?v=_zoeeR3geTA

The ability of simple automated machines stashed in a maintenance closet to churn out screens of arbitrary size as-needed is not far-fetched in a world of interstellar travel.

We are talking about transporting tons of equipment trough light years of radiation many times stronger then the one that is already frying computers in satellites and probes within heliosphere, heck even on Earth's surface it's enough to flip bits in RAM dies. The simpler and radiation resistant stuff you can pack on board of transport ship the less effort you have to put in shielding that equipment during transport.

As for that passive LCD - I don't see how is that an argument for anything disputed about CRT. This is a far cry from manufacturing exact usable universal LCD display of resolution of even 200x320 that is not slower than snail in terms of responsiveness.

> We are talking about transporting tons of equipment trough light years of radiation many times stronger then the one that is already frying computers in satellites and probes within heliosphere, heck even on Earth's surface it's enough to flip bits in RAM dies.

Your original post postulated a species who has solved that which for us, with our known physics, is unsolvable, that being faster than light travel and/or very near light speed travel.

And yet, with such incredible technical knowledge far beyond what our present day knowledge tells us you discount that this same species has not already solved the radiation shielding problem?

By the time your fictional species has solved the FTL problem, they are likely many decades/centuries past having already solved the radiation shielding problem.

>And yet, with such incredible technical knowledge far beyond what our present day knowledge tells us you discount that this same species has not already solved the radiation shielding problem?

Yes, that might be possible.

1+ for low resolution (up to 1024x768), because it is hard to create more than one tube in one case, because of limited throughput and charges interaction. Essentially, electron beams push off each other, so it is really hard, to create more than 3-4 electron beams in one case.

Really, each beam is cloud of charged particles, and if two such clouds intersect, they will scatter, and will cause image distortion.

So must feed all image through 3-4 beams. And even with so low number, it is not easy and have imperfections.

More read next.

2. no. tft lcd, essentially, is large dram chip (each Thin Film Transistor have some memory effect, and in few tft designs, display cells are just memory cells, so cpu could access them via memory-like interface, or via system bus). In lcd, neighbor cells are so disconnected, that real hi-res displays work as 3-4 or even more logical displays in one physical, and this solves throughput problem (some monitors just used 3-4+ physical connectors).

3. no. This is limited by throughput and charges interaction.

4. unfortunately, no. Analog computers defeated by digital, because it is really hard and expensive, to make analog precision better than ~1/10000, but digital could stack few bytes, and even on old 8080 easy achieve 24bit (10^-6), or 32bit (10^-9) or even 64bit (10^-18).

5. partially agree. Small transistors more prone to single events, but large more prone for accumulated dose, because appear radiation matter move effects.

So real rad-hardened computers have few alu-s and circuit, which could disconnect non-working alu and connect spare.

ps it may sound non-politely, but really good read on magnetic tapes is Donald Knuth, and fortunately, their mathematics is very similar for hdd-s.

Are there any manufactures that still make a good CRT or is it like compact cassette mechanism where all new manufactured ones are junk.

Follow up question. Are there application where the CRT is preferred? And don't say to play old nintendo games, that does not count.

My dream setup would be to set up a computer system around one of those large monochrome SAGE raderscopes.

There is a debate as old as LCDs as to whether CRT or LCD is better for oscilloscopes.

The problem is complicated, but people argue that CRT is better because of the higher refresh rate, persistence effects of the phosphor holding charge, and no ADC quantization errors.

Most of those problems are more or less solved these days, though.

But you have to admit, there's a certain kind of elegance to old CRT oscilloscopes. You're effectively taking the signal you want to measure, and connecting it to an electron beam. Your signal directly alters the path of the electrons, which you see as a wiggle on the screen.

> Are there application where the CRT is preferred? And don't say to play old nintendo games, that does not count.

There's a huge range of games where CRTs are preferred. If old NES doesn't count, maybe other old games do. Vector CRTs are really irreplacable by modern screens, rasterizing is a usable approximation, but it's not the same. CRTs are nice for new games too, although if you get higher resolution CRT TVs, some of them have digital processing with delays, like modern TVs too; it turns out it's hard to build a CRT that can do all of 240p, 480i, 480p, 720p, and 1080i well, and you end up wanting to massage the picture. Light gun games really need a near zero delay output to work.

It's hard to fill a hole in an arcade cabinet designed for 25" 4:3 CRT with anything else. (Sometimes you can put a 16:9 monitor oriented vertically, but not in a sit down car/tank game)

I hope that one day, large 4:3 displays are produced again.

Physical handling of bare TV-style CRTs outside of their protective containers/cases is extremely dangerous due to implosion risk from dropping, striking, or exposing them to temperature extremes. Good luck with safely handling them in low gravity situations. I would not want one sailing around a room I'm in.

At least they should try to avoid the explosive instrumentation that causes your keyboard to light on fire if the ship is damaged

OLED manufacturing is pretty much printing. No need for molten glass, aluminizing or phosphor deposition.

Here I thought you were going to talk about Critical Race Theory ... and I was all set to get up in arms (whether you're pro or con) because scifi should be about the science!

Good on ya!

Harder sci-fi may be more focused on the science but a big component of sci-fi as I understand it is exploration of humanity and its social dynamics in unknown/challenging environments. In which case CRT might indeed be relevant in some scenarios…

It can be about both, tbh. Dune was like that...it was not only super detailed on the science side, the environment and biomes being so detailed and all, but it also dealt heavily with politics and religion and how either can be abused by charismatic rulers.

In addition, shows like Stargate, Star Trek, and Babylon 5 also had heavy themes of politics despite being hard sci-fi