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Why CRT in sci fi deep space ships actualy make sense

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Re: Why CRT in sci fi deep space ships actualy make sense

#21

Post by rolenthedeep »

somat wrote: post #16

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.

Re: Why CRT in sci fi deep space ships actualy make sense

#22

Post by Findecanor »

themoonisachees wrote: post #10
Gordonjcp wrote: post #8

Earlier quoted context omitted.

> 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…

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.

Re: Why CRT in sci fi deep space ships actualy make sense

#23

Post by Teever »

PaulHoule wrote: post #14

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…

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

Where can I learn more about this?

Re: Why CRT in sci fi deep space ships actualy make sense

#24

Post by rolenthedeep »

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.

Re: Why CRT in sci fi deep space ships actualy make sense

#25

Post by bee_rider »

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.

Re: Why CRT in sci fi deep space ships actualy make sense

#26

Post by cf100clunk »

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.

Re: Why CRT in sci fi deep space ships actualy make sense

#27

Post by cf100clunk »

tjpnz wrote: post #15

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!''

Re: Why CRT in sci fi deep space ships actualy make sense

#30

Post by toast0 »

somat wrote: post #16

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.

> 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.

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