[subego]

Guy popped his visor in vacuum, and then exhales once he closes it.

Pretty sure the change in pressure would have violently expelled the air in his lungs. I was always taught to hyperventilate and do a deep exhalation before exposure to vacuum.

Not sure if it was open long enough for the fluid on the surface of his eyeballs to start boiling.

[Spheric Harlot]

Originally Posted by subego 

Guy popped his visor in vacuum, and then exhales once he closes it.

Pretty sure the change in pressure would have violently expelled the air in his lungs. I was always taught to hyperventilate and do a deep exhalation before exposure to vacuum.

I'm pretty sure that this was explicitly covered where the woman crosses from one ship to another through vacuum.

So it's not so much "bad science" as, er…continuity issue?

[subego]

Originally Posted by Spheric Harlot 

was explicitly covered

Will be?

I don’t remember that, so it’s probably yet to come. I’m on S1E8 or 9 or something.

[Spheric Harlot]

Oh wow, okay. It's not even really started yet.

Enjoy!

[ghporter]

One BIG quibble that even Arthur C. Clarke brought up in 2001: a Space Odyssey was when Bowman takes a big, deep breath before blowing the hatch on the pod and blowing himself into the emergency airlock. Not a good choice, since the sudden pressure difference between the lungs/face and vacuum would be “unpleasant” to say the least.

The “better” choice would be to take that big, deep breath, then exhale (most of it) before exposure to vacuum. This would be similar to “prebreathing” in diving. Very short term exposure to vacuum, as in Bowman’s trip into the emergency airlock, would not be pleasant, but would be doable.

Why would someone want to open their helmet when outside in vacuum? Miss a spider when suiting up?

[MacNNFamous]

I noticed in the earlier episodes the loose shit flying around was a lot bigger deal, but as the series went on it just seemed to not matter.

[reader50]

Originally Posted by ghporter 

Why would someone want to open their helmet when outside in vacuum? Miss a spider when suiting up?

When you need to scratch, you NEED to scratch. It's all you'll think about.

I don't know if you can hold your breath against vacuum, but if so, a few seconds to scratch would work. I don't plan to test the scenario.

[reader50]

Originally Posted by Spheric Harlot 

I'm pretty sure that this was explicitly covered where the woman crosses from one ship to another through vacuum.

I've watched The Expanse through S4, and don't recall this. Maybe you're thinking of that BSG episode, where they jumped across to a Raptor, *didn't* hold their breath, exposed their lungs to vacuum, and spent time in medical because of it? Note: why didn't they torch their way into the lock, or apply power directly to the lock mechanism to force it to open? BSG science issue.

ps - if The Expanse does have such a scene in S5 or S6, just ignore the question. Spoilers are evil.

[subego]

Originally Posted by ghporter 

Why would someone want to open their helmet when outside in vacuum? Miss a spider when suiting up?

It was to pull what looked like giant booger off the top of his head.

[subego]

Originally Posted by reader50 

BSG science issue

I cut BSG some slack because you can trace its lineage back to Star Wars.

I’ve only seen the first two episodes. I thought it was great, but the ex-to-be wasn’t into it.

[subego]

Originally Posted by reader50 

I don't know if you can hold your breath against vacuum, but if so, a few seconds to scratch would work. I don't plan to test the scenario.

You could still probably do it for a few seconds. You’d just pass out more quickly because you can’t start with full lungs. I see the bigger problem being the sudden drop in the boiling point of water.


More bad science: a popable visor would need some kind of latch, or it would just blow open.


Edit: and I think one would really have to fight the thing to get it closed unless the air supply was turned off first.

[subego]

What’s with all the greebles on their pistols?

That’s the thing about pistols. The design was totally nailed over 100 years ago.

[Spheric Harlot]

Wow. I had to google that term, which sent me down a rabbit hole of universal greeblies and Hasegawa Leopold gun kits.

Thanks!

[subego]

You are most welcome! It’s a great word.

Finished the first season tonight. No bad science to report.

Approved of the non-audience abusive finale.

[subego]

Originally Posted by ghporter 

Miss a spider when suiting up?

Clarke wrote a great short story where the “space suits” were more like very tiny spacecraft.

A guy begins to hear scratching inside his “suit”, and gets progressively more terrified. Then he remembers a previous user of the suit had died in it, and begins to believe the suit is haunted.

 

Turns out a kitten had crawled inside.

[reader50]

Originally Posted by subego 

Finished the first season tonight. No bad science to report.

Is it still Dad-approved?

[subego]

I’d say so. If he’s complaining about anything it’s the storyline is complex enough it can be a little hard to keep track. The “previously on” montage in episode 9 was a good call.

[reader50]

The Expanse does have a major science glitch, but it's not one of your examples. And it's not their fault.

I'm not convinced by any of the bad science examples offered so far:
• Bad guys have self-sealing suits. Well, the good guys have them too. You see an arm amputation in the first episode. The guy survived suit decompression and bleeding into vacuum. The only way that could work is if his suit sealed off-camera.
• The Knight probably had a suit recharge station in the damaged airlock. It should have had a 2nd recharge point, but corporate budget cuts, etc. So sad, but most lifeboats are not needed during the life of the primary ship. And it might have saved a few hundred credits.
• Sound in space does happen in limited fashion if there is a nearby source of plasma or gas. Like a rocket exhaust, or say, a ship being vaporized.
• The visor may have a mag-lock to seal it. In many ship compartments, they have gripper handles with mag-lock bases for locking down cargo. They look like safety grab bars, but they're not welded or bolted into position. Presumably they use room-temp superconductors and small batteries. Put the bar where you want it, flip the switch, and it's as good as welded to the hull. Turn it off to reposition. Working the same way as the mag-lock boots, only way stronger. Such a visor seal would avoid mechanical latches, and be more reliable - there's less to break. About scratching his face or removing zero-G sweat buildup, I suspect the helmet seals at the neck and/or around the face when needed. So he didn't decompress the entire suit.

The one big science glitch concerns Ceres. The Expanse is based on a book series by the same name. When they wrote the first book, NASA's Dawn probe hadn't yet reached the real Ceres. It was thought that Ceres was mostly rock, with water ice in cavities. Density was low, indicating empty space, and/or ice. The Expanse runs with this old theory, that Ceres had a decent amount of sub-surface ice. All mined and removed by Earth and Mars before the present day.

However, Dawn revealed Ceres is a water-world once similar to Europa. Europa is tidally heated, but Ceres doesn't have a heat source. So today, it's all frozen up. It has a rocky core, with an ocean's worth of ice on top. And a dust layer surface, preserving the ice against sublimation. The real Ceres has so much ice available, it's implausible that it could all be carted away.

Unfortunately, by the time Science discovered this, it was already baked into the story. Enough that they couldn't even change it for the TV show. The assumption was baked into the System politics and economics too thoroughly.

[subego]

Good call on the mag-locks. I withdraw the challenge.

They still screwed up with the breath-holding though.

I should make it explicit my point about recharging air supplies isn’t strictly a science argument. It’s about inferring from other examples of technology whether they would have devised a ubiquitous solution to this problem. That was the point about self-sealing suits. If that’s ubiquitous (as you argue) then it’s evidence the much simpler issue of recharging an air supply is also ubiquitous.

That said, I’m not convinced that’s how the guy in the first episode survived. I’m sure some sort of “auto-tourniquet” would be cheaper than the fully self-sealing kind.


I also say the jury’s still out on rotary space cannons. While we’re at it, I doubt shooting space cannons at human targets in what amounts to a closed room is the kind of problem they did devise a solution for.


Edit: if there’s a recharge point in the airlock, then Shed (R.I.P.) should have gone to it, charged up his suit, and then went back to do his MacGyver shit. Take as long as you want to fix the antenna now. Edit 2: ah… I think I misunderstood. Broken airlock means broken recharge station. Got it.

My hypothesis is the writers needed to create a reason for tension in this scene and they kinda whiffed.

It’s not that what they came up with is impossible or something, it’s that there are numerous more plausible ways they could have made this a timed mission.

[subego]

Here’s some conjecture that’s got some basic science enforcing it.

Even this far along, spaceships would still be cramped. The interiors of these spaceships are full of space (heh) better suited to critical supplies.

[subego]

Originally Posted by reader50 

mag-lock

Challenge resumed!

What use case is important enough to warrant a system with an open failure state?

[reader50]

Please explain. I'm not sure what that means.

btw, you'll get a better look at mag-lock clamps during Season 2. They come up a few times in S2 and S3. You might want to postpone the topic until you're that far in, as we can't really provide usage examples until then.

Usage example you've already seen: the extra security locks on Julie's door on Ceres. I didn't think about it until just now, but they're probably mag-locks rather than physical latches. I don't remember an activation click, only an electronic tone when they're released. If they do have room-temp superconductors, those are likely to get worked into everything imaginable. Superconductors are just too useful.

[reader50]

Originally Posted by subego 

... a system with an open failure state?

I think you mean, it opens if it fails. So I guess you'd prefer a lock that when it fails, it locks you into your suit.

For Sale: Used space suit. Needs new visor latch. Previous occupant included.

[subego]

Originally Posted by reader50 

So I guess you'd prefer a lock that when it fails, it locks you into your suit.

Yes.

I can cut myself out of a suit. If the suit opens in space I’m dead.

If the lock failing will kill me, I need to get something very useful out of the bargain. Being able to scratch my nose isn’t enough.

[subego]

Originally Posted by reader50 

•Sound in space does happen in limited fashion if there is a nearby source of plasma or gas. Like a rocket exhaust, or say, a ship being vaporized.

They showed the Cant getting nuked again in E9. It makes noise.

Yes, a microphone placed right next to it would pick up (very loud) sound for the fraction of a second before it was incinerated.

[subego]

Originally Posted by reader50 

most lifeboats are not needed during the life of the primary ship. And it might have saved a few hundred credits.

Was that a lifeboat, or a shuttle? I thought it was a shuttle. You could theoretically use it as a lifeboat, but you might want some more acceleration couches.

Also, they use credits and not wala-dolla?


More seriously, I feel there would be like ice bucks or something. At the least, even if there wasn’t a currency pinned to it, ice would be the true measure of wealth.

[reader50]

Originally Posted by subego 

Was that a lifeboat, or a shuttle? I thought it was a shuttle.

They clearly use it as both, and I've called it a shuttle more often than not. Naomi referred to it as "one leaky lifeboat". The MCRN people referred to is as "your ship".

[subego]

It strikes me as shuttle first and foremost, but I agree it would be used as a lifeboat in an “abandon ship” scenario. I was being silly about the couches. Presumably it has those folding jobbies we see on the Donnager.

Speaking of the Donnager, wouldn’t suiting up before the railguns come out be a good idea?

To be fair, until there’s a hull breach, I may want to scratch my nose.

[subego]

Imagine using one of those iPad thingies while wearing Mickey Mouse gloves.

[reader50]

Originally Posted by subego 

Speaking of the Donnager, wouldn’t suiting up before the railguns come out be a good idea?

Absolutely. They didn't expect the attacking ships to have railguns, and they were overconfident. The Martians made several tactical errors.

Note that the attackers were also overconfident, tried to capture a ship with a self-destruct, and didn't scram fast enough when someone left at high-Gs.

The Martians technically "won", in that their story and a ship survived. But not a single survivor on either side, and they haven't gotten anything but information back. The attackers wanted Mars implicated in the Canterbury's destruction, then silence everyone involved. With capture of the Donnager as an optional bonus. The attackers failed on all 3. So pyrrhic victory for Mars.

[subego]

Originally Posted by subego 

Yes.

I can cut myself out of a suit. If the suit opens in space I’m dead.

If the lock failing will kill me, I need to get something very useful out of the bargain. Being able to scratch my nose isn’t enough.

To expand, current space suits use a zipper. If this fails during EVA, I die.

Do I get something out of this bargain? Yes. Being able to put the thing on and take it off. These activities are critical to its use. I posit opening a visor has no similar critical utility.

[subego]

Originally Posted by reader50 

Absolutely. They didn't expect the attacking ships to have railguns, and they were overconfident. The Martians made several tactical errors.

This is another thing like the lack of ubiquitous recharge points for space suits. It’s possible, but implausible.

A good military knows this type of procedure is exactly the sort of thing people are inclined not to follow, so they take great pains to beat the impulse out of you.

The entire command abandoned a procedure which should be reflex? That’s not a tactical error, it’s dereliction of duty. The lives of the crew depend on the bridge being operational. Had the bridge depressurized, instead of the crew sacrificing themselves to destroy the enemy, the enemy would have instead destroyed them, and it would be 100% the fault of command.

[ghporter]

Current space suits’ zippers do NOT seal the suit. They provide a surface for the seals to press against, and the pressure inside does the work. Yes, if you open the zipper when in vacuum, bad things can happen, but these are extremely robust zippers and I don’t know of even a minor failure involving the zipper.

Here’s a great piece of info on how the seals worked on an actual “flown to the moon” suit - Neil Armstrong’s to be specific. (Item 2)

Fun fact: the pressure garment for the Apollo program was made by a company called ILC Dover. ILC stands for International Latex Corporation, and they were located in Dover, DE. They were - at the time - a division of Playtex.

[subego]

Originally Posted by ghporter 

Current space suits’ zippers do NOT seal the suit.

Along those lines, the mechanism used to lock a poppable visor closed isn’t necessarily capable of providing a seal. The bond formed by a mag-lock might be strong, but will it be airtight? Off the top of my head, that needs precise (and therefore easy to damage) machining, an o-ring, or yet to be discovered materials science.

With the first two, even if it’s a mag-lock, the seal is the most likely point of failure, not the locking mechanism. I imagine it’s the same with the zipper.

That doesn’t mean I want to have the mag-lock as an added point of failure, and it still makes me hinky. The most important question about a poppable visor still remains…




ButWhy.gif

[Spheric Harlot]

The whole actual premise of the series is so far out — not to spoiler S2, we're talking mythical substances that have, er, magical properties — that I find it really amusing that people are discussing the physics of space suit seals as they relate to the portrayal in the series (NOT talking about the discussion of space suits itself, mind — that shit is interesting)…

Besides, it's really about politics, anyway.

Is there a point of talking about air seals on the TOS Enterprise shuttle bay as "bad science"?

[subego]

I’d be mad at you about spoilers, but the ending of S1 gave me some suspicions.

The early episodes were far better than normal when it came to the science, so I had high hopes. I also appreciated the science-based politics, like who gets drugs to counteract low gravity.

[Spheric Harlot]

Let's put it this way: The actual plots of the series haven't even really begun yet. :-)

[ghporter]

Originally Posted by Spheric Harlot 

Is there a point of talking about air seals on the TOS Enterprise shuttle bay as "bad science"?

“Force fields” solve all sorts of technical issues, don’t they?

Yes, force fields hold in the air on the shuttle bay, so there’s no need for fancy stuff like air seals adn such.

A side benefit is that they didn’t necessarily have to depressurize the bay to launch or recover a shuttle, since slipping through the force field magically allowed that transition. But using magic force fields comes at a cost. How can you fire phasers or photon torpedos with shields up? The buzzword explanations get complicated…

[subego]

Shields should always be up in Star Trek, because if they’re not, I beam a photon torpedo onto my opponent’s bridge.

[Spheric Harlot]

Originally Posted by subego 

Shields should always be up in Star Trek, because if they’re not, I beam a photon torpedo onto my opponent’s bridge.

Ah yes. Shields. The "Good Science". Star Trek certainly is full of it.

[subego]

The one time the science really bothered me was when Murdock Barkley becomes super intelligent he says “I see the entire universe as one equation, and it’s so simple.”

The problem I have is no one going “you should write that down”

[Spheric Harlot]

Originally Posted by subego 

The one time the science really bothered me

You apparently haven't seen TNG episode "The Chase".
The whole premise is such utterly ludicrous pseudoscientific Trek bullshit ("starmap built into our, the Cardassians', and the Klingons' genetic code by benevolent forefathers aeons ago, discovered simultaneously by all three cultures, and the search for the missing fragment converges on an uncharted planet where Crusher's tricorder triggers a holographic recording explaining that they're all one and should live in peace") that it's almost obscene.
I absolutely cannot bear watching it. It's like they had leftover pages from a bunch of middle school interns and desperately shoehorned them into a story arc to transport a message. Fucking terrible.

It's even worse than the Darmok of Tanagra episode, which warps my entire existence just trying to work out how that might have worked.

There's a German-dialect home-dubbed video version of "The Chase" (German name: "Das fehlende Fragment") from the 90s that's been transferred from VHS circulating the webs for a while. They make Riker a bumbling idiot and turn the whole episode into the prep for a moped race, instigated after Riker's dad has found his old cycle in a corner of the basement. Problem is they no longer have gasoline. So the fragments they've discovered by some weird coincidence (LaForge's random senseless babbling doesn't really explain it) are actually parts of the formula to synthesise gasoline.

It's marvellous. I was SHOCKED to see the original after this version and discover that the ridiculous dub actually makes a whole lot more sense.

Also, the dub has singing Klingons.

[subego]

Originally Posted by Spheric Harlot 

You apparently haven't seen TNG episode "The Chase".

Well, I was joking. The bad science in Star Trek doesn’t actually bother me because it’s Star Trek. What exactly were you expecting?

What I expected from The Expanse was based on it being pitched to me as hard sci-fi.

[reader50]

Originally Posted by Spheric Harlot 

... we're talking mythical substances that have, er, magical properties ...

Originally Posted by subego 

What I expected from The Expanse was based on it being pitched to me as hard sci-fi.

I disagree - the science is indeed hard SF in The Expanse. At least, as much as science was known when each book was written. Which was 2011-2021, so pretty modern. They certainly speculated about engineering that hasn't been developed yet. Like smartphones evolving into a slimline glass-like terminal.

Unfortunately, I can't disagree with many details until you're a few more seasons in. Spoilers evil, etc.

On the visors, if they use a mag-lock, that only applies the closing force. A gasket would provide the actual air seal. Assuming it's done with superconductors, you don't necessarily need an ongoing power source for the lock. You bleed off the circulating electrons to release the lock. I'd expect the visor to stay locked, even with a full loss of suit power.

Magnetic field losses would eventually drain the lock, but in a practical sense, the lock shouldn't fail before your air does. To force a fail-open scenario, you'd need to puncture the suit to damage the superconducting coils. But if you've punctured the suit near the visor your head, you've likely solved all your problems already.

[subego]

You have convinced me the mag-lock could be reliable enough, but I’ve moved on to the gasket.

Before I get into that though, I want to backtrack to earlier spacesuit design.

Current space suits have a detachable helmet. My assumption is the main benefit is the ability to wear the suit without needing to use up life support.

IIRC, the suits the Cant crew uses have attached helmets, which would necessitate some other method of wearing the suit without life support, like our friend the poppable visor.

What are the reasons to abandon the removable helmet paradigm? None come to me off-hand.

[reader50]

The helmets are removable. Check 1x4, between 34 and 35 minutes in. Holden has reached the holding cell, and the prisoners are about to suit up. There's a shot of Naomi holding her helmet separately. Shot lasts about 2 seconds. In 1x01, when they board the Scopuli, they also see a loose helmet in a corridor at one point.

We never actually see the Cant people put helmets on or off. I suspect the costuming hadn't built a realistic seal. Despite an enormous budget for a TV show, they couldn't do everything. I want to say we see helmets go on/off later on, but I'm not remembering for sure.

[subego]

Excellent! Thank you!

There doesn’t seem like there’s anything broken with the removable helmet paradigm which needs to be fixed with a onesie design. So no problems there.


This brings us back to the gasket.

I still have no clue why I’d want a poppable visor. I don’t know it’s for. What am I supposed to do with it? I can’t spec a gasket if I don’t know why the mechanism it’s attached to even exists.

[reader50]

Why do motorcycle riders have a visor that opens (on nice helmets)? Why not just pull the helmet off? (bug or rain windshield maybe)

If you assume the helmet is inconvenient to add/remove, then the visor gives a quick way to duck into the ship and back out again. For scratching, snacking, or easy talking. Also, if you're wearing the suit before a battle, but haven't decompressed the ship yet. Helmet on = you're ready. Get hit by a surprise shot, and the air is whooshing out? Click the visor down and you're good. The Cant suits also have visors that open, though they have large frames. Presumably economy helmets, on the corporate budget.

Most of the above reasoning doesn't hold if helmets are quick and easy to put on.

[ghporter]

Until recently, air flow in a motorcycle helmet with the visor closed was close to nonexistent. Modern helmets have better ventilation, and some even have fans - for both air flow and cooling. Dang I wish I’d had one of those back in the 80s in Austin summers! So the visor can open to get fresh(er) air, change inside air temperature, etc.

Note: I ALWAYS go with full face helmets. I spoke with a guy behind the counter at a motorcycle shop once, and he said his only bike accident was at less than 20 MPH, when the car in front of him stopped hard before he could react. He vaulted that car and slid, face down, for about 40 feet. He had his helmet to show me, and the chin bar was all but ground through…if it hadn’t been a full face helmet, he wouldn’t have had a jaw.

[subego]

Originally Posted by reader50 

Why do motorcycle riders have a visor that opens (on nice helmets)?

Honestly, I don’t know. For reasons similar to why I don’t want a mag-lock, I’ve never been on a motorcycle.

Best guess: so people can hear you speak?