?

Log in

No account? Create an account
 
 
25 January 2018 @ 02:59 pm
_Last Merge_ Xen rewrite  
Feel free to explain what would really happen with such an implosion.

Around the corner and off . . . feeling . . . odd, hair on the back of his neck up . . . in fact all of his hair . . . Static? He maneuvered awkwardly . . . spotted the cam at the top of the down staircase. If he was across the corridor, right up in that corner, it might not pickup any little blips as he exited the bubble . . .

Through the open lattice of the metal stairs he could see the guards, one of them waving expansively as he talked.

Xen finger walked across, toward the back wall, possibly the wall of the ring containment . . . Warped light hard and smooth and eased out of the bubble. It zipped away instead of the usual float.

Didn't notice that, last time I was sabotaging a mag center . . . but then I don't think I released a bubble, then, either.

Xen eyed the wall.

I can feel the magnetic field . . . so how about one bomb shoved through this wall right here?
He plucked one bubbled bomb off his arm, keeping a solid grip on it. Shoved it into the wall . . . attached it on the far side and shoved it all the way in. Mentally shoved it deeper.

The bubble popped.

The wall bulged out, glowing hot.

Xen threw himself away and to the side.

Crap, a hundred kilos of metal and chemicals trying to coexist with the stone of the wall! Good thing solids are mostly empty space . . . probably there weren't any atomic nuclei close enough to fuse . . .
And those are fire alarms. And I need to get out of the way of the guards running this way . . .

Xen jumped and grabbed the tread of the upper stairs and swung his body up out of the way got the ball of one foot on another tread.

The guard grabbed the support post and swung around to head down . . . Put on the brakes, scrambled to stay on his feet and turned around to gawp at the bulging wall. Not really glowing hot, but . . .

His calls to the other guards and their yelled replies and exclamations when they spotted the wall exceeded Xen's rusty knowledge of their language. Dismay and cursing, a call for a techno—technician or scientist—was clear enough.

Xen shifted his grip and reached to his right. Got a grip on the upper stairs, and a foot down on the rail of the lower and eased out . . . More running feet . . . and no way he could slide by them. He muscled over the upper stair rail and trotted up to check out the upper floor.

Pressure hoses, empty bins . . . I'll bet they've got something, a powder perhaps, chemically identical to the ring material. Open the shadow zone. Gate the powder to the target, then bring it in and pump it in to merge with the ring. Must be tricky, getting it here fast enough that the ring doesn't start merging with other stuff.

He pulled off the second bubbled bomb and slid it behind equipment and stuck it to the wall.

No time for exploring. I think I need to leave. He felt the location . . . couldn't quite . . . I'd better get further away.

He trotted back to the stairs, where everyone was getting out of the way of some new people, firefighters, perhaps . . . Except the techo exclaiming in horror and waving his arms . . .

Xen decided to believe him and bolted down the stairs, turned into the main hallway and ran, weaving through spectators. Shields up!

The splash of water, the hiss of steam.

The whomp of the weakened wall giving into the pressure differential.

The near vacuum of the ring room sucked all the air out of the building. Xen joined the bodies tumbling back toward the end of the hallway. Threw a pull spell and stopped, scrambled to his feet and sprinted for the front doors as the super cooled spinning ring shattered . . . and was almost contained within its damaged walls.

A blast of arctic air shoved him against the outer doors, blowing them open. Xen staggered away, stopped to feel the location, the tower look out room, the teleportation spell, power . . . and step out into the dark room and trip over a soft thing that yelped indignantly.

"Sorry, Pig." He blinked and focused on Rael, lowering her rifle, Barracuda jumping up form beside her. "Well, that was fun. Let's go home now."


 
 
 
ekuah on January 25th, 2018 10:38 pm (UTC)
Some comments here:
1.
Until now it seemed to me that when someone popped a bubble, the contents just displaced the matter that was there before.

So why does the matter now merge?

When two different, solid substances would suddenly occupy the same space, would result in some very unstable (= very kaboomy) chemical compounds.
No slow heating, but a VERY intense explosion. (far more violent than any chemical explosion)

2.
Another problem:
Even if Atoms basically are mostly empty space, there is an atomic nucleus somewhere in there.
That two given nuclei are hitting each other is maybe very unlikely but there is an insane number of atoms per gram of matter.
(50 000 000 000 000 000 000 000 atoms per gram of carbon)
That makes it quite probable that there will be some atoms forced to fusion. The results are quite nasty from a radiation point of view.

So my opinion is, that a sudden merge between the bomb and the wall, would need a huge amount of handwaveium to
-keep it canon
-keep Xen alife
-keep it plausible

3.
Another point is, that vacuum/shockwave combo.
First :
"The near vacuum of the ring room sucked all the air out of the building."
It must be a huge ring room to suck the building nearly empty.
The pressure difference can only be 1 bar or 14.5 psi at max (you cant have less pressure than an completely evacuated vessel).
The air currents involved would not be like a leaking air tank (which can have several 100 psi of pressure)
Then:
"A blast of arctic air shoved him against the outer doors, blowing them open."
Where does this blast comes from?
The supercooling? You know the boiling off of helium is not really fast. There could be a gust of cool air (which would also be asphyxial) but not a explosive blast.

4.
You would not use a wall to separate a vacuum from the atmosphere.
At least it sounded like a normal plaster/concrete/brick wall.
When I read 'wall', then I think of a normal 'building wall'.



I don't want to be pushy here.
Are you interested in constructive suggestions to make the plot more physically sound?
(of course with changing as less as possible of the action itself)

Edited at 2018-01-25 10:48 pm (UTC)
Zan Lynxzlynx on January 26th, 2018 11:50 pm (UTC)
Re: Some comments here:
Some things I thought of in response to your thoughts:

The dimensional bubble bag was popped abnormally. It should not have done that. Which means that the normal rules about interaction don't necessarily apply here.

I agree that just a wall won't hold vacuum but it is entirely reasonable that the pressure vessel is up against the concrete wall and Xen went through both of them.

I'm not sure about sucking all the air out. It will depend on the relative cubic volume of the vacuum chamber and the rooms and halls of the building. If the doors are closed and the vacuum and building have similar volumes, the resulting air pressure will be mostly half normal everywhere. I am sure there would be a very big bang at first. Then even a half atmosphere of pressure is enough to open doors.

I think the arctic air is just cold from being outside. However, even though I assumed that, I can't find any description about air temperature in the earlier snippits so I guess my mind just made that up.

I agree that the air would not be cold from the vacuum chamber. If there's no air in it, it has nothing to convect for temperature change.
matapampamuphoff on January 27th, 2018 03:55 am (UTC)
Re: Some comments here:
I'm adding stuff to get the picture in my head onto paper. Pixels, whatever.

The containment wall are some very thick stone-like substance. Strong enough to contain the sudden desire of a whole lot of atoms to get further away from each other. But when the cold water hit the hot stoneish stuff, it shattered.

The ring chamber takes up most of the space in the building.

The blast of cold air is the result of the fast spinning supercooled ring shattering from the thermal shock of the warm air and further damaging the containment and thus the equipment associated with it, liquid nitrogen tanks and such.
ekuah on January 27th, 2018 07:03 am (UTC)
Re: Some comments here:
@zlynx
the phrase was:
""A blast of arctic air shoved him against the outer doors, BLOWING THEM OPEN."
So the blast must have come from the inside.

We could argue here about popping open the bubble naturally against ripping it open unnaturally, but that is not my point.
A sudden merge of these two very different solid substances (wall and explosives) wouldn't gives the result of a slow heating. The explosiv compound from the bomb would just detonate due to the sudden pressure shock.

Also, you would never build the chamber wall of a pressure vessel directly up against a concrete wall.
The pressure changes in the vessel causes the metal to shrink and expand slightly. You have to avoid any contact with the concrete.
I'm quite sure that Xen could feel this gap.
Also, pressure vessels need to be able to be inspected from the outside, that even widening the gap.

@Pam
I know you are a Geologist by trade and I'm more of a chemist and engineer, but I know of no stone like substance that:
-you can build chambers of
-can hold vacuum
-would shatter under rapid cooling
Concrete or any stone aggregation is lousy for holding high vacuum and won't shatter under cooling.

Solid stone could shatter under rapid cooling, but is lousy for building.

A pressure vessel needs to be made of metal or some reinforced and coated polymers.



Edited at 2018-01-27 09:23 am (UTC)
ekuah on January 27th, 2018 07:44 am (UTC)
Re: Some comments here:
My humble suggestions to plug the physical plot holes while keeping the plot intact:

Xen places the bomb bubble inside the vacuum chamber wall (made of thick steel)
The bubble pops and the bomb displaces a part of the chamber wall.
Now, bomb material makes a lousy pressure seal, so the vessel start to leak there.

The technos scramble to seal the leak by any means, because the chamber MUST be kept under vacuum. But they fail.

Now, when you spin a disk rapidly it will deform a little bit, the outer edge will not be perfectly flat anymore. But that is no problem as long the disk spins in vacuum.
As soon as you add air, the surface of the disk will start to move the air molecules it comes into contact with. Mechanical energy is is transferred from the disk to the air. This adds tangential forces to the disk, causing it to wobble and warp.
Try to find a you youtube video named "CD Shattering at 170,000FPS! - The Slow Mo Guys" At the end of the video you see how the disk rotates at a different speed than the shape of the disk. Rapidly bending and warping the material.

A super cooled material is usually quite brittle and doesn't like to flex and warp. So it shatters.

Some of this debris damages ether some compressed air tanks or a steam boiler, creating the blast to shoving open the doors. Rupturing a compressed air tank would create a cool blast.

So why not some ruptured liquid helium/nitrogen tank?
You see, liquid helium/nitrogen is not really kept under pressure but under low temperature.
So there is no pressure to release.
They would stay in their liquid form as long as you don't put heat into them.
Now heat must be come from somewhere. It has to be conducted from hotter parts.
And that is where the Leidenfrost effect comes into play.
"a physical phenomenon in which a liquid, in near contact with a mass significantly hotter than the liquid's boiling point, produces an insulating vapor layer keeping that liquid from boiling rapidly"
So any spilled liquid helium/nitrogen would boil off 'slowly' or at least too slow to create a blast.

P.S.
Sorry for the long post. It is just for explanation why one result is something more physically sound than the other.
It's not meant that you should put this boring stuff into the story.

Edited at 2018-01-27 08:06 am (UTC)
ekuah on January 27th, 2018 10:57 am (UTC)
Sorry, it me, again.
Had some more ideas while doing laundry.

How about this.
Xen plants his first bomb without problems. And just when he try to set his second bomb, the Healos give the machinery a test spin. Which ruptures the first bubble and set the chain of events into action.
This would keep Xen away from the first bomb blowing up.
And would explain why the machinery is in full speed spin. (instead of slow spin to keep the ring round)

Second:
Disk/ring burst and some debris ruptures a liquid nitrogen/helium pipe. The liquid nitrogen/helium pours over several nitrogen/helium high pressure gas cylinders.
(I'm go out a little bit on a limb here, but I'm guessing that stressed metal and rapid chilling with liquid nitrogen/helium doesn't mix well.)
The gas cylinders burst and creating a fine nitrogen/helium spray forming the cool blast.
(The compressed gas would atomize the liquid nitrogen/helium circumventing the Leidenfrost effect. The liquid nitrogen/helium would baffle the explosion of the gas cylinders. Dampening it to a mere blast.)
(Anonymous) on January 27th, 2018 10:54 pm (UTC)
Re: Some comments here:

There shouldn't be enough volume of vacuum to suck all the air in, and it cannot be that fast.

There are two reason's to pull the vacuum: 1. to make a rotating material not experience the drag of air. 2. to keep something cold (I've dealt with sensors that need to be very cold to work properly) by eliminating convection of air. In either of these cases, you want the wall to be close to the rotating material, and also close to the cold material. It doesn't gain you anything to have more distance from the walls, and it does cost you lots of energy and time to pump the vacuum on a larger volume.

Even if the volume of the rotational material is small compared to the volume of the vacuum chamber (which it really shouldn't be), the hole created by the section of wall failing will effect things very close to it, but it will also quickly reach a state where the air is throttled at the hole - it cannot go through the hole fast enough to drag people in the hallway toward it, unless the hole is vastly larger than the hallway. Even if the hole is roughly the same size as the hallway, it also draws from the stairway, the room at the top of the stairs, and all the secondary hallways and rooms.


I find it hard to believe that something bad enough to make the wall bulge and get hot on the outside didn't also cause some effects on the inside surface of the wall.

I think one problem is difference in terminology. A Containment wall would be something very tough and resilient to fragmentation, and/or resistant to radiation. In other words, a containment would be the wall that would contain the explosion, or disintegration of the spinning disk and stop radioactive material from spreading.

The *Pressure vessel* would NOT be in the same place as the *Containment* wall. Every pressure vessel that I've ever dealt with is either spherical or cylindrical with spherical ends. I can concieve of one that isn't spherical for use in *only* one atmosphere, but it seems really unlikely that the pressure seal is the same place as the containment wall. (other comments about needing to inspect the outside of the pressure are valid)


So the sequence I imagine is, the bubble pops and causes noticeable effects on the outside of the wall. But since the wall does NOT contain the vacuum, the vacuum failure and/or cold failure have to be caused by something else.

How about: the bubble/bomb actually does cause at least some fusion effects. This changes the electro-magnetic properties of that section of the wall. The dimensional effects of the facility go through the wall (hence the effect on bubbles), so this creates an unbalanced force on the rotating magnets. It takes a little bit of time for these magnetic changes to propagate through the rotating machinery, and the flight panic is generated by alarms that warn of impending ring failure. The changing magnetic characteristics of the rotation then also feedback into the material of the wall, dumping significant local heating. Kablooey, and the already damaged containment section fails. The ring is already failing, but it starts a more spectacular phase of it's failure and blows through the containment hole.

Xen obviously feels the bubble pop. Physical action to get out of the way of reacting guards. Don't need second bomb, since it doesn't do anything, unless you need physical evidence for Helios to find about sabotage. Then Xen feels the change in the field and shields. Explosion sends him down the hallway (Wheeee!)


Darqref