Reflec Revisited

[kilemall]

After going over the laser thing again, I just don't see how Reflec 'armor' is going to work over all those potential wavelengths.

Ya, might be a narrow band within each spectral range to have to protect against, but again, multiple spectrum.

So, rather then focusing on deflection/diffraction, how about the effect?

The primary mechanism is superheating a sliver of flesh or vehicle or incoming weapon.

So if you have a coating or material technology that deals with the heat, the laser is rendered impotent.

There have been some versions of Reflec that have referenced cooling layers underneath the deflection, but not the primary design principle.

Seems to me such a suit would be highly useful for engineering, foundry/smelter/welding of heavy metals, desert survival gear, and firefighting.

So if that were the case, then the suit would be more available then canon writing (or maybe its available to those professions with a license, law level dictates).

The Reflec suit would also be by default an external garment, both to avoid allowing clothes or other tools underneath to burn up, and prevent lasers or fire to burn through a vacc suit.

Could be the underneath suit version is on the order of a concealed weapon law level wise, only used for military/LE or VIP protection.

And it could still have the Reflec title because the common materials render as shiny and the common ignorance perception is the laser bounces off.

That would make the people who got the external suit version both painfully obvious that they have Reflec, and easier to spot. And just a little exposure will show they have the underlaying not so legal version.

Finally, such a technology would be useful for starship skins. I'm thinking a major portion of the cost of streamlining is a layer of Reflec for reentry purposes, not strong enough for armor per se, and that armor levels for the various HG/warship build versions of the game include Reflec layers built in, something like Chobham armor.

What do you think? Anything I am missing here?

 

[Quint]

I have to admit that Reflec is one of those things I prefer not to think about very hard - and tend to ignore in game.

Truthfully I think that some sort of heat-sinking/dispersing weave of fibers makes more sense than a "reflecting" material, but that's just me - I have no science to back it up.

D.

 

[atpollard]

My father was a Research Chemist before he retired. One of the projects that he worked on was a plastic coating that would absorb radar in one wavelength and re-emit it in a different wavelength.

A weave of fibers blended to each absorb energy in a different narrow part of the spectrum and emit it across a broader spectrum could be perceived from an external observer to be 'reflecting' invisible lasers weapons as harmless visible light.

 

[Spinward Scout]

Reflec?

 

[atpollard]

The secret is in the internal force that causes you to aim for that tiny area of armor.

 

[Condottiere]

 

[Enoki]

An easier solution would be to have it made of an advanced material that can absorb / displace massive amounts of heat. Aluminum nitride comes to mind as a material with a high thermal conductivity. Assume something a lot better is found in the next several thousand years like that.
So, the suit absorbs the light of the laser as heat spreading it so rapidly it can't penetrate. A thin metal foil or something is added behind this to protect the user from local heat concentrations if they occur.

 

[flykiller]

My father was a Research Chemist before he retired. One of the projects that he worked on was a plastic coating that would absorb radar in one wavelength and re-emit it in a different wavelength.

any particular direction? if so then there's stealth in space.

 

[atpollard]

any particular direction? if so then there's stealth in space.

I don't really know.
It was DARPA/DOD stuff, so I just heard the funny stories ... like when the sample failed because the lab tested the wrong side, so they covered it in tape and stamped it TEST OTHER SIDE, then it passed.

I know that they made an IR neutral cover for tank guns and he kept saying that as soon as they perfected the plastic coating for radar he was painting his car and paying his last speeding ticket ... ever.

I think it was part of a multi-layer stealth technology. One coating changed the wavelength, another absorbed most of the new wavelength and some sort of structural baffles trapped the radar that passed through.

 

[kilemall]

And what about those missiles? Ground or space, missile shooters would prefer a missile that survives laser fire.

 

[atpollard]

An easier solution would be to have it made of an advanced material that can absorb / displace massive amounts of heat. Aluminum nitride comes to mind as a material with a high thermal conductivity. Assume something a lot better is found in the next several thousand years like that.
So, the suit absorbs the light of the laser as heat spreading it so rapidly it can't penetrate. A thin metal foil or something is added behind this to protect the user from local heat concentrations if they occur.

There was a fireproof coating that had something to do with bromide.
The more it was heated, the more it expanded to provide thermal insulation.
It was for a paint on fireproofing for wood or steel. (Beaten out by a cheaper technology).

It could form the 'ablative' version.

 

[kilemall]

Thoughts on the starship armor aspect?

I always liked the image of strapping on chunks of ablat to a starship as a grungetech blue collar solution to armor.

 

[kilemall]

I'm coming to the conclusion that ALL ships have Reflec already built in, in the new definition I'm giving it, as a survival aspect of both getting hit by solar/ion storms and the like, and what a hit means with a laser (since I think most lasers are going to be hitting most of the time below 1 LS).

This is why our ships can blaze into full speed landings/takeoffs with lower tech steel hulls without specialized material or coating or maintenance.

Heh, does that mean Ablat equates to our lower tech space shuttle tiles?

 

[Enoki]

Well, one possibility would be to have two sheets of material separated by a small gap and the space filled with a gas that when exposed to vacuum turns solid. The outer sheet's back and the inner sheet's front are not perfectly flat, but rather are slightly wavy, and both surfaces are highly reflective.
What would happen here is the laser would penetrate the outer layer then reflect off the inner, subsequently scattering in all directions before it can penetrate the second layer.
The gas near the hole created in the outer layer turns solid plugging the hole and sealing the ship up.

As for an ablative material I'd suggest foamed rigid carbon insulation.

When I was designing and building high temperature furnaces a long time ago, I used this stuff on ones that ran in a vacuum. 15 cm of it will knock the temperature from 2200 C inside to about 30 C on the outside. That stuff would absorb laser fire all day. The only drawback is you have to have a vacuum or inert atmosphere to use it.

 

[nobby-w]

[ . . .]
So if you have a coating or material technology that deals with the heat, the laser is rendered impotent.

Reflec doesn't have to be 100% efficient. If you shoot a powerful enough laser at it then the inefficiencies will be sufficient that it absorbs enough energy for the laser to burn through it.

[ . . .]
So if that were the case, then the suit would be more available then canon writing (or maybe its available to those professions with a license, law level dictates).

In Real Life, few jurisdictions have laws that prohibit ownership of body armour as it's not actually an offensive weapon. Although I haven't read T5, most of the editions that I have read don't go into law level affecting body armour - with the possible exception of Battle Dress, although that may be apocryphal as I can't think of where this might be specified.

[ . . .]
The Reflec suit would also be by default an external garment, both to avoid allowing clothes or other tools underneath to burn up, and prevent lasers or fire to burn through a vacc suit.

Pretty sure CT describes it as being worn under other armour. It could still do its job if worn this way, particularly if it was intrinsically tough enough to handle heat from a laser vapourising soot deposited by shooting through the external armour.

In the context of CT, the idea was that cloth armour is reasonably effective against anything but a laser, and reflec was effective against lasers.

[ . . .]
Finally, such a technology would be useful for starship skins. I'm thinking a major portion of the cost of streamlining is a layer of Reflec for reentry purposes, not strong enough for armor per se, and that armor levels for the various HG/warship build versions of the game include Reflec layers built in, something like Chobham armor.

I wouldn't characterise that as a major portion. Just building an airframe with airfoil surfaces for manoeuvring is a significant cost in itself. You could certainly assume a reflective layer without causing anybody an existential crisis.

 

[kilemall]

Well, one possibility would be to have two sheets of material separated by a small gap and the space filled with a gas that when exposed to vacuum turns solid. The outer sheet's back and the inner sheet's front are not perfectly flat, but rather are slightly wavy, and both surfaces are highly reflective.
What would happen here is the laser would penetrate the outer layer then reflect off the inner, subsequently scattering in all directions before it can penetrate the second layer.
The gas near the hole created in the outer layer turns solid plugging the hole and sealing the ship up.

As for an ablative material I'd suggest foamed rigid carbon insulation.

When I was designing and building high temperature furnaces a long time ago, I used this stuff on ones that ran in a vacuum. 15 cm of it will knock the temperature from 2200 C inside to about 30 C on the outside. That stuff would absorb laser fire all day. The only drawback is you have to have a vacuum or inert atmosphere to use it.

Interesting- but 15cm works out to 6 inches, not exactly something you can strap onto your body armor or put on a ship without messing with the volume tonnage something fierce.

Of course, future tech etc., so we could figure a 1cm future variant of the above.

The vacuum part could be assumed to be sealed, and when something pokes through the armor it degrades just because the seal is broken and the air is reducing it's effectiveness.

 

[kilemall]

Reflec doesn't have to be 100% efficient. If you shoot a powerful enough laser at it then the inefficiencies will be sufficient that it absorbs enough energy for the laser to burn through it.

Well that's true of ANYTHING. Most of the Traveller games assume that more juice eventually overwhelms reflec, a laser tank is going to cut through reflec armor guy no problem.

In Real Life, few jurisdictions have laws that prohibit ownership of body armour as it's not actually an offensive weapon. Although I haven't read T5, most of the editions that I have read don't go into law level affecting body armour - with the possible exception of Battle Dress, although that may be apocryphal as I can't think of where this might be specified.

Mongoose Traveller, I guess having a British slant on things, has extensive rules on body armor limits, particularly in the 1E Agent book.

A lot of RL body armor sellers will not sell to anybody but LE or military, so it doesn't have to be a law level per se.

Pretty sure CT describes it as being worn under other armour. It could still do its job if worn this way, particularly if it was intrinsically tough enough to handle heat from a laser vapourising soot deposited by shooting through the external armour.

Yes CT describes it as basically laser armor underwear, but I think does not consider what that means for Our Heroes in Vacc Suits. The fact that your character did not take the full damage does not mean the oxygen sucking out of the suit was a great result.

I am postulating a distinction, the effective difference of a reflec Open Carry vs. concealed, so it makes sense that firefighters or engineers all have it but why the underwear version is rare as per rule and general canon.

In the context of CT, the idea was that cloth armour is reasonably effective against anything but a laser, and reflec was effective against lasers.

Indeed, but clearly the idea also was that the laser buyers/users had a reasonable expectation of having the superior weapon in most cases, and it takes effort to overcome that advantage.

Since I am postulating a different take on what reflec means, I need a reason for why it would be in the hands of people that need to handle hot environments but rare enough to not obsolete every laser.

I wouldn't characterise that as a major portion. Just building an airframe with airfoil surfaces for manoeuvring is a significant cost in itself. You could certainly assume a reflective layer without causing anybody an existential crisis.

Exactly, it would be a key component of space/atmo interfacing survival, and hey it helps against laser weaponry too.

Suggests those poor bozos in TL7, maybe TL8 ships should take horrible damage to lasers.

 

[nobby-w]

[ . . . ]
Mongoose Traveller, I guess having a British slant on things, has extensive rules on body armor limits, particularly in the 1E Agent book.

Although the UK has restrictive firearms laws there is no legislation that governs civilian ownership of body armour. There are some laws in the EU and a handful of other jurisdictions (e.g. Australia) with laws that cover it, but this is the exception rather than the norm.

In practice, I think it's a sort of attempt to balance the game by making anything powerful hard to get.

I'm of the view that an infantry section, S.W.A.T. team or a Posse is a serious threat to most Traveller parties, so I don't worry a lot about balancing the game by making stuff too hard to get. A while ago, in a different forum I wrote this article about police in a sci-fi game. The executive summary is something like: 'Great!' you've just shot up the Tactical Response Unit with a FGMP. Now you've got Motoko Kusanagi after you.

As an alternative, just don't roleplay with dicks.

Link to a summary of legislation that restricts body armour ownership or use.

 

[kilemall]

In practice, I think it's a sort of attempt to balance the game by making anything powerful hard to get.

Of course, but I want a justification especially as I expect to have at least one external suit in the Ship's Locker for firefighting or hot reactor work.

I'm of the view that an infantry section, S.W.A.T. team or a Posse is a serious threat to most Traveller parties, so I don't worry a lot about balancing the game by making stuff too hard to get. A while ago, in a different forum I wrote this article about police in a sci-fi game. The executive summary is something like: 'Great!' you've just shot up the Tactical Response Unit with a FGMP. Now you've got Motoko Kusanagi after you.

Ya, actions have consequences.

Link to a summary of legislation that restricts body armour ownership or use.

http://www.criminaldefenselawyer.co...e/when-its-illegal-to-own-a-bullet-proof-vest

http://www.bulletsafe.com/body-armor-law.html

Basically, felons are not allowed to have them, some jurisdictions tack on extra years to sentences or have separate charges for using body armor in a crime, and they can't be transported or exported without Federal approval (that last one I would take to prohibit export to the local starport, if such a thing existed).

Some limit body armor even by non-felons in certain situations- note Louisiana, or Topeka Kansas on school property.

There are bills introduced to limit body armor to approved people, but they have not got to the point of being voted on yet.


You're allowed to travel with your own set of body armor, including chemical gear, long as it is declared and you show intent to bring it back- no personal exporting.

https://www.law.cornell.edu/cfr/text/22/123.17



Here is a summation of laws with some country limits noted. As you mentioned, the EU forbids military grade armor and Australia and apparently some Canadian provinces requires a license.

http://www.safeguardclothing.com/articles/body-armor-us-laws/




If there was a Traveller Law Level applied to armor, I would think BD illegal at level 2, CA level 3, CES and Cloth somewhere around 6-7, and Mesh at 9.

Reflec isn't so clearcut to me, could be at level 2 when energy weapons go, could be 5 at personal concealable for the traditional undersuit, and 9 for the external firesuit.



Incidentally, in the US the Traveller Law Level would be a bit different as bladed weapons are more likely to be controlled or outlawed then guns.

https://en.wikipedia.org/wiki/Knife_legislation#United_States

 

[Enoki]

One thing to note here is that TL would definitely play a role too. Somebody with TL 15 cloth body armor might well be wearing something that at TL 7 or 8 is unrecognizable as body armor. At the lower TL they might mistake the wearer's body armor as simply a jacket or "normal" clothing.

Maybe body armor on a low tech world expects someone to be wearing metal plate, or maybe thick leather or cloth where a high tech equivalent is much lighter, thinner, and looks like street clothes.